chris.knudson
Well-known member
Handy for that too. I didn't even think about the USB on the CIOKS - I usually just use that to charge my phone during gigs.
What's on the workbench?
- Thread starter PedalPCB
- Start date
Nostradoomus
Well-known member
Same haha. If there’s no secure spot to leave it otherwise.
chris.knudson
Well-known member
Very clever.
kanengomibako
New member
I am relieved to know the diode model number clearly.
Actually, the one I analyzed had "D1" open (before analysis). I wonder if this is a coincidence...
Robert
Reverse Engineer
Ahh now that's suspicious. I also measured across the clipping diode pair before removing the epoxy (from R6 to VREF) and it was open in one direction.
The diode appeared to have been intentionally crushed when I removed the epoxy.
I just assumed "Ahh well, maybe I broke it?" ... but that bothered me because I didn't use excessive force or enough heat that should have damaged the glass...
Since yours was also open that makes me wonder if the diode is a decoy, especially when taking the decoy transistor into consideration.
The pedal sounds completely different and the Gain control is much more manageable without that diode in circuit.
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kanengomibako
New member
Hmmm, we need to find out if another one has asymmetric clipping...
jimilee
Well-known member
Crushing a decoy diode seems excessive to me. I wonder the they have broken ones laying around and use those.
Bricksnbeatles
Member known well
Unless they don’t know it’s a decoy diode. Maybe when developing it they broke a diode and they were like “omg! I discovered tone gold! The secret to a good crunchy tone is to crunch a diode,” not knowing that breaking it just makes it as if it’s not there at all
Except that it's now an ungrounded tiny antenna
chris.knudson
Well-known member
Does that by chance use an LM3914?
Robert
Reverse Engineer
It does, for now anyway.
chris.knudson
Well-known member
I have a whole bunch of them -- been looking for a project to use them on.
Erik S
Well-known member
chris.knudson
Well-known member
They can be photoshoped back in...
It lives! It doesn't squeal, whine, or hum! 3+ days off and on over these snow days (education has plusses and minuses) and finally sussed it out. Sushibox SmPS for plates (220, which is lower but fine) and a separate 12vdc supply for filaments and the Arduino for switching and LCD screen
3 Marshall preamp channels:
Parallel triodes 18watt with individually biased cathodes (lite iiB style)
Plexi with an M/N taper fader between dark and bright channels
Modded JCM800 from ampgarage ideas. Brighter but mean
This is a proof that I can do it. So now, on to the 4 channel Fender preamp, and then other fun preamps. You don't want to see the front - it's a repurposed telecom rack chassis from work
3 Marshall preamp channels:
Parallel triodes 18watt with individually biased cathodes (lite iiB style)
Plexi with an M/N taper fader between dark and bright channels
Modded JCM800 from ampgarage ideas. Brighter but mean
This is a proof that I can do it. So now, on to the 4 channel Fender preamp, and then other fun preamps. You don't want to see the front - it's a repurposed telecom rack chassis from work
Attachments
I have one pedal I need to bug fix with a similar “pcb mounts tube upright, but lay it down with wires across the pcb” - squeal city - how have you managed it!!
