Hoffman Amplifiers Tube Amplifier Forum
Other Stuff => Effects => Topic started by: markmalin on November 17, 2022, 09:10:11 am
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Forgive me guys, this is my first attempt at building a fuzz pedal. I wanted to build a 2 transistor Fuzz, like the tone bender MK1. I bought a pair of Germanium PNP transistors from a vendor, but the schematic they supplied is totally confusing me - the way they have (or don't have) the grounds labeled. I get it that this was an NPN schematic that they modified to wire PNP (positive ground, for lack of a better word). But I don't understand how you would hook up the "ring" on the input and output jacks. I've attached this schematic on top of another that I have for a Tone Bender which makes total sense to me. What was meant by x'ing out the normal ground symbol at the bottom of his schematic and putting in "+ 9V".
Again forgive me ignorance. I was going to wire it up like the Tone Bender schematic until I looked at the piece of paper that came with the transistors.
Also, any reason I can't use a normal 9V wall wart on a Germanium fuzz like this? Is it better to use a battery, or doesn't it matter?
Thank you
Humbly,
Mark
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The red 9V wire from the battery clip goes to the input socket ring connection.
The black wire goes to the collector load resistor supply node, eg the 10k, 1k (and decoupling cap if fitted).
It’s by far best to use a battery. It’ll last a long time.
There’s a lot of ‘ifs, buts and it depends’ with an external power supply.
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The red 9V wire from the battery clip goes to the input socket ring connection.
The black wire goes to the collector load resistor supply node, eg the 10k, 1k (and decoupling cap if fitted).
It’s by far best to use a battery. It’ll last a long time.
There’s a lot of ‘ifs, buts and it depends’ with an external power supply.
Ok, so then the output jack's ring is the same node as the input jack ring (i.e same electrical node as the Emitter on Q1 and the bottom of the 1K Fuzz pot). I guess that makes sense now.
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Don't use a TRS jack for the output. Only the input jack has a TRS jack and its purpose is to disconnect the battery when no plug is inserted into the input jack.
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… the output jack's ring is the same node as the input jack ring (i.e same electrical node as the Emitter on Q1 and the bottom of the 1K Fuzz pot). I guess that makes sense now.
Are you getting the sleeve and ring mixed up?
Like sluckey notes, input socket is TRS, output is TS.
Sleeve connects to the box and circuit common for both sockets.
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Don't use a TRS jack for the output. Only the input jack has a TRS jack and its purpose is to disconnect the battery when no plug is inserted into the input jack.
Ah, that's right. Thanks - this is finally making some sense. I appreciate the help, guys!
Mark