Problems with TF and Distortion

[neo84]

Hello everyone.

I'm running the TF in the effect loop of my Marshall JVM410H and getting problems with noise and feedback when I'm using the TF with distortion from my Marshall. I'm also running an ISP Decimator for reducing noise in my effect loop in front of the TF.

When playing some slow lead parts with delay I get more noise than I can hear my actual playing. Without delay there is no problem so the problem is a combination of the delay effects and the high gain sounds of my amp.

Can you give any advice how to change my setup to reduce those problems? How are you using high gain sounds with delay and reducing the noise that is coming with it.

Greetings from Germany,

Neo

[timothyhill]

Hey, Neo! I think your problems may have to do with a level mismatch, but let me ask a few questions first…

It sounds like the problem is more pronounced on the distortion channels, they are always noisier than the clean channels, but is there any increase in noise in the clean channel as well when you use the TF in the loop? It wouldn't be very significant, maybe almost unnoticable. Since the loop on the JVM410H can be active for any channel, if the problem is only on one channel, it may be the amp. I doubt that, though, and am guessing you'll hear a slight noise increase on all channels.

Which loop are you using? The JVM410H has two loops, one "serial/parallel" and the other "power amp insert/serial"… Either will work, but I'd guess you're using the "serial/parallel" loop so you can turn it on and off with the Marshall's footswitch or channel memory.

If you are using the "serial/parallel" loop, what settings on the amp are you using? What's the FX Level? What mix are you using? If you're using less than 100% wet, do you have the TF set to DRYKILL?

Just to make sure, you said that you're running the Decimator before the TF, right? That's good, because if it was after the TF, the changes in level due to the echo repeats could cause the Decimator to let more noise through than it normally does.

Loop Send >> Decimator >> TF >> Loop Return

Try disconnecting your Decimator or at least leaving it off temporarily… I know this will be noisier, but what I'm curious about is whether the noise still increases when turning the TF on and off when the Decimator's not part of the picture. Just trying to make sure that the problem isn't in the Decimator by removing it from the chain.

Finally, what are your level setting on the TF? I'd try setting both switches on the TF to "Amp/Guitar," the amp's loop level to -10dBV, and the loop mix to 100% wet. (The TF's DRYKILL should be OFF in this case.) While the "line" setting on the TF seems appropriate with a loop level of +4dBV, in my experience, this can be noisier and may be where your problem is.

That's about all I can think of right now… let us know if any of the above helps, or if not, exactly what your settings are and we'll see if we can get this one figured out for you.

[tamburash007]

whoa, whoa.

hold a second.

+4dB is for effects – means amp/guitar on eventide.

-10dB is for line level isntruments (rack units) – means line level on eventide

and killdry ONLY when in in paralel loop, when in series; no.

[timothyhill]

I didn't suggest that KILLDRY be used in a series loop. You're right, it's for parallel loops. I suggested that the loop be set to series and KILLDRY be set to OFF.

I disagree with your assessment of levels, though. +4dB is a higher-level signal used in the US for professional audio. It's equivalent to 1.737 volts peak. -10dB is used for consumer audio, equivalent to .447 volts peak.

From the Marshall JVM410 series manual, "The +4dBu/-10dBV switch allows you to configure the loop for its use with either professional equipment (+4dBu setting) or with guitar level effects like effects pedals (-10dBV setting)."

From the TF Manual, "Most guitar amp?s Effects Loop run at Line Level so set TimeFactor?s Input and Output Level Switches to ?Line.?"

The switch on the amp allows you to select whether the loop runs at line or instrument levels and the TF should be configured accordingly.

I suggested that the OP try running the loop at instrument level, as in my experience, it seems be to quieter this way.

[timothyhill]

Just as a note, in almost all situations, I find that line levels are quieter and I was more than a little surprised that, in my setup, this is not the case with the factor pedals. However, this is just my experience with my system. Bottom line, use whatever settings work best and sound best for you in your rig.

Neo, my original reply was simply meant as a rough troubleshooting suggestion. Basically, just trying to isolate the problem. Once you figure out exactly where the problem is, it'll be easier to fix.

[tamburash007]

yep, i stand corrected…

anyway, when i tried to use timefacor in a loop with the amp/guitar – -10dB, it was peaking, when using linelevel, +4dB, not:)

[timothyhill]

Yeah, I've seen it peak at the -10dB setting and not at the +4dB setting, too. That makes sense… if the signal is at +1dB, it would be 11dB over the -10dB setting, but still under +4dB by 3dB.

Neo, let us know if you have any luck figuring out your noise problem, ok? So much of this depends not only on the pedal settings, but on the design of the loop in the amp. There are more than a few quality loops out there, but they're all somewhat different, not necessarily better or worse, just different. I'm sure that explains why I've found the Factors to be quieter in instrument level loops… it's the loop I'm using it in.

[neo84]

Thanks for the detailed answers. I'm getting to my rehearsal space this afternoon and will see If I can find out something more.

Just to make sure that we are speaking about the same "noise". For example I can play some lead parts using a high gain sound without any unwanted feedback BUT when using the TF it feedbacks a lot more. I think that makes sense with the db settings.

I'll report back what's going on :).

[timothyhill]

Hey, Neo! Just to make sure I'm following you, the noise is only an issue when using the TF while playing leads, right? I'm still thinking it's a level problem… the decimator's taking out the noise when you're not playing and when the TF's on and you're playing enough to cover the noise up, but not when you're playing sparse leads with the TF on. At least that's what I think is going on… it'll help to know what your exact settings are.

[neo84]

I can play with delay using clean or crunch sounds without any problems. Only in high gain sound Is get a lot of feedback in between playing which makes the delay useless.
In short: High gain without delay: No noise while playing and in breaks.
with delay: noisy feedback while playing and a lot of feedback when not playing or breaks in slow lead parts.

I did not have much time to test your advices but I did one thing which seems to improve the sound a lot.  My amp loop and the TF were both running in guitar level mode. I changed the TF to line level and it seems to be much better. I still need to try the different combinations on loop/TF to find out the best for me.

Thanks!

[timothyhill]

Good, glad to hear that you've made some progress… Finding the best combinations of settings takes some time, but I'm sure you'll get there. Keep us posted on your progress, ok?

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