July 2008

Have I finally found the best CD player in the world ? Am I close ? I am pretty close.  (that's what she said )

  Someone signed Thomas - who tried to build a commercial DAC using internet forums as a motivator and opinion source -  spent many years optimizing the TDA1541 circuit and arrived at the dual differential balanced config with CS8414 as receiver and two TDA's as DAC . I think  It was born as a collective order of a DIY kit by a group of audiophiles. Or so I understood from the discussion on the forum. I am sorry if I misinterpreted the story.

The story of this  project  is here:

Later on I found this (or very similar indeed)  PCB set to be used in SATCH DAC from Hong Kong


the design idea behind this product is very very simple.
Take the best DAC in the world, mate it with the best receiver chip, add overkill power supplies to each individual power receiving point separately and put it all in a great box and voilla. You have the SATCH.  What separates it from the crowd of good chinese DACs is that the chip comes from 1985 and the receiver chip is new. So it is the BEST OF BOTH WORLDS in one box. Best of old and best of new.   Nobody back in 1985 when the TDA1541 was made dreamed about the receiver chip as good as the Cristal CS8414 chip. (the one on adapter board). The TDA7110 of 1985 just can't compare.

Being a TDA1541 fetishist I could not resist the temptation. FINALLY ! Someone made a TDA1541 machine which is not from museum. At last I can sniff around the PCB without inhaling dust and spider webs. At last there are capacitors which are not dried like prunes. The Carbon C14 test reveals that this product is NEW!
So lets take advantage of my curiosity, my naive stupidity - and let's take this baby for a spin. Let's find out if the SATCH people did their homework and managed to improve over  the Philips CD304 MK2 - the first TDA1541 machine that I know of.

Funny, the huge blue caps around the TDA  turned out to be 100nF by 250 V as the datasheet of Philips advocated - precisely 100 nF. But why 250 V ??? There is 7 V DC only. Anyway, I expeccted to see something closer to 1 uF there.


My letter:

I have a technical question if I may.
I noticed strange capacitors around the DAC - the 14 decoupling caps.
They are very large, because they are for high voltage rating. If they were for 63 V they could be 4 x smaller (I mean physically smaller, not capacitance). Why did you choose a 250 V rating if there is only 5 V at the DAC legs ?
And from my experience these caps  should be bigger.
In some machines they are 100nF, in some machines (better ones) these caps are 200 nF. I noticed improvements when upgrading the 100nF caps to 400 nF.
So why you chose only 100nF ? Is is by choice ? Wouldn't a bigger cap be better ? At least on MSB ? Arcam ( a good company) puts 470 nF tantalums for decoupling on 4 legs of DAC - the most significant bit ones.
Thank you for clarification.
I thought that SATCH is a result of really good homework, and no compromise approach, the ultimate TDA1541 machine, where nothing is left to chance.

I worked with 100 different TDA1541 machines and my favourite implementations are from NAIM with lots of tantalums. After lampization, when 6 opamps are removed, the NAIM players with 1541AS1 really blow my mind.

Lukasz Fikus

Here is what Simon and Mr. Bran  from DIYHIFISUPPLY had to say about the cap size :

Hello Lukasz,
First, 100nF are the standard per datasheet.  Larger values changes the sound, but if the result is better is debatable.
Second, while 250V is indeed overkill, but thicker film means lower microphonics. So there is nothing "wrong" with using 100nF/250V Film capacitors. They maybe used to achieve a specific sound.

OK, fair enough, we have cleared the ground at least. The proof will be in listening.

Ordering info from VERY professional and friendly store:
Don't forget to ask for a handful of obbligato caps when you order.

I am now (July 2008) working on lampization of the Satch.

Upon inspection, out of the box, the DAC makes really good impression. The box is a little ugly, nevertheless solid. But the front panel is Wadia-like so  to speak. Very nice.
The PCBs are first class, but we are used to it from Hong Kong.
They follow some good principles that we already learned to adore as well:
- each power consumer has separate voltage regulator,  In total - 10 regulators . The best count so far, with Copland being second best but it has the whole mechanism and the display to take care of because it is the whole CDP.)
- each electrolyte is 10 times bigger than reason dictates
- each electrolyte has an MKP bypass (orange, probably Vishays)
- the closer to power consumer the smaller and better the capacitor
- the resistors are not SMD but traditional
- the chips are in the sockets
- the digital input is trully ballanced, XLR ready for AES/EBU (!).
- the oversampling can be disabled (as should be)
- the clock can be reclocked internally by a precision clock circuit but anyway - no reclocking sounds better.

I discovered, that the two goldish  small transformers are for signal output. I absolutely don't need them, they are optional and unnecessary. So we can remove them and gain extra free space for lampizator.

There are countless jumpers that set various options like over sampling, internal reclocking etc. By the way - there is a separate high end clock provided if we decide not to use the clock recovered from the signal of the transport.
Frankly - I don't need these jumpers. I want the DAC to work absolutely only in NOS mode without the SAA7220 in the system. So the people who designed it could have saved some money and time and remove two transformers, all jumpers and dipswitches and also the whole SAA7220 chip.  I removed the 7220 and it is not consuming big power now. It was getting very hot.
I will use the 7220 to convert  some other player to become a good transport because the 7220 generates pure SP-DIF signal on the leg 14.
I tried the SATCH DAC with op-amp stage provided. It is simple and well made and opamps are first class 5534.
The wiring of the factory SATCH  DAC takes 15 minutes if we skip the signal transformers as unnecessary option.
We basically wire the AC power input and two AC secondary outputs. Plus the incoming SP-DIF digital signal by the coax cable. And the output from dac to RCA's. The outer part of digital input RCA should be grounded to the system ground (big central jumper solder point) . This improves the "squareness" of the wave.
That's all.

The sound in stock form: it is really VERY GOOD. I could not detect any fault in the music which I know intimately. I could not complain about anything except the lack of the finest micro details, which we call plankton here in Poland. The top end of the spectrum compared to even mediocre lampized CD players is a little bit missing. It's there,  but it isn't at the same time. Just like electrons in an atom.  But the mids are super pure and natural. The singers stand in front of me without any veil. I wish they were without clothes too. Bass is clean and strong and deep. No booom boom. So far so good.
Compared to other TDA1541 players without lampizator - this one is in top league, where the three NAIMs are residing alone. That means this DAC has huge potential. I think it is better than my reference TDA1541 player - NAIM CD3. At least - non lampized versus non lampized - the SATCH rules. So if it beats the NAIM before lampization, how it will be comparing after lampization ?
NAIM CD3 does not have a better power supply than the DAC, does not have a better clock, TDA1541 is the same, and the output is the same. So chances are - the SATCH will beat the NAIM and reach for the top position in my ranking.

Looking at the parts, power supplies, caps, filters etc. - this player does not need any upgrading except if you wanna go full black gate which is another story entirely.  My own trick is not to spend $$$ for B-G caps but instead I bypass the stock electrolytes in power supplies of the TDA1541 and CS receiver with  47 uF/16V  tantalums. the result is similar to B-G job.
After a week the DAC shows very strong performance, and improved marginally from the first test. The Nichicon Muse capacitors which it is full of, are good, but nothing to write home about. I feel that Oscons and Blackgates or Elna Cerafines are better.

I would say that with the optional super op-amp which you can order from DIYHIFISUPPLY  - for most of people this DAC would be the perfect source without lampizator. So you can go ahead and buy it, it has my seal of approval. Send me good wino if you like the SATCH.
I believe that it would be worth to order the S1 DAC - crown variant to make this player even better. That should cure the plankton issue.  What I did - I ordered from ebay the old champion - the TDA1541 non A and non S1 which I like the most of them all. The TDA1541 inside the SATCH  is in the socket so it can be swapped within seconds and compared. For the asking price - I would say - order it with S1 or even S2 and premium opamps. It would be still worth its weight in gold. In reality the price would be roughly 700 bucks plus 140 shipping. At this price of the dollar - a steal really.

To do justice to such great DAC I decided to build a deluxe lampizator  based on the best octal tubes - the antique USA 12SL7GT production from 1945 - 55. The black glass Kenrads, RCAs, GEs, WEs and Sylvanias, and also the Russky 6N9P metalbases with radioactive cathodes.
Why the 12 and not 6SL7 ? Because they are 10 times cheaper and work the same way except  12,6 V heaters. But 12V is easier to build than 6 so what the hell.

As shown above, in my search for perfection - I added tantalum bypass to the most critical caps around TDA1541 and I also increased the decoupling caps in most significant bits pins to be 600 nF like in the ARCAM designs with TDA1541. I really trust the ARCAM people.  For me the 100nF is not enough.

To verify it I checked the TDA1541 chip with the scope. There are minimal noises everywhere - on all 3 supplies and on all decoupling pins (14 of them).
The scope trace improves very much with every additional capacitance added to power and to decoupling.
I tried oscons, teapos, Rubycon standards, MKS, MKT, MKP, and tantalums. I did not have the CERAMIC caps on hand which would be the best for megahertz noises. Anyway - the small 2,2uF tantalums seemed to work best so I used them.

This is the anode high voltage supply: a simple bridge plus a CRC filter. C1 is 800 uF, C2 is 220 uF, and R is 1K.
The rifa cap is a bypass of the big Lytics which suppose to kill diode noises.

After completion I wasn't happy with the sound. It can't compete with normal TDA 1541A players which I modified before. The sound is nice, but no Nirvana.

I analysed the circuit with a scope.
All power supplies are contaminated with noise. Here is what my scope shows:

This is the -15 V supply on leg 15 of tda.

This is the +5 V leg 28th of the DAC. I tried various caps in various positions and I was able to go down by half with the noise.
Still, the player is un-inspiring.

The SATCH dac is working with my old Grundig converted to be a transport (tweaked and improved).

This is the already lampized SATCH preparing for the new BATTLE OF GIANTS 2008
The description of lampization will continue ......

O man it is difficult to reach perfection. I spent 5 evenings trying to improve the satch. I knew it must be better than OK.
First, I added a 2,2 uF tantalum as DECOUPLING bypass - so I increased the decoupling capacitance in all 14 capacitors 22 times! 22 fold. Instead of the Philips datasheet recommendation of 100nF there is 2300 nF now. But what did Phillips people know back then in 1985 ? Nothing. They had no idea that the TDA1541 will be their best ever. They never used it properly and now we poor mortals have to re do their homework.
Anyway, despite protests from Mr. Brian of DIYHIFISUPPLY - I did the mod.
It improved the sound, being more full and more open, but not enough.
Then I added noise killing caps on all power supply legs of the TDA1541 directly. It halved the noises.
Then I removed the SAA7220p/B completely.
Still no nirvana.
Then I removed the reclocking option. OOoo something is beginning to appear. Something like NIRV.  Not full nirvava yet.

Then I started to question the old octal tubes. I used all my artillery - 6SN7GT, 6SL7GR, 12 SL7, 12 SN7, the 6H8C, 6N9, Russkies, Chinese, American, British and Dutch. All were okay but not good enough.
I rewired the lampizator to be noval and the game continued. In goes 6H6P, 6H1P, ecc88, e88cc, 6922, 6dj8 - teslas, harmonix, brimars, sovteks, amperex. The novals sound significantly better than the old octals. I am surprised how much better in fact. There is more energy, more spark, more life in them. The octals behave like riding an old horse.

Then I remembered my Guru Evgenniy saying to me years ago: Lukasz, if nothing works - try the 6H2P.
So I did, for the first time ever I used this miniature tube from Russia. Internally it looks like no other. It has a funny looking guts.
The datasheet reveals extreme parameters : amplification of 100, and current below 1 mA
Pinout is fortunately the same as the others.

Do you know already where this story is going ?
You are guessing right. That tube redefined the sound. It is the single most shocking discovery in my whole years of lampization. It is that good.
Initially I thought that this can not be true. I was careful to draw conclusions. I had to triple check if something was not fooling me. Or perhaps someone slipped something in my drink. But no. No problems. The tube is ideally suited for working with I out of TDA1541 - the weak current signal and resistive conversion.
It is such synergy - as if the two were really meant to be together, like Romeo and Juliet.
I listened all night and every new CD I pulled sounded as If heard for the first time.
Many newbees say this sentence, but in my case - I heard a lot. But nothing prepared me for THIS.

Remember don't get confused - it is NOT this tube
6H2P 62 it is THIS ONE: 6N2P 62 photo - look at this great site:

and the datasheet: is HERE

My lampizator is:

Ua = 150 V
Ia - 750 micro Amperes (0,75 mA)
Rk - both = 200 Ohms
Rconversion = 100 Ohms
Schematics SRPP or TOTEM POLE
lampizator for TDA 1541A

There we go - we have a new King, and knowing what is inside  the SATCH and what is possible today - I do not believe that soon someone will surprise me and build something better.  I will just casually check the newest wolfson - The WM8741. It is the only candidate for bettering the TDA1541.
(ironically two months later the Buffalo DAC came and bettered the SATCH at 1/2 the price.)
I can only imagine improving the SATCH itself.
1. Blackgate everywhere
2. chokes in power lines to each pin separately
3. s2 chip or NON-A, (I have the regular A)
4. Copper foil paper in oil capacitors in the output decoupling (0,47uF)

Above: signal stealing points for lampization.

Above: tubes are mounted where the useless signal transformers used to be.

Above: there is enough space near the power transformer for the new transformer and two unregulated  supply filters for lampizator.


Above: another angle view on lampizator inside satch dac. The output caps I used were SCR KPSN tin foil 1,5 uF / 100V. I love these film and foil caps.

SATCH dac TDA1541A

Above: the receiver chip CS8414 on adapter board, the jumpers J7 and J8 open, and dipswitch 1 on ON. Saa7220P chip completely removed.
The DAC ready for singing.

I also suggest to replace the wire in jumper J1 (supply to the receiver) with a small coil.

Having said all that I have no idea WHY NOBODY makes it like that in the first place!? Why I had to remove 60 % of circuitry before the DAC started really singing?
Why don't build a simple no reclocking no output opamp no oversampling - dac, a super stripped down variant and provide the tube output. And the whole world would go crazy about the TUBESATCH.  What a way to make CD history END.  28 years after it started somewhere in Eindhoven.

I will be watching DIYHIFISUPPLY website for the news from Mr. Brian.

Meanwhile I remain,
Yours truly -  Doctor Lampizator in the state of Bliss.

We can argue, that a 700 Bucks DAC should play well in the first place, and we would be right.
It is better to build such SATCH from scratch  and the green PCB comes to the rescue (from Analogmetric). It is basically SATCH on one PCB, which by the way is a much nicer PCB than that of SATCH:


Analogmetric DAC

Analogmetric DAC

We can buy the GREENDAC for circa 15 USD and we need to populate only less than half of parts, but this time no mercy only the best parts need to apply. I suggest blackgates all over the place. And the S1 chip if we can find genuine one.
We can skip the whole clock, reclocker, SAA filter and related power supplies. I even omit the receiver for SPDIF and I will use i2S wchich is free of charge (built into the TDA)
Analogmetric ebay store sells even kits with a bag full of all needed parts. What a deal if you can solder !!!

Analogmetric DAC

Meanwhile Brian at DIYHIFISUPPLY has lampized the SATCH and prefers it this way, am I not surprized ?
Still, I havent got the Wino for all my efforts and their increased business.