Improving the Coupling Capacitors for Better Tone Sounding

[ruffrecords]

It is a fact that capacitors with a large varying voltage across them will produce distortion. Steve Bench used 70V rms in his test which is about +60dBu!!!

Steve Bench's tests were conducted with 0.1uF capacitors. When a properly sized capacitor is used as a coupling between circuits, the voltage across it is miniscule. A typical 47uF coupling capacitor in a 10K circuit will have a voltage across it easily more than 120dB lower than this.

On the other hand, in an EQ, there are significant voltages across capacitors so non-linearities are more likely to be detectable.

Cheers

Ian

 

[GrannyGremlin]

What I enjoyed the most in this video, was this claim:

"Anybody who really know what they're doing in electronics will tell you that that that the coupling capacitors definitely are one of the more audible parts of any circuit"


I would love to know the opinion of people "that really know what they're doing in electronics" about this statement,
people that are very experienced and we can trust, even if just a few.

This is a complicated answer because it does not allow for a statement of magnitude, but just relativity, and in that sense the statement is correct simply because coupling caps are in the signal path, while almost all other caps are not (a few exceptions). Not only that, they are the biggest caps in the signal path (capacatively coupled outputs excepted, but those are not used in guitar amps that I have ever seen). But how much one actually hears caps, even when in the signal path is another matter.

Where he is wrong is that paper in oil caps are a good idea. We have already explained why they are not above. Like I've passed on guitars because the seller advertised that the tone caps were changed to vintage russian PiO (a right mess waiting to happen inside an expensive instrument that could damage other components or the finish, and since already old vs new prod, probably altready started that slow process; no thank you.

I do not believe (except with some limited exceptions re noise and other factors) that different caps types make any tonal difference. At the very best, this difference would be a point of diminishing returns. The only reason to change a cap is due to failure, needing/wanting a different value, or because the current cap type is suboptimal (old paper in oil, old electrolytic either of which may fail, and have likely already drifted significantly in value, or renmoving electrolytics from the signal path, and cheap ceramic discs, etc - tantalums can have a lifespam, just generaslly much longer than electros; noise issues w silver mica, but eg Fender nerds love them in the tone stack).

 

[opacheco]

It is a fact that capacitors with a large varying voltage across them will produce distortion. Steve Bench used 70V rms in his test which is about +60dBu!!!

Steve Bench's tests were conducted with 0.1uF capacitors. When a properly sized capacitor is used as a coupling between circuits, the voltage across it is miniscule. A typical 47uF coupling capacitor in a 10K circuit will have a voltage across it easily more than 120dB lower than this.

On the other hand, in an EQ, there are significant voltages across capacitors so non-linearities are more likely to be detectable.

Cheers

Ian

Dear Ian,
Steve is talking about the DC biasing can change the performance curve D-E in caps too. Here we can linearize this curve of not! and this is a posible in ours units.

Best regards
opacheco