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.

My first source was a heavily modified Marantz CD63. this seems like aeons ago. Then the foray to DACs began, first with TDA1543, then TDA1545. you could say that the seed of Monica was being sown around this time.

I later changed the transport to Philip’s CD-Pro2. Wow! Huge jump in sonics. Puts down so many other transports. However, for some reasons which I couldn’t comprehend, my CD-Pro2 module died on me. 2 pieces of CD-Pro2 later, I decided I had enough.

Then the switch to PC audio and hence started playing with a Squeezebox media player. Sonics wise the CD-Pro2 still makes a better transport but the convenience of playing off pc more than makes up for loss in sonics. And yeah, I heavily modified my Squeezebox unit too.

Well everything’s good for now but then… the revelation of the QLS Hifi’s QA550 SD card player! Wow! Immediately you hear the gulf in the sonic quality between the Squeezebox and the QA550. Fed with a Kwak Clock, the sonic improvement is even greater.

So if things are so good now, why fret? Unfortunately the user interface of the QA550 is akin that of a turntable, which is almost zilch. After being spoiled by the user interface on the Squeezebox (including the touch screen Squeezebox Touch), the QA550 is a step back in time…

So the journey for a better source starts again. Damn it.

I have heard lots of good things about the m2tech Hiface but I’m not interested in SPDIF as the I2S interface proves superior (to think that so much time/money/effort has been wasted!).

So John Kenny‘s modified I2S Hiface seems like the perfect ticket! (Unfortunately John isn’t selling the pcb module anymore).

Many many weeks later, finally got it built.

Boy, that one sentence didn’t show you how much work I did.

This is what I did:
As I2S consists of 5 lines of signal, you have to decide on a proper interface. there is no standard interface here so i settled for the RF45 network port which is used by many companies (m2tech, North Star and Zenden etc) too for I2S duties.

So got to build an I2S Monica that accepts I2S input via RJ45 interface.

While doing so, I might as well try this excellent looking “Weipu” connectors for analog signal duties. So this I2S Monica accepts I2S via RJ45 then outputs analog signal via Weipu connectors.

A Beyonce was later built using Weipu connectors. And to have more fun, instead of the Microchip controller I used before, I now put in an Arduino controller. The 8 digit LED display is really cool too.

Hey, since we are already at this stage, I built a new Charlize but using Weipu connectors.

Lastly i had to haul up my old Mac Mini to audio duties and transfer all the music files to a new hard disk.

So is it any wonder I’m so short of time?

Do notice I “standardized” my chassis. These are actually key holders made from recycled rubber wood. [trying to be green … ]

Oh well, finally got everything built and… the sound makes it all worthwhile!

Wait! I’m not done yet.

I also installed the very cool Pure Music Player. Oh my! What a nice software! It could upsample (which I can’t be bothered with) or play native sample rate of your audio files up to 384kHz sampling rate. And the hiface supports all this. If you have to ask, well, higher sampled material sounds better!

Higher sampled music does the highs so much better. At first I wasn’t sure of all the highs but then as you listened, damn in, I’ve been missing so much all this while! Scoped waveforms back this up. [Of course vinyl folks will tell you nothing beats infinite sampling rate. gotta give this to you guy!]

So after all this work, I’ll say everything is worthwhile!

The highs… could give you a high! Have never heard so much highs coming out of the system. This took a while to get used to but now with the silky highs, boy, everything sounds so much better now.

So am I done here? Again, not yet!

My I2S hiface is a Mk2. Apparently John Kenny has just released Mk3, so there’s more mods to be done. And more sonic blasts to be had!

One thing for sure, this won’t be the last time I rebuild my system. That’s the fun of DIY!

The post Rebuilding my system appeared first on diyparadise.

I have been playing with CD transports for a while now, culminating with the really excellent CDPRO2, but with the advent of PC based music, and related media players like the Squeezebox, CDPs slowly lose out in favour.

And with media players, once you modify them ala Crazy DIYers, the gain in performance puts many esteemed CD transports to shame. What more, these media players are really cheap! I don’t have to tell you how expensive it is to procure a CDPRO based transport. Go google yourself.

However, as much as I enjoyed my highly modified Squeezebox, CDPRO2 based transport still trumps. There just seems to be a glass ceiling where we are still trying to break.

But then when I heard of SD card players, I got interested. This got the makings of an ultimate digital source.

What’s so great about it? Purportedly no moving parts, hence better reliability; less jitter, hence better sonics etc.

I consider prototyping one myself but the engineering efforts takes time but fortunately our Chinese brothers in Shenzhen QLS Hifi offers a built up WAV player for not a lot of moolah.

On the other hand, this WAV player ONLY plays 16-bit 44.1kHz WAV files. So no MP3, no FLACs, no 24-bit gizmo etc. No, nope, None, Nilch, Nada.

So what’s so great about this WAV player? You just got to listen to it.

Easy. Just play music through it.

Feeding it WAV files and playing off stock, the first few hours was good but not great but after some hours of running in…. Wooooooooooowwwwwww!!!!!!

I was speechless.

I was stunned.

I was… dumb strucked.

Here is this humble looking fella (stock standard!), trouncing my highly modified Squeezebox with upgraded external Paul Hynes power supply.

And putting the CDPRO2 transport to shame.

What more does one want?

Being a greedy bastard, I opened it up and looked for modding potential.

There are Sanyo Oscons all around. Not exactly SA grade but still no slouch. There is a 7805V pre regulator followed by 3 LM1117 regulators. One for the DSP chip (this guy does all the hard work, reading off the SD card, updating the display and sending out I2S signal), one for the oscillator clocking this chip and another for the I2S-SPDIF generator. Impressive!

The pic below however, isn’t stock standard anymore as itchy-fingered me just have to work on it. I swapped the pre pre-regulator cap with another Oscon and removed the SPDIF RCA and Toslink sockets. I replaced the SPDIF RCA with a BNC socket. This should be the way to go!

Also, I replaced the output pulse transformer (there’s already one inside) with a Newava make.

Note that there is I2S output available on this player. On another player, I tapped this out and fed to an I2S-EIAJ convertor to feed directly to mojo (which accepts EIAJ readily). This my bro, beats the SPDIF interface! But it took me a while to hear the difference while Gabriel (who has much better ears than me) detected the improvement right away. So if you can’t hear any improvement, get a pair of better ears!

All in all, I’m so happy with this little guy, I use it as my reference these days. Yeah, the Squeezebox has a nice display and offers loads of convenience but the SD player gives the best sonics.

Sounds familiar? It’s like the CDP offers lots of convenience but the turntable gives best sonics.

So what do I make out of it? This SD card WAV player is like a Digital Turntable.

The post Digital Turntable appeared first on diyparadise.

Okay, here’s just a few things I have done over the past few weeks (or is it months) to improve the sonics of my system.

First thing first. Monica!
Even though I specified 220uF in the Mojo power supply for TDA1545, I had only 100uF when I tried her out. Thus with Black Gates Super E, total capacitance is 200uF. But the PCB was designed for 220uF Super E, so that’s 440uF capacitance in total.

So after finally ordering these caps, put them in and.. Wow! Lower noise floor! By my dummy ears, I’ll say around 2.7896dB quieter. Okay! I made that up! But it’s at least 2dB quieter as I have to crank an additional 3dB setting to hear hiss coming out of the speakers. Err, mind you, these are ~100dB speakers…

The above pic shows Mojo integrated with Monica3. You may notice there are a few additional modules there… Blame the 2 Pauls (Needs and Hynes!)

Paul Needs told me about these modules he got from Paul Hynes. According to him, major improvement to Monica’s sonics! Well, you know me, if anything could milk more honey out of my lady (err I mean ma dac), I’ll go for it!

So after I got the 5V and 0.83V regs from Paul Hynes, incorporated them into Monica + mojo. The 5V reg is actually a “super shunt” so it still needs a constant current source, and what better CCS than Paul Hynes’ CCS2? The 0.83V reg is fed off the 5V reg. So what we have is this :

With these mods, Monica + mojo improved a whole new level! If before, you have been stunned by this combo, now you’ll be peeing in your pants! Well, assuming you haven’t done so. Hee hee…

Both the 5V and 0.83V regs should be in stock couple weeks later.

Err, just realized the CCS2 has been obscured by the 0.83V reg in above pic…

Next comes Charlize!
First thing I did was change the power supply. Have been so happy using this Hitachi battery which out of all the batteries I tested, gave me the widest grin. I actually got a Paul Hynes PR3 earlier and did the power supply for Gabriel, but I never got to listen to it in my system as Gabriel liked it so much he wouldn’t let me take it back!

Couple months ago, bought this Stillpoints ERS fabric. The sales copy is very interesting. An average of 50dB attenuation from 10MHz to 17GHz! Wow!

Of course, I can’t test this figure but I could use my crummy ears and see if I could hear any difference. After all, whatever spec means moot if I can’t hear any sonic improvement.

Tried inserting strips in the center of the air core inductors, but couldn’t hear any difference. Wrapped around the inductors… Yes! Not surprising as the inductors are coiled such that the fields radiate outwards. Improvement isn’t as huge as all the previous tweaks on this page, but worth your time and effort! Certain instruments like cymbals gain “body” and “definition”, if it was a mash of splishy-splashy noise earlier.

And the tweak is so easy to apply! Definitely reversible. Just be careful not to come into contact with any solder joints or component leads as the ERS paper could be conductive.

But we are not done yet! Last but not least, installed 2 pieces of this wood diffusor behind my horns.

Few months ago, visited an audiophile friend about 300km away and had quite an epiphany listening to his system. You see, I kind of regard many of the audio “tweaks/accessories” as snake oil – at least those that I can’t understand. Usually will just attribute any sonic improvement as psychological rather than real improvement. So imagine our surprise to come across this audiophile who has almost ALL the tweaks one could think of.

And listening was a revelation! The host was kind enough to let us listen with and without some of the tweaks. After just few seconds of listening, I was shocked. Gabriel was shocked.

From now onwards, we only regard the hyper inflated price as snake oil, but not the sonic improvement!

For starters, I’ll start with something I could understand and believe. Yes, no snake oil here. Just a simple diffusor. Will progress and experiment with other stuffs later.

All in all, it has been a fun journey but you know with audio, this journey never ends!

The post What I’ve done over the past few months to improve my system… 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.

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If you have been to our forum lately, you’ll notice that what started as a thread whereby martinbls laments the “slow sound” he got from Monica, slowly evolved into a thread where with fellow members contributing, we now have another winner tweak for Monica! And all of the ss i/v stage users!

Okay, martinbls asked the question. Member assendor (hats off the most diligent member on the forum now! Thanks a lot Jonas!) then gave him some suggestions, of which the most potent was his mentioning of Nelson Pass’s First Watt B1 Buffer Preamp. The basic idea is to convert Monica’s highish output impedance to a nice low impedance.

Then member PaulN, (sharp as he always is!) saw the potential right away and suggested incorporating the JFET stage Q100, Q101 (and likewise Q200, Q201)
directly at Rudolf Broertjes’ SS I/V Gain Stage, just before the output capacitors.

All other components are not needed as we already have 1/2 Vcc from the SS I/V stage.

It’s one thing to suggest, but another to build it right away and report to the forum! Within couple of hours, I was kinda shocked to receive an email from PaulN saying he has built in the tweaks and reported the positive results!

Boy oh boy! Now that is something!

So today, even though I’m supposed to be working… I thought I could sneak in half an hour for this tweak. Well, that eventually became couple hours of listening!

Okay Mr Nelson Pass recommends 2SK170 low noise audio transistors. I don’t have this and it’ll be quite a pain to acquire them since my local (as in within 10 miles) supplier does not have it either.

But then I have lots of 2N3819. Okay, the noise figure isn’t as beautiful as 2SK170 but I’m like a hungry man looking for food. If it’s edible, I’m going for it!

So I incorporated the 2 FETs per channel into Monica3. Some soldering acrobatics is required here. Hey, I know YOU are one solder gymnast! Send me pics of your best work!

Now I didn’t put in any resistors before or after the FETs. I’m always of the (stubborn) opinion that if it’s not needed, then we don’t put them in. Yes, I’m aware these are RF transistors. Yes, I’m aware non-oversampling DAC has the 44.1kHz component riding… Yes, I’m aware I’m stubborn. You enjoying yourself there?

Ha ha!

Now the sound? PaulN’s excitement is justified! I have been communicating with him quite regularly the past few months and I really trust his ears. He makes me feel like I have tin ears due to his excellent hearing ability. Hey, wait a minute, most folks make me feel the same way. Perhaps I need to check my hearing…

I’m digressing. But PaulN is right! The power of a good tweak is everything is better! Better definition, better detail retrieval, better bass, even transients improved! … Damn it, why didn’t I think of this earlier?

As such, I take my hats off (both literally and non-literally to PaulN, Mr Nelson Pass, assendor and martinbls. You guys have just completed Monica!

You see, all this while I have been pensive about this as I never like her highish output impedance. I thought a good solution would be to couple with our tube preamp which through its output transformers would solve this impedance “thingie”. Well, now even with the tube preamp, the improvement is still amazing!

Okay, I can see you nit-picking there! Nah, I don’t think I’ll bother with 2SK170. You see, the signal voltage we are dealing here is about 1Vrms. The 2N3819’s noise figure isn’t anywhere close. Well, perhaps one day I’ll try 2SK170 but for now, I’m just happy to listen!

Okay, here’s another tweak which only YOU can work it out.

You know, for the recent audio show, actually we have Monica3, Charlize2 etc built up for the show. However, just a week before the show, wanted to try something different (like we have so much time in the world just before the show…)

I like the idea of a DAC-preamp, so wanted to integrated Monica3, our new volume control and the tube preamp all into one chassis. Hence we have this girl…

Since the electronics and the external power supply is all the same, the only possibility for such an improvement is the fact that we have greatly reduced the number of interconnect links between component.

Let’s see, Monica3 to Passive Preamp (our new volume control), then Tube Preamp.

That’s 2 interconnect cables plus 4 RCA connections (plug/socket) per channel.

Why heck, our interconnect cable is no slouch. It’s the same wire we use in the internal wiring. And it’s shielded as well.

Why heck, we liked it so much, we later incorporated Charlize2 into the whole mix! So look ma, no interconnects!

So, the BEST interconnect is NO interconnect cable!

The post More ways to kick arse your system! appeared first on diyparadise.

Yeah, this is the Kuala Lumpur International AV Show 2008. Our debut at an audio show.

Note that source is from the Mac Mini on the far right.

St Cloud and the Hedlund Horn. The St Cloud is more suitable for this small room but can’t play that loud due to its 3″ driver. Most of the time we play the Coral Beta 6 in the Hedlund Horn. Most folks when they see both speakers, ask for bass!

Closer look.

2 digital source is used alternately. The modified Squeezebox and the CDPRO2-based transport.

The top rack shelf is for signal path only. Bottom shelf for power supply. Each power supply has its own balanced isolation transformers.

The all-in-one. Perhaps should call it “All or Nothing At All”.

Requires a digital input and output goes to speakers!

The best interconnects are NO interconnects.

Enough about the system! My thoughts are blogged here.

KL International AV Show 2008 – First day

KL International AV Show 2008 – 2nd & 3rd days

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Or would you prefer this "conventional marketing drivel"? Courtesy of MKC.

There you go audio nuts!

Are you DESPERATE ENOUGH?

How now brown cow?

USD300. Lead time about 2 weeks. Fully handmade.

Fedex to USA, USD17.
Fedex to most countries in Europe, USD25.
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diyparadise.com

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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!

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