Quad Pre Modded for Stereo

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JD said:
I have loved the sound of my quad pre but the mono output of Ch1 & 2 has bugged me so I decided to seperate the preamps so I could run them in stereo.
I installed another input for ch2, removed the reverb and eq/reverb mixer circuit, used the recording outs for new outputs after the eq circuit of each channel.
I used 2 short cables from the new outlets to the effects returns which makes them separate channels bypassing the mixer circuit
I removed LDRs 2, 3, 4, 5, 6, 7,14 and 15, as these were used to allow switching between Ch1 and 2.
I always had a problem with volume and high end loss when using Ch1 and 2 together before now they sound great together.
I installed pull switches for lead mode, with LDRs bypassed the clean channel is always engaged so it works the same as the preamps in the Mark amps, I run the TC Electronic mimiq pedal in front of the quad into 2 x cabs sounds great its a keeper for sure.

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I am confused, i just read the manual for this unit and it is the same as the studio preamp....meaning stereo out operation....how is it you had to mod it to do something it already does? (yes the individual channels come out mono, but they sum to a stereo output after the effects loop...meaning all effects and signals already come out stereo(frankly any division of the signal before the effects loop is pointless, because the signal is fed mono into any effect and then the effect adds its stereo mojo.....unless what you did was to make a stereo effect unnecessary and make the unit feed into the stereo outs without an effect to split the signal.....which to my way of thinking is also unnecessary......or did you go with both units feeding out at the same time so you get a different signal from each side....ie, mark ii right and mark iii left).....please clarify)
 
Stereo input Stereo output, Mark 2 on the left Mark 3 on the right. When I was using it before I modded it I was only using 1 channel and thought it was a bit of a waste So I thought why not use both.
If you read my first post it says I was getting tone loss with both leads activated like one was sort of cancelling the other out.
Now no tone loss, sound is so much better, I was going to sell it because of this and I got 2 x Studio Pre's for stereo now I use the Quad.
Using it with the mimiq pedal gives a great stereo spread which I use on the input because it sounded like crap using the stereo returns before I modded it.
Mimiq pedal works a lot better before the Lead channel.
 
My Quad also suffered from that tone suck when both channels were engaged... it also suffered the same issue when both GEQ's were engaged via the footswitch even if i was only playing 1 channel... yet if both GEQ's were engaged via the toggle switches there was no tone suck... had a tech go over it he said its a design flaw of the unit... i cant believe theres not more info on it or more people havnt noticed it... its a huge issue along with the fact than channel 2 is half the volume of channel 1 on the same settings... ive had my tech fix all this up but yea these Quads while a great way to get high quality cheap mk tones they are still limited to 1 or 2 great sounds at a time like the mkiii is... if i had my time again ide get a mkiv, triaxis or mkv even... my entire quad setup incl tech fees cost the same as a used mkv.
 
Fantastic mate... especially with no outboard eq thats really capturing the tone... how does it compare to the Mike B C++ studio pre you had?
 
Thats a good spot... mine doesnt have a pull over lead drive either... and i cant find any pics of another Quad that has this... part of the modding?
 
I installed the pull switches for the lead that removed the need for the FU 2 Footswitch as I removed all LDRS except Lead and eq as I was getting terrible tone and volume problems. Way to many LDRS in this thing. I tried replace the lead master Ldrs but could never get them to work properly so just used a relay instead to switch lead mode and lead master.
I installed and full stereo effects loop with bypass switch, I use it with a Axefx 2 for effects and cabinet modelling.
It is now a full stereo preamp, Ch1 is left side and ch2 is right side a perfect preamp now.
 

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