TDA1541A S1 come back!!!

apassgear · 6th May 2003, 04:06 PM

After dusting my old Magnavox CDB650 and solving some problems, with the help of this wonderfull forum, I was ready for some listening.

At the beggining things were not looking very promising so I changed most all caps from the main board and also shortened the leads of the bit caps under the DAC. Things got much better but after some time I had problems with the drive not wanting to read the whole cut and was kicking out most of the times.

So I changed all the caps at the servo board underneath the CD drive. Well that did it.

Before going on I will say that all the caps had been changed about 15 years ago to good quality Panasonics HF and HFS with a couple of other brands. I was surprised to find some of caps leaking some green stuff (Panasonics). This has happened also on other gear, so don't take it for granted that if it is a P they are OK.

Well, much to my surprise the sound has changed to an exceptional one remainding me of analog days and in some ways even better. Huge sound stage and very deep plus lots of detail. Now of course I have better amplification so this also helps.

My amazement is that I can hint that there is a lot more than can be had from this chip, since I still hear details that are not fully resolved plus a certain lack of bass and HF could be better.

A general description of the actual CDP is that it has been Poogeed by Jung article in AA. Still an oversampled design using decoder SAA7210 and digital filter SAA7220 plus a TDA1541A S1 DAC.

The I/V is per Jung, if I remember this is a AD844 CF Opamp, but I'm not using a buffer so the signal goes directly from the I/V opamp stage through the output caps to the line amp. This analog section is fed by two Jung/Sultzer regs using a separate PSU. That pretty much sums it up.

I'm currently bulding a couple of PSU to feed the DACs this I assume will help the overall sound.

My main concern at this point is how can I deal with the laid back bass and better the HF.

I do have some ideas that have been posted on this forum such as the Rbroer analog stage and the Kuei OPA660 or the Adagio vacumm stage. Hopfully one of these may bring back the missing balance.

Any suggestions???

Peter Daniel · 6th May 2003, 04:33 PM

Quote:

Originally posted by apassgear

My main concern at this point is how can I deal with the laid back bass and better the HF.

Any suggestions???

It's only based on what I've heard from Elso, but maybe you should try TDA1543?

Elso Kwak · 6th May 2003, 05:06 PM

Quote:

Originally posted by Peter Daniel

It's only based on what I've heard from Elso, but maybe you should try TDA1543?

Hi Peter,
What did I say before thinking first?....

Bass slam depends on analog powersupply, including the one feeding the TDA1543, clock in the CDP, and circuitry used for IV-converter and outputbuffer. Besides discrete circuit I am using hefty push-pull outbuffers in the IV and output.
It is my all-out attempt to get the same bass slam from the CD as from the LP.
I realize I only partly succeeded...

HF I believe is better from the TDA1543 and bass also....
Kuei Y.W. I realize this is my own personal taste as heard on my set including K-hornspeakers. I know you don't concur...

apassgear · 6th May 2003, 10:04 PM

Elso,

After reading your post I imagine that my main problem is not using an output buffer.

I understand of course that bettering the other aspects will still improve things.

Coming back to the I/V and buffer what would be your suggestion taking in consideration that I have at hand the following Opamps?

AD8620AR
AD825AR
AD811JR
AD827
LM6172IM
LM6181IM8

apassgear · 6th May 2003, 10:18 PM

Peter,

Using 1543 would mean to redo all the PCB, I dont think even that the number of pins are the same.

Beenig an old and trashy CDP I dont think it's a good idea to to put much work on it since the remaining life of the lasser is dificult to predict. So in this case I only want to test the potential of the DAC and use it until the lasser dies and maybe in a future redo the PCB using another CDdrive but using the same DAC.

Regarding the 1543 I would like to test it but I'll have to wait until the end of the year. I have read a lot about it on this forum and looks very promising

Elso Kwak · 6th May 2003, 10:22 PM

Quote:

Originally posted by apassgear
Elso,

After reading your post I imagine that my main problem is not using an output buffer.

I understand of course that bettering the other aspects will still improve things.

Coming back to the I/V and buffer what would be your suggestion taking in consideration that I have at hand the following Opamps?

AD8620AR
AD825AR
AD811JR
AD827
LM6172IM
LM6181IM8

Hi Tony, I would use none of the above.
Sonnya's circuit comes closest to mine:
Jfet/bipolar PCB and Schematic (finaly)

Peter Daniel · 6th May 2003, 10:34 PM

Quote:

Originally posted by apassgear
Peter,

Using 1543 would mean to redo all the PCB, I dont think even that the number of pins are the same.

Beenig an old and trashy CDP I dont think it's a good idea to to put much work on it since the remaining life of the lasser is dificult to predict. So in this case I only want to test the potential of the DAC and use it until the lasser dies and maybe in a future redo the PCB using another CDdrive but using the same DAC.

Regarding the 1543 I would like to test it but I'll have to wait until the end of the year. I have read a lot about it on this forum and looks very promising

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.

apassgear · 6th May 2003, 11:41 PM

You are a good salesman Peter. Do you work for Philips? (just kidding).

As much as you show on the pic this is a much simppler circuit than what Elso suggested as an output stage!!

Which circuit are you following?

Is the DAC a special selection?

apassgear · 6th May 2003, 11:52 PM

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???

mlloyd1 · 7th May 2003, 12:26 AM

Search for a thread started by Jocko on a simple IV converter

OK, I found it:this one

mlloyd1

[QUOTE]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??? [/QUOTE ]

6th May 2003, 04:06 PM	#1
apassgear diyAudio Member Join Date: Nov 2002 Location: Viña del Mar, Torreon	TDA1541A S1 come back!!! After dusting my old Magnavox CDB650 and solving some problems, with the help of this wonderfull forum, I was ready for some listening. At the beggining things were not looking very promising so I changed most all caps from the main board and also shortened the leads of the bit caps under the DAC. Things got much better but after some time I had problems with the drive not wanting to read the whole cut and was kicking out most of the times. So I changed all the caps at the servo board underneath the CD drive. Well that did it. Before going on I will say that all the caps had been changed about 15 years ago to good quality Panasonics HF and HFS with a couple of other brands. I was surprised to find some of caps leaking some green stuff (Panasonics). This has happened also on other gear, so don't take it for granted that if it is a P they are OK. Well, much to my surprise the sound has changed to an exceptional one remainding me of analog days and in some ways even better. Huge sound stage and very deep plus lots of detail. Now of course I have better amplification so this also helps. My amazement is that I can hint that there is a lot more than can be had from this chip, since I still hear details that are not fully resolved plus a certain lack of bass and HF could be better. A general description of the actual CDP is that it has been Poogeed by Jung article in AA. Still an oversampled design using decoder SAA7210 and digital filter SAA7220 plus a TDA1541A S1 DAC. The I/V is per Jung, if I remember this is a AD844 CF Opamp, but I'm not using a buffer so the signal goes directly from the I/V opamp stage through the output caps to the line amp. This analog section is fed by two Jung/Sultzer regs using a separate PSU. That pretty much sums it up. I'm currently bulding a couple of PSU to feed the DACs this I assume will help the overall sound. My main concern at this point is how can I deal with the laid back bass and better the HF. I do have some ideas that have been posted on this forum such as the Rbroer analog stage and the Kuei OPA660 or the Adagio vacumm stage. Hopfully one of these may bring back the missing balance. Any suggestions???

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6th May 2003, 10:04 PM	#4
apassgear diyAudio Member Join Date: Nov 2002 Location: Viña del Mar, Torreon	Elso, After reading your post I imagine that my main problem is not using an output buffer. I understand of course that bettering the other aspects will still improve things. Coming back to the I/V and buffer what would be your suggestion taking in consideration that I have at hand the following Opamps? AD8620AR AD825AR AD811JR AD827 LM6172IM LM6181IM8

6th May 2003, 10:18 PM	#5
apassgear diyAudio Member Join Date: Nov 2002 Location: Viña del Mar, Torreon	Peter, Using 1543 would mean to redo all the PCB, I dont think even that the number of pins are the same. Beenig an old and trashy CDP I dont think it's a good idea to to put much work on it since the remaining life of the lasser is dificult to predict. So in this case I only want to test the potential of the DAC and use it until the lasser dies and maybe in a future redo the PCB using another CDdrive but using the same DAC. Regarding the 1543 I would like to test it but I'll have to wait until the end of the year. I have read a lot about it on this forum and looks very promising

6th May 2003, 11:41 PM	#8
apassgear diyAudio Member Join Date: Nov 2002 Location: Viña del Mar, Torreon	You are a good salesman Peter. Do you work for Philips? (just kidding). As much as you show on the pic this is a much simppler circuit than what Elso suggested as an output stage!! Which circuit are you following? Is the DAC a special selection?

6th May 2003, 11:52 PM	#9
apassgear diyAudio Member Join Date: Nov 2002 Location: Viña del Mar, Torreon	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???

7th May 2003, 12:26 AM	#10
mlloyd1 diyAudio Member Join Date: Feb 2001 Location: illinois	Search for a thread started by Jocko on a simple IV converter OK, I found it:this one mlloyd1 [QUOTE]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??? [/QUOTE ]

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