Rangemaster - two builds, completely different sound?

[nils]

Hi there!

After I heard a friend's rangemaster clone I thought, shoot, why not, and put one together. I didn't really need one, but it's simple to build and sounded like a bit of good clean fun . To my surprise the two units sound completely different even though they only differ in two points: The input cap and the transistor type.

I used a flip switch to select 3 input cap settings (2.2nF, 5,5nF and 9nF) and a EFT83C. My friend's unit has a fixed 7.2nF and an AC122 or AC128 (I'm not sure). While his unit sounds thick and rich, mine just sounded thin and weak. I've played around a bit with the input cap (actually I put in sockets so I can swap them out when I try it at the rehearsal studio next time) and ended up with values somewhere between 20 and 30nF, and now it seems to be OK-ish. What exactly is the reason this is so? It it really just transistor variation (had no chance to try a different transistor yet), or could I have done something wrong on an easy build like this ? I expected some difference in sound, but not a huge one like this.

Any opinions?

[nils]

oh, wait, there's another difference: I also added a reverse polarity protection diode across the PSU. But I don't really think THAT's the problem

[MartyMart]

Yup, transistor type makes a HUGE difference, even two AC128's will have a different "tone"  !!
Coupled with other cap changes, you've got a different beast
I like a standard Rangemaster, but one with say 20n - 47n caps is full range and can add
a nice "growl" !
Or, just switch them .....

Marty.