IIC+ mod to Quad?

Triaxis, Quad Preamp, Stereo Power series, Recto Preamp

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Mark I
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Post by Mrakk » Wed Dec 12, 2007 9:10 pm

Interesting but where are those A/B clips? :(
Also, does anyone know how much is the output impedance on the normal and effect send outs? Is it the same?


Mark II
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Post by schnarf » Wed Dec 12, 2007 10:19 pm

I never posted A/B clips of that, but I did mess around with it for a bit and basically I didn't notice a difference.

Mark I
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Post by Mrakk » Thu Dec 13, 2007 2:31 pm

Does anyone know if the output impedance is any lower on the offects send vs normal out?

Mark II
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Post by EOengineer » Thu Dec 20, 2007 2:12 pm

I just gave this a try last night. Essentially my 2:90 is dead right now, so I slaved out of the studio pre effect send into the return on my 2 channel recto head.

There is an interesting thing I noticed in functionality here, as the lead drive knob and Lead master seems to be interactive in producing different types of crunch. Quite odd. Also, the lead drive produces a HUGE increase in volume as you start to turn it up. I rarely use it above 2 on my pre anyway, so it isnt a huge issue.

There is a BIG difference in the audio when comparing back and forth between using the effect send or the main outs on the studio pre. Out of the effects send, the crunch and high gain tones do sound and feel bigger and more dynamic. The top end is more present, and in general I feel like it did generally liven the pre up a little.

Im starting to feel the itch. That 2:90 might be making its way back to Mesa for a repair REAL soon. If this sounds this good through the recto's power section, I REALLY want to hear it through my 2:90.

Mark II
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Post by bunyok23 » Thu Dec 20, 2007 2:27 pm

i modded my studio pre to c+ specs then sold it.i now have another one w/c im planning on modding.this version seems to be tighter, more mark iv ish.

studio pre to effects return of dual rec sounds huge!

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Mark III
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Re: IIC+ mod to Quad?

Post by Littleb » Tue Jan 05, 2010 1:29 pm

Would Mesa themselves do it?
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Darth Bacelar
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Re: IIC+ mod to Quad?

Post by Darth Bacelar » Mon Jul 05, 2010 6:08 pm

It is normal when you connect the Quad like that, the pull deep doesn´t work? In both channels.

Or maybe a tube is screwing me... XD

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Re: IIC+ mod to Quad?

Post by JD » Tue Nov 27, 2018 4:56 am

I think I managed to trace the schematic a few things left off which I have added Black is existing and red is from C+ schematic.
Channel 1 modded to C+ and channel 2 modded to C++
I also disconnected the eq ldrs and wired up directly to toggle switches. using footswitch also causes volume drop there must be something else going on as I still get volume drop engaging eq via footswitch even though eq not getting switched as it is now manually done via toggle switch
Seems to be common problem from other posts on forum, while switching manually with toggle switch engages eq without drop in volume. Cant use footswitch to switch eq but I never turn it off so no worries for me.
Also disconnected recording out circuit.
I might also bridge LDR 8 & 10 mid circuit isolation as original circuit was not switched.
Mesa Boogie Mark 3++ RGX 60W
Axe fx 2
Mesa Boogie Quad Preamp with C+ Mod

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