[Ace o' Spades]

Is it possible to use a non-balanced amp design (PIMETA, CMOY, PPS, etc) and use two of them to make a balanced design? I guess a dual power supply would be required too...

I want to experiment with balanced gear, probably starting with a KSC75 if I can build an amp for it.

Thanks!

 

[a1rocketpilot]

Sure it is! Basically, for a fully balanced setup, you make an amp with 4 channels (so 2 CMoy's or 2 Dynalo's (or Dynahi's)). For amps like the Pimeta, PPA, M3, and others, you leave the ground channel unpopulated, unless you want an amp that can handle both balanced and unbalanced inputs. There is a good explanation on AMB's M3 website as to how to do this. Go to the Other Options section. You basically feed one channel the +L/R signal and the other channel receives the -L/R signal.

You don't need a dual power supply, though it may help. Thats basically the difference between a balanced setup and monoblocks, only this time, the monoblocks are in the same case.

Aditya

 

[Pars]

One place to start: Doobooloo's balanced MINT amp thread, here. The MINT was Tangent's predecessor to the PINT, which was a single opamp w/buffers 2 channel amp meant to fit in a mint tin.

As far as the active ground channel amps (Pimeta, etc.), I'm not sure how well these would lend themselves to balanced configuration, without disabling the ground channel.

 

[Ace o' Spades]

Thanks for the replies! I might make a CMOY again as $$$ permits, though fitting it all into a serpac will be the hard part.

If I were to use an unbalanced input how would that work? Also using an unbalanced input would mean that I could use a standard RK097 potentiometer?

Thanks

 

[a1rocketpilot]

If you were to only have an unbalanced input (which would require some circuit trickery), a regular dual gang potentiometer would be just fine. However, you are then going to have to find some way of creating a positive and negative waveform. One way to do it is to use an IC made by TI called the DRV134. It takes in an unbalanced signal and makes it balanced. Its original purpose was for balanced line drivers, to transmit signals across hundreds of feet of balanced cable without distortion. Another thing would be to use one inverting and one non-inverting opamp. That would provide a simpler solution. However, I have never heard of anyone making a balanced amp like this, and I don't know if it is because of a flaw in that design or whether no one has ever bothered.

Aditya

 

[khbaur330162]

Where's Fitz? Did he not do this for Steve with those two Darkvoices? How the heck did he do it?