Rebote 2.5 problem

Started by Eero, February 02, 2008, 03:53:42 AM

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Eero

Hi, this is my first post to the forum! Just completed a Phase 45 which sounds promising, although I have to do some experimenting with the fets... I have also built an ax84 HO-tube amp with an fx-loop.

I'm having a problem with my Rebote 2.5 build. I'm getting delay, but it's very noisy and staticy. Also, the dry undelayed signal has no low end at all compared to the bypassed signal. The repeats-pot is doing almost nothing, I consistently get only one repeat. When I turn it up for more, only the first repeat is clearly audible, the rest are very weak and buried in the static.

I measured the voltages at the IC-pins and all seems fine. Then I did some audio probing, and noticed that immediately after the first .082uF (used a .1 here) cap after the input all the low end is gone. I get good clean signal from pins 7 and 1 of the TL072, but no low end. What should the .082 cap do anyway? Now it seems as though it's working as a hi-pass filter filtering out anything below 500Hz or so...

As for the PT2399, I get the lo-pass filtered signal on pin 15, with no static. The delay out from pin 12 has lots of static. I'm getting lots of static from other pins of the PT2399 as well.

Any ideas? It seems like I have at least two separate problems here:
1) no low end in the dry signal
2) Static from the PT2399 and repeats pot not working (I assume these two are related...)

I've checked my component values and solder joints. I reflowed a few that looked suspicious, with no effect.

Any help greatly appreciated!


Eero

#1
I sorted out the problem with the lack of lowend by replacing the .1 (.082 in the schematic) input cap with a .047uF cap.... could the .1 cap I had hve been bad?!?

Also tried replacing PT2399. Repeats pot still does nothing....

Eero

Ok so no one replied, but I solved the problem... I had mistakenly put in 100pF caps instead of the 82nF and 100nF ones! Works perfectly now, although the board is a bit of a mess with all the soldering/desoldering...