Hi,
I' am in the stage of designing a preamp to go with my amp, but after some thinking i got stuck with this question / prob
Now, its about the volume control ( potentiometer )
The amp should have some ( 4 ) unbalanced inputs, and 2 balanced inputs, the outputs ( 2 ) are balanced. The prob is at the balanced inputs, there are 2 ways to go from here
1. Convert al inputs to balanced, then balanced volumecontrol and last but not least balanced amping for the output
2. Convert al balanced inputs to unbalanced, then use a stereo potentiometer, and then convert the unbalanced to balanced and amp it.
Now the second situation is easy to build, but its not the best situation, becous all the balanced inputs would lose all there benefits becous they have to be converted 2 times.
Situation 1 is the best i gues, but lots of practical problems here, for stereo i would need a 4 way potentiometer, and thats very hard to get, and even if i find one, its would not be off a very good quality, with is defenetly needid in a preamp. An other possebelity is an attunuator ( the thing with the XXX resistors, spelled correctly ?? ), but, lots of work and same prob here, 4 way is very hard to get. And even if i pull this true, the system would have to be 100% perfect or it wil lose some balanced information, also not good.
Now my question, are there other approuches to this problem, easy'er solutions, are do i just want to mutch with the balanced thing. Its has to be analog, no digital stuf, thats also a solution ....
Please some comment and advice
Greetz Rudy

I' am in the stage of designing a preamp to go with my amp, but after some thinking i got stuck with this question / prob
Now, its about the volume control ( potentiometer )
The amp should have some ( 4 ) unbalanced inputs, and 2 balanced inputs, the outputs ( 2 ) are balanced. The prob is at the balanced inputs, there are 2 ways to go from here
1. Convert al inputs to balanced, then balanced volumecontrol and last but not least balanced amping for the output
2. Convert al balanced inputs to unbalanced, then use a stereo potentiometer, and then convert the unbalanced to balanced and amp it.
Now the second situation is easy to build, but its not the best situation, becous all the balanced inputs would lose all there benefits becous they have to be converted 2 times.
Situation 1 is the best i gues, but lots of practical problems here, for stereo i would need a 4 way potentiometer, and thats very hard to get, and even if i find one, its would not be off a very good quality, with is defenetly needid in a preamp. An other possebelity is an attunuator ( the thing with the XXX resistors, spelled correctly ?? ), but, lots of work and same prob here, 4 way is very hard to get. And even if i pull this true, the system would have to be 100% perfect or it wil lose some balanced information, also not good.
Now my question, are there other approuches to this problem, easy'er solutions, are do i just want to mutch with the balanced thing. Its has to be analog, no digital stuf, thats also a solution ....
Please some comment and advice
Greetz Rudy

How 'bout something like this?
<center>
<img src="http://www.q-audio.com/images/pre2.jpg">
</center>
The input will readily accept balanced or unbalanced inputs and you've got a balanced output.
Simple.
se
<center>
<img src="http://www.q-audio.com/images/pre2.jpg">
</center>
The input will readily accept balanced or unbalanced inputs and you've got a balanced output.
Simple.
se
Rudy said:Situation 1 is the best i gues, but lots of practical problems here, for stereo i would need a 4 way potentiometer, and thats very hard to get, and even if i find one, its would not be off a very good quality, with is defenetly needid in a preamp.
Actually <a href="http://www.dact.com">DACT</a> makes a good quality, 4 gang stepped attenuator. As does <a href="http://www.goldpt.com">Goldpoint</a> I believe.
se
Oh, and if you can locate your preamp in close proximity to your amps (or if you're going to have an active output stage on the preamp), you can go this route too:
<center>
<img src="http://www.q-audio.com/images/pre3.jpg">
</center>
Only problem would be the 5k attenuators. DACT only makes 'em down to 10k, but you could ultimately make your own.
se
<center>
<img src="http://www.q-audio.com/images/pre3.jpg">
</center>
Only problem would be the 5k attenuators. DACT only makes 'em down to 10k, but you could ultimately make your own.
se
Re: Re: Balanced / unbalanced volume control, possibel ?
Thx Steve, i think i will go with this one
Didn't even know these thingies existed
Greetz Rudy
Steve Eddy said:
Actually DACT makes a good quality, 4 gang stepped attenuator. As does Goldpoint I believe.
se
Thx Steve, i think i will go with this one
Didn't even know these thingies existed
Greetz Rudy
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