Jfet BOZ

... so this pre amp is not suitable where you need to swing voltage up to 2v into a lowish gain amplifier ??
If you don't mind 5% THD at 2V output, you'll be fine.

My BoZ and BoZSE produce 17V p2p of swing before any degeneration of sine wave. I run mine on 27V. I'm using the BL series of jFets.
I suppose you mean JBOZ. If that's so, 17V p2p is 6V RMS. JBOZ puts out 2V with 5% THD at 16V PS. I don't know how much THD you'll get with 27V PS at 6V RMS output, but if you like the sound, everything is fine.

If you mean the old BOZ (with MOSFET) that's another pair of socks...
 
Ex-Moderator R.I.P.
Joined 2005
hey, I can report that I have got a simple jfet boz test amp up and running for my bass guitar

+17.5V before Drain resistor
7.1V measured over it (1250ohm)
-82mV measured over source resistor (15ohm)
carbon film resistors
signal resistors are metal film

needs volume att and buffer
 
Ex-Moderator R.I.P.
Joined 2005
How are you using it?

only one jfet so far
so its just mono, but split to 2 outputs/RCA going to a 2 channel stereo preamp

but hope to have more of them later ;)

dont know if this is of any use to you guys
but for my particular project its clear to me that every gain stage must have its own attenuator to control the gain, and as a result, additional buffer

so to those who have a B1, but desperately needs the additional gain, just put the simple jfet in front of the B1
could be there will be minor grounding issues to deal with
or could just a small ad-on with its own battery supply( I think Nelson also suggested battery)
 
Ex-Moderator R.I.P.
Joined 2005
related power supply
well, I never tried those little 1ohm series resistors, and thought this might be a good moment for it
and I can only say ouch
this happened yesterday, before any of my posts here
I didnt notice at first, but the downwards slide had begun, hunting other 'sound improving' adjustments
which probably gave me a clown award :clown:
but also learned something very interesting

fortunately that sweet sound I had experienced earlier came back instantly when I removed the series resistance
it may lower noise, and some claim quite a lot
but to my ears it definately kills this little curcuit, and what it does best
for me personally, series resistors are out, sorry