Members lingua latina Posted March 19, 2006 Members Share Posted March 19, 2006 I've been thinking about going with a QSC power amp and the new BBE tube bass preamp. Since the QSC (and all power amps) has a channel A and B how do you properly route the single pre out to the power amp? As well how do you route the A nd B out to a single cab or cabs in parallel? I assume this is what is meant by "bridging". Just wondering how to do...Thanks. Link to comment Share on other sites More sharing options...
Members BigPigPeaches Posted March 19, 2006 Members Share Posted March 19, 2006 Most bridgeable power amps have banana plug connectors, four of them in a row. Two on the left for Channel A, two on the right for Channel B. Plugging the banana plugs into plugs 2 and 3 usually bridges the amps together. VERY IMPORTANT: make sure you have the polarity correct or you will cause major damage. There are usually separate inputs for both power amps, and one or the other is the default input for a bridged situation, i.e. if you plug into PowerAmp A input, it will run to PowerAmp A output if non-bridged, or to the bridged output (there is usually a switch for bridge/non-bridge also). However, plugging into PowerAmp B input will not route to bridged no matter how you rig it. Make sense? Link to comment Share on other sites More sharing options...
Members lingua latina Posted March 19, 2006 Author Members Share Posted March 19, 2006 Originally posted by BigPigPeaches Most bridgeable power amps have banana plug connectors, four of them in a row. Two on the left for Channel A, two on the right for Channel B. Plugging the banana plugs into plugs 2 and 3 usually bridges the amps together. VERY IMPORTANT: make sure you have the polarity correct or you will cause major damage.There are usually separate inputs for both power amps, and one or the other is the default input for a bridged situation, i.e. if you plug into Preamp A input, it will run to Preamp A if non-bridged, or to the bridged output (there is usually a switch for bridge/non-bridge also). However, plugging into Preamp B input will not route to bridged no matter how you rig it.Make sense? Yes, I think so. The first paragraph has to do with outputs and the second with inputs for the power amp- right? I am a bit confused when you talk about preamp A or B input. I'm visualizing a preamp with a single 1/4" balanced out. This same preamp will have two inputs: one for active and the other for passive basses.Am I missing something? Link to comment Share on other sites More sharing options...
Members BigPigPeaches Posted March 19, 2006 Members Share Posted March 19, 2006 Originally posted by lingua latina Yes, I think so. The first paragraph has to do with outputs and the second with inputs for the power amp- right? I am a bit confused when you talk about preamp A or B input. I'm visualizing a preamp with a single 1/4" balanced out. This same preamp will have two inputs: one for active and the other for passive basses.Am I missing something? Sorry, I misspoke in my earlier post. I edited that post to make it correct. The preamp output (should only be one) goes into the PowerAmp inputs, either A or B. Link to comment Share on other sites More sharing options...
Members Rippin' Robin Posted March 19, 2006 Members Share Posted March 19, 2006 If you DON'T want to bridge, you'll want a pre-amp with TWO pre-amp outs. Either that, or you'll have to find a Y-splitter cable. Some power amps have dual inputs for a single channel, you can use a patch cord to link those channels. I guess I only confused you more now. Link to comment Share on other sites More sharing options...
Members mike fitzwell Posted March 20, 2006 Members Share Posted March 20, 2006 Originally posted by Rippin' Robin If you DON'T want to bridge, you'll want a pre-amp with TWO pre-amp outs. Either that, or you'll have to find a Y-splitter cable. Some power amps have dual inputs for a single channel, you can use a patch cord to link those channels. I guess I only confused you more now. The QSC RMX series power amps can be run in Parallel Input mode. The description from the user manual: The "Parallel Input" switches let you operate the amplifier in parallel mode, delivering the same signal to both channels without using a Y-cable. Each channel drives its own speaker load, with independent gain, filtering, and clip limiting. Worked great when I ran mine like that. Link to comment Share on other sites More sharing options...
Members Gearhead17 Posted March 20, 2006 Members Share Posted March 20, 2006 I would suggest going onto the website and reading the manual. The switches on the back allow one sound source to go to two different cabs or one sound source mono-bridged into one cab or two sound sources to two different cabs. I use to own the PLX2402 and found it too be powerful and clean sounding. I now play a SVT 2 PRO because I love the Tube Amp Growl and I can't stand super clean sounds any more. http://www.qscaudio.com/products/amps/plx/plx.htm QSC amps on sale!!! http://www.musiciansfriend.com/live/navigation?N=100001+701268 Link to comment Share on other sites More sharing options...
Members L-1329 Posted March 20, 2006 Members Share Posted March 20, 2006 One note on bridging a QSC, or at least the PLX series amps. You have to use a specially set up speak-on cable to run bridged. Only takes about a couple of minutes to set up, as only one end has to be modified to I think +1/+2. There are dip switches on the back that you set for bridged mono, and this cable out to the first cab. To chain in other cabs you use regular two wire speak-on's. My recommendation is to get a poweramp powerful enough for each channel to drive it's own cab, and run in two channel parallel mode vice bridged. Gives you much more control, and there is no special cables or switch changes to make. Link to comment Share on other sites More sharing options...
Members Ace Of Bass Posted March 20, 2006 Members Share Posted March 20, 2006 Originally posted by L-1329 One note on bridging a QSC, or at least the PLX series amps. You have to use a specially set up speak-on cable to run bridged. Only takes about a couple of minutes to set up, as only one end has to be modified to I think +1/+2. There are dip switches on the back that you set for bridged mono, and this cable out to the first cab. To chain in other cabs you use regular two wire speak-on's. My recommendation is to get a poweramp powerful enough for each channel to drive it's own cab, and run in two channel parallel mode vice bridged. Gives you much more control, and there is no special cables or switch changes to make. I once worked to get a sound system to work in an old church recently refitted with a new sound system by people with no {censored}ing clue how to set up pro audio. We had to do in on a saturday. Took me and my buddy till about 4am saturday to get it working for the 8am service. Huge pain in the ass, and even after we got everything else sorted out, there was still those freaking Speakon cables we had to set up those freaking cables. Luckily my friend had a little experience with those, and could do it, as I'd never used speakons before. The RMX series thank god doens't have those annoying things. Link to comment Share on other sites More sharing options...
Members Rippin' Robin Posted March 20, 2006 Members Share Posted March 20, 2006 Originally posted by mike fitzwell The QSC RMX series power amps can be run in Parallel Input mode. The description from the user manual: The "Parallel Input" switches let you operate the amplifier in parallel mode, delivering the same signal to both channels without using a Y-cable. Each channel drives its own speaker load, with independent gain, filtering, and clip limiting. Worked great when I ran mine like that. Ooh, that's nice. My old Peavey CS800X had that as well, but my current power amp doesn't, so I have to run a Y-plug after the second compressor stage. Looks dodgy, feels dodgy is not professional at all Link to comment Share on other sites More sharing options...
Members Undertoad Posted March 20, 2006 Members Share Posted March 20, 2006 It looks dodgy and feels dodgy, but it should work OK. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.