post here where the DIY gurus lives: my dual bissell eats V!

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Mr White
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post here where the DIY gurus lives: my dual bissell eats V!

Post by Mr White » Sat May 02, 2009 11:50 am

as I said I post here because maybe I can get little help from you DIYers :hail:

just got my Dual Bissell Generator a couple of days ago and love it!!!!

but testing it I found something that i dont understand, it seems a fault but I'm not sure:

when I use it to process GATE or CV no problem it behaves normally.

so I tried it to do some glide/portamento like effect and I noticed that when i patch it between my RS140 & a VCO, with all knobs set to not affect incoming signals in every way, pitch change (VCO frequency decrease a little), it seems that it eats away some Voltage!

so when I use it I have to manyally adjoust the VCO to the "new" pitch to match....

I think at this point is for sure a faulty component, anyone that can help me find a way to spot it and fix it??? :hail:

thanks! :hail: :hail: :hail:

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BugBrand
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Post by BugBrand » Sat May 02, 2009 12:25 pm

Is the tracking still correct? ie tracks fine, but is offset by some cents..

If so, probably just a little DC offset somewhere in the circuit - may be possible to counteract, but possibly tricky. Have you asked the builder? (livewire?). In many ways I'd say its not really a problem, just a little annoyance --- ie, retune your VCOs and all is ok.

[I could suggest swapping opamps, but don't want to as I was the person who recommended Argitoth to try trimming his VCOs..]

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Post by Mr White » Sat May 02, 2009 12:38 pm

BugBrand wrote:Is the tracking still correct? ie tracks fine, but is offset by some cents..

If so, probably just a little DC offset somewhere in the circuit - may be possible to counteract, but possibly tricky. Have you asked the builder? (livewire?). In many ways I'd say its not really a problem, just a little annoyance --- ie, retune your VCOs and all is ok.

[I could suggest swapping opamps, but don't want to as I was the person who recommended Argitoth to try trimming his VCOs..]


thank you for help BugB!

it seems to track correctly, just an offset.
I checked difference in V of the input signal and output signal to be for example: 2V in to 1.99V out and 4,67V in 4,65V out. so it seems almost a good tracking.

I'll try to send an email to Mike Brown but as usual I expect a very long-waiting reply!

I'm going in studio right now for further test to describe the problem more in deep...

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Post by ndkent » Sat May 02, 2009 12:50 pm

Have you tried other combinations of modules or tried using a buffer before the Bissell? Could be the interaction of what you have in specific is causing a droop.

Haven't really been following threads but I do hear a fair number of complaints that modular makes think their modules are tight enough for accurate portamento and either they aren't, at least in combination with what a person wants to use it's not. Anyway it's worth it if possible to confirm the voltage loss is the same with a different brand or combination before you alter things.

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Post by Mr White » Sat May 02, 2009 1:03 pm

ndkent wrote:Have you tried other combinations of modules or tried using a buffer before the Bissell? Could be the interaction of what you have in specific is causing a droop.

Haven't really been following threads but I do hear a fair number of complaints that modular makes think their modules are tight enough for accurate portamento and either they aren't, at least in combination with what a person wants to use it's not. Anyway it's worth it if possible to confirm the voltage loss is the same with a different brand or combination before you alter things.


you pointed out it right.

I had the same idea, that's why I'm going to further test.

Shawn told me that is very common with analog slew limiters, he tested those he has and they almost do the same of mine...

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Post by felix » Sat May 02, 2009 1:47 pm

I don't know if my Dual Bissell does this exactly, but I do know that it always smoothes things a little bit, even with the knobs turned all the way down.
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Post by Mr White » Sun May 03, 2009 6:18 am

felix wrote:I don't know if my Dual Bissell does this exactly, but I do know that it always smoothes things a little bit, even with the knobs turned all the way down.
i can definitely say that my bissell eats half a semitone or so. And yes, it tends un smooth everything

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Post by Mr White » Sat May 09, 2009 11:50 am

I found a stupid way to fuck up the voltage drop:
mix the Bissel out with a constant V offset provided by my M36.
done and works fine.
so for all having this problem here the trick!

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Post by Mr White » Sat May 23, 2009 9:29 am

WTF...

yesterday I patched in my bissell over a 2-3 octave arpeggio,

but I found that the trick of the last time does not work on a greater voltage range!

offset is not the same accross 2-3 octaves so if I add a fixed voltage to the output of the bissell to compensate the eaten one it almost works on one octave range but not on two or more!

I can tune the offset but in a very short range, so for example in that arpeggio lower noter are in tune but higher notes are detuned, fuck!

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Post by Funky40 » Sat May 23, 2009 4:08 pm

toral OT sorry:

BugBrand wrote: [I could suggest swapping opamps, but don't want to as I was the person who recommended Argitoth to try trimming his VCOs..]
what happened ?

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Post by wetterberg » Sat May 23, 2009 4:18 pm

Funky40 wrote:toral OT sorry:

BugBrand wrote: [I could suggest swapping opamps, but don't want to as I was the person who recommended Argitoth to try trimming his VCOs..]
what happened ?
IIRC he maladjusted things so bad he was like "they're brokened" and sold everything.

oh Argi...

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Post by Mr White » Fri Jun 19, 2009 8:25 am

still does not work, I tried also buffering it....

it's possible that all bissells behave like this!?

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