Noise problem with Rubidium Reverb/DBA Reverberation Machine

[Addy Bart]

Should I still do an R21 mod or change R20 as suggested above? Also, is the C4/R6 mod needed, given that I am trying to restore treble?

All I really want to do is restore treble and get more pronounced reverb on one of the channels (I guess it's the "sun" channel?)

If this is all you want to do, just swap the resistor (R16 on the PCB). If my YouTube demo is still linked inside the BOM, you can check out how that sounds. I'm sure there are worthwhile improvements on the circuit though.

[aishabag23]

FWIW, I built ..... the Surfy Bear FET Reverb. It uses a regular-sized tank. It sounds really great, but craps out from the over-heating issue many builders have reported experiencing. Such a bummer, 'cuz it really sounds good to me.

sounds interesting. be the one that gets it fixed - start a thread!

Still trying! Not sure what to do, short of installing a fan at this point. The designer of the circuit says the pre-fabbed PCBs have less tendency to overheat, but apparently it can still happen.

[cnspedalbuilder]

If this is all you want to do, just swap the resistor (R16 on the PCB). If my YouTube demo is still linked inside the BOM, you can check out how that sounds. I'm sure there are worthwhile improvements on the circuit though.

@addybart, thanks for reply. I had tried R16 at 5k6 as suggested in the Anthony mod on the build doc but changed to stock value because gain was too high for me. I am amazed at how quiet the pedal is in the YouTube video, because mine is raunchier. The circuit sounds really good if it were an "always on" pedal, but I just need it to have more treble to play better with the rest of my rig.

EDIT: Also, I am not sure why one of the sides has little discernable reverb--from what I can see on other forums, this seems to be a known issue, though I haven't seen any clear solution.

I saw this update on tagboard effects: "Test values between 0 & 10K for R1 to improve Bright Sunshine side."

[anotherjim]

This is what I'd do.
I've kept C12 as 10n and raised both R20 and R21 to 100k. It should be fairly easy to do on the pcb.
If the reverb is too quiet with "blend" maxed, there may be losses in the switched tone networks going into the brick - which can be dealt with.
One other flaw I see is the way all the opamp + inputs are biased by pairs of 1M resistors such as R8 & R9. The flaw is that any noise on the 9v supply is passed to the amp inputs and if the amp has gain, the noise is magnified. The pcb has some power filtering, but a particularly noisy power supply could cause trouble. Still, the work needed to fix that is excessive I think.

[cnspedalbuilder]

Thanks for taking the time to do this. I was going to try out your previous solution but this looks much simpler!

[Addy Bart]

Something that I did later to my build (which is not in the video), is to remove the 470p cap around the gain pot. I just snipped one of the cap's legs to test if I preferred the tone, and I liked how much brighter it became. If you do this carefully, and you don't like the result, you can easily reconnect the leg with a little solder.

Just to clarify, R16 on the pcb is R1 on the vero at tagboards. If I build another, I think I would use 10k instead of 5k6. With the 470p removed, the sunshine side is a bit too loud.

I also added Neil McNasty's layout for the Huminator to get rid of psu whine from my 1-spot. I went through different values for the 100 ohm resistor in that circuit... I think I ended up using 22 ohms. I'd start with that and go higher if you need to. My experience from making 3 of these is if you lower the voltage too much, the Belton brick starts making crazy noises.

[rockola]

Hello, I built the Rubidium Reverb 2.0 from an OSH Park PCB. It's based on the Death by Audio Reverberation Machine. Info on the PCB and schematic here: http://felix.kalium.org/upload/share/builddocs/RubidiumReverb_Builddoc.pdf

I have a different problem: the DPDT switch holes on the PCB are @ 4.0 mm pitch. All the switches I can find are 4.7 mm pitch. Is there a particular switch that would work there, or is wiring the switch off-board my only option?

[PRR]

> 4.0 mm pitch

The switch grid is not square. What's the mm going sideways?