The culmination of all the hard work, experiments and listening tests of all the DIYers here! Most significant tweak has to be the “3 transistor mod” suggested by Paul Needs and Paul Hynes. Who would have thought we have such a bottleneck there? A major major upgrade in sonics in every way!

Shown here built up with the Paul Hynes regs and CCS2 plus 3 Audioslaves for the I/V stage.

Now offering mojo2 PCB.

Note that only one supply is needed as the PCB traces provide power to the individual regulators.

The PCB has been designed to fit Paul Hynes CCS2 and Regulators particularly the 5.4V and 0.83V regs. So no more string of diodes etc. If you prefer the simplicity of the original mojo, it is still being offered for sale. If you are budget conscious, you could build whichever reg you prefer and fit into mojo/mojo2.

mojo2 kit.

The kit has all the SMD components (resistors, capacitors and ferrite beads) soldered on so you only have to mess with the through hole components. [yes, thanks for the applause!]

It has everything you need except — regulators, Black Gates capacitors and output coupling capacitors. Oh yeah! Solder, elbow grease and the most precious commodity of all – time.

mojo2 map.

The map above shows CCS2/5v4/0p83 regulator pinouts.
If you fit in the Paul Hynes 5v4 regulator at “5V” location above, you only use Output and Ground.
If you are budget conscious, you could use Audioslave here or even a LM/LT1086-5V regulator as the pinout is the same – I, O and Gnd.
The rest of the regulators are straight forward.
The 12V and 18V regulators share the same pinout as the 5V reg, namely I, O and Gnd.
If you don’t want to use regulators here, just short I and O together but be careful with the CCS2 as it can’t take >17VDC.

However, due to the tight fit, the electrolytic capacitor of the CCS2 may come into contact with the solder joints on the 0.83V regulator, a simple suggestion of insulation tape on the top of the capacitor should do.

As mojo2 accepts EIAJ input, you could just feed EIAJ signal to it directly. Shown here is my current favourite digital player! Sounds best on a chopping board!

Though not shown, the ribbon cable feeds directly to the EIAJ input of mojo2.

The QA550 SD card WAV player reads bits and bytes directly from your SD card where a DSP chip does all the hard work here. This chip then outputs I2S signal to a CS8406 I2S to SPDIF convertor then outputs SPDIF downstream. This is where you hook up your DAC and let your digital receiver process this SPDIF and extracts I2S/EIAJ signal back to feed to your DAC chip.

Now, we could circumvent all this data processing and simplify it. All the attendant processing can’t be good for the signal no? Since there is already I2S signal onboard (straight from the DSP chip), we could feed to our I2S-DAC chip!

Monica’s TDA1545A requires EIAJ so here comes Black Crow! An I2S to EIAJ convertor board.

The above shows Black Crow’s pins directly mounted on the I2S pads of the QA550 which its designer very nicely provides us. The oscillator was also removed and now fed by a single supply version of a Kwak Clock 7. I’m too lazy to build one so I bought some DIYer’s version. [Thanks Patrick!]

So how’s the sound?

Going I2S is worth it! Installing the Kwak Clock (or some other low jitter design) pays off well!

Dare I say it?! Digital has never sounded so analog!

The post What’s better than mojo? mojo2! appeared first on diyparadise.

There are 2 Paul Hynes’ regulators we want to introduce here. Well, if you include the CCS, then there’s 3.

First, there’s the 5.45V regulator for TDA1545A VDD. Then there’s the 0.83V regulator for the TDA1545A VREF. Lastly there’s the CCS2 for feeding the 5.45V regulator.

So first step is to identify how to incorporate all these regs. Ideally we would like to place them as close as possible to the chip which we want to regulate its voltage. So in this case, we want to place them as close as possible to the TDA1545A chip, yet without leaving a mess of spaghetti wiring. (pray hard…)

Here’s what I did. Found that the best place to wire in the 5.45V reg is on the PCB where the 220uF cap is supposed to go. If you have both caps installled, then you could solder them at the bottom of the PCB.

Ditto to the 0.83V reg, best place is on the PCB where the 47uF caps reside. Note polarity.

Now there are many ways you could integrate these regs in. One way is to cut the PCB trace, disconnecting the string of diodes to VDD but if you don’t want to, you could desolder the 1N4148 diodes (all or at least both at each end).

The Paul Hynes regs’ pins are labeled I(nput), O(utput) and G(round). Descriptive enough? When mounting the 0.83V reg, I found it’s easier to desolder the I lead and wire it this way. This goes to the CCS2 input.

More pics here.

Aha… Integrated with Monica SPDIF-EIAJ module. Note that power for the module is taken from this mojo board. For better isolation, i put in a ferrite bead too.

Hey! Since we are on a roll, might as well add 2 more regs! Now there’s a reg for each channel of the SS I/V stage as well. [These new regs will be called ACDC in line with our preference to name our minor products over rock bands.] In order to do this, don’t install any jumper on LSUPPLY.

And so that’s what I did. So we now have regulators for every stage of Monica.

Err, this guide helps explain better how to power the individual stages of mojo.

And what does all this hard work give you?

Aye caramba! Muchhhhhhhh better sonics! SE-PA-RA-TION is superb!

Since I’m such a nice guy, for those who are more budget conscious, you could use AudioSlave here and retain the original CCS structure. You’ll need to break the PCB trace linking the string of diodes to TDA1545 VDD (pin 5) though. Err, with AudioSlave, you could go up to 25VDC.

There you go! Have fun!

The post Mojo-fy your mojo! 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.