cool reverb apart from switch spdt 'pop' issue

[samhay]

The bottom of R10 goes to Vb and the (-) input of IC3b should not be connect to R10 or Vb.

[deadastronaut]

ok, i just stripped off my breadboard and started again to tidy things up a little..

i now have this...but no reverb at all...is this ok....i'll double check everything in a mo.

R13 ok? vb at pin 9 0k?.

edit: just checked, sound but no reverb at all..

[slacker]

You need to switch pins 9 and 10 IC2c.

[deadastronaut]

cheers ian,. done that, still no verb..

how is pin 12/13?.

[slacker]

Sorry missed those before, yeah they need flipping as well.

[deadastronaut]

am i losing it or am i back to were i was before i tried '' non inverting'' ?

arghhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh my head...

just to clarify i was trying out 'non inverted' ...even though i have no idea what effect or trouble that ''inverted' may cause if any....


the window is looking very promising..

[slacker]

No the crucial bit is IC3b, that is now non inverting, so bypass/dry is now not inverted.

[deadastronaut]

ahhh i see...cheers man.

[deadastronaut]

righto, so this should work ok then?..

just asking as i'm not getting verb...but i'll check my breadboard over again..(hows that sw2)

[slacker]

Looks fine to me, I think you want a cap before the wet/dry or connect the pot to VB instead of ground, don't think that would stop it working though. I'd get it working at the output of ic2d just in case it is the output stage that's causing problems.

On the inverting question, if you only use tails bypass then in a "normal" signal chain git >> pedals in series >> amp then there's not really an issue. The signal will always be inverted, but there aren't many scenarios where that matters.
If you use true bypass though then in bypass the signal is not inverted and when you engage the effect it inverts, this might cause some problems, I can't think of any off any top of my head though.
It's really only a problem if you start mixing signals in parallel then you can get cancellations if the signals are out of phase.
I think it's generally just good practice to keep the dry signal "in phase".
Before anyone starts on me, Yeah I know the Echo Base is inverted

[deadastronaut]

right i have it working...sort of.. (as above schemo)

but its no where near as full and as much feedback/decay as before...with C20 at 1uf, i get hardly any verb at all...dropped that to 100nf, but still moody..

and feedback/decay is cut short.....even when i change 33k to 22k...which oscillated like hell before...and feedback pot hardly does anything.

when i have wet dry pot to ground...with 100nf instead of 1uf wet dry works.

but if i put that wet/dry pot to vb, the switch pops like f...

also bypassed (sw2) is way louder than when verb on.

so still a few niggles..

[samhay]

Increase R6 for more wet volume.
You don't want the wet/dry pot to Vb. You may want this pot to be 100k though.

[deadastronaut]

morning...been blown away yet...was a nasty storm down here..

changed R6 to 47k..bit better..if i put it up to 100k it blows the ass out of it (mass distorts)

something defo not right with the feedback though, its gone like the problem we had with some of those earlier mods...really cuts off quick.

hardly any decay at all really.

[samhay]

Got a bit damp this morning, but I seem to have been far enough north to miss most of the wind. Hope you are keeping out of the worst of it.

Perhaps try increasing R9 instead of R6 - this will bump up the gain after the brick, rather than before it.
Does the feedback still cause oscillation when the effect is on?
If so, the feedback loop is ok, but the bypass switching needs more work - perhaps try removing (or lowering) R3?

[deadastronaut]

''Does the feedback still cause oscillation when the effect is on?''

no not at all...dies off very quick,

i can adjust R3 to a higher value whichgives a louder output, but at the cost of the reverb being quieter..

[samhay]

what happens if you set R3 to be e.g. 47k?

[deadastronaut]

just makes overall level a bit louder..

[samhay]

Is the overall level the bypass level, the level of the effect, or both?

[deadastronaut]

Is the overall level the bypass level, the level of the effect, or both?

both.

[samhay]

ok. I think this is the time when we start to appreciate why mixers usually use inverting op-amps.