Blown away by this DAC

[mjw21a]

I can't quite remember the values so you'll need to check the values printed on the existing ones. I think the white ones are 1uf ? Or were they 0.47? Just get the value from the existing caps. Bypass with either 0.01uf Duelund silver bypass caps or Russian silver mica's

Yes those are the green caps.

I'd suggest getting someone good with a soldering iron to do the work as the solder used in this thing is a nightmare to work with. Likewise install DIP8 sockets so you can easily change OPAMPS.

Once you've done all nods try the original TDA1541 again. The early production models were generally more musical sounding so you may actually prefer it. I generally prefer the Holland made chips rather than the Taiwanese or Chinese made chips. More natural sounding to my ears though really it's all down to personal preference.

If you find the Sparkos too neautral, get a pair of Burson V5i-D OPAMPS. They're more natural sounding, and put the Sparkos in the position near the RCA sockets.

 

[potopisin]

OK Mj, got most of that, I have ordered the 8 pin sockets for the op-amps.
I am about the order these. ""Arizona Capacitor 0.47uF 600Vdc Blue Cactus Series"" to change the two little green ones.
As for the two bigger white ones..!! It says on them.

MMA 2WI – IJ – F
1.0MFD +-5%
.CDEC-250VDC
85°C 60HZ HE
I take it that they are 1uF.

Now when you say Bypass with either 0.01uf Duelund silver bypass caps or Russian silver mica's

What do you mean by Bypass. Just swap them out for the new ones..?

Massive thank you again.

Paul.

PS. I have attached a screenshot of the Dueland capacitors and numbered them. If you get a chance would you have a quick look and just tell me which one (pair) you think i should get.

 

[potopisin]

Screenshot

 

[JoeESP9]

I replaced the op-amp in my Topping D-10 with one from Sparkos. IMO there was/is an audible improvement.

 

[mjw21a]

A bypass is a small cap wired in parallel with the larger cap. The Duelund silver bypass caps do something very special when wired across Miflex KFPM-1 in this circuit.

Yeah, the white ones are 1uf.

 

[potopisin]

Thanks again MJ for the reply


I have now received my sparko op amps x 2.

I have some op amp sockets. And a pair of Arizona Blue cactus.

While I am fitting them, I will order


2 pcs. MIFLEX KFPM-01 Capacitor, 1.0uF 600Vdc, Copper Foil Polypropylene Film

Not the
…..KFPM01H410G Miflex 0,1uF 100nF 600VDC 2% 18x39mm Copper Polypropylen… !!!!!!!

.

And 2 pcs. Duelund 0.01uF 600Vdc JDM Series Silver Foil & Wax/Oil Precision BYPASS Capacitor.

Do I replace the two white caps that are in with the Miflex KFPM-1.
Then in the two holes on either side of the newly fitted Miflex KFPM-1 (as seen in the picture) Solder the Duelund 0.01uF.....?

Realy sorry to be a pain, i am buzzing off doing this but brand new at it...!

 

[mjw21a]

Yes, the 1uf. Here's some photo's of mine once complete. I used Neotech UPOCC wire to aid in placement of the caps as they're otherwise too large, and too close to tubes etc. Note that the Miflex KFPM-1 and Duelund silver bypasses are wrapped in the Chinese equivalent of Dynamat Extreme (Ping Jing) as this gives a large reduction in hum on these two caps.

As you can see I was also running a NOS reclock module which brought a rather massive improvement: https://www.ebay.com.au/itm/Nos-rec...m2f2e8158b3:g:LMsAAOxyq5NRC4LM&frcectupt=true

You'll also note change of cap at the end of the TDA1541 and each side of the two Sparkos OPAMPS for better electrolytics, the caps and values changed around the TDA1541 itself and some caps changed for polymer caps. The improvement was not subtle. That said someone else made those changes for me so I can't detail it for you beyond this.

 

[potopisin]

Hi mj, the Miflex KFPM-1. arrived today, they look a little bigger than yours in the picture. Are these definitely the right ones, can you tell by the pictures attached? I just laid them in the DAC for size comparison.

 

[mjw21a]

Those look fine. I have the Duelund silver bypass caps across them, and then wrap both in Dynamat Extreme. They hum otherwise.

Bend the leads so they become little hooks. Makes attaching the Duelund silver bypass caps and extension wires easier. I also shortened the leads to avoid shorting them out on anything.

 

[codimension1]

OK, just want to make sure people realize that what comes in the ebay dacs are fakes.

I am becoming interested in DACs built around old R2R chips such as the 1541, etc. My question is whether the fake versions of the 1541 or 1543 being included in many of these made in China NOS DAC designs are actually modern copies of the old R2R chips, or whether they are just DS chips in fake R2R packages. If they are copies of R2R chips, then at least they are still R2R - but I thought that the technology to produce monolithic R2R chips was just too expensive to continue with, and hence became abandoned after the 1541 / PCM63 / PCM1704 heyday (and hence how would the tooling for their production - even of copies - still be around?).. On the other hand, if these are DS chips masquerading as R2R, then how do they work at all in these circuits designed for R2R chips ?

Thanks in advance for any insight you can offer !

 

[setup1]

I am becoming interested in DACs built around old R2R chips such as the 1541, etc. My question is whether the fake versions of the 1541 or 1543 being included in many of these made in China NOS DAC designs are actually modern copies of the old R2R chips, or whether they are just DS chips in fake R2R packages. If they are copies of R2R chips, then at least they are still R2R - but I thought that the technology to produce monolithic R2R chips was just too expensive to continue with, and hence became abandoned after the 1541 / PCM63 / PCM1704 heyday (and hence how would the tooling for their production - even of copies - still be around?).. On the other hand, if these are DS chips masquerading as R2R, then how do they work at all in these circuits designed for R2R chips ?

Thanks in advance for any insight you can offer !

I’ve built and modified a couple of Chinese TDA1541 DAC kits and none of them came with the TDA1541 chip, thus confirming what you already know, these older multi-bit chips are too expensive to manufacture.

AFAIK, the fakes to be avoided are the “re-stenciled” select grades of TDA1541 with S1and S2 suffixes, more information at DutchAudioClassics. Adding an S1/S2 + a star or two to a regular TDA1541 is much easier than tooling for production.

Like the OP said, use “pull-outs” from broken TDA1541 CD players. That’s what I also do.