Vox McCoy Transistors

[vanessa]

Thanks for all your help about the caps!

I was wondering if there was any difference between the 2N2222A transistors and the BC109's. I have heard that the originals had BC109's.

I was looking for a replacement for the BC109's and I saw that mouser shows a cross reference to them as the NTE123A and the 2N2222A's. The later are cheaper. Looking at each ones chart (for the BC109 I used the Philips BC109C specs, and for the 2N2222A I used the Central Semiconductor specs) They all seem to have the same gain values. Is there some sort of tone difference between them?

:?

[R.G.]

For any transistor with similar gains, it is highly unlikely that you'll be able to hear a tone difference.

[phillip]

For McCoy transistors look for a pair with gains between 300-350.  Take the one with the highest gain and put it in the Q1 position.  The one with the lowest gain goes in the Q2 position.

The lower gain helps to enhance the bass a little so it's not so shrill like ones with high gain transistors like MPSA18.

Phillip

[R.G.]

The lower gain helps to enhance the bass a little so it's not so shrill like ones with high gain transistors like MPSA18.

Can you tell us how that happens? What about the lower gain enhances the bass?

[bwanasonic]

If you socket the transistors, you can conduct your own experiments on which transistor sounds best at that particular moment. Sometimes while playing my electrics unplugged, I can convince myself I hear a difference between having the neck or bridge pickup selected! This is not a claim of super hearing, but a statement of how subjective hearing is.

Kerry M

[dadude]

Wow you can hear a difference between the neck and the bridge pickup when your guitar is unplugged??? You must be part Great Dane! LOL Just messing with ya Kerry.

[jrc4558]

Or you could always use generic 2N088 (lower noise than 2N2222 or BC stuff) and install a 1K trimmer on it's emitter instead of the resistor.

[Phorhas]

I have a real 1967 Vox wah and Q1 is indeed a BC109, but Q2 is some kind of dome-topped thing... I can't make up the writings on it.

For any transistor with similar gains, it is highly unlikely that you'll be able to hear a tone difference.

Experiments are always a good thing. for Q2 there will be no real impact on tone, since it is a buffer, but Q1 can indeed change the tonal character. I hear real differances between trannies in some circuits, in a fuzz face in particular. there are audiable differances between BC109c, B549c, SC1815, 2n5089, and I'm sure there are more, I just recently tried these.

My 2 cents