IIC+ mod to Quad?

[ytse_jam]

Yeah the overall output is useless but you can still use the channel masters. I have tried both my studio and Quad running via the fx send into my poweramp and it does sound a bit better, a bit....more, if you will.

how about the low/line switch? does it affect the tone or is it purely a level control?

 

[4nkam]

It's just the level signal control, I didn't have to switch it from where it was at on either unit, so it still sounds great. The only change, if you switch it, is that the volume is either fine or too low.

 

[psychodave]

Can the output be modded to be more like the effects send...so that the volumes work correctly?

 

[ursinus]

send it in. It is the safest and best way. Man, I miss my Quad......

 

[ursinus]

Yeah the overall output is useless but you can still use the channel masters. I have tried both my studio and Quad running via the fx send into my poweramp and it does sound a bit better, a bit....more, if you will.

By using it this way, you are using one less stage of pre-amp tubes before going to the drivers in your power amp. I preferred to wire it this way because it was less compressed, much more dynamic..... 8)

 

[Mrakk]

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?

thanks

 

[schnarf]

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.

 

[Mrakk]

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

 

[EOengineer]

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.

 

[bunyok23]

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!

 

[little-b]

Would Mesa themselves do it?

 

[Darth Bacelar]

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

 

[JD]

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.

 

[FedWar]

JD, schnarf are you both still online and reading this?
I'd really like to discuss the effect of the missing circuit (resistor/cap series + parallel) at the end of the quad ch1 lead section.
Is that critical for the IIc+ sound?
I have both triaxis and quad, and the triaxis has it, and it has a bite/gnarl that I like better (except for the other issues of the triaxis we all know).

 

[JD]

The Quad does have these components they are just not on the schematic.
The values are a little different though
https://ibb.co/4Nhrjpk

 

[FedWar]

.

 

[FedWar]

The Quad does have these components they are just not on the schematic.
The values are a little different though
https://ibb.co/4Nhrjpk

Wow, thanks JD, you are a life saver!
So the circuit is there :O

I was under the impression that quad lead2 was having more of that bite/gnarl in the mids more similar to triaxis lead 2 yellow (iic+) and mark iic+ sounds (petrucci etc)
more than lead1 and that puzzled me.

I am now wondering if the fact that lead2 has values more similar to iic+ is the reason?

May I ask you if you did any change in order to improve the quad, or make it sound closer to the C+?
Did you change those values, did any of the mods make any difference in the end?

btw, I am using quad, triaxis (and other pres) mainly with a 295, but I also have a 2:90 in my studio rack

thanks again!

 

[JD]

I Changed it to match the C+ spec wise, and I am very happy with the result.
Ch2 is basically a C++ with a few different resistor/cap values.

 

[FedWar]

I Changed it to match the C+ spec wise, and I am very happy with the result.
Ch2 is basically a C++ with a few different resistor/cap values.

Thanks mate for confirmation.
I'd like to change the ch1 to c+ spec as well! Are the ones in the photo you posted posted the only required changes?
Thank you!

Las question i promise

 

[JD]

Other Schematic
https://ibb.co/yWt9x5n