# how the hell would i....

Discussion in 'Amps and Cabs [BG]' started by Eric Cioe, Jun 18, 2001.

1. ### Eric Cioe

Jun 4, 2001
Missoula, MT
run a ampeg svp preamp along with a gallien krueger 400rb head? i want to be able to switch between the two at 1 switch,

i was thinking run my bass to an A/B box, 1 cable to my GK, the other to the ampeg, run the out of the ampeg to my effects return of the GK, so it woulduse only the power amp. i out put to 1x15

2. ### Brad JohnsonSupporting Member

Mar 8, 2000
Gaithersburg, Md
DR Strings
With what you're describing you won't be using your effects section as a loop but rather as a line in. The SVP is the only thing the amp section of your GK will "see". You've broken the "loop" at that point.

Are you saying you want to be able to switch between the SVP and the GK's preamp section? I guess (haven't looked at a 400RB in a while) that you could take the effects send from the GK and the output from the SVP and run both into a buffered A/B box and send the single output to the effects return. Two functioning preamps into one amp.

3. ### Eric Cioe

Jun 4, 2001
Missoula, MT
all i want the GK to see is the ampeg

4. ### Brad JohnsonSupporting Member

Mar 8, 2000
Gaithersburg, Md
DR Strings
Then you've lost me.

"run a ampeg svp preamp along with a gallien krueger 400rb head? i want to be able to switch between the two at 1 switch,

i was thinking run my bass to an A/B box, 1 cable to my GK, the other to the ampeg, run the out of the ampeg to my effects return of the GK, so it woulduse only the power amp. i out put to 1x15 "

When you say you want to be able to switch between two, what are you talking about?

What do you think you need a switchbox for?

I've no idea what the second paragraph means, now.

5. ### Eric Cioe

Jun 4, 2001
Missoula, MT
i want to run another preamp into only the power section of my GK. i need a switchbox so i can switch between clean GK tones and Overdrive Ampeg tones.

6. ### ChasarmsCasual Observer

May 24, 2001
Bettendorf, IA USA
You can't run a bass directly into the power stage of any amp. The impedance will not match up correctly.

If you want to run the Ampeg pre, plug it into the effects return of the GK. This bypasses the the GK's preamp.

If I am reading correctly, you want to set up a single footswitch to switch between two "channels" Gk's clean and Ampeg's dirty. Remember that the GK preamp contributes as much to its clean sound as anything, so bypassing it is not going to do what you want it to do.

It would probably work like this:

Get a signal splitter to split the bass signal. One cable into the regular input of each preamp. Run out out of the GK effects out into an A/B box and also out of the Ampeg's preamp out into the A/B box. The out of the A/B goes into the effects return of the GK.

What you are now doing is feeding both preamps all the time and the A/B is deciding which signal goes into the power stage.

Good luck.

Chas

7. ### Brad JohnsonSupporting Member

Mar 8, 2000
Gaithersburg, Md
DR Strings

You need to make a decision. These are two different things.

If you're saying you want to use the SVP as an effect (overdrive), just put it in the effects loop. Is the effects loop on your amp switchable (is there a switch to turn it on and off)?

8. ### Eric Cioe

Jun 4, 2001
Missoula, MT
..i want to be able to switch between the two, and have each pre amp compleatley independent so i only get the SVP or GK sound

9. ### Brad JohnsonSupporting Member

Mar 8, 2000
Gaithersburg, Md
DR Strings
Then you didn't really mean this:

all i want the GK to see is the ampeg

Chasarms' suggestion will do what you just asked. It's a little cumbersome because you'll have to switch the input on the first a/b box to select which preamp your bass is going into AND you'll have to switch the second a/b box to select which preamp is feeding the amp section of the GK.

10. ### Michael Wiley

Jun 21, 2001
San Diego County, Ca
Try out the Mesa-Boogie M-2000...2 seperate channels, all foot switchable...Ch #1 is designed for overdrive, #2 is the clean side, and you can combine the channels if you want to...I played one these things for 5 years, and I was able to get any sound I wanted out of it...Good luck!

11. ### ChasarmsCasual Observer

May 24, 2001
Bettendorf, IA USA
My suggestion was to use a signal splitter out of the bass rather than an A/B box. The would allow you to use only one foot switch. All and all, it seems like a lot of trouble to create a two channel amp, but if you gave the gumption to make it happen, go for it.

Chas

12. ### Brad JohnsonSupporting Member

Mar 8, 2000
Gaithersburg, Md
DR Strings
That's true...my bad. I agree, it does seem like a lot of trouble...

Michael, The M-2000 is an excellent amp but...I think he wants to use what he has