FiveeveN has linked to the answer, wise to read it.... But I assume your having trouble working out how to run this on a single supply? I'm adding a quick edit of Rods circuit which should help. Everything in between the input Caps and output cap runs at Virtual Common or Half supply. Caps are likel...

Does turning the speed knob effect the speed of the ticking?
Phil.

Thanks Mr 57, Brilliant explanation, Wish I knew this years ago.
Phil.

Maybe check that Transformer, I can't see enough but it looks like the Tx has 6 leads and the back of the PCB shows all 6 soldered.
The center lead on the primary should be left open, (as per schematic) if it's grounded them you would loose a lot of volume.
Phil.

Have you tried this yet?

Common (neg of your 9V pedal PSU) goes to the MAINS EARTH terminal.
Do not rely on alloy case for ground return.
Phil

Oh dear :shock: Well if there is that much damage then for sure you have carbon particles all around that area which could well be creating a pathway for the hi voltage to trace through. Sounds like you will be forced to rebuild the Board if you want it to be reliable. :( This is why you see flame p...

Remember electrons flow to the Highest voltage potential. :hmmm: Any power Valve would burn through the screen rapidly if the Plate voltage ever falls lower than Screen voltage. As the amp is old the plate pin might be arcing across the socket somewhere which will pull plate voltage down. And I woul...

Oh dear, As the Amp has already had Screen grid issues then the sockets may have hair line carbon traces (which you can't see) and once that happens it's likely the new tubes will arc again along the same path, in which case it's a Socket replacement. Also worth note is that EL34's are notorious for...

If you are going to run mains to a metal case (your module one I presume) Then For safety reasons alone you definitely need to tie the mains earth to that metal case otherwise it could be deadly if something goes wrong. :twisted: As *mauman* already noted, post a layout or picture of the setup as th...

Hi Kiltro, An LM7809 would have no trouble dropping 9volts, They are rated up to 1Amp. FWIW, I use a Laptop power supply which delivers 19VDC at 4Amp and then use an LM7809 for the lower voltage pedals. IIRC I just added a series 220R resistor before the Reg chip and a small heat sink to be on the s...

Thanks phatt, excellent info. I think the pulldown resistor in the input is just to stop the switch from clicking from capacitive buildup of voltage since the LED is also going through it, or maybe backwards charge potential on the input cap, I remember popping being some issue with it. Yes R1 is j...

Glad to hear it helps you Manfred, The sensitivity of the input is the issue. Remove R1 as it's likely irrelevant,, R2 is the dominant load. Try looking at it this way. As *mictester* noted the input Z is way too low to be useful for guitar. OK you change R2 to 1Meg and you raise the input sensitivi...

My only issue(s) with this design is that I would have made R2 a larger value, to raise the input impedance to prevent loading on either the previous effect or the guitar pickup. I've also been wary of exposing op-amp FET inputs to the outside world - they can be more susceptible to static than a s...

As you have built some Rat circuits, I would try putting a simple buffer in front. Just look at Tube screamer for clues. Or as mentioned, try another opamp. As for the guitar treble bleed trick yes it can help but there are other things you could try. I swap the tone side of my Strat switches which ...

I see it drawn as a Variable Resistor and as such it would effect the output volume, at least down to the value of R22 If If pin 1 was grounded (bypassing R22) then at zero the output would be nil, a dead short across the signal path = no sound. I've seen this Variable Resistor idea used as Volume c...

No, it's a fair bet it's just a silicon diode used for reversed polarity protection.
D4 most likely blew because some one used a reversed plug supply. opps

Glad to help,, if you want more distortion then reduce the value of R5, Below 10k will likely cause problems.
Phil.

I would just replace D4 and see if it comes to life.
Phil

Yep sims although not always perfect can certainly help you find how/where tone is won and lost. You can try this out but understand I've not built this circuit but having built many similar circuits over many years It a fair bet this should work & sound better. If you want more bass make R9 56k...

Hello, I just simulated your circuit and I'll add my observations; Input Z is very low for guitar, You are likely better served by making U1 a buffer input as you can make up gain in later stages. Regards the tone problem; You have little treble response. the issue seems to be partly due to C2 &...