TDA1541A S1 come back!!!

[apassgear]

Mlloyd,

Thanks for the reference, I've seen this thread before, but strange I don't see a Joko's full schematic.

I wonder if I should use a simpler approach, something like Kuei proposal with the OPA660, but unfortunately I don't have this Opamp.

[Elso Kwak]

Originally posted by apassgear
Elso,

Thanks for the input but your suggestion is far reaching for me, I'm looking for something simple and good, not a discreet opamp.

Any further suggestion in lieu???

Hi Tony,
One of the first things I did to my Sony was replacing opamps by AD827, 12 years ago! Then I added a discrete output booster. Very simple circuit by Walt Jung using only two transistors. I continued and eventually made a complete discrete opamp.
You can use BUF634 but I found it less transparant than a discrete buffer.

Interestingly BUF634 is used by Wadia, Madrigal & Linnenberg.

Of the list of opamps you mentioned I tried the AD811 as IV-converter only. In my Philips CD-650 I tried the LM6171 too in the original position as IV-converter and outputbuffer.
I liked the AD827 more in this player. I have a dislike for the AD825.
AD827 is obsolete now and succeeded by AD826.

[Marlowe]

Originally posted by Peter Daniel



You don't really have to redo anyting. Here's how complete TDA1543 circuit is looking like, including PS: 1 chip, 5 resistors and 2 caps. You can build it in one hour

Even without reclocking it sounds amazingly good. A friend of mine listening to it, commented that it's better than Copland and I know for myself, that it's better than Bel Canto.

Wow! that's so simple.
I wonder about the detail of this circuit, please... :>

[Peter Daniel]

Here's the detail. The other two bypass caps are SMD, Y5U and X7R type, soldered directly to the pins underneath.

[Peter Daniel]

And here's PS, taken from a first Kusunoki DAC. I will be experimenting with different arrangements still. Also the output voltage is reduced to 5V, as it works better.

[Marlowe]

Hello Daniel,

This circuit is simple and pretty, I want to do it somewhen. Thank you very much.

[apassgear]

Peter,

Thanks for the posted circuits.

I understand that the 1543 is considered by Philips as a budget DAC but I wonder if there are some special selections?

Heard also you built a multichip version a la Kusunoki but you seem to preffer the single chip?

[apassgear]

I requested some OPA660 to try TL I/V but they are out of stock.

So for the moment I intend to try the AD811 I/V. Could you point me to a circuit using this implementation?


Coming back to the CDB650 I can report that with further brake-in the bass is coming in nicely but somewhat rounded at the low end. I also realized that the CDP is inverting so changed polarity to the speaker cables.

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I noted also on the bass speaker certain low freq movement which is related to the sound but certainly not actual signal. The movement is like what you have on analog with disc wrapage.

My first impresion is that it is a PSU voltage IM.

[Peter Daniel]

Originally posted by apassgear


I understand that the 1543 is considered by Philips as a budget DAC but I wonder if there are some special selections?

Heard also you built a multichip version a la Kusunoki but you seem to preffer the single chip?

Sometimes budget chips are better, because of simpler design. And I found out, that simple circuits usually work better. I tried 4 chips and 2 chips in parallell with different voltages and clearly a single one with 5V supply works best. More resoulution, smoother and relaxed. I also tried Lundahl transformers at the output, but they definitely degraded the sound. A friend of mine tried those transformers at the output of oversampling DAC (SF DAC1) and he was raving about them.

Actually I can't complain much about that circuit. It only needs more extention in HF, more soundstage and slightly improved tonal balance. When this is achieved, it will be a very good DAC. I compared it to modified high end one box player (which supposed to be one of the best currently) and this little DAC was still a match. Looking at simlicity and investment, I'd say, it's not bad

[apassgear]

Peter, you sold me, I have ordered some 1543.

In the meanwhile I'll continue to play with the 1541, and then compare.