Modding a Quad for stereo?

[Livingston]

Would it be possible to modify a Quad preamp with 2 inputs, one for each channel? I'm sure it's possible, so really what I'm wondering is whether it would be a reasonable undertaking (that is, DIY-able or at least cheap for a tech to do). I know it has stereo returns for the effects loop; that's not what I'm looking for.

 

[disassembled]

I would say no to the DIY'er because it doesn't have two completely independent signal paths. I bet it would be impossible for an average DIY'er to do this alone and a tech would charge the cost of buying a studio pre or similar.

Not worth trying IMO but it is certainly doable with enough hacking and destroying of the original design.

Why not get two studio preamps?


Greg

 

[Livingston]

Well, if it were relatively simple and/or cheap, I think it would be obvious why it would be preferable to have a stereo quad rather than 2 studios (1 Quad is cheaper than 2 studios and takes up one less rack space). But I guess it isn't.

 

[dmt]

You could conceivably take the two outputs form the back of the preamp and run those into a stereo effects unit, so long as you make sure the output isn't too hot, as well as perhaps impedance. That way you could independently control each channel that way.

You could also use a stereo power amp, preferably with a stereo fx loop, and insert the effects there. This would be ideal for delay effects or flange etc since you would have a overdriven signal at that point.

If you are trying to use 2 guitars at once, or to beable to switch between two guitars, you could use an A/B/Y box before the preamp input. That way you could use interchange between two inputs (guitars).

Not sure what exactly you are trying to accomplish. More details would help.

 

[disassembled]

You could conceivably take the two outputs form the back of the preamp and run those into a stereo effects unit, so long as you make sure the output isn't too hot, as well as perhaps impedance. That way you could independently control each channel that way.

You could also use a stereo power amp, preferably with a stereo fx loop, and insert the effects there. This would be ideal for delay effects or flange etc since you would have a overdriven signal at that point.

If you are trying to use 2 guitars at once, or to beable to switch between two guitars, you could use an A/B/Y box before the preamp input. That way you could use interchange between two inputs (guitars).

Not sure what exactly you are trying to accomplish. More details would help.

he wants to make the quad 2 seperate preamps so he can use one guitar for each channel.

Basically he wants to make it equivalent to having 2 studio pre's.

Greg

 

[dmt]

Use an A/B/Y box to switch between inputs. Use the foot switch to change channels.

 

[Livingston]

No, actually I want to use a stereo signal from my audio interface, which will sometimes be used for stereo keyboard sounds (B3 model with Leslie simulator), computer music, etc, as well as bass. So going after the preamp would be of no use. I basically want to replace my Tube works stereo tube reverb with the Mesa, but it doesn't look like it's going to happen. Because of the duplicate controls, I had assumed the Quad was designed as two Studios in one enclosure; guess not.

 

[disassembled]

No, actually I want to use a stereo signal from my audio interface, which will sometimes be used for stereo keyboard sounds (B3 model with Leslie simulator), computer music, etc, as well as bass. So going after the preamp would be of no use. I basically want to replace my Tube works stereo tube reverb with the Mesa, but it doesn't look like it's going to happen. Because of the duplicate controls, I had assumed the Quad was designed as two Studios in one enclosure; guess not.

The quad is based off of a Mark IIC and III.

Greg

 

[Livingston]

Eh, ok? Not sure why that's relevent. If you mean, "why not just get the Mark II?" Bass players need much more power than guitarists to reproduce low frequencies with the same perceived loudness. I have a 1600 watt power amp, which works very well and weighs only 21 lbs, so I would rather pair it with a preamp than use a (comparitively) low-powered head.

Edit: oh, I just reread my earlier post, and I realize why you said that. Sorry for the confusion.

 

[Livingston]

.

 

[EdgeOfDarkness]

Use a line mixer like the Rane sm26, It will not be stereo, but it will allow you to use more than two inputs in the front of the quad.

 

[Livingston]

No, that would not work at all for my purposes. Thanks for the suggestion though.