A-B switch for effects and pre-amp split between amp input and effects return

[telecopy]

Please advise on this idea. I have a Whirlwind compressor, a Whirlwind graphic EQ, a TC Electronic tuner, a Darkglass Vintage Microtubes, a Tech 21 VT Bass, and a 3 Leaf Enabler pre-amp. Amp is a Gallien-Krueger 400RB. I have one bass. I am thinking about an A-B switch with a cord to the amp input and a cord to the amp effects return. The goal is to be able to use the pre-amp(s), bypassing the GK pre-amp, when desired. Has anyone reading this done something similar before? I thank you for your time..

 

[sprag]

Is there a dry/wet knob for the effects loop? I imagine you'll want that around noon and adjust for any volume difference between the preamp and your effects. This may cause a volume drop as your not getting any signal from 1 but only using 50% of the other.
This is all speculation

 

[telecopy]

Is there a dry/wet knob for the effects loop? I imagine you'll want that around noon and adjust for any volume difference between the preamp and your effects. This may cause a volume drop as your not getting any signal from 1 but only using 50% of the other.
This is all speculation

No, the GK 400RB does not have an effects loop blend.. I thank you for your response. I did think about that, too. I'm just thinking of having the GK tone, and also having a totally different tone from the pre-amp pedal(s) available quickly.

 

[bongomania]

In this case you would NOT want to use any blending, that would defeat your purpose. To do what you want, there's a hangup: Just plugging the chain into the loop return will defeat the GK's preamp regardless of where the bass is plugged in. In order to use that preamp, you need to make it so the fx loop send can connect to the return. So you will actually need two A/B switchers: one to select where the output of the bass goes, and one to select whether the input of the effects chain comes from the bass or from the fx loop send. In this way, the loop is always engaged; for your clean GK tone, you just switch each of the preamp pedals off. You could add a third pedal, for a master true bypass.

 

[telecopy]

In this case you would NOT want to use any blending, that would defeat your purpose. To do what you want, there's a hangup: Just plugging the chain into the loop return will defeat the GK's preamp regardless of where the bass is plugged in. In order to use that preamp, you need to make it so the fx loop send can connect to the return. So you will actually need two A/B switchers: one to select where the output of the bass goes, and one to select whether the input of the effects chain comes from the bass or from the fx loop send. In this way, the loop is always engaged; for your clean GK tone, you just switch each of the preamp pedals off. You could add a third pedal, for a master true bypass.

Thanks bongomania. So you get what I'm thinking about. I don't think this is very far-fetched, is it? I would like to have the GK clean, and the option of totally bypassing that tone for something more dark. What I see is: bypassing (off) on pre-amp pedals when in GK (a) mode. Stomping "on" pre-amp(s) in "b" mode. If you were in my shoes, how would you achieve that flexibility?

 

[bongomania]

Weeeellll.... On the one hand, doing like I described with two A/B switches will get you there, and I can't think of a better method. However if the question really is "what would I do", I would just use the GK as a power amp, and pretend its preamp isn't even there. Which is no slam on the GK preamp, it's great-- but I would still let it go. I'd use a different pedal for my clean preamp tone.

 

[Dave Neal]

Please advise on this idea. I have a Whirlwind compressor, a Whirlwind graphic EQ, a TC Electronic tuner, a Darkglass Vintage Microtubes, a Tech 21 VT Bass, and a 3 Leaf Enabler pre-amp. Amp is a Gallien-Krueger 400RB. I have one bass. I am thinking about an A-B switch with a cord to the amp input and a cord to the amp effects return. The goal is to be able to use the pre-amp(s), bypassing the GK pre-amp, when desired. Has anyone reading this done something similar before? I thank you for your time..

Hi there I am playing with this idea and was wondering how you eventually solved it. The idea is to have one clean input and then with an a/b box and a y cable be able to create a second channel into the return. I have been mucking with this tonight and seem to loose some power. Let me know your thoughts.

 

[Aidil]

Hi there I am playing with this idea and was wondering how you eventually solved it. The idea is to have one clean input and then with an a/b box and a y cable be able to create a second channel into the return. I have been mucking with this tonight and seem to loose some power. Let me know your thoughts.

Boss LS-2 does what you've asked and even more...

Plug in your bass to LS-2 Input,
wire the LS-2 Output to your amp effect return,
wire the LS-2 loop "A" Send to amp front input, wire the amp effect send to the LS-2 Loop "A" Return,
wire your effect pedals (including preamp pedal if you have one) to LS-2 loop "B" send and back to loop "B" Return.

Dial the LS-2 MODE to "→ A → B → BYPASS →" and then:
when you stomp the LS-2 so "A" is lit, you'll be using only your amp's preamp without any interventions from the effect pedals, tweak the "A" LEVEL knob as required,
when you stomp the LS-2 so "B" is lit, you'll be using your effect (preamp) pedals without additional coloring from your amp's preamp, tweak the "B" LEVEL knob as required,
when you stomp the LS-2 so neither A nor B is lit, you'll have a clean channel (you'll be using only your bass [if it has] internal preamp).

Dial the LS-2 MODE to "→ A + B MIX → BYPASS →" for a mix output from the pedals and amp's preamp or a very dry signal from your bass only (w/o any coloration from amp's preamp or pedals).

Many other combinations are possible with the LS-2.

 

[Dave Neal]

Boss LS-2 does what you've asked and even more...

Plug in your bass to LS-2 Input,
wire the LS-2 Output to your amp effect return,
wire the LS-2 loop "A" Send to amp front input, wire the amp effect send to the LS-2 Loop "A" Return,
wire your effect pedals (including preamp pedal if you have one) to LS-2 loop "B" send and back to loop "B" Return.

Dial the LS-2 MODE to "→ A → B → BYPASS →" and then:
when you stomp the LS-2 so "A" is lit, you'll be using only your amp's preamp without any interventions from the effect pedals, tweak the "A" LEVEL knob as required,
when you stomp the LS-2 so "B" is lit, you'll be using your effect (preamp) pedals without additional coloring from your amp's preamp, tweak the "B" LEVEL knob as required,
when you stomp the LS-2 so neither A nor B is lit, you'll have a clean channel (you'll be using only your bass [if it has] internal preamp).

Dial the LS-2 MODE to "→ A + B MIX → BYPASS →" for a mix output from the pedals and amp's preamp or a very dry signal from your bass only (w/o any coloration from amp's preamp or pedals).

Many other combinations are possible with the LS-2.

So a ycable on the return and an a/b box wont cut it?..

 

[Aidil]

So a ycable on the return and an a/b box wont cut it?..

where do you plan to position the Y cable? Enlighten us with the whole connection that you have in mind.

Any how, you've said it yourself that with Y cable you've seemed to loose some power.

 

[Dave Neal]

where do you plan to position the Y cable? Enlighten us with the whole connection that you have in mind.

Any how, you've said it yourself that with Y cable you've seemed to loose some power.

Ok.. so I have my main preamp input I want to a/b a bass bone into return section. I am using my send and return to feed my Aphex 204 and a symetrics 501 comp. If I ycable the bass bone to the return on my amp I should be able to have a selection of three channels . 1 channel A direct input, channel B.. bass bone into return with Ycable... bass bone select-able two channels plus boost/loop. I could or should be able to even Ycable the bass bone to the Aphex and the 501 to be able to utilize them. Thanks for your input Aidil. My amp is a tube works RT 3300 with send and return level gains and a wet dry effects mix.. parallel.I will be doing some more signal routing later on in the day and yes I should have picked up that LS the other day.. Your thoughts are welcome.Invalid Link Removed

 

[tech21nyc]

The approach we recommend is to split your signal from the bass. I usually use a TU3 tuner but any stereo pedal will work. You could possibly use the tuner out on the amp as well since that is tapped directly after the input but before the EQ.

Once the signal from the bass is split send one cable to the input of the amp and the other to the input of the preamp/pedals etc you want to run to the amp's efx return. Next you take the amp's efx send and plug that into the A channel of an A/B box. Then take the output of the second preamp(s) and send that to the input of the B Channel of the A/B box. Finally take the i/o port of the A/B box and send that to the amp's efx return. Channel A will now be the sound of your bass directly into the amp and Channel B will be the other preamps. Basically a channel switching amp.

The only thing with the 400RB is the Boost section comes after the efx loop so keep that in mind.

 

[telecopy]

Hi there I am playing with this idea and was wondering how you eventually solved it. The idea is to have one clean input and then with an a/b box and a y cable be able to create a second channel into the return. I have been mucking with this tonight and seem to loose some power. Let me know your thoughts.

I found a great solution. In another of my posts.. Two Quilter Tone Blocks. Radial Bones Twin City switcher. One Tone Block clean and low, other with lows cut and gain boosted. Sounds awesome. I have lows going to Bag End 15 and overdrive to Bag End 12.
Might not be loud enough for some.. But it sure does sound rockin'..

 

[Dave Neal]

I found a great solution. In another of my posts.. Two Quilter Tone Blocks. Radial Bones Twin City switcher. One Tone Block clean and low, other with lows cut and gain boosted. Sounds awesome. I have lows going to Bag End 15 and overdrive to Bag End 12.
Might not be loud enough for some.. But it sure does sound rockin'..

So in the end you ditched the Gk send and return switching ?

 

[telecopy]

So in the end you ditched the Gk send and return switching ?

Yes. I like the utter simplicity of the Quilter