Simplistic NJFET RIAA

[Salas]

Obbligatos are very good but plain good. MR are high range. Silver in Oil is the most I would buy from Mundorf. Those hybrid oilers you keep them away from heat in valve amps btw. Clarity has a TC range of can style HV PP caps I saw, much cheaper than MR. Maybe good for rectification filtering to SSHV2 in #26 preamps they use that reg a lot.

 

[RCruz]

Could be with big caps. We should tap them when connected on the scope alone. Because if we tap them phono connected, maybe other stuff rings on the high gain board too.

In my initial Benz riaa build that used a british hand made pcb, I could hear noises just by tapping the ft3 coupling caps, the decoupling EL caps or the output caps.

Now my p2p builds are much sturdier and I glue the caps to the board so no microphony at all.

I do not think Mundorfs are more microphonic than any other caps.

 

[Salas]

Tie wraps and some 3M double face tape can do wonders in general.

 

[Salas]

...Or the messy hot snot gun liberated.

 

[RCruz]

Tie wraps and some 3M double face tape can do wonders in general.

That is precicely what I use

 

[RCruz]

A good alternative to the supremes might be these Intertechnik cap plus: https://www.intertechnik.de/Shop/Cross-over-parts/Capacitors/Audyn-Cap-Plus/1768,en,280

And if you need a fuller sound, these are quite good https://www.intertechnik.de/Shop/Cross-over-parts/Capacitors/Audyn-Cap-KP-SN/1768,en,277
I use these Tin foil caps in my pedja buffer, producing a magical full sound.

 

[vgeorge]

Just changed the Rload and the 47K resistors to Zfoils.
I was not expecting this sound improvement!
Got more clarity and transparency, as well as more information.
Not cheap but I think it was money well spend at the end.

 

[merlin el mago]

Just changed the Rload and the 47K resistors to Zfoils.
I was not expecting this sound improvement!
Got more clarity and transparency, as well as more information.
Not cheap but I think it was money well spend at the end.

Welcome

 

[merlin el mago]

Try FT3 for interstage.

 

[vgeorge]

What I use is better than FT-3, had FT-3 before.
http://www.ebay.com/itm/Russian-Tef...pt=Vintage_Electronics_R2&hash=item33706a6ffb

 

[merlin el mago]

Please could you elaborate subjetive differences? I see the cap uses silver, possible the sound is more focused, tight & treble than with aluminium foil...

 

[RCruz]

I also used those... not bad but I prefer FT-3 that has silver terminations

 

[vgeorge]

From what I remember FT-3 was a little bit more mellow sound, but I got more information and better highs from K-72. Maybe more accurate.
Also FT-3 was 100n and K-72 47n.
I got bigger improvement by changing these 2 resistors, something I didn' t expect to be really honest.

 

[merlin el mago]

Next upgrade output caps Mundorf Silver Gold Oil.

To compare caps better share the same capacitance & voltage because I did a lot of comparisons and if are in the signal way can be modified the corner frecuency.

 

[vgeorge]

I use silver oil now. I am not going to get new caps now! Do not think that going to silver gold is worth the extra money.
I also wanted to lower corner frequency down a bit.

 

[RCruz]

Just changed the Rload and the 47K resistors to Zfoils.
I was not expecting this sound improvement!

Did you measure both resistors (the ones you had before and the ones you have got now) ?

Particularly the 47k... what where the real values and the new ones ?

 

[vgeorge]

The real value is 47k. I had 47,1k takman metal film and now 46,93. You think this difference might have an influence? Especially on definition.
Also Rload was 180R shinkoh.

 

[RCruz]

The real value is 47k. I had 47,1k takman metal film and now 46,93. You think this difference might have an influence? Especially on definition.
Also Rload was 180R shinkoh.

Yes.... lowering the 47k that much influences sound in the way you describe. (Slightly tighter bass with much more snap) (and an overall increase in output)

Remenber this is the "bass resistor".

If you rise the value above 47k you get a bump with an apex at 40Hz and will feel more bass and less snap. (and an overall decrease in the output)

if you have measured all your actual riaa parts, I can run a simulation for you.

 

[vgeorge]

I need to find my notes. If I do I will let you know. Maybe tomorrow. Thanks for the offer anyway!
I still think these resistors are special somehow.

 

[RCruz]

The resistor on rload has a very significant effect, but the values of the riaa caps are even more important for the final result (in this case, independent from the resistor type).

Let me know your values and I will post a simulation just for fun