serious EQ crossover problem

[mindmatter]

Hi all,

just found out why my pedals sounded so different on the clean channel every other day..the treble and presence knob of the overdrive channel affect the clean channel!
Found it by chance while testing some OD pedals and tried to adjust the distortion of the OD channel to that of the pedal on the clean...every time I changed the treble setting on the OD, the clean with pedal sounded completely different.
Try turning treble and presence all the way down and up while on the clean channel - it's is not as effective as on the OD channel itself, but still very audible, especially with OD pedals running in front.

Now I dunno if your QR does the same or if it's just a fault in mine , or is it so by design?
Let me know if any of you have the same problem.
thanks!

[dcf]

does your qr have 3 or 4 preamp tubes,

[mindmatter]

it's a 4 pre-tube model.
I had a great email exchange with Scott about this, he said that it's partly due to the shared circuit design of the 2 channels, and partly because the boosted signal of OD pedals is so strong it gets past the LDRs they use for the channel switching. He said it normally would not affect the clean that much if treble is set between 9 and 3 o'clock.

it's not that much of a problem now that I know what is happening, and I can now adjust the pedals accordingly. I was just so surprised how drastically my pedals sometimes changed their treble for no apparent reason.

I basically use OD pedals on the clean to have a very low gain crunch sound I cannot get on the QR without setting the gain very low, which in turn would then affect my high gain sound

[splawndude]

interesting - thanks for sharing

[thetonejourney]

Thanks so much for posting this. I am having the same issue with my Quick Rod. I was having trouble finding anyone else' posts about the issue. I dealt with it by making sure that one of the two treble knobs are all the way down since the presence and both treble knobs seem to affect both channels. Also just for reference this is happening with no pedals as well.

I would love to know more of Scott's take on it and whether newer models still exhibit this issue. My model is probably a 2013 or 2014 model. Anyone know?

[gtrjunior]

Just to add....last week I emailed scott with a similar question.
I was rolling preamp tubes and thought I heard some differences in the OD channel even though I was swapping V1.
According to the owners manual V2 is the first gain stage of BOTH clean and OD while V1 is the second gain stage of ONLY the clean channel. Obviously V2 will affect the tone of the clean channel but my question is would the opposite also be true...would V1 have any affect on the OD side.
He responded that since my amp was a 2016 model, each channel was independent of one another.
So I’m assuming that at some point he decided to use separate signal paths/circuitry for each channel?

[gtrjunior]

Ok, I just plugged in this morning before work and with my QR, the presence control is global. It affects both channels. The OD treble affects the OD channel only.