Dual preamps into one power amp?

bigblue · #1 05-18-2011, 05:34 PM

Forgive my probably simple question but I don't know the answer, can I have 2 preamps (like an Ampeg and an Alembic) running into the inputs of one power amp like a QSC and just plug into which ever preamp suits the sound I'm after at that moment? I think haveing this ability and the ability to run 1 or 2 Avatar 4x10's with the QSC would be extremly flexible and cover alot of ground tonewise, can it be done? I need to have motown thump with my P Bass (through the Ampeg preamp) and yet be able to nail the hi fi slap funk sound with my Jazz Bass too which the Alembic would nail....would this be a weird setup?

Selta · #2 05-18-2011, 05:41 PM

Depends on which poweramp you have. Mine PLX2 has two channels, so I can plug one pre into one side and one into the other.

Ric5 · #3 05-18-2011, 05:44 PM

You can run effects parallel like this --->>> bass effects

bigblue · #4 05-18-2011, 06:02 PM

Ray, I am pretty much thinking your current setup is what I am looking to do with the addition of another preamp that way I could cover more tones. I was thinking the 1804 looked great but was worried it would be too much power for me but I really like the idea of being able to run one or both Avatar 4x10's and I can always turn the volume down. Thanks!

Selta · #5 05-18-2011, 06:06 PM

Yup man. It's cake to do, too. The way I do it is with an ABY box that sends my signal to both pres, and I switch as I want/need.

funkydanbass · #6 05-18-2011, 06:16 PM

Check out the Coleman Audio GT6.. It's a 1RU switching device that I used to hook 3-4 preamps upto several outputs, (Ie. Poweramp, Tuner etc).

Welcome to colemanaudio.com

Downunderwonder · #7 05-18-2011, 10:28 PM

Whatever you do, don't connect more than one amp channel into each speaker or parallel set of speakers. The working channel will drive the other channel in reverse and you'll be releasing the magic smoke in a microsecond.

I would A/B the preamps into the amp.

Bread Knife · #8 05-18-2011, 10:40 PM

Quote:

Originally Posted by Downunderwonder

Whatever you do, don't connect more than one amp channel into each speaker or parallel set of speakers. The working channel will drive the other channel in reverse and you'll be releasing the magic smoke in a microsecond.

I would A/B the preamps into the amp.

Once the magic smoke comes out, you pretty much can't get it to go back in there. This is a very important point.

carl h. · #9 05-18-2011, 10:48 PM

Quote:

Originally Posted by Bread Knife

Once the magic smoke comes out, you pretty much can't get it to go back in there. This is a very important point.

Difficult, but not impossible!

Selta · #10 05-19-2011, 12:16 AM

Quote:

Originally Posted by Downunderwonder

Whatever you do, don't connect more than one amp channel into each speaker or parallel set of speakers. The working channel will drive the other channel in reverse and you'll be releasing the magic smoke in a microsecond.

I would A/B the preamps into the amp.

I wouldn't, and don't currently. Kind of defeats the purpose for what I do, and then I only use 1 channel of my amp, which is just a waste

.

Of course though, you don't want to connect two of any kind of amp to one cab - this is no different.

Downunderwonder · #11 05-19-2011, 02:21 AM

Your diagram is very non-specific as to what is plugged into what.

Just to ram it home: a dual channel power amp is TWO amps in one box, careful as ye go.

Downunderwonder · #12 05-19-2011, 02:24 AM

Quote:

Originally Posted by Ray Salamon

Depends on which poweramp you have. Mine PLX2 has two channels, so I can plug one pre into one side and one into the other.

If he followed this and then put both amp channels into the same cabs he'd be smoke city.

Eg: URGENT Drummer may have fried my WT800

Selta · #13 05-19-2011, 08:37 AM

Quote:

Originally Posted by Downunderwonder

If he followed this and then put both amp channels into the same cabs he'd be smoke city.

Eg: URGENT Drummer may have fried my WT800

Which is precisely why I agreed that you don't plug both channels into one cab.

zaubertuba · #14 05-19-2011, 04:39 PM

Here's a silly question--if you're not biamping or running two cabs, why not just bridge the amp (most pro stereo amps do this with just a flip of a switch)?

Of course then you would pretty much *have* to mix down the two preamps and send just one signal to the amp, anyway.

Selta · #15 05-19-2011, 04:59 PM

Quote:

Originally Posted by zaubertuba

Here's a silly question--if you're not biamping or running two cabs, why not just bridge the amp (most pro stereo amps do this with just a flip of a switch)?

Of course then you would pretty much *have* to mix down the two preamps and send just one signal to the amp, anyway.

You're missing the point. OP and I aren't looking for a sum of our preamps. Two totally different tones to be kicked in and out as necessary.
Also, the PLX2 does not do bridging. Even if it did, I would still run my setup in the exact same way that I do now.