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Volume control for individual speaker

juptonstone

juptonstone

Member at Large...
I have 2 amps and two pairs of speakers connected to one preamp. It's a Carver c-6. The amps are a Magnavox 196-20 connected to a pair of Polk RT-800s... And a Dynaco Stereo 80 connected to a pair of old Advent Prodigy towers.

I obviously only have one volume control, although the Carver does support 2 stereo amps. My problem is that the Dynaco drives the Advents with more power than the Magnavox can... And although the Polks are more efficient, they are completely overpowered by the Advents. Is there is simple and non harmful way to reduce the volume level of the speakers.. At the speaker, or the amp, without major surgery?
 
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The "non-surgical" option is to buy external attenuation pots that can be installed in one of two places--between the preamp and the overpowering amp, or between the overpowering amp and the speakers.

The "surgical" option--even detailed in the Carver C-1 manual is to change the resistors that are placed right before the preamp output jacks to alter the output of pre-out 1 vs pre-out 2--not at all complicated, but you will have to figure out the resistance value change to get the amount of attenuation you need. You can do that by trying different resistor values in the line between the pre and amp until you obtain acceptable results and than add that value to the currently installed one for the total resistance of the new resistor to install into the preamp.
 
Thank you... But that does not allow for future changes in amp or speaker, unless you perform surgery again. Can you recommend another way? Maybe using an external resistor? Also this is a C-6, which is identical to the C-16, so a different kind of surgery might be necessary in this case. I don't know that I'm willing to risk the preamp for that, so the Extertal option I think is the best... if there is one.


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If you do perform surgery, yes, you will have to probably do it again if you change amplifiers. The procedure is the same for your amp as a C-1, they all have the resistors at the end of the circuit going to the preamp jacks.

For external options, you can buy speaker volume controls that are intended to be mounted in individual rooms to control volume in individual rooms on a multi-room system, so they are not hard to come by--that would be mounted between the amp and speakers. You can also utilize a passive pre or attenuator (also readily available) to place between the pre and amp.
 
You can connect the 2 amps TapeREC (out) to AUX (in). Then you have separate volume control. Connect one set of speakers to each amp. The TapeRec amp is source where you plug in TT CD player etc.
 
rwartner said:
You can connect the 2 amps TapeREC (out) to AUX (in). Then you have separate volume control. Connect one set of speakers to each amp. The TapeRec amp is source where you plug in TT CD player etc.
Click to expand...

I have one set of speakers going to each amp, but I am having difficulty understanding how you propose connecting the amps at the preamp end. I have one preamp, that has separate inputs for two power amps. It also has inputs for two external processors... However, there is only one volume control, unless I somehoe ran the amp through the tape recorder! And that would not be a good thing... Lol!
 
I have one preamp, that has separate inputs for two power amps.
Click to expand...

I assume you mean it has two outputs for two separate power amps.

It's not cheap, but I would use a passive preamp between one "amp out" from the main preamp and the loudest power amp.
http://www.goldpt.com/sa2.html
That's just one example, I'm sure there are other units on the market or you could build one yourself.

Essentially, you want to adjust the input sensitivity of the loudest power amp (or whatever power amp you want to attenuate).

You could easily add an input sensitivity control to your maggie, if that's the amp you want to attenuate. Look at a schematic for the Fisher SA300 or SA100 power amps, they use potentiometers at the input to adjust the amp's sensitivity.

IMG_3979_zps63e160dd.jpg


https://www.google.com/search?q=fis...orums%2Fshowthread.php%3Ft%3D532595;3090;2190
 
I'm also looking into something like the, more for a hidden volume control the kids can't get to, do the wall mounted type volume control work without adding degrading the music too badly? An my reason for the control between the amp and the speakers is so I can bump up the resistance so I can see more meter action on my amp for late night listening, as well as setting a maximum volume so the kids can use my stereo just not blow up the speakers.
 
Perhaps this: preamp -> amp1 AUX amp1 TapeRec (output) -> amp2 AUX.

Mine is laptop USB -> DAC -> AMP1 AUX AMP1 TapeRec -> amp2 AUX.

My DAC is essentially a preamp. (inputs, outputs and volume control)

AMP1 and AMP2 source is same music. When you output from TapeRec it passes through directly from the input, not affected by AMP1 volume control or tuning. So AMP2 gets same music that AMP1 does, it is as if it is connected directly to preamp.

Make sure to turn down all volume controls first. The volume level that passes through is what the preamp is set at. Then you can adjust volume of both amps and level the speakers. I do the same thing.

From what I have read, in theory you can connect an infinite number of amps this way. Never read any negative comments saying this is bad, harmful etc.

There are 3 reasons I do this: Speakers are in different rooms and want separate volume control. Speakers are 6 OHM so I don't want to connect 2 pairs to amp. I like amps and this is good reason to have more.
 
I like the control freak, will likely do it, but still thinking about the idea between the speakers/amp, and if I can do it without a hit to the sound quality. When I look at one of these in wall speaker volume controls, seems like it's going in and out of a lot more "things" than what a passive preamp does.
 
In-wall volume controls often waste power through simple heat dissipation to decrease the volume.

Doing it at line level is a much less wasteful process, so to speak.
 
Yeah, thats the kind of thing I worried about. In my case I listen late at night and I get no meter movement on my amp, silly yes, but I want bouncing meters. Might just have to attenuate the signal a bit then. Thanks for the further responses to an older thread.
 
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