ilfungo

Re: PRR-176 Vari-Mu REV 2 *Updated Docs 7/1712*
« Reply #20 on: July 30, 2012, 07:07:59 AM »
thanks Abe
The PCBs arrived today!!!
Sorry for a stupid  question:
is possible to add something like  Drip time constant PCB on this project?
Thanks
« Last Edit: July 30, 2012, 07:44:43 AM by ilfungo »


abechap024

Re: PRR-176 Vari-Mu REV 2 *Updated Docs 7/1712*
« Reply #21 on: July 30, 2012, 08:29:30 AM »
thanks Abe
The PCBs arrived today!!!
Sorry for a stupid  question:
is possible to add something like  Drip time constant PCB on this project?
Thanks

Great! Glad you got them. Time constant, like an "auto-release" found on the SSL? It would surely be possible, I think just adding a resistor network along with the caps would work. I'd have to double check the SSL schematic to be sure....

Yea, you could make it on a switch, and switch out the release pot, or somehow incorporate it. Then build up something like on the GSSL just scaling down the capacitance/resistance values to 1uf (or 2uf) or whatever you want! there are no rules.
AC Sound - some DIY circuitboards

ilfungo

Re: PRR-176 Vari-Mu REV 2 *Updated Docs 7/1712*
« Reply #22 on: July 31, 2012, 07:59:30 AM »
Sorry any news about new wiring guide?
Thanks


someone can tell me how to do input (Log 10k) and Out (100k Log) stepped with Lorlin switch?
Thanks

abechap024

Re: PRR-176 Vari-Mu REV 2 *Updated Docs 7/31/12*
« Reply #23 on: July 31, 2012, 11:33:04 AM »
Sorry any news about new wiring guide?
Thanks
www.acsoundstudio.com/prr_176/rev_2/REV2_PRR_176_WIRING_GUIDE.png

Quote
someone can tell me how to do input (Log 10k) and Out (100k Log) stepped with Lorlin switch?
Thanks

http://www.quadesl.com/attenuator.html

hope this helps!
Best,
Abe
AC Sound - some DIY circuitboards

ilfungo

Re: PRR-176 Vari-Mu REV 2 *Updated Docs 7/31/12*
« Reply #24 on: July 31, 2012, 02:09:32 PM »
Thanks Abe!!!

I do not understand "Total attenuation db"? :o

abechap024

Re: PRR-176 Vari-Mu REV 2 *Updated Docs 7/31/12*
« Reply #25 on: July 31, 2012, 03:05:35 PM »
Thanks Abe!!!

I do not understand "Total attenuation db"? :o

Ok, thats a good question, because if using a lorin you only have 12 steps, so you want to maximize usable steps. I would say for a compressor -40dB max attenuation might be a good starting point. But it depends. you might want to wire up a potentiometer first and see what range on the potentiometer you use the most then measure the resistance and us that to make your lorin switches.
AC Sound - some DIY circuitboards

ilfungo

Re: PRR-176 Vari-Mu REV 2 *Updated Docs 7/31/12*
« Reply #26 on: August 01, 2012, 08:51:10 AM »
Thanks Abe I make some experiments...

For GSSL Time Constant can i use this?

Should I change something or I can copy it?
thanks

abechap024

Re: PRR-176 Vari-Mu REV 2 *Updated Docs 7/31/12*
« Reply #27 on: August 01, 2012, 10:17:29 AM »
Thanks Abe I make some experiments...

For GSSL Time Constant can i use this?

Should I change something or I can copy it?
thanks

Well looking at it I would say give it a shot. Just copy the 750k/91k & 0.47uF/6.8uF and switch it into the circuit, though I don't expect it to react exactly the same, you'll probably need some tweeking with values and you'll have to modify/change the existing PCB. I find the comp to be pretty musical as is, and never felt the need for an "auto" release, but who knows, you don't miss what you've never tried!
AC Sound - some DIY circuitboards

ilfungo

Re: PRR-176 Vari-Mu REV 2 *Updated Docs 7/31/12*
« Reply #28 on: August 01, 2012, 09:49:07 PM »
sorry ... , something is missing in the second channel?
 ???

 :)
« Last Edit: August 01, 2012, 10:04:20 PM by ilfungo »

herrmann

Re: PRR-176 Vari-Mu REV 2 *Updated Docs 7/31/12*
« Reply #29 on: August 02, 2012, 01:45:34 AM »
I think it's the same wiring as the L channel.


baadc0de

Re: PRR-176 Vari-Mu REV 2 *Updated Docs 7/31/12*
« Reply #30 on: August 02, 2012, 05:11:41 AM »
Received! Nice boards, love the smilies

EDIT: also, isn't this board of the variety where if you link it, only the left controls are "in"?
« Last Edit: August 02, 2012, 07:31:36 AM by baadc0de »

abechap024

Re: PRR-176 Vari-Mu REV 2 *Updated Docs 7/31/12*
« Reply #31 on: August 02, 2012, 10:29:35 AM »
sorry ... , something is missing in the second channel?
 ???

 :)

Haha! Sorry 'bout that. I'll update the picture. Thanks for pointing it out!


Received! Nice boards, love the smilies

EDIT: also, isn't this board of the variety where if you link it, only the left controls are "in"?

Thanks! And yes, when stereo link only the Left controls work, makes it a lot easier to setup stereo cohesiveness, instead of trying to match attack/release  controls.
AC Sound - some DIY circuitboards

ilfungo

Re: PRR-176 Vari-Mu REV 2 *Updated Docs 7/31/12*
« Reply #32 on: August 03, 2012, 02:51:00 PM »
I just finished the rev 2!
I have a strange problem on the first channel:
when I go up with the output pot (full CW) increases the compression ....
even with no input signal, the meter starts to score more and more compression ...
I checked all connections and they seem ok.
What can be?
Has anyone finished the REV 2?
thanks

ilfungo

Re: PRR-176 Vari-Mu REV 2 *Updated Docs 7/31/12*
« Reply #33 on: August 04, 2012, 03:11:51 PM »
Problem solved ( bad trimmer)...
with Lundahl 1540 (as interstage)
optional resistor value?
thanks

ilfungo

Re: PRR-176 Vari-Mu REV 2 *Updated Docs 7/31/12*
« Reply #34 on: August 06, 2012, 08:49:08 AM »
Hello ABE I got a strange problem:
the first channel
pot output from half to three quarters, and distorted sound strange, if I decrease or increase, the problem goes away .....
rechecked all components
replaced the doa
replaced all ICs
but nothing changes ..
What can be?
Thanks

abechap024

Re: PRR-176 Vari-Mu REV 2 *Updated Docs 7/31/12*
« Reply #35 on: August 06, 2012, 11:16:04 AM »
the first channel
pot output from half to three quarters, and distorted sound strange, if I decrease or increase, the problem goes away .....
So just he first channel? have you check the pot? Does it happen when stereo linked/not? compression not? bypassed etc...?
AC Sound - some DIY circuitboards

ilfungo

Re: PRR-176 Vari-Mu REV 2 *Updated Docs 7/31/12*
« Reply #36 on: August 06, 2012, 12:01:46 PM »
Yes just the first channel
I changed the pot but nothing has changed.
always the case (compression in or out)
in mono and in stereo,
The only thing I've noticed that if I exclude physically
U1 or U2 the problem goes away ...
 :o

ilfungo

Re: PRR-176 Vari-Mu REV 2 *Updated Docs 7/31/12*
« Reply #37 on: August 06, 2012, 01:17:47 PM »
This is a sample of the noise output pot.
starting from zero up to the maximum...


http://www.sendspace.com/file/xyn9u6

abechap024

Re: PRR-176 Vari-Mu REV 2 *Updated Docs 7/31/12*
« Reply #38 on: August 06, 2012, 03:08:56 PM »
Yes just the first channel
I changed the pot but nothing has changed.
always the case (compression in or out)
in mono and in stereo,
The only thing I've noticed that if I exclude physically
U1 or U2 the problem goes away ...
 :o

So if you take out the ne5534 or the tl072 from the sidechain it doesn't make that noise? That is strange, quick fix is you could strap a 10pf to 100pf capacitor across your output pot, that would probably help. when did you start noticing this? have you cleaned your board of flux?
AC Sound - some DIY circuitboards

abechap024

Re: PRR-176 Vari-Mu REV 2 *Updated Docs 7/31/12*
« Reply #39 on: August 06, 2012, 03:09:56 PM »
have you tried trimming the threshold gain down on that channel?
AC Sound - some DIY circuitboards


 

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