Solid State Pultec...new pics...

[saint gillis]

Beautiful, how does it sound?
  What is the difference in matter of sound between op amp in & out and transformers in & out ?

 

[JW]

Very cool. Would love to hear some subjective comments between the sound of the original transformers and what you've used prior.

 

[radiance]

They ARE the original transformers...and it sounds like ...well, a Pultec I guess?? It's rather clean actually. Without transformers it would be even cleaner but I have build it for the Triad sound...

 

[jensenmann]

You should consider to swap the filter caps to mica wherever possible. This makes quite some difference.

 

[radiance]

You should consider to swap the filter caps to mica wherever possible. This makes quite some difference.

I might redo the whole filter board ...dunno, that thing that's in now was one big hack to make it work...and yes, will try mica off course

 

[mitsos]

You should consider to swap the filter caps to mica wherever possible. This makes quite some difference.

I saw the Lang used some mica caps on the highs. Haven't tried them myself, but I'm curious as to what have you compared them with and what kind of difference did it make for you? I know, very subjective, but.. still want to know.  cheers!

 

[jensenmann]

They just seem to sound cleaner, with less artefacts, than other caps. At least in the HF band. I´ve compared mica caps in different circuits with MKS, MKP, MKT, KT, MKC, FKP and whatnot and always mica was the winner. The only type that came close was FKP. That´s my personal taste though. Better check it out yourself in your specific circuit.

 

[mitsos]

cool, thanks for the breakdown.  I think you know I like FKPs! That was my first eye-opener cap test. Simple opamp circuit, input cap, FKP won, night-n-day.  Problem is they get really huge so they become impractical (besides expensive).  Going to grab a few micas to test, I think I only have a couple of very small values on hand.

thanks again!

 

[radiance]

Hell, I love artefacts!  ....but I think they're FKP's in there...

 

[jensenmann]

Mica caps get crazy expensive beyond 1nF and are huge compared to other types of same value. There are (harder to find) 100V micas which are a great deal smaller than the usual 500V rated version. In my 8channel Trident EQ I decided to leave 6 channels with styroflex and improve only 2 channels with micas, just for cost reason. Beyond all the audio-blahblah micas are very stable in tolerance and temperature and - afaik - have the lowest dielectric absorption.
@radiance: if you´ve compared the artefacts then you´d know for sure that you don´t like them, esp. MKT artefacts sucked bigtime. FKPs still are an improvement over all others except mica (in my book).

 

[radiance]

@radiance: if you´ve compared the artefacts then you´d know for sure that you don´t like them, esp. MKT artefacts sucked bigtime. FKPs still are an improvement over all others except mica (in my book).

I did some comparisons in the past...somehow, I always settled for MKP or FKP...Actullay I liked MKP the best but these things are very hard to get in small packages...and yes availability will always be an issue in deciding what goes in there...