London Power sustain kit

[freshtapescent]

SUS-2 - Sustain & Compression Enhancer for Cathode Bias

Anyone care to venture how it works? Anyone install this kit?

 

[bparnell57]

I have no experience with this kind of circuit, but based on how they mention it is an envelope filter, I bet it limits gain at first and increases it as the note decays to compress the signal making it last longer. The bigger the input, the less gain, smaller, more gain, a simple passive compressor built into a tube amp. Thats my guess. BTW, you could do this very interestingly with a 12av6 or a 6H6 for an AVC (automatic volume control) as a radio has to make all stations have relatively close volume.

 

[freshtapescent]

Bump? Anyone else?

 

[PeteMcK]

the pcb looks like a simple diode limiter

 

[nigelwright7557]

I have seen circuits that rectify the audio signal to produce a DC voltage that controls a mosfet volume control.
The higher the voltage the more the output signal is cut.

 

[freshtapescent]

That sounds about right...know of any schematics?

 

[Enzo]

Why not contact London Power and ask Kevin how it works. I don't know that he releases schematics, after all he SELLS the product, he doesn;t need you making your own. But it won;t hurt to ask, the worst he can do is say "no."