Building a Rangemaster; need a Germanium PNP tranny...

[Miza]

Gonna build some pedals over summer. Got all the bits for a DIYGuitarPedals' ToneMaster http://www.diyguitarpedals.com.au/shop/ ... r_V1.2.pdf, except the PNP transistor.

Anyone got anything suitable they'd be happy to part with for a not unreasonable sum?

Also, I have some cheaper silicon ones, 2n3904 and 2n5088 that I could use, but would I be wasting my time using these?

[Kev77]

Any use?

[Darth Sabbathi]

I have an OC44. No idea if it's any good, but in theory should be the thing... Yours if you want it.

IMG_2157.jpg (87.22 KiB) Viewed 3289 times

[Snarblinge]

you can use many transistor types in there, the two you have can work and if they are what you have, then I'd build with them. especially if you are learning, don't practice on a rare germanium transistor without using sockets.

that said, the circuit and instructions call for a pnp transistor. to use an NPN in there instead, you will need to reverse the polarity of the power supply, and any polarised caps. you will also need to check the pinout of any transistor you use, against the one(s) recommended in the build doc.

[Miza]

I have an OC44. No idea if it's any good, but in theory should be the thing... Yours if you want it.

IMG_2157.jpg

Thanks man, yeah I'll take it.
I'll PM you.

[Miza]

you can use many transistor types in there, the two you have can work and if they are what you have, then I'd build with them. especially if you are learning, don't practice on a rare germanium transistor without using sockets.

that said, the circuit and instructions call for a pnp transistor. to use an NPN in there instead, you will need to reverse the polarity of the power supply, and any polarised caps. you will also need to check the pinout of any transistor you use, against the one(s) recommended in the build doc.

I will definitely use sockets for the transistor, and probably for C1 and C2 as they set the upper and lower values for the tone knob.
I'll test it with a cheaper tranny first too.
The DIYGuitarPedals circuit uses a power inverter (charge pump) to allow normal neg-centre power supplies to be used, which I gather means a PNP transistors must be used? And it looks like an OC44 is PNP anyway?

[Miza]

Any use?

Thanks Kev, think I'm ok for diodes. Cheers though.

[Snarblinge]

yeah I think you are sweet with oc44, just if you want to make with the two you have, youll need to flip everything. as they are npn

[Miza]

yeah I think you are sweet with oc44, just if you want to make with the two you have, youll need to flip everything. as they are npn

Oh right, good to know, thanks!
So anything that starts with 2n is typlically NPN?

[sizzlingbadger]

yeah I think you are sweet with oc44, just if you want to make with the two you have, youll need to flip everything. as they are npn

Oh right, good to know, thanks!
So anything that starts with 2n is typlically NPN?

no, it means two junctions, diodes are often 1N as they have 1 junction.

From Wikipedia
The first semiconductor devices, such as the 1N23 silicon point contact diode, were still designated in the old RMA tube designation system, where the “1” stood for “No filament/heater” and the “N” stood for “crystal rectifier”. The first RMA digit thus was re-allocated from “heater power” to “p-n junction count” to form the new EIA/JEDEC EIA-370 standard

[Miza]

Cheers - I have much to learn.
My first pedal (Tayda TS808 clone) worked first try, giving me undeserved confidence I know what I'm doing.

[Marshmallow]

These are fun builds! good luck with your build. I used OC44 for mine. Here are some photos to help you out!

[Miza]

Looks great. You've gone for the classic rangemaster box/look? So will that sit on top of the amp?

[Miza]

And finished.

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[Miza]

Worked first time. No issues.

Tight squeeze getting everything into a 1590a enclosure though. Took a bit of force. Won't be rushing to do another one this size.

Thanks to Darth Sabbathi for the OC44!