[K3cT]

Is there any point for using cream-of-the-crop boutique capacitors in let's say, PPAv2's bass boost circuitry? I'm thinking of taking it to the extreme with VCap Teflon or some nice PIO.

Since these caps lie in the signal path, one can expect that they have to be of a reasonable quality but I'm still not sure there is any merit in going all the way or not. All being said, fire away guys! I'm interested in your opinions.

 

[FallenAngel]

Sounds like a bad idea personally, but I use VitaminQ. You do have to consider that you're purposefully adding non-linear distortion (by definition of "bass boost"), why bother with boutique caps.

The caps are actually not exactly "in signal path", they're in the feedback loop.

 

[K3cT]

Thanks, FA. The literature I read seems to suggest polypropylene most of the times but I just wonder how other materials will work.

 

[amb]

The feedback loop is very much "in the signal path"; so yes, you should use good capacitors there. That said, you should use something that would fit in the PCB pads. Do not tombstone-mount the cap or air-wire large caps off-board. The feedback loop of an amp should be kept very short. Extra lead length from the cap adds inductance and could cause instability.

 

[K3cT]

Quote:

Originally Posted by amb /img/forum/go_quote.gif The feedback loop is very much "in the signal path"; so yes, you should use good capacitors there. That said, you should use something that would fit in the PCB pads. Do not tombstone-mount the cap or air-wire large caps off-board. The feedback loop of an amp should be kept very short. Extra lead length from the cap adds inductance and could cause instability.

How did you manage to read my mind?!

Assuming space is not a concern, how does bypassing a PIO with a Teflon sound for this purpose? This is probably a very far-fetched idea but who knows...

 

[amb]

I'd just use polypropylene film caps for this.