Pars
Can Jam '10 Organizer
- Joined
- Oct 28, 2003
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Quote:
The BJTs are quite cheap, as in ~0.13 to 0.19 each, so I would get alot more than "a couple extra" in order to ensure some decent matches. The FETs on the other hand are rather expensive. If you can swing one extra pair, do it. Socketing these, as Dan said, will make it easy to swap out to get the best uncompensated match you can before you start in on the pots and LEDs. I would concur with Dan that putting the 10K pot in parallel with around a 550 or so ohm resistor (instead of the 500 ohm) will give you close to the full 500 ohm adjustment range (and I did run into this being a slight problem on one amp once).
| Originally Posted by robzy A huge thankyou to both Garbz and dgardner! Not only do i now know how many trans to order but also have a better understanding of the circuit 
Now i just gotta make sure that all the trans come from the same gain class and im set! (Im gonna get a couple extra just incase one of them is wwaayy off i think). Ohh... one thing i just realised - would unmatched JFETs also be fixable with the current bias? And if not how many would i need for a decent match...  Rob. |
The BJTs are quite cheap, as in ~0.13 to 0.19 each, so I would get alot more than "a couple extra" in order to ensure some decent matches. The FETs on the other hand are rather expensive. If you can swing one extra pair, do it. Socketing these, as Dan said, will make it easy to swap out to get the best uncompensated match you can before you start in on the pots and LEDs. I would concur with Dan that putting the 10K pot in parallel with around a 550 or so ohm resistor (instead of the 500 ohm) will give you close to the full 500 ohm adjustment range (and I did run into this being a slight problem on one amp once).
