All Test Devices ATD - PB-1 Transducer Pre-Amp/Booster [schematic]
- modman
- a d m i n
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https://www.linkedin.com/in/richard-mintz-67603124
They even built stuff for Maestro...
I had never heard of this company, headed by
They even built stuff for Maestro...
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- theehman
- Diode Debunker
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I think I may have their volume pedal. I'll check tomorrow.
Ron Neely II
Electro-Harmonix info: http://electroharmonix.vintageusaguitars.com
Home of RonSound effects: http://www.ronsound.com
fx schematics and repairs
Electro-Harmonix info: http://electroharmonix.vintageusaguitars.com
Home of RonSound effects: http://www.ronsound.com
fx schematics and repairs
- Manfred
- Tube Twister
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Here my guess of the schematic in accordance with the PCB shown above, as far as the components could be identified.
- Manfred
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I'm sorry, I drew the circuitry wrong, here the corrected schematic:
- Manfred
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Why the hell does the edit function sometimes not work?
C2 was still incorrectly marked, here again the schematic:
C2 was still incorrectly marked, here again the schematic:
- soulsonic
- Old Solderhand
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Nothing to do with this, but woah...can't help but notice the "British Steel" looks almost the same as the Paranoid
"Analog electronics in music is dead. Analog effects pedal design is a dead art." - Fran
- Manfred
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I found out that the right transistor is an E201 JFET due to the case color, this is the predecessor of the J201 JFET.
I ran a simulation of the circuit with a J201 and a 2nN5088 transistor choosing the unknown capacitors so big that they have no influence on the signal.
The circuit works fine with these both transistors.
The maximum gain of the booster is 10 as expected,this is determined by R9 divided by R3.
I ran a simulation of the circuit with a J201 and a 2nN5088 transistor choosing the unknown capacitors so big that they have no influence on the signal.
The circuit works fine with these both transistors.
The maximum gain of the booster is 10 as expected,this is determined by R9 divided by R3.
- Manfred
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Thanks, you are right.Intripped wrote:R1 looks like 470k and R3 6.8k
Sorry, I probably copied the part in the layout and forgot to change the value.
The simulation gaves a gain of 2.9 with the corrected values.
Here the corrected layout and schematic: SprintLayout6.0-file:
- idy
- Breadboard Brother
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Any insight into the feedback(?) between the two transistors, R9 and C2?
- Manfred
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C2, R9 and R3 form the negative feedback loop.
The gain Au = Ao/[1+A0*R3/(R9 + ZoutStage2)]
Ao is the open loop gain when R9 and C2 are omitted.
The gain Au = Ao/[1+A0*R3/(R9 + ZoutStage2)]
Ao is the open loop gain when R9 and C2 are omitted.