Colorsound Organ Wah + Swell Transistors

joepopp · April 17, 2019, 11:10:23 AM

The battery bonked into into one of the transistors on my Colorsound Wah + Swell and shorted it. I can't seem to find a replacement part number.

It's labeled "MBC 3498"
Any help most appreciated!

Kipper4 · April 17, 2019, 01:24:15 PM

Didn't Dino have a thread about this circuit.

I guess it depends what the transistor does in the circuit.
If we had a schematic and a pointer to which transistor you damaged it would be easier to comment. If'n I get chance I'll google it.

Good luck.

anotherjim · April 17, 2019, 01:44:01 PM

It's a BC349B. I can't help more than that. There are probably many alternatives.
Mind you, in the pic, the leads look twisted together anyway. Take it out and test it? Battery gunk doesn't often short out the parts themselves but more likely to rot the wires off at the body or pcb.

joepopp · April 17, 2019, 01:49:16 PM

anotherjim:
DOH! My old eyes could not see it correctly.

Thanks for the tip!

A guy bought the pedal and it stopped working. I think the battery bashed the transistor and the legs touched together and it shorted.

Joe

bluebunny · April 18, 2019, 02:28:01 AM

Untwist it. Small mechanical shocks won't kill a transistor.

joepopp · April 18, 2019, 08:29:02 AM

I tried to untwist it. No Sound.

I am going to put in 2N3904 listed as a BC349B in this link
https://english.electronica-pt.com/components-cross-reference?ref=2N3904

Will report back!

bluebunny · April 18, 2019, 05:13:15 PM

Quote from: joepopp on April 18, 2019, 08:29:02 AM
I am going to put in 2N3904 listed as a BC349B in this link

Bear in mind that the pinouts are different. 2N3904 is EBC. BC349 is CBE.

duck_arse · April 19, 2019, 11:13:46 AM

Quote from: bluebunny on April 18, 2019, 05:13:15 PM
Quote from: joepopp on April 18, 2019, 08:29:02 AM
I am going to put in 2N3904 listed as a BC349B in this link

Bear in mind that the pinouts are different. 2N3904 is EBC. BC349 is CBE.

it's a litle hard to see in that tiny photo posted, blue, but that particular transistor appears to be a Motorola, with its pins marked, and also appears to be the opposite of the usual BC pinout.

duck_arse · April 20, 2019, 10:53:30 AM

where are my [our] manners - joepopp - welcome to the forum.

joepopp · May 01, 2019, 08:22:38 AM

Sorry for the late reply all.

I did have some 2N3904 lying around and installed them and the pedal now works fine! They are EBC just as the BC349B are labeled. The legs were twisted around so left to right the legs are BCE. Thanks for all of the help. I did source some original motorola BC349B transistors from England just to be true to original circuit. I installed these and didn't notice any difference at all in sound.

I truly appreciate all the help!

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Colorsound Organ Wah + Swell Transistors