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Re: SB3 tone control

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5/12/2000 8:45 PM

Re: SB3 tone control

That tone control will load down the output of the SB3. I can suggest two options the first is to put a buffer stage between the output of the FETs and the tone control circuit. The second is to scale the values in the tone control circuit. Supposing you still have the 100k pot from the original SB3 tone control: use the 100k pot, you can then increase the 1k resistors to 4.7k, increase the 220ohm resistor to 1k then reduce the 220nF caps to 47nF.

Regards
Rob

5/12/2000 8:48 PM
aron	Rob, Can he put the FET source follower circuit described in Jack's Mini-Booster article in front of the tone circuit?

5/12/2000 9:40 PM
Rob	I'm not 100% sure which article that is (got a link?) but a source follower should work. Having said that, I suspect it could sound different than an opamp version (whether it's better or worse is up for grabs), mainly because the source follower could clip asymetrically depending on the FET used. An opamp buffer will clip more or less like the following tone control. Regards Rob

5/13/2000 2:04 AM
Gord	Thanks guys.....get back to you soon!

5/13/2000 2:15 PM
Doug	>That tone control will load down the output of the SB3. Wait a minute, I thought the TS tone control was an active control. Will that still load down the signal? Doug

5/13/2000 8:10 PM
Rob	Yes, the TS9 tone control has a particulary low input impedance. Active circuits will load things down just as much as passive ones unless you design them specifically not to - _often_ that just means putting in an active buffer. Regards Rob

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