switching transistors

[BEMUSofNrthAmrca]

Do any of you own a pedal with a socket for switching transistors?

I've got a treble booster which allows me to switch out germanium PNP resistors. It was one of Scott Humphreys first Vitamin G prototypes, so it has sockets for the transistor and a few of the capacitors.

So far I've tried an AC188, NKT275 and I just recently tried out an old GE-1 tranny. All have slightly different sounds. The GE-1 seems to be the loudest and most aggressive, which is weird because I took it out of an old Radio.

It's a lot of fun.

 

[mmcm4]

Switching transistors usually isn't effective because of varying bias points. This system looks very practical for switching clipping options (not suggesting you buy one, but the idea is neat): http://www.farndurk.com/index.php?product=toneplugsystem1

 

[whoismarykelly]

Bias points in rangemasters arent especially sensitive. Generally a higher gain transistor will give more volume and grit.

 

[Structo]

The transistor sockets are pretty much standard equipment on DIY pedals or pedal kits.
And since Ge transistors are so unpredictable in how they will sound, it is needed to roll a few
transistors through the pedal to see which one performs and sounds best.

For those that want to do this, be sure to double check the transistor's polarity.

For example, the AC 188 is a PNP type transistor so the pedal most likely has a positive ground.

While the AC187 is a NPN transistor, using a negative ground.

It seems when manufacturing Ge transistors back in the day, the PNP were easier to make so there is a lot
more of those around than the NPN transistors.

 

[BEMUSofNrthAmrca]

Thats why I was sure to check whether the GE-1 I found was PNP or NPN.

Theres a few more PNP Germanium transistors I'd like to try in this booster.

I find the NKT275 pairs very nicely with my NKT275 Sunface. It works out almost like the Sun Lion. But I like the way this GE-1 pushes the tubes in my tube amp. This booster is great for making notes stick out when playing big full chords, and with the GE-1, this happens even more so.

 

[frankie5fingers]

Try an OC44 or OC170. Here's a datasheet comparing a bunch of the old Mullard and Newmarket transistors. Some of them can impart some real magic in a treble booster.
http://www.datasheetarchive.com/OC44-datasheet.html#

 

[BEMUSofNrthAmrca]

Cool. Thanks a lot for that.

I've since switched back to the NKT275 in my rangemaster style treble booster.