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Old 9th February 2013, 01:29 PM   #1211
tinitus is offline tinitus  Europe
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Quote:
Originally Posted by robertor View Post
1 step and already sounds, second step and it sounds too strong.
to prevent this, or use an 20k input pot or what?
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
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Old 9th February 2013, 03:02 PM   #1212
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Quote:
Originally Posted by tinitus View Post
try mount resistor from wiper to ground
i don't know what is wiper.
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Old 9th February 2013, 03:02 PM   #1213
Floric is offline Floric  Europe
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Originally Posted by tinitus View Post
maybe close, but maybe you forgot the 330ohm in series to ground ?
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

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Old 9th February 2013, 06:22 PM   #1214
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Originally Posted by Floric View Post
Just wanted to avoid a bad surprise on your side... (I already had surprises like that)
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
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Old 9th February 2013, 06:26 PM   #1215
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Originally Posted by Floric View Post
... I would have added a resistor of some kR before the 10k pot.
forgot to try that too will see what it does, thanks
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Old 9th February 2013, 06:28 PM   #1216
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Originally Posted by robertor View Post
i don't know what is wiper.
wiper is the center pin of the pot.
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Old 9th February 2013, 06:31 PM   #1217
tinitus is offline tinitus  Europe
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Quote:
Originally Posted by robertor View Post
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
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Old 9th February 2013, 06:40 PM   #1218
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ok, thanks tinitus, thanks guys.
I tried this Boz, which I think is great sounding, but the B1 will jump in my audio set up.

but......stay tuned.
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Old 10th February 2013, 05:47 PM   #1219
tinitus is offline tinitus  Europe
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Originally Posted by Floric View Post
.... 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".
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
Attached Images
File Type: png bass pre fet front att balance.png (33.3 KB, 367 views)
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Old 10th February 2013, 10:58 PM   #1220
Floric is offline Floric  Europe
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Quote:
Originally Posted by tinitus View Post
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!
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