mine works very well too
although a different 2-stage mono version with 2-channel split, for my bass guitar 
Attachments
power supply:
rob vs BoZ 2 - 0
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rob vs BoZ 2 - 0
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the big question:
waiting to build a DAC which is based on the TDA1541, the Boz will be connected to the output of the PC.
I would not use the potentiometer as the volume would be controlled by the PC.
I must to replace the potentiometer 20k of Boz with some component (resistor, capacitor, resistor and capacitor)?
the question comes for not using two potentiometers.
unnecessary in this case.
thanx
waiting to build a DAC which is based on the TDA1541, the Boz will be connected to the output of the PC.
I would not use the potentiometer as the volume would be controlled by the PC.
I must to replace the potentiometer 20k of Boz with some component (resistor, capacitor, resistor and capacitor)?
the question comes for not using two potentiometers.
unnecessary in this case.
thanx
I must to replace the potentiometer 20k of Boz with some component (resistor, capacitor, resistor and capacitor)?
no, you have 1k in series, and 1M to ground
unless you have too high output from DAC, and is overdriving your jfet Boz
mine works very well too
Sorry, might be a fault thought from my side, but if you turn the 10k pot up for full volume, the JBOZ in the first stage will only see 660 R to ground. This is a little low, I think it will give you "real Distortion".
My intention is always to try that the stuff I built works with every setting of the knobs - I often tend forget the boundary conditions by the time...
Just my 2ct.
Best regards
Flo
maybe close, but maybe you forgot the 330ohm in series to ground ?
yes, there is a little distortion at full volume
but the gain so excessive I have to use a buffer with further attenuation
anyway, I have tried other resistor combination on the pot
all sound differnt
this one is so far the best
also because this special resistor 'curcuit' seems to interact better with the following balance pot, making it work more
but no, its far from ideal, and just a proto to see how it works
most are random components I found
but it works, and I havent been able to kill it yet
tough little amp
then you don't need the gain, but could do with a unity gain buffer, like the B1
but you can try with a simple voltage devider instead of the pot
its basicly the same just with a fixed setting
or you could use switch with a few optional settings
if you look at your pot(schematic), you will notice that its basicly just two resistors changing value
when the series impedance goes up, impedance to ground goes down
and your load impedance and pot value is the sum of both
so I will suggest you replace the pot with a 3 or 4position switch mounted with fixed resistor attenuation
No, from the wiper to ground there are two 330R in series, 660R in total. Just wanted to avoid a bad surprise on your side... (I already had surprises like that)
If the gain is too high for your needs, I would have added a resistor of some kR before the 10k pot.
Best regards
Flo
you are right...thanks
but so far its no problem
basicly the red marked resistors are only there for the following balance pot
or else it doesnt work enough
the balance pot is the real wrong part of this
should just have been two attenuators instead...but this was an experiment to make simple balance control, and not to be copied directly
next one will be better
i don't know what is wiper.
the wiper is the variable pin from your pot, the one marked with an arrow in schematic
but if its your PC, I wouldn't mess with that
forget what I said about resistor on pot
your real problem is way too much gain
looks like this now
replaced the 330ohm to ground with a 680ohm
tried other resistor combinations
also the 'ordinary', and with bigger resistors
all resulted in more distortion
also looked at where I could place a cap
works exstremely well like this
not exactly sure what it does, other than lowering impedance with rising frequency
but the result is that the balancing pot is much more effective now, and adjustments very audible, and easy
turning balance pot change the sound from dry to airy, and thats about it
well, guess I should say, one output is driving the bottom end, and other channel the top section
and from now on it belongs in my bass guitar preamp thread
Attachments
looks like this now
replaced the 330ohm to ground with a 680ohm
tried other resistor combinations
also the 'ordinary', and with bigger resistors
all resulted in more distortion
also looked at where I could place a cap
works exstremely well like this
not exactly sure what it does, other than lowering impedance with rising frequency
but the result is that the balancing pot is much more effective now, and adjustments very audible, and easy
turning balance pot change the sound from dry to airy, and thats about it
well, guess I should say, one output is driving the bottom end, and other channel the top section
and from now on it belongs in my bass guitar preamp thread
O.k. then you are going in the direction of 1k for full volume. Not much for the JBOZ but in every case better than 660R.
Did not realite that your schematic was built for your bass guitar preamp. For stuff like this, anything goes. As long as it does not damage the gear. For music playback, I think we should avoid distortion to a decent degree.
I used to play the bass guitar too, so I know, that you sometimes need a lot of "good" distortion
Have fun with it!