ProtoDAC TDA1387 X8 project

[michaelagiles]

I should know by now to check spellcheck!

[hifinet]

Good Morning!
I have a kit ordered and have been looking at the build guide etc.
Do you think there is any advantage to a small film bypass on the decoupling caps?
Also - I recall you had used the discrete r2r day from bigbulb. Do you find this Potomac superior? I have one of his AD single chip designs and love it! this set me on the multibit NOS trail and was contemplating the R2R hat before I saw this design.
Thanks!

I have not tried a bypass cap on the power supply decoupling caps. I am still trying various combinations of electrolytics. Based on results with a polymer cap (see below), I am guessing a film bypass cap would not be beneficial. Sound quality changes quite a bit with decoupling caps, and I think the sound of this DAC can be tailored to personal preferences with decoupling caps.

So far, Panasonic FR sound best to me. The most realistic. Silmic II sound very good, big sound, but just not realistic. I know it's personal preference, type of music, system factors (including the DAC power supply), but that's where I am with classical music in my system. 

I have tried a polymer cap 680uF 7 mohms ESR with a 1000uF Nichicon UKA, but that didn't sound good at all. Very grey, sterile, no color.  

Two 1000uF Panasonic FR-A 28 mohm ESR sounds very good, but just slightly lacking color. The same cap combined with a UKA or Audio Note Seiryu was very good.  

Two FR-A 1000uF 41 mohms ESR Panasonic EEU-FR1A102LB (DigiKey) are the ones to get.  Tiny little caps. Cheap. Excellent sound. Big deep bass. Soundstage in a realistic perspective. I recommend starting with these. Be sure to give them a 60+ hour burn in. These are still improving, long after 60 hours.

I have two of Ew's DACs, the AD1865 and the Discrete DAC. Discrete DAC sounds better than AD1865. In my opinion, this DAC sounds much better. I very much like the sound of passive I/V paralleled TDA1387 DACs. I arrived at this DAC after my experience with L1387 and TeraDAK.

[hifinet]

Forgot to mention that the module has eight ceramic decoupling caps, one for each chip (probably 100nF MLCC). It also has eight ceramic pin 7 decoupling caps (probably 1uF).

[michaelagiles]

Thanks!
What comes with the kit?
MG

[hifinet]

Please see post 1 of this thread, which gives a detailed description of parts included in the kit.

Regarding the electrolytic decoupling capacitors: Two audio quality power supply decoupling capacitors consisting of two of the following: Panasonic FR, Nichicon UKA, Nichicon FG, or Elna Silmic II.

Based on current stock, I have Panasonic FR-A (EEU-FR1A102LB) and Elna Silmic II on hand.

[rh2018]

A big thanks to Mark Winkler for sharing his excellent ProtoDAC project

I received two TDA1387 x8 modules from AliExpress and whilst waiting for the recommended caps I decided to build a unit on perf board with components I had on hand.

The SQ is excellent and improving as the caps burn in. Natural and non fatiguing sound. Even without optomised components the ProtoDAC is more musically satisfying than PCM50xx chips in other Rpi HAT's I have on hand.

I recommend any moOde DIY enthusiasts to order components or a kit from Mark (@hifiamps) and enjoy a very satisfying result.

Richard

p.s. No luck posting image. Is there a how-to to copy and paste images?

[Tim Curtis]

Images are added by uploading the image file.

Look for the "Attachments" section below when composing a post.

   

[rh2018]

Thanks Tim,

Click image to enlarge:

   

[hifinet]

Thank you very much, Richard.

[fdealexa]

Hi everyone,
I bought the kit at the end of April, I received it on May 16th and the following day it was already online, on the moOde I listen to every day.
Since that day I have to honestly say it's my favourite DAC: very warm sound and at the same time punchy and wide as scenery.
I must say that I am really satisfied with my purchase: thanks HIFINET.
Greetings and thanks for your attention,
Francesco