Aquaboy to dark? Cap Question

[hoyager]

Hi there, I am wondering if someone can tell which cap is filtering out the highs?

The second one I've built feeds back more on the lower notes than up high

I've used all mylar green caps on this one as opposed to box caps on the first one, but should that have made alot of difference to the tone>?

Would a dodgy delay chip have this affect maybe?

Andy

[madbean]

I don't think the BBD will have any effect here. It is possible that the difference in cap types could be producing a darker result. There are three sets of filters that control the frequency response of the delayed signal. These are the components b/w R11 - Q2, R25 - Q3 and R29 - Q4. The first set is pre-empahsis and the second two sets are post-emphasis.

To get the most bang for you buck, you could try socketing C12, C13, C23, C24, C25, C26 and try either smaller values or different types of caps there.

Or, you could do this instead: socket C25 and C27 and try smaller values there (say 470pF and 100pF, resp.) Using smaller values with those two may be all you need to add a little more high end back into the signal.

[hoyager]

Awesome, thanks man, I found replacing C23 has done the trick, the green one there might not have been the right value (not sure how to read the values on those), cause the difference is night and day. I replaced it with a 1n wima box in parallel with a ceramic 1n, which I read somewhere (for an unrelated application) as having a certain tone (distortion)

Andy

[hoyager]

SOunds amazing. Just a thought, when you touch the delay time pot it grounds it and there is modulation in effect, depending on how much of the pot leg you're touching.

Could I potentially mount a small pad of something outside the box and connected to the pot leg in question, for manual 'tape' manipulations?

Andy

[eniacmike]

a cool way to do body contact mods on pedals is to get something like a brass drawer handle and mount it to the pedal  and connect it to the spot you want to have body contact access to.

search "body contact circuit bending" for more info on that kind of stuff.

[madbean]

I've had the exact same thing happen on the original AP boards that were done through FSB. It's really wild. Actually, I could get mine to modulate just by waving the board...no touching required.

I posted about it, and I think someone suggested that it could be the wafer in the pot moving slightly.