Hoffman Amplifiers Tube Amplifier Forum
Other Stuff => Effects => Topic started by: Shack on August 16, 2016, 05:39:02 pm
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my TS9 is a 90s model with a maxon board and the wrong op-amp in it, but it hasnt worked in years.....id like to fix it rather than buy a new one.
I suspect the LED is shot, and im not sure if the switch is the issue or the LED......or the transistor bypass system...I put power to it and plugged a cable to the input, and have 9 volts at the anode of the LED, and my signal goes through the pedal, but doesnt change when I hit the switch.
I would love to mod it to an 808, but wont attempt it until I have it working. Does anyone have advice about what to do with this, id hate to throw a 100 dollar pedal in the trash if theres a chance I can bring it back to life, and my solid state electronics knowledge is limited.
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You can test the led with a diode mode tester on a DMM. Also most op-amps have a block diagram that can help you test them, they behave a lot like a diode at rest and if you know which legs to test in the right order you can confirm if they're passing the diode test as well, if I recall. (I've seen a video on this, but don't recall when/how so I've never done it myself). If you can rule out the diode, then it may be the op-amp anyway. Usually good design puts the led in a separate path so that even if it is 'out' the circuit should work, but that may not be the case.
~Phil
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I would guess it is the switch. I have never seen anything but the switch fail in these and I have seen a lit of these. Try jumping the switch first.
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yea, thats what ive suspected all along. so glad I didnt just throw it away years ago, thx guys