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How to build a Phono RIAA preamp & DAC ?

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Ptitmickey

Active Member
Hello guys,

I usually just speak french, so excuse me for my bad english...

I started the construction of an Hackernap amplifier that you can follow the address below :
http://www.pinkfishmedia.net/forum/showthread.php?t=174353

And to continue my experience in the DIY , I would make a Preamp which is adapted for hackernap.

Specifications :

  • Source selector
  • Volume control
  • Bass control
  • Treble control
  • RIAA phono preamplifier (MM-MC)
  • 3-4 analog inputs (RCA)
  • 1 analog output (RCA)

Would anyone advise me on a mounting or components of bases to be used ?

I've seen Allan is used a B4 buffer preamp with his hackernap...
Could you give me more informations about this schema or others same type ?
I think add a RIAA phono input is not a problem...

Thanks in advance for your help & best regards.

Nicolas
 
Hello guys,

I've updated my post with new specifications, after reflexion, I think it's better to build a good preamplifier, and a separate DAC...

Ideas or build exemples are welcome.

Thanks
 
Moppit said:
Also interested in this Andy, thanks for the link but Er... any good pointers on where the real information is in this thread? (posts, pages etc) as at this size it is rather difficult to navigate...
Click to expand...

Haha - yes, it's certainly daunting! :D

I believe the links in the first post have been updated to be the latest circuit(s?) but if you post a direct question to Salas (the designer), I believe he will advise you.

Regards,

Andy
 
A couple of years ago I built a DAC/Pre/Phono/Headphone amplifier with three transformers all in one case. I used a Salas RIAA as above, with a DC-B1 and an ebay AK4393 DAC. I then re-built it with the phono in a seperate case, and the phono is now a Paradise.

I think it is achievable, if I were making it I would get a full width case (430mm) and put the transorfmers at one end and the phono and the pre at the other end.

The Salas RIAA is very good and an easy build on veroboard but not easily adjusted for MM and MC gain, and also depends on the idss of the 2SK170's you have, you are best off buying a batch of them and measuring all of them. Genuine 2SK170's aren't easy to come across for reasonable money now, but are worth getting as there are lots of circuits that use them.

Do you need gain on your pre-amp? If no, I find the DC-B1 buffer works really well (and also uses 2SK170's) If you do need some gain, the JC-2 is a good option (and also has a long thread on diyaudio). There were some people selling genuine 2SK170's on diyaudio, have a look on there.

I find that with "normal" MC's 60dB gain gives me enough headroom to only need a buffer as a "pre" (even when using my 0.14mV Denon DL-S1) and "normal" MM's 40dB gain is fine. I use a Hackernap power amplifier which has a "standard" input voltage requirement.

The PDF in this thread should be useful:

http://www.diyaudio.com/forums/analogue-source/129126-simplistic-njfet-riaa-495.html#post2308275
 
Hello guys,

I finally make choice to use "Elliott sound products" to realise the preamplifier and "Hifiberry" for the DAC...
So, you will find below some used components informations :


I'm searching a good power supply regulator for Hifiberry 5V 2A...
The transformer will be custom with 3 windings.

Thanks for your feedback or eventually comments about this configuration.

Regards

Nicolas
 
Hello guys,

I'm finnaly on the road with ESP products, you will find below some pictures of project modelisation. But I'm not sure of best choice for audio input selector...

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Drawings are designed with first proposition.

1. Proposition with relay module PCB

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2. Proposition with elma selector wired directly on outputs RCA

l2_line_extender_001.jpg


Find below a drawing with module description

https://www.dropbox.com/s/5lwn9o2ujirducs/2017.02.14_Preamplificateur.pdf?dl=0
 
Ptitmickey said:
Hello guys,

I usually just speak french, so excuse me for my bad english...

I started the construction of an Hackernap amplifier that you can follow the address below :
http://www.pinkfishmedia.net/forum/showthread.php?t=174353

And to continue my experience in the DIY , I would make a Preamp which is adapted for hackernap.

Specifications :

  • Source selector
  • Volume control
  • Bass control
  • Treble control
  • RIAA phono preamplifier (MM-MC)
  • 3-4 analog inputs (RCA)
  • 1 analog output (RCA)

Would anyone advise me on a mounting or components of bases to be used ?

I've seen Allan is used a B4 buffer preamp with his hackernap...
Could you give me more informations about this schema or others same type ?
I think add a RIAA phono input is not a problem...

Thanks in advance for your help & best regards.

Nicolas
Click to expand...

Hi
I now use the Avondale 821A pre amp boards in preference to the B4 buffer boards as I prefer that bit of extra gain

Its a lot to ask putting a Phono Pre and a Dac in the same box and noise will effect the quality of the output IMO.
I have a separate DAC (M2Tech Young) and an external Paradise Phono stage
If you have an internal DAC and Phono stage try local shielding of them and a separate power supply for each
Also the input RCAs should go to the phono and dac CBs directly via an individual selector switch and the output go to the overall rotary input selector switch if that makes seance ?.
I agree that the ELMA switch is the best I have tried
Good luck with this sound like a great project
 
Thats a really nice job your making of that amp there well done
Can't wait to see the finished article ;)

Alan
 
Hello Guys, some news...

But some questions too...

- Where can I connect inputs ground on input selector PCB ? On output ground ?
- How can I set main output disable when headphone is connected ?
- Is it right to have a separate control volume for headphone ?
- Is it better to connect directly headphone preamp on input selector, so without tone control on headphone ?

Thanks in advance for your interest.

Regards

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