Building the ultimate NOS DAC using TDA1541A

Is it worth it?

According to the datasheet, the improvement is in the low level performance (THD+N at -60dB, -47dB vs -42dB).

This was just what I was looking for, as I am now trying to get highest possible resolution from the DI4T. In practice, sound is getting very transparent and refined now.

So yes, it's worth it.

However, I have to point out that these modifications only make sense when the rest of the DAC electronics and connected audio equipment are capable of resolving this kind of resolution.
 
My S2 chips

Hi EC, my chips appear genuine. I did extensive research on fake S2 in the market, most comming out of Asia. I seen several examples of obvious and not so obvious fakes. I bought them from a guy who reportedly worked for Philips Tawain. I paid about $100 USD/chip several years ago, but I can't locate the guy anymore. I will have to look into it more to find the guy, but I don't know if he still have any stock left. Several people compared his S2 with the standard chip and found it to sound significantly better, smoother and cleaner sound. I have standard TDA1541A chips so I will be able to compare my S2's with the standar chip when I build the DI4T.
 
DI4 main PCB

Hi ecdesigns,

I was wondering when the new DI4 main PCB is available.

I am planning for a long time to build the DI8, but if the DI4 sound beter I rather build the DI4, and have some tdat 1541's spare. I was very impressed by the DI8 hearing it at your place, some time ago.

DJN
 
:)

Sorry Max. Didn't mean to be cruel - just trying to stop the for sale adds on this thread before they get out of hand.

As long as the "thread owner" does not complain...:angel:

You see, the "marketing" on the forums is good when there is a "cooperative spirit": I help you; you help me. That is the wonder of the internet...making people (who had not the slight chance to...) meet and cooperate.
When the spirit gets "competitive" instead of "cooperative", things usually get nasty...:(

IMHO.

I have no working DAC at this point.

That is a shame, having so many fine offers out there. ;)

Best regards,
M
 
Bulk metal foil resistors

Hi djn111,

but if the DI4 sound beter I rather build the DI4, and have some tdat 1541's spare. I was very impressed by the DI8 hearing it at your place, some time ago

The DI4T is the result of two years of continuous research and systematic improvements. I used every trick I could come up with in the DI4T. If you were very impressed by the DI8M, you will probably be totally blown away by the DI4T.

This doesn't mean it can't be improved further. Just yesterday I decided to remove the housings of some S102 bulk metal foil resistors, after reading some reviews of so called naked bulk metal foil resistors (bulk metal foil resistive element without housing).

I added a picture showing this step-by step dismantling of a Vishay S102.

1) The original S102 bulk metal foil resistor
2) Sides carefully cut away using a pair of sharp side cutters.
3) Side view, showing the resistive element inside.
4) Black housing removed, the brown protective coating is probably silicone rubber.
5) Protective coating removed (peals off very easily).
6) Rear view, the black line is glue, stabilizing the wires.
7) Small CNC milled PCB soldered to the resistive element for better stabilization.
8) Rear view.
9) Close-up of the resistive element. It consists of a maze of thin traces, forming multiple mobius loops (non inductive). The small dark spots on the left are the links evaporated by a laser, required for close tolerance tuning. Each link short-circuits a specific resistance value, when evaporated, this resistor value is added in series with the main resistor. By evaporating specific links, fine tuning up to 0.01% can be achieved. The two large darker spots on the right are the connections between wires and foil.

All parts are non-magnetic, verified this with a strong magnet, this is also desirable for Audiophile resistors.

I didn't expect any improvement at all, it's just a housing...... Well first listening tests suggested that I replaced the bulk metal foils with completely different, superior sounding resistors.

My best guess is that this might be caused by thermal issues.



I was wondering when the new DI4 main PCB is available.

I plan to have a small batch of professional PCBs manufactured soon. I will probably start with the CS8412-based version that I am currently using in my DI4T prototype.
 

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