siemens v272 and gaincontrol? possible?
- Thread starter digichild
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Help Support GroupDIY Audio Forum:
Adding variable gain to a V272 is quite easy: Just replace the resistor in the feedback loop with something like a 500k pot. I'm sure someone here will help you identifying this resistor if you ask nicely (Don't have the schemo in front of me right now).
The V272 should be good for up to 60dB of gain.
Best of luck.
Michael
The V272 should be good for up to 60dB of gain.
Best of luck.
Michael
rafafredd
Well-known member
what if you make R16 or R22 a pot instead of a trimpot?
[quote author="rafafredd"]what if you make R16 or R22 a pot instead of a trimpot?[/quote]
good idea,so if i xchange r16 which is rightnow 10k to a pot with 100k for example do i get a higher gain?
how much higher is the gain-is there a formula for it?
good idea,so if i xchange r16 which is rightnow 10k to a pot with 100k for example do i get a higher gain?
how much higher is the gain-is there a formula for it?
[quote author="mig27"]I replaced R9 (2k2) and R15 (20k trimmer) with a linear 100k pot.
A 200k pot should give you even more gain.
Hope that helps.
Michael[/quote]
ok-i tried first the r16 which wasn`t satisfying at all
now i xchanged r15 and the result is much better-but r9 is still on the board...
the unit is now with a friend to get tested propperly...
A 200k pot should give you even more gain.
Hope that helps.
Michael[/quote]
ok-i tried first the r16 which wasn`t satisfying at all
now i xchanged r15 and the result is much better-but r9 is still on the board...
the unit is now with a friend to get tested propperly...
I think is possible to gain the unit just like the tab V372, without changing value resistor simply add a resispor or a pot betwin two pin on rear connector, in tab V372 they're pin 9 and 10 if I remember right.. you have to look at the schama..try it out..
[quote author="mik"]I think is possible to gain the unit just like the tab V372, without changing value resistor simply add a resispor or a pot betwin two pin on rear connector, in tab V372 they're pin 9 and 10 if I remember right.. you have to look at the schama..try it out.. [/quote]
sorry i dont understand this at all...
[/quote]sorry i dont understand this at all...
V372 is just the equivalent of the siemens V272 both got the possibilty to change his gain without change resistor value here and there on the PCB board. for expamlpe: if you look at the schematic of V472 neumann, that is an amp boards with near close function of V372, V272, you will note an optional resistor between two pin, nomined Rg , or Rk I do not remember .. raising this value, the V472 can gain up to 40/46db in my V372 there's the same possibility, thay are pin 9 , 10 on rear connector, In you V272 you have to finde it by your self, because I do not have any siemens schematics.
A lot german modules amp gots this facilyti,even in active fader amps , made by neumann, tab, siement telefunken, etc... is logical to think that even you board got this facilityes too.
A lot german modules amp gots this facilyti,even in active fader amps , made by neumann, tab, siement telefunken, etc... is logical to think that even you board got this facilityes too.
[quote author="mik"]V372 is just the equivalent of the siemens V272 both got the possibilty to change his gain without change resistor value here and there on the PCB board. for expamlpe: if you look at the schematic of V472 neumann, that is an amp boards with near close function of V372, V272, you will note an optional resistor between two pin, nomined Rg , or Rk I do not remember .. raising this value, the V472 can gain up to 40/46db in my V372 there's the same possibility, thay are pin 9 , 10 on rear connector, In you V272 you have to finde it by your self, because I do not have any siemens schematics.
A lot german modules amp gots this facilyti,even in active fader amps , made by neumann, tab, siement telefunken, etc... is logical to think that even you board got this facilityes too.[/quote]
i looked at the v372 and now i understand-but if i look at the v272 i can`t see this option...a link to a lot of schematics is here:
http://www.kubarth.de/cgi-bin/diy/german/index
A lot german modules amp gots this facilyti,even in active fader amps , made by neumann, tab, siement telefunken, etc... is logical to think that even you board got this facilityes too.[/quote]
i looked at the v372 and now i understand-but if i look at the v272 i can`t see this option...a link to a lot of schematics is here:
http://www.kubarth.de/cgi-bin/diy/german/index
i looked at the v372 and now i understand-but if i look at the v272 i can`t see this option...a link to a lot of schematics is here: http://www.kubarth.de/cgi-bin/diy/german/index[/quote said:
Hi There! 8 years later, but this thread is still pretty helpful! I'm making a Siemens rack with 2x V272, 2x U274 and 2x W295B as a stereo rack for tracking and mixing. On which Pins did you put the Potentiometer for the v272? This would be very nice to add if this works well!
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You have to connect it inside, as a replacement for variable resistor R15. As it is, it offers a variation range of about 20dB. Increasing it to 50k would give an additional 6dB, at the cost of some increase in distortion at high frequencies.
Hi! thank you for your reply! Alright, so if i don't want to mod it to heavily in a cosmetic way can i just connect that to some unused pins and then to my potentiometer on a different chassis? or do i need to put it straight on the spot of R15? And if i understand correctly, R15 is Input i suppose? so does that make R16 Output and can this also be done to the output than?
Yes you can.
No, it doesn't work like that. It's a Negative Feed Back gain control; it acts on both the input sensitivity and the output level.
No.
No.
