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groups buy TDA1541AS2 chips, money back gurantee

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hi peter,

yes, this phots was taken from old cd-94.
where do take it, am my old photos post to old tda1541a ultimate dac was copy!!! may e was the reference material I take to make sure the chips was real or not. I forget it! If the photos was your photos, very sorry for that I will post another one from my
Cd-94.

Looks the old photos from china may be te same stock longer time. but this chips from china!!!!!!! I was sorry worry too many fake chips.Is it same as my stock from taiwan.

I was so worry for this since it cost lot of money for this chips.
I will buy two way insurance for the parcel & thought they were real.
I will call the seller from taiwan take more photos to me to versify.

thx

thomas
 
hi peter,

Are U sure the chips from wany was real chips.
??

I will call my chips supply tomorrow for this conditions, if he take photos from another website. I will request more photos & versify that they are!!
If the chips sales not honest, I will release all the order since I still not transfer money to taiwan, i only checked all the cost such as insurance , forwarder charge only. I hope to accumulate groups order because I need this chips to test my parallel balance 1541a dac. can I call wang about the chips still on hand or not. if yes, this will be a good news for diyers & I can directly buy some from him in cheaper price.

thx

thomas
 
I'm not sure how it goes, but most of the pics in this thread were posted 3 years ago by a forum member Elib, who had a large stock of those chips. He sent me 2pcs to try (without asking for payment). After I tried, and posted the results on this site, numerous other members bought those S2 chips and everybody was satisfied.

There is substantial difference between A/S1 version and S2. Personally, I would go for S2, as I prefer it. When I was talking with Wang few weeks ago, those chips were still in stock.

If Thomas wants to organize GB on those chips I can supply Wang's e-mail and I'm sure the price will be much better this time.
 
hi peter,

pls send wang's email& call no to my email address
thomas_siu@hotmail.com

I will directly call him or email to him. I will deal the price too. Hope the price will better. At least can save some postage, insurance for me. If U sure the chips was real. I thought the groups buy can get the chips in cheaper price. This will benefit to all diyers. There will had approx USD 20 price different!!! Ha ha, so good news.


very thanks peter..for your informations.

tx

thomas
 
hi peter,

I got wang's email already. I will email to him for detail.
I will try to deal about better price too.
if the chips all were real one. I will pay for them first & keep some on hand, may be john's forum some diyers had interest too.
I will sellto john's forum member insame price as chips coming price.


I had another questions. Do U think parallel more standard chips will better than two or four chips. Do U had this experience????
pls share experience.

very thanks for your assistance.

thx

thomas
 
I would never go for more than one chip with TDA1543, and with your early board, I noticed that two 1541 chips in parallel were better than a single chip, but only when oscillator pins were connected (as in Lesha DAC), otherwise I preferred a single chip.

While placing more chips in parallel may have some advantages, it will also bring disadvantages which will be overpowering any positive effects.

I would rather go with a fully balanced circuit. I have such conversion circuit schematic (based on SF DAC2) and it was alredy tested with TDA1543 chip with pretty good results.
 
hi peter,

I was prepare the full balance 1541a dac, since will only use two chips per machine, but can parallel one more chip in each channel.
That means max will use two chips in each channel.
In my test result. if parallel two chips need to adjust the I/V otherwise some distortation will occur. My full balance was use CPLD for each chip.
that mean one chip for left channel + & -, right channel will be same too.
buffer I will choose 2sk389 for them.
any comment for this, I also try the BC109 was quite good because I had some military gold plated on hand. I try TNT audio BC109, modify Nelson D1 IRF610 & combine irf610 with 2sk170 also very good.
But I lke TNT BC109 most, improve several points some in the circuit & running more current because I chose BC109C to test. now still testing because the HDAM & 2Sk389 module was approx funish already. diyers can directly plug & play in Op-amp sockets.

thx

thomas
 
tube-lover said:
...otherwise some distortation will occur.

Indeed, I also got distortion when paralleling those chips and had to swap some of them for best results.

The circuit that was used in balanced version of TDA1543 was posted here: http://www.fotosik.pl/showFullSize.php?id=f504c84d32d84ebe It also allows to change the phase.

The DAC worked well in proper setup without any buffer (best combination was connection to TVC) otherwise I was using circuit as in atachment.
 

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  • ml_buffer.pdf
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hi peter, this is a good method for balance dac in reasonable cost. I will prepare the circuit & show U later. now onl hand write o my hand. I hope to collect some advise from U too.

BTW, are using the TVC directly connect to the dac??

is it same use 10K loading into it? I will prepare the nano-amorphous TVC later, if funish will send one for U to test.

thx

thomas
 
Yes, I connect DAC directly into S&B T102 transformer stage (the needed coupling cap is only 0.1uF, in case of using expensive V-Caps it's quite convenient). V-Caps are probably one of the best coupling caps available. The bypas caps on TDA1541 that I liked back then were those green ROE MKS you can see in a picture of CD-94

I'm presently using modified BiDAT with CEC TL0 transport: http://www.diyaudio.com/forums/showthread.php?postid=899119#post899119

I'm still using TDA1543 DAC in other system and TDA1541S2 in my Marantz CD-94.

I'm coming to conclusion that all of those DAC chips, when properly implemented, can provide very satisfying sound, the major difference is not in a DAC chip itself, but depends mostly on implementation.

I recently got hold of Pedja's DAC board and will be putting it together as well.
 
hi peter,

I will post one set of my standard ver.3 dac PCB to U. I would like to know the different of pedja & mine. I hope can improve my weakness which compare with pedja, pedja design was a high funish design, john's too. but I hope can preapre some in reaonable dac to limited biuget diyers to share the happiness of diy.

very very thanks for your helpful.

thx

thomas
 
hi peter,

I'm coming to conclusion that all of those DAC chips, when properly implemented, can provide very satisfying sound, the major difference is not in a DAC chip itself, but depends mostly on implementation.

I would like to know what is the meaning of properly implemented???

In my experience was the IV & buffer & power supply was the most important, secondly was the chips & re-clock.

am I right???


thx

thomas
 
hi peter,

yes, your opinions was perfect right!!!!

The By pass caps i the powere supply was very important.

I try several types & at last that I choose was epcos & ERO foil 0.01uf

hope this can help.

Actually the major priority of dac was

1. Power supply( fast ,stable & low nose)
2. IV & Buffer. use fet or jfet, not use op-amp.
3. Ground.
4. quality of chips.


is it same as yor opinions, peter??

thx

thomas
 
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