TDA1545 – possible to piggy back?

[jnewbold]

Hi all,

I have built a TDA15454 DAC (NOS with passive I/V) with the battery PSU suggested by Kuei Yang Wang at post #21 in this thread:
Simple, good quality DAC

As for the TDA1545, just to put some cats among the pidgeons, I came across an interesting circuit from a French On-Line Mag, originated in the "dustcircle" of Pierre "Mr. MDI" Johannet for modding the Philips and Marantz Players using TDA1545 output Stages (Philips CD71X/72X and Marantz CD3X/4X) which I have attached.

You could use three "D-Cell" NIMH Batteries in this circuit, taking care to have a suitable "standby/float plus fast" charger which is simply disconnected when the Player is unmuted. Given the very low current Draw of this circuit you would likely get 2 - 3 Month battery life out of three non-rechargable high performance batteries, so completely omiting the charger and all may also be an option.

This would likely make for a VERY cost effective modification for the Philips and Marantz Players of this type, elimiating any active output Stage. Not shown in the Schematic are the Output Coupling Capacitors.

Oh, before I completely forgte, for adventerous souls, you could use a simple Silicon Diode (1N400X for example) string where each battery is replaced with three diodes as supply. Simply feed this diode string with a few 100mA current (from an LM317 connected as current source and a seperate mains supply) and things should work quite well to, you could even seek out adjustable references that can handle a few dozend mA and can supply 1.5 to 1.8V. In all cases I'd probably place one each BG NX-HiQ or Sanyo Os-Con on the Reference and Supply pin of the TDA1545 to ground.

My question is whether the TDA1545 can be operated in piggy back mode, and if so, what changes to the Iref & Vref (or anything else) would be needed. Also, how many 1545 chips can be piggybacked?

Cheers,

Joe

[mvollb]

Hi,

check this, the 1545 is not far away from the 1543.

Michael

DIY Fidelity TDA1543 Non-oversampling DAC

[jnewbold]

Hi Michael,

Thanks for reply. I have seen that thread and have built a 8 x tda1543 Dac (DDDac) (and an 8 x TDA1543A for EIAJ from a Sony CDROM)

The requirements for I/V conversion for TDA1543 are a bit different to TDA1545. I don't know enough to know whether TDA1545 can be used in parallel, or whether the particular I/V requirements for TDA1545 prevents parallel operation.

At present I am using a single TDA1545 with passive I/V and battery (for the moment).

I remember reading something on a DIY website not so long ago that was sceptical about TDA1545 in parallel, but I can't find the article now.

Cheers,

Joe.

[mvollb]

Hi,

this is the output part of the 1545: what happens when you keep R 4 (for each dac a separate one) as is and adjust R3 for the same reference voltage as before? When you stack these devices you need more current for the additional dacs - the voltage drop at R3 will be higher. So lower the value...

michael

[maxlorenz]

>>> I have seen that thread and have built a 8 x tda1543 Dac (DDDac) (and an 8 x TDA1543A for EIAJ from a Sony CDROM)<<<
Hi Joe:
I completed my DDDAC1543 today

Can you comment briefly about sonic differences between it and the 1545DAC?

Thanks
Mauricio

[jnewbold]

Hi Mauricio,

I would say that the TDA1545 ( after just a few hours of operation) has a slightly more refined midrange than the TDA1543 and presents the female voice with a little more clarity.

I think the TDA1545 has a little more depth in the soundstage, although I don't think that this is major consideration.

My TDA1543 DAC uses Black Gate N output caps and Riken resistors while the 1545 uses Elna cerafines and Holco resistors. I don't know how these differences affect the relative sounds. My suspicion is, not much.

There are several other threads on this forum where people have expressed various opinions about the relative merits of TDA1543 vs TDA1545 (and TDA1541) posted by DIYers like jean-paul, Elso Kwak, Peter Daniels and Kuei Yang Wang (Thorsten Loesch) and others. They make interesting reading.

Personally, I could live quite happily with either 1545 or 1543, but prefer 8 x 1543 because of its higher output and more dynamic, if slightly less refined, sound.

Hope that helps.

By the way, I haven't yet got around to trying the suggestion of michael in post #4 above to see if I can piggy back the 1545. I hope to be able to try it this weekend, or next week.

Cheers,

[maxlorenz]

Thanks Joe!
Maybe this guy Yeo at:
http://diyparadise.com/dackit/1545bdackit.html
will know if they can be biggy-backed.
TDA1545 with a CDPRO transport. Maybe the ultimate project for me

>>>TDA1543 DAC uses Black Gate N output caps and Riken resistors <<<
I too like the Riken, to increase warmth and presence wich the DDDAC has already. Did you try increasing capacitance here?

>>>and Kuei Yang Wang (Thorsten Loesch)<<<
Do you mean they are the same person? I allways read his comments with fruition. This guy knows about what is he talking about

Greetings
Mauricio

[jnewbold]

Hi Mauricio,

>>>TDA1543 DAC uses Black Gate N output caps and Riken resistors <<<
I too like the Riken, to increase warmth and presence which the DDDAC has already. Did you try increasing capacitance here?

The DAC with Black Gate N 4.7uF caps uses TDA1543A chips. 1543A accepts EIAJ or Sony format.

I have also built a DAC with 8 x TDA1543 with Crystal receiver 1543 accepts I2S from Crystal. This uses 220uF Elna Silmics bypassed by 2.2uF Axon polyprop and .022uF Wima polyprop and I/V with Vishay resistors. I like that combination but it seems to me that the 8 x TDA1543A with 4.7uF BG N, with no bypassing, has a slightly tighter and more articulate base.

This is not necessarily a straightforward comparison because the 1543 is fed with I2S from the crystal (Tent XO reclocking as per Doede DAC) and uses Rotel RCD965BX as transport, while the 1543A is fed EIAJ directly from the Sony chip with no reclocking. My preference is for the 1543A and Sony from NEC CDR.

I intend to reclock the NEC, one of these days.

By the way, I am currently using a single TDA1545 (with Elna Cerafine and Holco) in place of the 8 x 1543A DAC with the NEC CDR and there is not not so big a difference between the 1545 and 1543A as there is between the two versions of 1543. It could have something to do with the Sony chip in the NEC outputting EIAJ and no receiver between that and the DAC.

All of the above variations use passive I/V.

>>>and Kuei Yang Wang (Thorsten Loesch)<<<
Do you mean they are the same person? I allways read his comments with fruition. This guy knows about what is he talking about

Yes, they are one and the same. (Just as an aside, Kuei [Thorsten] is not wildly enthusiastic about passive I/V for TDA1545 and has offered a valve output which I might try, one of these days,)

Something else to think about. I have a CDP which uses a TDA7310 decoder with 12S output. I am building a new power supply and will use the same 8 x TDA1543A DAC board but replace the 1543A tower with 1543 chips, and then see how that combination compares with EIAJ direct. The Phillips transport can also be rechecked with a Tent XO, (11.2xxx).


Cheers,

[jnewbold]

Hi Mauricio,

QUOTE]TDA1545 with a CDPRO transport. Maybe the ultimate project for me
[/QUOTE]

I think the CDPRO outputs I2S while the TDA1545 (and TDA1453A) accepts only EIAJ. There have been some EIAJ to I2S conversion schemas offered on this forum, but you might be a better advised to use an I2S DAC such as TDA1543, TDA1541 or any of the other I2S DACs that have been posted on this forum.

You could do a search under CDPRO as starter. I know that Peter Daniels has initiated a thread on the making of a CDPRO and there are several others - but I can't direct you to the threads.

There will be at least one that suits your skill/budget/perseverance level.

I have chosen TDA1543/A and 1545 because of my low skill/budget but high perseverance level. Perth is also one of the most isolated capital cities in the world and getting parts here is a problem and postage is costly, so I tend to gravitate to the projects with a low parts count.

Cheers,

Joe:

[pburke]

while you're getting ready to rebuild your DDDAC - here's a link to what I did over the last few months to "rebuild" mine. Maybe a little over the top given your comments about budget, but before you build a new DAC that sounds just like the old one, this link may give you some new ideas:

My new 16-chip DDDAC

Peter