1 Preamp into 2 poweramps

[BlackSwamp]

I have two main outputs on my GAS Thalia and McIntosh C28 preamps and have hooked up 2 power amps to it.

My ears tell me something bad happens when I do that. Especially with phono. What happens to the signal inside the preamp that would cause this? Or is the problem elsewhere?

TIA

 

[Toasted Almond]

You mean one power amp plugged into each output for a total of two power amps, or two power amps plugged into each main output for a total of four?

The two power amp set-up shouldn't bother anything. I also can't see how the four amp set-up would be any different, but it might.

Toasted Almond

 

[BlackSwamp]

Hey TA,

It did read like 4 (I edited it), but I meant two poweramps total.

 

[Toasted Almond]

Hmmm. Nothing bad SHOULD happen, but I trust your ears when you say there is bad juju in there. Perhaps something ISN'T up to snuff. Does it occur on both the GAS and the Mac?

Toasted Almond

 

[WildWest]

I have a GAS Thalia. Do you really like that pre? I used it once a while back. Quickly unused it too. I hated it and it now collects dust in my shop. ( sorry, no offense meant )

 

[BlackSwamp]

WW,

None taken, actually I do like it. It seems to do well with phono and doesn't screw with the sound (unless this problem is related). Not too sure about the purple hue to the faceplate but so it goes.

TA,

I originally thought so, but hooked the C28 back up and it seems to be unaffected by the temporal anamoly aforementioned. The GAS definetly was though, I could hear the sound cut down on the one set when hooking up the rca cables to the other power amp that was off. Unhook the 2nd set of RCA's and instant volume boost.

 

[THOR]

Can you show a diagram on how you are hooking everything up?

 

[EchoWars]

It's output impedence is too high, apparently. Or the input impedence of one or both of your amps is too low.

If the GAS is cap coupled at the output (and it probably is), loading the output is making the cap go from a coupling device to a filter. That is in addition to the signal amplitude loss.

 

[BlackSwamp]

EW,

I knew it wasn't only in my head. separate they sound great but together it sounds like crap. The C28 seems to handle it better but it still ain't right therefore it ain't going to work as is.

 

[EchoWars]

Ya know...if you really like that thing, the output could be buffered so that impedence is no longer an issue...

 

[BlackSwamp]

I may revisit that idea but when I do it will most likely be with the Foreplay preamp. That thing rocks!

First things first though, I hear a 33000 and some asprin calling my name. Almost done pulling the components.

 

[THOR]

Dingus how were you hooking the two amps to the pre amp? I have had four amps to one pre amp before with no trouble, but the symptom you are describing happened to me when I did it wrong, here is a crude diagram of what it should look like:

 

[Don C]

I'm wondering if one amp inverts phase, and the other does not.

 

[BigBoom]

i see what ur sayin don me too man but dude seriously why not just one big one i mean i am not saying it is a bad idea i think it is real pimp dog but wouldnt it be cheaper for just one