Modifying the Russian TDA1543 DAC off eBay.

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Yes flac/wav are my mainstay, but for now I am dabbling in MP3 VBR, not CBR, I think CBR sounds apsolutley dreadful.

I wish they were encoded in OGG frankly, OGG sounds far more accurate to the original wav/flac than MP3 ever was and will be.

Thank you for the suggestion about the capacitor change on the CS8412, I will add it to the pile of modifications to do, I welcome any further additions that you or anyone else wish to suggest that I try.

I don't know the DAC in my Sony amp, which is a Sony STR-K670P, I might open it up tomorrow and try and hunt it down.

now playing: Freda Payne - Band of Gold. in FLAC
 
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Cheers for that, thats a great suggestion which I was thinking of doing too, but at the final stage, yes, replacing all of the traces with high current copper point to point wiring and simply just breaking off the old traces...

Thank you for the link, elektrotanya.com is really good huh, its saved my butt quite a few times.

After I'm done modding this TDA1543 I might have to pull out the original TDA1541 (NON-A, NON-S) chip out of my Marantz CD player and build a new project surrounding that.. It just has something that I want to find out more about.

Harry Nilsson - Can't get by without you [live] (FLAC)
Has nice vocals, a bit of atmosphere, not as much as I'd expect (probably other system components affecting this, probably also a mastering issue)
Paper Lace - The Night Chicago Died (FLAC)
Pretty good analog sound to go with it, clear and transparent vocals (within my system's limitations), good clear instruments.
Tams - Hey Girl Don't Bother Me (FLAC)
Even clearer than the last 2 tracks, pretty nice vocals, nice trumpet.

np:
Jimi Hendrix Greatest Hits by Sony Music released in 2010
Crosstown Traffic
Significant improvement in vocals.
The Wind Cries Mary
Significant improvement in vocals.
 
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I agree with you that VBR sounds better than CBR.
and I also agree that OGG sounds better than mp3.
But basically I don't bother with lossy formats.
Although some mp3 320's can sound pretty good. But no matter how good the psycho acoustics are, there is no substitute for the real deal.

Since on the topic. Try converting some of your .flac to .wav and tell me if you can hear any difference.
 
Jimi Hendrix - Castles Made Of Sand (FLAC)
Is truly truly amazing, the stereo imaging is amazing, Jimi is up in the air at the front of the room talking down to me, and he fades into the right or left channel, aswell as swappiing positions with the guitar, I even heard a lower level of voice in there that was completely muddled before on the old resistor values.

It sounds very very analog.

Jimi Hendrix - I Don't Live Today
Could copy even the very low level voices at the end of the track.

Jimi Hendrix - Up From The Skies
Groovy maaaan.
 
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I think its safe to say that replacing those resistors with higher values has made a remarkable improvement in loudness and clarity.

I want to draw your attention however to what feels like an apsolutley remarkable modification.
I pulled out the two 0.022uF Russian Polyester In Oil capacitors and replaced them with high value Electrolytics.

Out of curiosity I have had this urge to put more capacitance on the output coupling capacitors, so I did, I just put a 1uF capacitor on one output and a 10uF capacitor on the other channel.

The thing came alive, I'm currently watching 12 monkeys and the vocals and music sound so analog it isn't funny.

I MUST STRESS that as far as I can tell the sound has NOT become more muddled, infact it has opened up more, which is rather strange you would think that with electrolytics they would color the sound. Please note though I am comparing this change with the Russian caps... so maybe the Russian caps are really terrible.

I like the change.
 
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Jimi Hendrix - Castles Made Of Sand (FLAC)
Is truly truly amazing, the stereo imaging is amazing, Jimi is up in the air at the front of the room talking down to me, and he fades into the right or left channel, aswell as swappiing positions with the guitar, I even heard a lower level of voice in there that was completely muddled before on the old resistor values.

It sounds very very analog.

Difference = Slightly more muddled when compared to using the russian caps, I didn't pick this up while watching 12 monkeys.

Stereo seperation is all over the map, it doesn't sound much if anything like it used to.

Jimi Hendrix - I Don't Live Today
Could copy even the very low level voices at the end of the track.
Vocals have a deeper throat sound to them, like they are coming from the chest more.

Not as good as when I first heard it.

Jimi Hendrix - Up From The Skies
Groovy maaaan.
Strangely, sounds better, there is a guitar which sounds really natural now with this capacitor change, whereas before it sounded more fake before, like it was being plucked without any force.

Vocals sound pretty natural, but still in the slight chance that you get to listen to Jimi alone without the guitar, he sounds muddled again.

So conclusion is that, for movies, electrolytic appears to win, so far, but for music, the russian polypropylene in oil caps win.

I think I know whats going on, with compressed audio, electrolytics appear to respond better, whereas with normal CD-sourced music, the polypropylene's win.

Reasoning for this is: Compressed shoutcast sources sound /great/ with these electrolytic caps, whereas before, yes they did sound good but they also sounded fake, but these electrolytic caps appear to 'hide' the bad parts of compressed audio and just let me enjoy it more....

I'll have to observe/listen to it for a week again to be sure on all of these points.

Nelly Furtado - Whoa Nelly! album sounds improved.
 
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@freax....is this page still alive? And are you still using the russian NOS dac? Because I'm think about buying one instead of the nos lite ah DAC.

The russian DAC kit was a waste of time because the capacitors used in the I/V stage which were shipped with it made it sound exceptionally muddled to the point of lunacy (to the point that you could only play 50s-60s music through it.

However it did sound great with the goldy tin coloured 0.022uF capacitors.

So the dac was modded a day or so after getting it and it is no longer the original design.

I pulled the DAC apart and am currently reusing the components for a dedicated rackmounted case with homemade/dremel drawn PCB boards. Waiting for parts to arrive from HK.

I'm currently studying a suitable shunt regulator which will enable me to have the least possible noise feeding the analog stage of the TDA1543 chip, I've even considered doing away with a voltage regulator and simply using a variable Rheostat to adjust the volatage to within 4.0v-8.0v to feed to the TDA1543 chip. The main reason for this is that I would theroetically get the performance of a high end 4uV super voltage regulator without the needed silicone. Just simply 12vAC Transformer -> Rheostat -> Bridge Rectifier -> Filtering Capacitor -> RC Stage -> DAC Analog stage.

I've also sourced a genuine TDA1543 IC from a Sony CD player which will after an initial power-on test of the new DAC will be taking the place of the (assumed) fake TDA1543 which came with the Russian DAC Kit.

I want to use the two russian 0.022uF capacitors which I added to the Russian DAC kit, which was the first modification that I made. The goldy tin poly capacitors. I will definatley be using substitutions and making corrections to the circuit after I'm done building it too but one thing which will survive the transition is the handwound chokes, I think the original russian guy who designed this was onto a really good low budget and worthwhile way of isolating each digital stage from one another. The wax paper coated iron cores impressed me, it saves having to buy dedicated premade chokes.

My suggestion to you that if you are still considering buying the Russian DAC kit that you should consider building it by sourcing the parts yourself and winding the chokes yourself on a PCB project board of your own, but if your just starting out then the Russian DAC Kit is worthwhile. But while it is an exceptionally simple design its main and only flaw is that it is too expensive for what you get. Though you could argue it is good value for money if your just starting out its only flaw is that the pcb board really lets it down in the quality control area, the traces are too thin.

The thin traces on the Russian DAC board for example started to break off when I tried modifying it and I had to add copper wire to replace the traces.

I will want to be making the best possible DAC I can on my budget while keeping to the KISS principle (Keep It Simple Stupid) with the use of common and easily obtainable discrete components. Enabling anyone to build this DAC, at any budget, without having to source Unobtanium components at high cost and not having to do a great deal of head scratching.

I therefore christen this new one "The Anarchists DAC". Because I have no idea how its going to sound, I have no idea what I am doing and I don't paticularly care. I just want good sound. And will be borrowing from everywhere in the design of the shunts/power supply and using random components that I have on hand which may or may not be the "right" types to use.

I currently have the revision 1 shunt volt reg in LTSPICE That is where I am at the moment.

Let me give you an idea of what kind of budget I'm working on, I'm hesitant to buy another roll of solder because it will be expensive and I'm quickly running out. But don't worry I'll buy another roll, just got to find the right time to do it.
 
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I would avoid the kits as they are largely a waste of time.

You can point-to-point build a really good Tda1543 - take a look at

http://www.diyaudio.com/forums/audio-sector/187748-pushing-limits-tda1543-nos-dac.html

There is a simple schematic supplied by Uncle Leon which is a great place to start.

The key points for a really good sound from the Tda1543 are:

1.Low noise regulators (not LM317/78**) with the small decoupling caps placed directly on (or very close to) the chip. Use 2 separate regulators for the CS8412 and 1 for the Tda1543.

2. EC Designs made a critical discovery - don't use pin 7 on the DAC chip. Leave this floating as otherwise it brings a lot of noise to the party. You simply replace the I/V resistors as shown with 680R resistors which are the connected to the +ve of a 3v battery instead of ground. The -ve of the battery connects to ground.

I have also incorporated a few tweaks to the input spdif and Coupling Caps and the final sound is well worth all the effort.
 
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I would avoid the kits as they are largely a waste of time.

You can point-to-point build a really good Tda1543 - take a look at

http://www.diyaudio.com/forums/audio-sector/187748-pushing-limits-tda1543-nos-dac.html

There is a simple schematic supplied by Uncle Leon which is a great place to start.

The key points for a really good sound from the Tda1543 are:

1.Low noise regulators (not LM317/78**) with the small decoupling caps placed directly on (or very close to) the chip. Use 2 separate regulators for the CS8412 and 1 for the Tda1543.

2. EC Designs made a critical discovery - don't use pin 7 on the DAC chip. Leave this floating as otherwise it brings a lot of noise to the party. You simply replace the I/V resistors as shown with 680R resistors which are the connected to the +ve of a 3v battery instead of ground. The -ve of the battery connects to ground.

I have also incorporated a few tweaks to the input spdif and Coupling Caps and the final sound is well worth all the effort.

I've been eyeing off that design by Peter Daniel for ages but cannot fathom the cost involved sourcing each individual resistor so I'm trying to go my own route instead.

Yes this is the path which I am going towards. Modularity of each chip on a dedicated PCB board is something that I desire and a dedicated feed to each chip. Taking more care for the one going to the TDA1543.

Also thank you for the Pin 7 idea.

Chokes have also been used elsewhere in other DAC designs, for example:
The Extremist DAC

I've also done some research into the sound of SLA batteries but that may be one thing which I will have to keep in mine as I would like to have battery backup. I could substitute with supercapacitors, interest in that is on the agenda.
Simple Voltage Regulators Part 1: Noise

Another thing which I have researched is shielding and modularity.

The shunt volt regulator which I'm considering using is this 2n3055 voltage regulator schematic as shown here:
http://www.eleccircuit.com/small-5v-regulator/

Schematic Number 2 on that page.

It has:
1) no Zener diodes.
2) Easy to obtain components.
3) As simulated in LTspice is by design a low pass filtering circuit, probably because of the 2n3055's inability to easily pass RF?

Both that are advantages in this idea.
 
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I've been eyeing off that design by Peter Daniel for ages but cannot fathom the cost involved sourcing each individual resistor so I'm trying to go my own route instead.

I just use carbon composite resistors and reasonable quality capacitors - the DAC cost £20 including coupling caps.

I also built 4 of the Bobken series regulators mentioned in that thread - they cost around £20 each.

Add to that a Jocko Homo input buffer (takes most of the remaining harshness away) for £15.

Plus a couple of transformers and the lot cost £130.

(components mostly sourced from China via eBay.com in The States if they are not on your local ebay)
 
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@freax, somebody said the same about the Russian DAC. So I never bought it. Instead I bought a Chinese 1541A DAC, the gold 1541 dac.

That was actually a good choice. It sounds much better than the lite DAC. I only changed the output caps and used 2 lechlance ppm mkp caps instead. And also put in a original TDA1541A IC from a old broken Arcam CD player.
 
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