I was shocked when he sent me the photo!

Few days later, I received this Discrete R2R DAC for Raspberry Pi along with a regulated 5V @3A supply. How nice is that?

I can’t believe how Ew managed to fit everything into this small board. Hey, this is a 24 bit DAC so there are 48 resistors per channel. (No sicko enjoys soldering this bitch!). Before we even get to soldering, these resistors need to be hand matched as resistor tolerance could cause significant distortion. (No sicko enjoys matching these tiny resistors!) The heart of signal processing is handled by the huge FPGA chip.

For comparison, here’s the Final Discrete Monica I built years ago.

Zoomed in just on the main board and you can see USB input via the Amanero, of which signal is fed to a huge FPGA module (underneath this PCB) where signal processing is done. Back then I had to learn how to code in VHDL in order to program the FPGA. Hey, programming is part of my day job but the coding sequence is sequential but with VHDL/FPGA it is in parallel. This messes up our thinking.

Sequential : Wake up -> Brush teeth -> Walk the dog -> Make coffee…

Parallel : Wake up AND Brush teeth AND Walk the dog AND Make coffee…

Err, how does this happen? Well, we human beings are not great at multi-tasking (despite what the fairer sex says). But machines can accomplish this. Telling the machine how to do this… can mess up our thinking.

Look at me! I have not been the same since I programmed VHDL/FPGA!

Okay, after digital signal processing, music signal is then fed to 4 clocked buffers and the ladder R2R resistors (hand matched as well). Also, i went nuts with shunt regulated supplies on almost every stage… Also, I went nuts stripping off sleevings off the electrolytic caps (this makes a difference so much so my deaf ears could hear it).

Needless to say, building the above was a back-breaking, eye-numbing, solder fumed fest. It was anything but pleasant. I was a self flaggellating fetish back then.

Okay, enough!

And then Mr Ew comes up with this cute little package! And he programmed the FPGA as well! Damn!

Assembled below with the power supply. My itchy hands have to solder in an extra 2200uF…

Man, I was still enjoying the AD1865 Raspberry DAC when I received this new baby.

And all I could say is…. It’s GLORIOUS!

There is difference in musical presentation between the AD1865 and this Discrete puppy. I prefer this Discrete DAC as music seems to be more “alive”. It’s probably a bit more forward too, but not that irritating in-your-face sense. More forward compared to the AD1865.

It has that… je ne sais quoi… that some girls have that make you fall head over heels over them. Sure there are prettier girls. Sure there are smarter ones (or if you prefer dumber ones). Sure there are more engaging company but… She has that je ne sais quoi and you keep returning to her.

Geez…. why did I bother building DACs when we could have Mr Ew build better ones?!

The post Discrete R2R DAC for Raspberry Pi appeared first on diyparadise.

That said, the typical audiophile tends to sit his fat ass down on hours and listen to music. However, I still prefer to get out and about!

When I moved house, I took this opportunity to rebuild my music source. Few months before that, my friend Ew asked me to try out his Raspberry Pi + AD1865 NOS DAC. So it’s the right time!

The obsolete AD1865 is a true R2R DAC chip from years ago. Older audiophiles may recall seeing its presence in some Audio Note DAC. Some folks will sense an air of gravitas in this little nugget.

To save me time, Mr Ew sent me the power transformer and a simple voltage regulator as well.

Here it is, wired up.

You can read more about this fine piece of equipment on Mr Ew’s webpage.

For me this is so simple to use! Using Moode player, this is a “headless” (no display) music source with all controls from my handphone.

And I stream Spotify.

Oh no! I lost all credibility as an audiophile!

It’s okay, it’s all about the Music!

The post Rapsberry Pi + AD1865 NOS DAC music source appeared first on diyparadise.

by Graham and Denise Woods

[Graham and Denise, very graciously, offers to write a review comparing the various iterations of Monica all the way from Monica2 to Discreet Monica. Thanks a lot for taking the trouble, mate!]

Way back in 2007 I wrote a review of ‘Monica 2’: an NOS DAC designed and built by Yeo, one of the treasures of the DIYer’s universe. Monica 2 is substantially similar to the original Monica (I’ll call her ‘Monica 1’), so my review could fairly apply to both.

I won’t repeat the detail of that review (originally posted on Yeo’s web site: www.diyparadise.com); however I do want to record that Monica 2 blew me and my wife Denise away, and convinced us that non-oversampling DACs have the potential to outperform any competition based on alternative circuits.

Those in the know will know that Monica 2 was followed by Monica 3, which reportedly offered substantial sonic improvements – and even more improvements if you took advantage of some mods and add-ons, most of which are still available (check Yeo’s web site for details).

Enter Discreet Monica: the latest DAC to be created by Yeo and still so recent (in early June 2012) that she’s scarcely half-way toward her first birthday.

Although she is an NOS DAC, in terms of circuit design the new lady is significantly different from previous Monicas. Just HOW she differs is something you can discover by visiting Yeo’s web site; in this review I’ll focus on how she sounds. I will mention her weight, since when I last checked that wasn’t mentioned on Yeo’s site. She weighs a little over 3 kilos: considerably more than all her sisters combined.

HOW GOOD IS DISCREET MONICA?’ THE JOURNEY OF DISCOVERY

For me the most helpful component reviews are those that include comparisons. Comparisons help me to measure the new component against components I’ve heard or at least against components that have been compared with OTHER components, and gradually I build a comprehensive ‘comparison matrix’.

My review of Monica 2 compared her with other highly regarded DACs or CD players that Denise and I had actually heard, all of which she eclipsed (among these were the Rega Planet 2000 and the Rega Jupiter players, two Naim players, almost all the Musical Fidelity DACs, the then latest Cyrus DAC, the Chord DAC 64, and the stratospherically priced dCS Purcell-Delius combination). To Denise and me the appropriate measure of comparison for Discreet Monica seemed obvious. It was the performance of Monica 3, the most evolved Monica until the birth of Discreet Monica and (in 2012) still available for purchase. Even more enlightening, we thought, certainly for us, but also for any potential buyer, would be a comparison among Monica 2, Monica 3 and Discreet Monica.

By good fortune I was able to borrow a Monica 3: well run in, and with no modifications. As a first step then, Denise and I compared Monica 3 with our own Monica 2: also unmodified, and still the DAC we use in our principal audio system.

MONICA 3 VERSUS MONICA 2

Because Monica 3 needs at least 15 DC volts we couldn’t use our regular 12 volt battery supply; yet we wanted to compare these two DACs on a level playing field. The solution was to use as our power source a laboratory-standard switch-mode variable power supply (available from Jaycar in Melbourne Australia), which would take its 240 volts AC from a sine-wave inverter (see below).

For Monica 3 we used 18 volts: i.e. a tad more than the 17.8 usually fed to her from her own wall-wart supply.

For Monica 2 we set the voltage to 12.5: i.e. approximately the voltage that would have been fed to her from her dedicated Trojan battery had we used it.

We used our customary system for the audition: a Rega Planet 2000 as the transport; VTL Super Deluxe preamplifier (actually a PR 1: an upgraded, completely dual-mono version of the Super Deluxe); VTL 90/90 semi-dual-mono power amp (KT 88 output valves; push-pull); tri-wired Whatmough 502i speakers; and a variety of interconnect cables and power cords, all of high quality. 240 volts AC was supplied by a sine-wave inverter fed from a large 12 volt battery bank (this battery supply is separate from Monica 2’s). The digital interconnects for the two DACs were identical except for a small difference in length and in termination (our Monica 2’s interconnects are hard-wired); analogue interconnects were of different makes but are sonically very similar.

Analogue sources didn’t feature explicitly in our comparisons of the three Monicas; however Denise and I play LPs as often as we play CDs, and our analogue front-end is the implicit benchmark for all our digital source components. It comprises a Michell Gyro SE turntable with isolated DC motor, a Michell TecnoArm (Cardas rewired; custom modified) and an Amber (read ‘Grado’) Europa cartridge.

For those who might be interested: our listening room is approximately 5.4 metres long and 4.2 metres wide at the listening position tapering to 3.7 metres wide at the speaker end (i.e. the side walls are symmetrical but not parallel), with a ceiling height that rises from approximately 2.4 metres at the speaker end to 2.7 metres just forward of the listening position and then falls again. Side walls and ceiling are plaster board; the timber floor is carpeted. The speaker-end wall is heavily draped; the listening-end wall is not uniformly parallel to the speaker-end wall but the section that is parallel is also heavily draped.

Before we began our audition we warmed the entire system at idle – minus either DAC – for an hour and a half, to rule out subsequent changes in performance based on factors other than the DACs themselves. Thereafter we connected the DAC that was to be auditioned and warmed it for twenty minutes, while we played an LP to keep the system ticking over.

As our source for the comparison we used what has become our standard test CD: Simon and Garfunkel’s ‘Old Friends: Live on Stage’. These days this disc gives us even more valuable information, since we own the equivalent DVD and have attended a concert in a similar-size venue in which Simon and Garfunkel presented very nearly the same material. In line with our usual practice, Denise and I took separate notes and didn’t swap impressions until the audition was over.

THE RESULTS

Despite our different preferences, Denise and I agreed on Monica 3’s areas of dominance.

The main areas of improvement over Monica 2 were:

a more spacious soundstage: wider and with more ‘air’.

greater detail: instrumental lines and lyrics were more precisely rendered.

tighter, more disciplined transients, right across the frequency range.

more extended treble AND bass, but especially the treble.

a more neutral presentation: in comparison Monica 2 sounded slightly veiled, slightly congested and slightly ‘plummy’: more like a warm but slightly compressed production on a much-played LP.

Monica 3’s treble was delivered with most, but not all, of that delightfully non-fatiguing ‘analogue’ quality that we fell in love with when we first heard our Monica 2. It was difficult to decide whether this difference should be scored in Monica 3’s favour or against it, because now we had to decide whether Monica 2’s ‘analogue’ sound was the result of the absence of digital artefacts or the result of her more veiled and plummy presentation. In the end we couldn’t make up our minds on that; regardless, I preferred Monica 3’s treble to Monica 2’s, whereas for Denise it was line-ball.

A definite negative of Monica 3, in our opinion, was a slight additional hardness in the presentation of this particular CD, especially at high volume: to be fair, a volume level that we would rarely dial up for constant listening. It needs to be said that this disc IS slightly hard intrinsically – as can be verified by listening to the equivalent DVD – so one could argue that all Monica 3 was doing was presenting it as it is. Even if Monica 3 was herself a contributor, for me her virtues outweighed that shortcoming and put her comfortably ahead of her older sister. For Denise, however, the contest was still too close to call.

Subsequent comparisons between the two sisters, playing thoroughly familiar discs featuring jazz, rock, folk, classical, male and female vocalists both solo and massed, confirmed the more ‘analytical’ conclusions that Denise and I had reached during our primary audition – and also confirmed that the slight hardness I reported on earlier IS, indeed, intrinsic to the CD itself. However those comparisons also sharpened our awareness of both the merits and DEmerits of each DAC.

Monica 2’s shortcomings remained the same, and I’ve alluded to them already. Monica 3’s flaws were more difficult to put into words; yet they were there: best summarised as a sonic irritation that on some CDs was so subtle as to be not worth mentioning but, on others, so evident that we were tempted to turn down the volume and/or cut the treble (via a custom-built tone control: usually switched out of the signal path). On balance, I still preferred Monica 3, despite her shortcomings, but Denise found herself leaning toward Monica 2, even though she fully acknowledged her shortcomings too. Ideally, Denise would have used Monica 2 for some CDs and Monica 3 for others; I would have gone with Monica 3 for all of them. However, we shared an unavoidable conclusion: neither of these DACs is ‘as good as it can get’.

It deserves to be reported that, powered directly by her own battery, Monica 2’s presentation became cleaner and less plummy. Even so, I still preferred Monica 3, and Denise was still undecided. How Monica 3 herself would sound on a battery supply is, of course, a question I can’t answer, but other users have reported on this, with some preferring battery and some a mains-derived power supply.

MONICA 3 VERSUS DISCREET MONICA

It was now time to compare Monica 3 with the new lady on the block.

As before, all preparation procedures and all system components that could be kept the same were, indeed, the same. The exceptions were the DACs themselves and their respective power supplies. For Monica 3 we used the variable power supply that we’d used in her comparison with Monica 2; Discreet Monica was powered by her own integrated mains-derived power supply, fed to her via a bog-standard kettle cord similar in quality and power rating to the kettle cord that is sold with Monica 3’s power supply. By now we’d discovered that, in our system, Monica 3 sounds at her best on 17.5 volts, rather than, say, 17 or 18, so we used this for the shoot-out between her and her new sister. We set Discreet Monica’s variable output pot to 9: one notch below maximum.

Again our CD for the audition was Simon and Garfunkel’s ‘Old Friends: Live on Stage’; and again Denise and I took separate notes and didn’t swap impressions until the audition was over.

Keep in mind that, at the time of our inaugural audition, Discreet Monica had had only ten hours of running-in (via a spare CD player into a headphone amp). This is important because, as with Monica 3 and Monica 2 before her, some of her capacitors are Black Gate n series, which reputedly take at least 150 hours to burn in properly. She also uses quite a lot of Rubicon ZLs, also slow to burn in.

THE RESULTS

It was inevitable that two listeners would have at least slightly different perceptions and would also use different language to express them. Even so, the similarity of our conclusions is remarkable. In what follows I’ve done my best to capture our combined, overall impressions.

I’ll deal with the more analytical, cerebral, aspects first.

Compared with Monica 3, Discreet Monica delivered perhaps a slightly more extended bass; but more compelling was the quality of that bass: tight, utterly rock-solid, with Discreet Monica in total control. Monica 3 is no slouch in this department but Discreet Monica did it better.

Discreet Monica’s treble was at least as extended as Monica 3’s but, again, it was the quality of her treble that set her apart. It was noticeably sweeter and somehow ‘richer’, as though it contained more information in this register.

Discreet Monica’s clarity, air and detail were at least the equal of Monica 3’s; but, here too, there was a difference in quality: more texture, body, the qualities that we’re used to with our best LPs.

Discreet Monica’s staging surpassed that of Monica 3. Basic parameters such as width, depth and height were much the same, but the identity and location of musical elements, including the subtle cues to the position of singers and band members and the crowd, were decidedly more discernible.

Discreet Monica’s timing was breathtaking, significantly superior to Monica 3’s, and puts her at the very top of the column among the DACs and CD players we’ve heard: including the Naim players. Allied to this: vocal and instrumental notes were presented with virtually no extraneous smearing or overhang. As you’d expect, this was particularly noticeable with percussion and with vocal sibilants.

That’s the head stuff. What about the heart and soul?

Within seconds of hearing the new lady sing, Denise and I were captivated by a rich, multilayered, fulsomely textured and utterly riveting presentation that was at least the equal of the best LPs in our collection. The sense of ‘being there’ was better delivered than on any other system and by any other digital medium we’ve heard so far. Further listening didn’t make us blasé: on the contrary, we had the feeling that we were becoming addicted (we discovered that we’d both had these responses when we discussed our impressions after the audition).

Back to the head now: how much better than Monica 3 did we think Discreet Monica was? (This intuitive global rating is one we try to apply to any piece of equipment we’ve short-listed for purchase.) Denise judged at least 40%; my note reads ‘at least 35% and as high as 45%’. So let’s settle on 40%.

AN UNEXPECTED COMPLICATION

In the normal course of events Denise and I would have taken our totally focussed critical listening no further. Certainly we expected Discreet Monica to improve as she notched up more hours, but we expected the improvement to be gradual and modest. After all, we’d heard no dramatic change in our Monica 2 during her first 150 hours.

What we would have done, however, is listen more casually to Discreet Monica playing a variety of familiar CDs, to refine, confirm, or possibly revise our primary impressions. We were preparing to do just that when word came through from Yeo that there might be a quantum leap in Discreet Monica’s performance after about fifty hours. This possibility was something we couldn’t ignore.

So it was back to the bench for the new lady: to be hooked up to a spare CD player and on to a headphone amp (and then a pair of headphones, so that I could check the sonic chain occasionally), with the CD player set to ‘repeat’. We left her like that until she’d clocked at least 150 hours. We were ready to audition her again.

MONICA 3 VERSUS DISCREET MONICA: ROUND 2

Rather than relying exclusively on aural memory, Denise and I put our first impressions on the back burner, and once more put Discreet Monica head-to-head against Monica 3. Again we took separate notes, and as usual we waited until after the audition to discuss them.

SECOND ROUND RESULTS

My impressions and Denise’s were startlingly similar: even down to some of the language we used. As we compared our respective notes – for this audition AND for the inaugural one – the fundamental qualities of this new DAC were easy to agree on, and it was evident that the extra hours of run-in had consolidated them.

The first thing I want to mention is that the nature of the first-audition differences between Monica 3 and Discreet Monica had persisted.

Second: the ‘quantum’ of difference had increased – but not by a huge amount. In other words, there had been no ‘quantum leap’ of the kind that Yeo’s email had prepared us for. (For the record: this time Denise judged Discreet Monica to be ‘at least 40% better than Monica 3’; I wrote ‘at least 40% and possibly 45%’. In referring to Discreet Monica’s first and second performances both Denise and I had used exactly the same words: ‘difference not night-and-day’.)

Third: all Discreet Monica’s qualities as we’d heard them during the first audition were present in the second, but the extra hours of run-in had lifted nearly all of them from ‘sensational’ to ‘sublime’.

One quality that had not changed was Discreet Monica’s timing: it was still so good that it’s difficult to imagine how it could be bettered.

The ‘analogue’ richness and detail (a result of the retrieval of more information), the purity and treble sweetness were still there, but now with more finesse; an analogy is a polished table that has been FRENCH-polished to a piano finish by a master craftsman.

The most striking improvement was in a quality that we’d both registered during the first audition but almost subliminally. Now it was so palpable that it was easy to describe. That quality is ‘effortlessness’. Everything she does Discreet Monica does effortlessly. One has a sense of a calligrapher’s brush allied with the horsepower and speed of an Aston Martin and the focus and precision of a Swiss watch maker. The result is NOT a constantly ‘dramatic’ – i.e. ‘ballsy’ – presentation: rather it’s an overwhelmingly convincing sense of ‘being there’, listening to real music, in a real venue, with all of the nuances, the peaks and troughs, the delicacy, the slam, or whatever qualities the actual performance had at the time it was recorded.

THE MONICA FAMILY: FROM COMPROMISE TO EMANCIPATION

With the second audition behind us Denise and I did what we’d always planned to do: we listened through Discreet Monica to a variety of familiar CDs featuring jazz, rock, folk, male and female vocalists and classical music. With one exception – which I’ll discuss shortly – nothing we heard led us to change our minds about this new DAC, but it did help us to understand what it is about Monica 3 that makes her ascendancy over Monica 2 less clear-cut than we might have expected.

Discreet Monica, in our opinion, does everything better than either of her two sisters does it. She manages this feat, I believe, because she never has to push herself beyond her quite extraordinary capabilities.

In contrast, while Monica 3 gives the listener more than Monica 2, it comes at a cost. Compared with either of her sisters she sounds brash, too much ‘in your face’, slightly unrefined. I have the sense that she’s trying too hard, pushing herself beyond her comfort zone.

Monica 2 avoids these shortcomings, but that comes at a cost too. Monica 2’s solution is to veil the music slightly and to compress it: especially at the treble end. So she sounds ‘sweeter’ than Monica 3, more ‘polite’, even slightly more ‘analogue’, but also less detailed and less dramatic.

With Discreet Monica you really can have your cake and eat it too: she combines the virtues of her two older sisters and then takes off into a realm of her own.

I want to record one more feature of this most recent addition to the Monica family: one that demanded a correction to an inadequately considered assumption Denise and I had made before we extended our CD sampling. Discreet Monica, unlike Monica 2, does not cover up the worst excesses of CDs. An atrociously recorded CD – the sort that cuts you in half and has you wondering about the hearing of the artist or the sound engineers – still sounds pretty horrible: Discreet Monica will not paper it over. As far as I’m concerned that’s the way it has to be. If you want a component that puts the fewest imaginable obstacles between the listener and the moment of recording, and IF the moment of recording was crap, you should expect to hear crap.

DISCREET MONICA IN PERSPECTIVE

I want any prospective owner of a Discreet Monica to keep this in mind: she dominates a proud lineage whose foundation member still outperforms all the ‘non-Monica’ competition Denise and I have heard so far. That competition includes the Chord DAC 64 and others (see above), and, more recently, the best CD players available from Creek and Cambridge Audio, the Sony SCD-XB790 SACD player (playing CDs of course), and the built-like-a-battleship Pioneer PD-S707, which was considered good enough to be a platform for CD audio at the 2004 Milan Hi-End Audio Fair. All the Monica family members are regal performers; Discreet Monica, in our opinion, is the unchallenged Queen.

HOW DO YOU PUT A PRICE ON DISCREET MONICA?

If you’ve read this far you’ll know that discreet Monica is the best DAC (and in fact she’s the best digital source of any kind) that Denise and I have heard; but does she offer good value for money?

The value-for-money question is usually a vexed one. The answer will depend partly on what you’re used to spending on your HiFi gear, partly on the price of the competing components (is it, say, $100 versus $300, or $5000 versus $8000?), and partly on what increment of improvement you demand for each increment in price – and all these factors interact. Whatever your calculus, it’s harder to apply it if you can’t be sure of the improvement you’re going to get – which is often the case if you’re buying a component on-line and you don’t have a friend or relative who can let you listen to the one they bought. Another complication is that it’s almost impossible to personally audition every competitor, either because of time pressure or because some contenders are inaccessible except if you buy them but too expensive to justify your buying them before you audition them.

And that brings me back to the vexed question – except that for me, in this instance, it isn’t vexed at all.

At a starting price of 2000 Singapore dollars Discreet Monica is quite a lot more expensive than Monica 3. However she’s not only in a different league: she’s in a different arena. She’s a radical departure from her older sisters in design and architecture and more expensively dressed, and I believe a prospective buyer should be comparing her with the most exalted competitors currently available, such as CH Precision’s C1, Light Harmonic’s DaVinci and Vincent Brient’s TotalDac D1 Reference. Of these, the TotalDac D1 Reference is the cheapest; including freight charges, import duty and taxes, the most basic version of this French DAC would cost me 8000 Euros. Alongside her legitimate competitors Discreet Monica, in my opinion, is an incomparable bargain.

There are some people, in any case, who will say you can’t put a price on the voice of an angel. For me Discreet Monica connects Earth with Heaven: what price should I put on that?

Graham Woods

[Graham Woods is a Melbourne (Australia) clinical psychologist and professional writer. Denise Oh is a business systems and knowledge management consultant, as well as a classically trained musician. Both are audiophiles and occasional DIYers.]

The post DISCREET MONICA: MISS RIGHT BLOODY FANTASTIC appeared first on diyparadise.

over the years, you have given us sooooo much. words can’t even describe the depth of emotions you have brought us, you have brought us to the pinnacles and depths of the human emotions. yes, we all know that music has that effect but with your singing, aha… like a true master, you make it look so effortless. damn.

but as much as the tda1545 has given us, i sincerely believe we have gone as far as we could with it. there may be more ground to be gained but this is likely in incremental iotas rather than quantum leaps.

as such, though i don’t like it, i have been seeing another girl. please, before you get upset, hear me out. give me a bit credit for being honest with you.

well, it has been a longggggg journey, a lot of ground work, a lot of wooing…

getting her to sing is one thing but coaxing her to sing her heart out… now that is a challenge!

faint heart never won fair lady, you know the saying, and i persevered. i kept at it.

many months later… she slowly yielded…

now, you know i love wood chassis but everyone else seems to prefer cold, hard aluminium. okay, if you want this, you’ll have it!

i wired her as a dac-preamp. err, since there is no gain stage, output is just slightly more than 1v. guess you can’t call her a dac-preamp? then how about “dac with variable output”? okay with you?

if you look closely, there are 4 black gates non-polarized n series capacitors per channel. these are the red capacitors. since these are now out of production, am i the only manufacturer in the world to still use it in my products? so be it!

note the series of resistors? that’s the key to her singing. these are high accuracy 0.01% and 0.005% resistors, and these form the ladder in “ladder dacs”.

note that the 2 identical boards are Left/Right channels. there is no commercial dac chip here. this is a discrete dac, so called as it’s made out of discrete components. [and a helluva components!]

okay, now let me tell you the virtues of this girl!

she sings like no other! she is truly unique.

hearing her sing, i have a feeling she is implying subtly, she’s too good for me.

over the years, i have seen many girls but, being the critic that i am, i could always nitpick. that’s why i have never stopped working here. the search goes on… [is this developing to an obsessive compulsive disorder?]

never mind me! but with her, the nitpicking stops. the search ends here.

for she is in a different league. for she has this rare ability to put away the oft-heard “digital/analog” debate away for good. for she sings and she sings and she sings!

thus i want to tell the world, i have finally found Miss Right. [not miss always right]

my dear monica, since you are the inspiration for my starting this path, since this is a discrete dac, i will thus name her Discreet Monica.

The post I Found Miss Right! appeared first on diyparadise.

mojo will be as a kit for now.

As you could see, I fancy black solder mask and silver plated PCBs these days. Looks and sounds awesome. Hee hee.

Parts List
24 Ohm Resistor x2
100 Ohm Resistor x2
820 Ohm Resistor x2
1000 Ohm Resistor x4
Takman 1/2W 5600 Ohm I/V Resistor x2     WOW!
Ferrite bead x6
1mH inductor x3
1N4148 Diodes x6
1N4007 Protection Diode x1
LM317 x1
Panasonic 47uF FM x2
Panasonic 220uF FM x3
200 Ohm Trim pot x2
Low Noise Red LED x10
Toshiba 2SK170 FET x4     WOW!
BF245C x2
BF245A x2
ZTX651 x6     WOW!
ZTX751 x4     WOW!
4-pin header pin

Notice that the ultra-low profile sockets and those excellent 0.1uF Panasonic film caps have already been soldered in for you. All together now….WOW!!!!!!

Assembling mojo
With mojo, first thing to do is to solder in the low-lying components – resistors, inductors and ferrite beads. From left to right, the resistors are 24ohm, 2 pcs of 100 ohm, 2 pcs of 820 ohm and lastly 4 pcs of 1kohm resistors at the far right end. The inductors are all 1mH.

And now you solder in the transistors. From Right to Left, 4 pcs of 2SK170, 4 pcs of ZTX751 and 6 pcs of ZTX651. The cascaded FET CCS we should come to it in a moment. Leave it blank for now. All transistors and FETS are to be installed such that they can be read nicely as viewed from the Left side, meaning viewing from the string of 1N4148 diodes end.

Update on 15th March 2009. New PCB corrects this already, so no “transistor cross legging” required.
Here is the painful part. This PCB’s cascaded FET section was designed for 2SK170 but this has now been ditched for BF245x which have a different Gate and Source pintouts. As such, I’ll have to trouble you to cross the legs of the FETs and protect them from shorting through heatshrink tubings. The FETS are 2 pcs of BF245C and 2 pcs of BF245A.

Now you could solder in the FETs. Note location of BF245C and BF245A. If you place them in the other way, the circuit will still work, but you’ll always have a niggling doubt as to whether this circuit could be further optimized. And it could! If you place these FETs in the prefered location.
Stuff the electrolytic caps, the LEDs (all have the same orientation) and trim pot.

Here’s another guide.

Power supply wiring is shown here. 15-24VDC, entirely up to you.

Customization
Here, I leave this entirely up to you to customize your mojo as everyone has different needs, so too with mojo! The resistor marked “RES” you could use this to drop voltage between the I/V stage and the TDA1545 circuitry. Shown here is a metal oxide 2W 33ohm resistor. Alternatively you could leave out this resistor and utilize the power supply connections beside to separately power your TDA1545 circuitry. Hey, whatever tickles your fancy ok?

If you feel like powering the SS I/V Left/Right channels with different power supplies, I’m certainly not going to stop you! Simply supply a separate VCC to “LSUPPLY” as shown. However, both channels will share the same ground. Should you desire to have the same supply for both channels, then just put a jumper on “LSUPPLY”.

Giving Monica some mojo!
Shown here is mojo being “mated” with USB Monica. Remove the TDA1545 chip from USB Monica, transfer to mojo PCB and plug in this double sided header pins. Note that one end of the header pins have larger plugs than the other. The larger one goes to mojo while the smaller one plugs into existing EIAJ conections (pins 1-4 of TDA1545). If you reverse this header pin, it won’t fit.

USB Monica, given some mojo, will sing for you even better than before!

Update on 15th March 2009. Mojo kits purchased on 15th March and onwards require no rework on your part.

Corrections on the PCB
I’m known as a klutz. I’m also hopeless at proof reading. So despite many attempts, I still made mistakes on the PCB. Here I rely on your grace to correct them on my behalf. Actually I corrected some. Places where the trace has to be cut, I have cut them with this cool PCB drill I just bought… Now you need to apply these jumpers.

The post Give me Mojo! appeared first on diyparadise.

Once upon a time, in a galaxy far far away, lived a Diyer by the name of CY Liew (whom by the end of this article we should give you a nickname!) who can’t decide between the TDA1545, TDA1543 and its many parallel permutations (or mutations). He could, of course, build many many DACs and choose one (what I would do) but he felt that such an approach is sooooooo “unmacho”, soooooo 20th century. So our friend here who, by the way, wears a soldering gun like a cowboy wears his gun, did the most logical thing any Diyer would like to do — build all of them in one chassis and switch to your hearts content.

And so begins the story… *cue music intro*

First of all, let me explain the features. The 4 switches at the right are for, from Left to Right, TDA1545, TDA1543 with active I/V conversion thru OPA627 opamp, then 4xTDA1543 and lastly 8xTDA1543. Cool moi?

Switch at center is power switch. At the far left, this is where it gets better… battery! Yeah our hero here can’t decide which he likes so Mr-Indecisive did the most manly thing there is. Instead of talking about the sound, he built all his doubts into this little box and listen it for himself. Now this is a MAN.

So there you have it! An out-of-this-world, whatchama-call-it, switch-as-you-please, whole-loads-of-fun DAC.

Also known as User-Selectable TDA1545, 4xTDA1543, 8xTDA1543 with passive I/V conversion and TDA1543 with active I/V conversion with both Mains AC and Battery Powered Option Non-Oversampling Digital Analog Converter(s). Phew!

Colloquailly also known as “Gua Tak Boleh Tahan” DAC! [insert foreign phrase of your language meaning “out-of-this-world cool until i’m almost stuck to the wall reading about this”.]

Anyway, one fine rainy Saturday morning, we had a listen to all the DACs in my humble system. It was so easy to select between DACs! All in all, there is a huge difference between them DACs. I prefer the 1545 in my system while CY “DAC Man” Liew prefers the single TDA1543 with OPA627 I/V conversion in his.

As you can see, we Diyers have lots of fun!

So folks, let’s give DAC-Man a round of applause for his wonderful engineering! DAC-Man welcomes praises at liew dot cy at gmail dot com.

PS: Err, DAC-Man, can we have an amp that switches between 45, 2A3 and 300B? Sorry, can’t resist!

The post A Deck of DACs appeared first on diyparadise.

Well, almost…

History of the DAC
Idea was conceived while watching some horrible B-grade movie when thoughts suddenly drifted to all those ideas/thoughts/experience “stolen” from everyone/everywhere on the Great World Wide Web. Then Head Honcho of Calv Acoustic Lab lended a GIGANTIC helping hand by laying out the PCB design. Needless to say, never bothered to finish that stupid movie.

Pre-requisite to build the DAC
As long as you can solder properly, know how to use a multimeter, know how to work logically and of course, relax with your favourite beverage (milk, coffee, tea, toddy, stout, beer, sake…), you are ready!

Work logically : Solder in all components except for CS8412 and TDA154x. Power up and measure that power supply voltages are correct. Then in goes last 2 chips. Power up again to make sure that power supply voltages are still correct. With TDA1545, check that one end of R18 is at 1/2Vdd while the other end is at some other voltage (~0.8V in mind). Then hook it up.

Don’t Worry, Be Happy
First of all, a very important point to know about these non-os DAC kits is that there is no gain stage involved. Thus the output voltage you get is just the pure voltage as generated across the current-to-voltage resistor. In other words, passive I/V conversion.

Because of this wonderful reason, these DAC kits will not put out 2V output like most conventional CDPs. If you are using single DAC chips, it’s more like 0.5-0.6V. If you parallel the chips ala 4xTDA1543 or 8xTDA1543, then the output level is higher. Remember, these are current output DACs so when you parallel the DACs, the current adds up and you get more current, hence more voltage output. 4xTDA1543 gets you to almost 2V while 8xTDA1543 gets you more than 2V.

If your system is low gain and needs all the swing from your DAC stage, do NOT be alarmed that you need to crank up your volume from 10 o’clock till 1 o’clock to get back the same listening level. There is nothing wrong going on here. It’s just that the DAC output voltage is lower, that’s all. It’s no different like connecting a lower sensitivity speakers at the output. You just need to crank up the volume, that’s all.

If you feel that it is important to listen at 10 o’clock as opposed to 1 o’clock, then feel free to add in a gain stage. This is where I’m stubborn, obstinate to the point of being a pain in the you-know-where. The decision to eschew convention is partly based on my experience of haven’t heard any gain stage at the DAC level work so brilliantly without destroying the purity of the DAC stage.

I have listened to opamp stage (even using OPA627), tube stage (using the ubiquitous 6922 variants etc) blah blah blah… but never liked its “flavourings”. Each time, my ears tell me that no gain stage is still better. Of all the gain stages I have heard (okay, I haven’t heard that many), the one most faithful to the DAC is the 12B4-based gain stage. With its mu of ~6, it’s just nice! However, due to its very microphonic nature, again, it’s hard to recommend.

Briefly pros and cons of a gain stage
Pros: more output, better dynamics, better bass.
Cons: loss of “sonic purity”, sometimes loss of micro detail as well.
So if you feel like you need a gain stage, you are on your own! *diabolical evil laughter ensues…*

Troubleshooting the DAC
This is the fun part. Okay, there is this Mr Murphy and his darn wonderful Law that makes this page necessary. After soldering everything and verifying all voltages are correct, here are some troubleshooting tips.

Problem : No sound. LED doesn’t light up when you pressed “Play” on your CDP.
The LED is just an indicator. More importantly, check pin 28 of CS8412 (the pin closest to LED). It should read ~5V when no music is playing and ~0V when you pressed “Play”. If it is ~0V when you pressed “Play”, then chances are you got the LED orientation wrong. If you still get ~5V, this means CS8412 was unable to “lock” to the incoming SPDIF signal from your CD transport. Check that you got the 75ohm, 100nF caps at the input wired correctly. Check also the PLL filter (470ohm, 220nF, 3300pF) are all placed correctly.

Also, measure Frequency at pins 1/2/3 of TDA154x pins. (Measure at the leads of the chip!) All of them should read something when music is playing. Pin 2 should read ~44.1kHz. If you could get some frequency measurement at these pins, this means all the digital signal is reaching TDA154x, then it’s highly probable that you have a dead TDA154x chip. If not, you could have a broken connection somewhere between CS8412 and TDA154x.

Problem : Distorted sound.
Check that you got the right I/V and Ref (R18) resistors in!

Problem : Got sound but I’m hearing things I’ve never heard before! Is there another backup singer on this track?
This is spooky. Call an exorcist!

Problem : My friends love the sound and wouldn’t return my DAC!
Those selfish bastards! Get new friends and new DAC.

Problem : My wife loves the sound! She said this diyparadise guy is her new hero. I’m jealous!
Lie to her that I look like a toad.

Problem : I can’t decide between mahogany wood, ABS plastic, or stainless steel chassis.
Ask your wife.

Problem : My dog/cat runs away when I play your DAC!
Are you using a super tweeter? If your system capable of up to 44kHz? Maybe your pets are irritated by this super-sonic noise. Hey, at least they can’t ruin your audio gear! They are also leaving you to listen in peace. So what’s the problem? Do you also experience less mosquito bites? I heard that mosquitoes hate this frequency too.

What else?
There’s certainly room for improvement! You could start a search for your “perfect” gain stage. You could build a super clock for asynchronous clocking between CS8412 and TDA154x. Details will be available soon.

Remember, this DAC kit is meant to give you a start in the wonderful sonic world of non-os. Now that I’ve got your attention, there are certainly many steps ahead in this wonderful journey.

Enjoy!

www.diyparadise.com

The post All you ever need to know about DAC kits appeared first on diyparadise.

Cloning Monica

Well, well, well, since her debut, Monica, and subsequently Monica2, has been so well received by so many audio enthusiasts worldwide that if you haven’t heard of her, you better get out from your cave! Inevitably, success brings its pitfalls. The obvious being :

1. being zapped out of life. Yeah, I have no life these days, quietly soldering and soldering, fulfiling the sonic hunger of audio enthusiasts all over.

2. I feel so good, so inspired, whenever I receive emails thanking me for such a wonderful piece of audio equipment! Well, as the cliche goes, Monica is MORE than an audio equipment. : )

3. Time and time again, I have found her jiving with gears costing more than 20x her selling price! Just proves what an amazing value she is. No wonder you guys are so in love.

4. I get so many veiled attempts at finding out how I build my baby. How I “inject” pixie dust and create music magic. Seems like quite a number of folks intend to CLONE Monica.

Oh well, since you try so hard to “dig” info out of me (short of sending the mafia to my door), let me come clean with you. If you want to clone Monica, at least do it right.

In this context, I define the “cloning” of Monica as utilizing the TDA1545A dac chip in similar configuration. Note that I don’t run TDA1545A per the datasheet. I use 2.2kOhm for the I/V resistors, 22kOhm for the Vref resistor and bias this pin at 1/2VDD. Nothing scientific but definitely different from the rest.

So if you want to clone Monica, at least do it right!

PCB
Needless to say, very critical component here. First started out with silver plated PCB but then switched vendor due to inconsistent quality problem. Current PCBs are all GOLD plated. We do this mainly for lead free reasons so that our European brothers and sisters could enjoy Monica’s magic too. You could say another reason is more “selfish” so that I breath in less lead in the solder fumes and won’t be so stoopid in the long run. You know what folks say about lead damaging our brain etc et etc? You know, me doing silly things like selling Monica too cheap. : )

Double sided with the top layer being one huge ground plane. Single side PCB just won’t cut it ok? Beside every electrolytic, there are provisions for you to solder in a small ceramic bypass cap for more effective power supply bypass.

Components
Digital circuitry is less fussy but eletrolytics are best with Low Impedance caps. I started with Sanyo Oscons but due to availability problems, then switched to Panasonic FCs and FMs. I find them just as good with insiginificant sonic difference.

The regulators are just basic 78xx series type. Nothing special I know but listening tests with shunt regulated types didn’t yield that much sonic difference so… why bother? More importantly 3 separate regulators are used for the digital receiver’s digital/analog circuitry and the reclocker circuitry.

On the analog side, caps have come and gone but only one cap, I will NEVER change (until I can’t source them anymore). And this is the non-polarized Black Gates N series 4.7uF 50V at the output. Have compared them with couple of polypropylenes etc but these little BG beat them all in terms of TRANSPARENCY. Well, size as well, ha! It is my aim for my audio gears to sound as transparent as possible, never interfering with the music. Meaning, the equipment does not get in the way of the music. You could try other caps, of course, but this will be your sonic preference, not mine. Entirely up to you here.

The power supply circuitry consists of a constant current source feeding a shunt regulator. The LM317 and resistor sets the CCS of 50mA while the series diodes form a shunt regulator. All this to regulate 5V. Absolute 5V is not critical but absolute stability is. As TDA1545A draws only 5mA max, the regulator combo only has to cope with 10% variation in its current. Such an easy job! It is for this reason that the power supply filtering is very clean here. Very nice. So much so that all the details in your music comes through unhindered. If it’s there, Monica will sing for you. She’s a great gal!

I once offered standard Black Gates for the power supply bypass beside TDA1545A. Not necessary at all as simple Panasonic FCs do a great job here. So don’t get too hung up on the Black Gates name. Not all of them are gold. The standard stuffs are really no big deal. Reserve your respect for the BG N series!

Other nifty details
Well, TDA1545A uses low profile sockets – which costs more but sounds better.
The PLL filter caps, it’s imperative to use polypropyelene for the 3300pF cap.
We love Monica when she sings with 80MHz oscillator.
The flip flop chip has to be ACT series or higher. With ACT, it’s good up to 125MHz. DO NOT USE the much cheaper HC and other slower series.
Only lead free solder is used throughout.

Assembly

	A local sub-contractor (read virgins born under the Virgo sign only) stuffs the PCB and solders in most components. Well, THAT was supposed to be the case but it was not meant to be as virgins are so hard to come by these days… So intead, I have normal folks like you and me stuff the PCBs but to preserve the magic, we only solder on full moon nights.
	I then solder in the surface mounted components and also wire in the jumpers. much tender loving care goes into this…
	Yes, they are hand soldered. Only lead free solder please.
	Taking a much needed bath!
	Testing stage. One full CD of songs will be spun. Current favourite is Tom Waits but could be any CDs. I build connectors wired to SPDIF output from a CD player, then there’s another connector at the analog output ends, hooked up to an amp, and then speakers. I guess a cool way to test her is to measure the soundstage produced from every Monica (ha ha!). Please don’t ask me to!

There you go. I hope you learned something about how I build Monica. You guys who want to clone Monica, I hope you find something useful here.

Thanks and enjoy your Monica!

The post Cloning Monica appeared first on diyparadise.

Rudolf Broertjes’ SS I/V Gain Stage

Greeings DIY brethrens!

Well ever since Monica conquered our hearts, there have always been questions from insatiable diyers asking for more more more!

Truth be told, Monica’s output is a little on the low side. Passive current-to-voltage conversion has its “beauty and beast” side. The beast side is of course current drive and low output. But the beauty… oh so beautiful… that I just feel that if we can’t find a suitable gain stage for her, then just let her be. Stay with this for now.

Then back in February 2006, CY “DAC Man” Liew shared with us his fabulous Grounded Grid Tube Gain Stage. If Monica sang before, now she’ll dance for you!

But DIYers will always be DIYers. Very soon, there were clamours for more, more, more again.

Then in February 2007, Ronald Verlaan shared on our forum this schematic by Rudolf Broertjes. Rudolf posted this schematic in diyaudio some moons ago.

Simple enough eh? The beauty of this circuit is that it sounds better than the vaccuum stage!

Plus you could power it at 12VDC though 18VDC is said to sound even better. For once, you could have your cake and eat it too!

I then contacted Rudolf but too bad he doesn’t have PCBs made for sale. I built a prototype and it’s rather time consuming. Besides without the benefit of a ground plane, noise issue etc could be a problem. So I requested Rudolf’s permission to build the PCB and sell to DIYers, especially Monica users.

And Rudolf agreed! So here you go.

Since this is not my design, and thanks to Rudolf’s generosity to share with all DIYers, I don’t want to profit from this. So the PCBs will be sold at a very low price, to cover costs, Paypal charges etc. You could order from our e-Store. http://store.diyparadise.com

Well, if that’s all to it, then it’s fine but I’m known to be a klutz many times. And this time is no different.

You see, when I built my prototype, for RSO1A, I used just a 82ohm resistor. And everything worked fine. Also, I couldn’t find any BF245A here so I went for the substitute of 2N3819.

As such, the PCB was designed for this.

When I got the PCBs in hand, then I realized a few things. Having a resistor instead of a trim pot for RSO1A is a BAD idea. Too many variations could give you problems. The LEDs’ forward voltage drop, transistor betas etc… All could affect the output DC voltage. Hence a few builds I did had output DC voltages ranging from 4VDC to 10VDC.

At 4VDC, Monica won’t sing at all. At 10VDC, she sings but off key (distortion!). This is why we want a trim pot! So to adjust output voltage to around half of VCC. So if you power her with 12VDC, then you want around 6-7VDC.

As such, there are a few mods we have to do here, no thanks to my clumsiness. Embarassing moments coming ahead…

For RSO1A shown above, we have R7 and R11 on the PCB. Have to fit in a trim pot in a resistor’s place! Fortunately it’s not as bad as fitting in a square into round hole… or something like that. This is how you do it. Carefully bend leg 2 to leg 3 and solder them together. Then spread it apart so that it sits in the PCB holes nicely.

Now if you prefer to use BF245A instead of 2N3819, there’s a bit more work for you too. You see, the semiconductor world is full of crazy folks who don’t understand “standardizations”. Source/Gate legs on both FETs are reversed! So BF245A has to “cross legs” and wear “stockings”. That’s heatshrink for you!

This is how it looks like. Shown here is for one channel only. Repeat for the other. My apologies again for this mess.

To integrate with Monica, this involves taking out components or if your soldering skills is suspect, just shorting them out. Err, either way you need to take out R19 and R20, then short the 2 inductors beside them all the way till C9 and C16. You could take out C9/C16 and use them at output stage of the I/V board and save yourself couple hundreds hours of running those darn Black Gates again.

A note about the LEDs. At first I tried those normal red LEDs but their forward voltage drop varies quite a lot between samples. In the end, I had to settle for these super bright red LEDs. They cost more but the forward voltage drops are pretty consistent. Only downside is you have to wear shades when playing music.

Okay, I exaggerated.

Building the SS I/V stage is very easy. Start off with resistors and diodes first.

R8, R14 — 820 ohm

R13, R16 — 100 ohm. Schematic above shows 270 ohm (RSI1) but as Rudolf himself said, 100 ohm sounds better.

R7, R11 — 200 ohm trim pot as shown above.

R9, R15 — is the critical I/V resistor. I recommend 3.3kohm if you use 12VDC supply. You could use bigger value with higher Vcc. Splurge on Kiwame, Holco, Riken, Shintoh… anything you like!

Next, we solder in the diodes. There are just 4 pieces of 1N4148 diodes. D2, D4, D10 and D14.

You could plug in the transistors now.

Q1, Q2, Q7, Q8 are all BC557.

Q4, Q5, Q6, Q10, Q11, Q12 are all BC547.

Q3 and Q9 are 2N3819s. If you prefer to use BF245A, then you need to cross its legs as shown above. Sorry again…

Now you can plug in those big fat LEDs. Be careful with orientation! + sign on PCB denotes LED anode – the longer of the LED leads. D1, D6, D9 and D8, D15, D16.

C13 and C14 of course is your output coupling capacitor. I recommend Black Gates N 4.7uF but you could choose anything you like. I left C12 and C20 blank but you could put in 1.1nF as shown in Rudolf’s schematic. Leaving it blank is good for now as we could measure across C12/C20 the output DC voltage.

Lastly C22 is the power supply capacitor. I use 220uF/25V Panasonic FM. Power input is labeled with pin 1 being the positive side.

Voila!

Upon power up, put your multimeter probe on C12/C20 and measure the output DC voltage. Adjust to around half of Vcc but it doesn’t have to be very accurate. I adjusted mine for 6.5VDC on both channels. I noticed couple minute upon power up, the voltages drift a little. Well, adjust again. After this adjustment, everything is fine.

I guess we are done now! Email or contact me if anything is unclear.

The post Rudolf Broertjes’ SS I/V Gain Stage appeared first on diyparadise.

Hello DIYers.

You may have came across my USB Convertor. That was meant as a temporary solution while I crack my head over a proper USB DAC. The USB Convertor outputs SPDIF (your vanilla digital output) which you could then feed your DAC. Now if you are looking for a dual usage DAC (meaning for both computer and CD/DVD player type), then this will be a good, albeit compromised, option.

However, if sonic quality is your utmost concern, then there is simply no business converting from USB to SPDIF then to DAC format again.

Therein lies a problem. Almost all the USB receiver chips in the market I know only outputs I2S and not the EIAJ format required by Monica’s TDA1545 chip. Boy, this isn’t fun.

I built a few circuits to convert I2S to EIAJ but wasn’t successful. More studies later… then I realized I need to climb up the highest mountain in this region, consult the guru there and sprinkle some pixie dust.

Nah, the guru wasn’t much help. In the end, after lots of diligent nights (and wee early morning hours) of pouring over datasheets and building prototypes, I finally got it done.

USB – I2S – EIAJ – Monica!!!

Let me be anal here and declare this as the first USB DAC using an EIAJ based DAC chip!

[You could make me fall flat on my face with big dollop of humble pie by pointing out to me which USB DAC in the market that uses an EIAJ based DAC chip.]

So what’s the big deal you may ask? Well, as always in audio, less is indeed more. Going through one less data conversion, the gain in sonic quality is…. va va voom! Like the real Monica!

If you are new to computer audio, I suggest you take a read of my computer audio pages.

So this PCB consists of a USB receiver chip, an I2S-to-EIAJ convertor and asynchronous reclocking scheme, TDA1545A circuitry and of course, Rudolf Broertjes’ SS I/V Gain Stage. All in one smoking PCB!

Simple enough eh? It looks simple from the top but underneath, there’s quite a lot of surface mounted components soldered on.

You could power her at 12VDC though 18VDC is said to sound better especially for the SS I/V stage. If you intend to go this high, I’d suggest heatsinks for the LM317 chip.

Better still, note that L3 is a diode instead of an inductor or ferrite bead. If you remove L3, you could power TDA1545 circuitry through J2 and power the SS I/V stage circuitry separately through J4. How about that? ; )

Wiring is very simple. Just hook up power supply (you provide of course), and output to RCA sockets of your choice. Input is simply USB from your PC. I’ll suggest a USB cable of type A jacks and off you’ll go!

No software to install, and no PC casing to dismantle.

Why heck, install both USB Monica and Charlize in one little case and you’ll have a smoking PC audio system!

Due to complexity of build, no kit is available yet. Assembled/tested USB Monica could be purchased from our e-Store. http://store.diyparadise.com

For once, let’s end it short and sweet.

And spend more time with Monica!

Update on 27 Nov 2007!!!

Plug and Play USB Monica in hard wood chassis like Monica 3 available now!

Enhanced PCB featuring some changes ala Monica 3. Note the Super E Black Gates… Yummy!

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