two pre amp, single power amp setup with a/b line switcher

[Reptileroundabo]

New to the world of preamps and poweramps, have been using combo heads for about 12 years and need a better solution to my needs.

I run both a bass and a tuba through my rig at shows and have been using a small mixer into my amp head for that time. Now im switching to a preamp and poweramp setup and need to know if what im planning to do is safe, or if there is a better way to do it.

What im thinking i may do is run my bass into the bass preamp and the tuba through a seperate mic preamp and then send the preamp lines into a a/b pedal line switcher. from the line switcher directly into the power amp. This will allow me to swap instruments between songs and mute out the preamp from the previous instrument through the pedal a/b switcher.

The big question, Is this safe for the power amp and pre amps? thanks in advance!

 

[B-string]

My concerns would be a possible pop when floor switching and the strong possibility of noise from the long cable runs between preamps and power amp. Why not a rack mount mixer to feed your power amp?

 

[bassmeknik]

How about using a relay to do the switching remotely without using the signal on the long run to the floor switch. The relay control circuit will not carry the bass signal only the on/off (A/B) signal to the relay. The simple single pole dual throw relay could be mounted in a small box left on top of the 2 pre-amps and jacks on the box for each pre's input and the output. Then add a jack for the remote pedal switch and small power supply. Now the floor switch can be hundreds of feet away and the pre's will switch on and off by relay.

This technology is simple and is used everywhere from your car or motorcycle to nuclear subs and airliners where ever remote control of an electrically powered device is needed. Google "relay" and read Wiki...

 

[Reptileroundabo]

Thats what i was worried about. I hate having to put a mixer between my equipment and my power amp. But there really doesnt seem to be any other option. I have a mixer that i can toss in the mix, i think i may still go with a a/b switcher as they are cheep to see if i have any issues with that first.

http://www.ebay.com/itm/Saturnworks...004?pt=Guitar_Accessories&hash=item27cefca78c

This is the one i was thinking about. plus i could run the a/b switcher into the mixer before the preamp to try to avoid a signal cut off directly into the power amp.

 

[Reptileroundabo]

How about using a relay to do the switching remotely without using the signal on the long run to the floor switch. The relay control circuit will not carry the bass signal only the on/off (A/B) signal to the relay. The simple single pole dual throw relay could be mounted in a small box left on top of the 2 pre-amps and jacks on the box for each pre's input and the output. Then add a jack for the remote pedal switch and small power supply. Now the floor switch can be hundreds of feet away and the pre's will switch on and off by relay.

This technology is simple and is used everywhere from your car or motorcycle to nuclear subs and airliners where ever remote control of an electrically powered device is needed.

any chance you have a link to the type of setup i could check out? seems easy enough, but a visual would be awesome!

 

[Bassmec]

Sounds like a job for a Lehle dual running backwards.

I use one to drive a pair of amps for clean dirty, but it works well with power amps that are relatively sensitive but better still with a high impedance buffer amp for the power amp like one of those economically priced no eq tube pres there are about today.

 

[Reptileroundabo]

Sweet little unit. I will deff look into one of them

 

[Bassmec]

Sweet little unit. I will deff look into one of them

Yup you won't break it!. The power supply isn't necessary, it only lights the indicator lamps. The awesome high impedance transformer is all that's required for noiseless, lossless action both ways round.

 

[CC7]

I did something similar to what you are wanting to do with my bass amp (switchable preamps into the same power amp),
I tested it with two or three passive a/b box's but there was always an unbelievably loud pop when switching.
I ended up using a Boss LS-2 which switches seamlessly.

There's a link in my sig to my preamp selector rehouse/build that my give some ideas. Hope it is of some help, I posted it
because I could find hardly any information when I was putting mine together.