Help using 4CM with a Marshall JVM410

[Paincakes]

Hello,

I am a new QC user with the mini, and I’d like to use it with my Marshall JVM410H in 4 cable method in order to run some effects in front of the amp (drive, chorus, etc), as well as in the amp’s effects loop (delays and reverbs), with the benefit of using presets to instantly recall different combinations of settings.

I understand using the effects loop block on the QC, and connecting all the cables needed into my amps input and effects loop. I can hear pre and post effects as expected.

My issue is that the tone seems noticeably muddy and quieter. I suspect I may have to adjust output levels on the QC, and I was wondering if anyone had any tips / best practices in order to get the most out of my amp and quad cortex in 4CM.

The JVM is a bit peculiar in that it has 2 effects loops:

One is serial / parallel with a Level switch that, according to the manual, is intended to be used “with either professional equipment (+4dBu setting) or with guitar level effects like effects pedals (-10dBV setting).”

The other is a “power amp insert loop connected right before the master controls. It is a line level loop so it is recommended to only use high headroom devices to avoid signal degradation.”

I have tried both loops, and in both cases, my amp’s rhythm tone sounds muddy even when all QC effects are bypassed. Something is going on, affecting my amp’s tone, but I’m not sure where to look.

Thanks!

[Paincakes]

I found this thread that I am linking here to bookmark for myself to try adjusting levels

Instrument vs. Line Level for the QC's FX loops

Hi guys, I’m loving my QC, but I have a new bass amp (Mesa Subway TT-800) and cabinet (Mesa Subway UltraLite 1x15) on the way and I’m working out some ways of making the two play nice together using the four cable method. One note that I was given by agedhorse over on TalkBass is that the FX loop on the QC will have to be set to instrument level for best results when using the four cable method with this amp. I don’t see options in the ins and outs section of the unit or in the FX loop blocks …

[Paincakes]

I made some good progress and the QC and JVM are playing nicely together at living room levels. Hopefully this will scale just as well at band practice levels.
Here is what I did so far (in case I forget, or others want to try this as well)

• QC Input level set to +2 dB (I am using a guitar with EMGs).
• QC Send 1 level set to -4.5 (this goes into the JVM’s guitar input). This part fixed my muddy tone. When set to zero, the QC appears to be sending a considerably boosted signal.
• QC Return 1 level at zero (this goes into the JVM’s parallel / serial loop’s SEND. The amp’s FX Level switch is pushed in (-10dBV) and the MIX is set to 100% wet).
• QC Out 3/4 level set to 6 dB (this goes into the JVM’s parallel / serial loop’s RETURN). This level boost fixes the annoying volume drop that occurs when the JVM’s effects loop is enabled.

That’s it so far! I’m pretty happy with the results. Hopefully this helps someone out.