@cybercow
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Fair enough. I’ve found that there is ZERO advantage to using a 308 in place of an OP07 – they are pin-for-pin and sonically identical.
Good luck!
So now you’ve built out a second Rat without any mods? If so, from where was the chip acquired? I would suspect the chip if building a 2nd one and getting the same results. Or quite possibly the same wiring error. Wiring errors are the easiest to trip over. Good clear photos of the second build?
Moriearty – admittedly I often get confused by textural descriptions of switching configurations. I always rely on visual affirmations when wired. I also leave a bit of extra wire if they are backwards when I first mount them so they can be rotated 180º if need be.
Sounds like you have toasted the FET. If there is +9v on the Drain of that FET, then it may indeed be bad.
Moriearty – your switch query is correct. When the toggle bat is to one side, the opposite side lugs are the lugs actuated (connected).
So yes, a lever (toggle bat) would push the contact to the <i>opposite </i>side.
The density of the wiring prevents me from making out what you’ve done with the Reutz mod. But I don’t think an error there would prevent the distortion from happening.
You could work your way backwards with signal tracing and start by checking if the center pin of Q1 (2N5459) has the proper signal. If there’s no signal there, check the left pin of Q1 for proper signal.
And in the photo, it appears that C10 may have been melted a bit in the top left corner. May want to dbl-check that too. (If you have proper signal at th center pin of Q1, C10 may be the culprit.
Oh, and as always, please verify that the voltage supply is indeed ~+9v.
Let us know what you find.
Years later I am still amazed at this project build. Not something one would want to do multiples of. Wonderful and ingenious concept.
We can better assist if you can provide some good clear photos of both sides of the PCB and all the wiring.
Meanwhile, based on your voltage measurements, there is definitely something pulling down the main supply rail. Try removing the ICs from their sockets and test the voltage supply points. If the voltage supply comes back up to where it ought to be, then you have a bad IC.
Make sure the 78L05 is producing +5v. And check the pin #5 socket of IC2 to ensure it reads ~+4.5v (½ of the incoming supply).
Joe – in my experience with the SWAH v5, (I’ve built a couple), I find that 47K works best. Regardless what the image in the build doc sys, follow the BOM – or better yet, read all the detailed notes in the “Build Notes” and “Mod Ideas” sections.
In my SWAH v5 build document, R27 is 7K9 in all three places (BOM, schematic and build image).
Neither R17 nor R27 are going to affect the voltage supply. “VA” should be the supply voltage at +9v. “VB” should be one half of the supply voltage at +4.5v. And “VC” should be +5v.
Greg – pretty there is a wiring diagram for the Tap-Tempo in the Tap-Tempo Build Document. I have a wiring diagram in my copy.
The Tap-Tempo build doc is here: Tap-Temp Build Document
I know the wiring diagram is for the D’Lay V2, but it’s easy to transpose the connection points. The Tap-Tempo “PT6” point still goes to R22 on the DLay board. Just leave out the “Time” pot & R22, and connect the Tap-Tempo “PT6” point to lug 2 or 3 of where the “Time” pot was supposed to go.
You can use a separate 78L05 regulator on the Tap-Tempo and supply it with +9v – OR – you can tap off the output pin of IC3 (“VB” on the 78L05 regulator) of the DLay board. If you use the “VB” jumper from the DLay board to the Tap-Tempo board, you can leave off IC3 on the Tap-Tempo board and jumper to the “VB_IN” point on the DLay board. V3 of the DLay does NOT have the “VB” conniption point, so you need to take it either from the output pin of IC3 (78L05) or from the anode of D2. (The anode of D2 is the side closest to C14.)
The Tap-Tempo board does NOT take a 3PDT stomp – it takes a 2PDT stomp. And yes, each board needs its own stomp. So the enclosure will have two stomps affixed to it in the end. They are just two different stomps – one 3PDT (9 lugs) for bypass on the DLay board and the one for Tap-Tempo is 2PDT (6 lugs).
Hope this helps.
Moriearty – most ceramic caps have about a 20% tolerance, whereas most film caps range between 10% and 5%. Other than that, as long as the voltage ratings are sufficient, there is no sonic difference. The only caveat to using ceramic caps is (in my experience) power supplies and timing circuits. Electrolytics are best for power supplies and films are better in timing (clock) circuits.
Moriearty – I don’t recommend a 100K pot for the Reutz mod. I’d stick with the 100R pot.
I’ve played around with the Reutz mod a good bit and find it really does make a difference. IMO, using a 100R pot in a custom expression pedal would garner the best of several worlds for the Reutz mod. A custom expression pedal with a 100R pot allows the foot to sweep across the 100R value for an interesting Rat build. Kinda like a Rat-Wah.
I never did do up a custom expression pedal. But I did find that if I really want to have a settable Reutz mod, an external 100R pot seemed best. That way, I could easily just tweak the Reutz pot. 100Ω is not much of a sweep. But in the Reutz mod it really does affect the tone.
You can do the Reutz mod anyway you like. I just think having a Reutz pot and a toggle switch is redundant. The switch does the same thing as turning the Reutz pot, if installed.
SammyD – Quite likely it will be difficult to do with a standard 4-way switch. How many poles does it have? Without a push-pull pot (or complex multi-pole, multi-throw switch) to provide that added switching dimension. Look for guitar wiring forums on FB or the web. Maybe try these sites that do all types of pick-up wiring . . . .
Good luck!