Does your MT15's loop suck too?

[Van Noord]

From day one, the loop has been terrible.
Whenever I put a pedal in the loop, the amp's output is diminished, and noise and hum gets introduced.
I've changed the effects loop tube, with no change. I also get a lot of RFI as soon as I put a pedal into the loop.
None of this happens when I plug straight into the amp, or put pedals in front of the amp.
It wasn't a big enough issue for me to send the amp back at the time, and honestly all I want to put in the loop is a reverb pedal.

 

[BrianC]

I did not have an issue with my loop at all. I DID have a problem with the massive HUM - sold it.

 

[andy474x]

I’ve not had that problem, mine works well. My board unfortunately does add some noise, but that’s no fault of the amp, it happens with all my amps.

Have you tried just a single cable in and out of the loop? If that works, could it be the pedal? On the PRS amps with loops that I’ve used, the loop output is post-MV, so it’s s hotter signal the louder the MV is set. Some pedals don’t like that, which sounds like it could be the case for you, maybe.

 

[Van Noord]

I’ve not had that problem, mine works well. My board unfortunately does add some noise, but that’s no fault of the amp, it happens with all my amps.

Have you tried just a single cable in and out of the loop? If that works, could it be the pedal? On the PRS amps with loops that I’ve used, the loop output is post-MV, so it’s s hotter signal the louder the MV is set. Some pedals don’t like that, which sounds like it could be the case for you, maybe.

A single cable end into the send creates a massively loud hum, single into the return is fine. Jumping the loop is also fine.
Any modulation, time based or volume pedal I put through the loop and the amp gets noisy, loses output and totally flattens out sound wise.

 

[andy474x]

What pedals specifically have you tried? If they’re known to work well with hotter loops, then yes it could be the amp. If not, could be the pedals.

 

[elvis]

My first step in setting up any amp loop is to put a buffer in series with the send. This usually fixes the level and tone issues.

Hum is a ground issue, and you can prove it by putting a pedal in the loop that is running on a battery. Isolated pedal supplies are generally the way to go here. Most built in pedal board supplies are noisy.

 

[Van Noord]

Pedals I've tried our are a DigiTech Digiverb, a Koko space reverb, a Boss Tera Echo, Boss GE-7, a DigiTech Hyper Phase and a cheap Chinese volume pedal.
All with the same results.
I've run the pedals by themselves off an independent boss power supply, as well as two or three on a daisy chain. Same results either way. I have not tried to run a single pedal just off a battery though.

 

[Deli6505]

Luckily, I have not had an issue with my loop at all. I currently have a TC Electronic Flashback delay and MXR Micro Chorus going to it and it sounds fine. I have, however, had some nasty hum coming from the front input but it turned out to be just a crappy cable. I must have gone through at least 5 different cables until I found one that was decent.

 

[elvis]

Def try with a battery. Most 9V supplies are not isolated and are a problem for hum. The voodoo labs supplies are great, but expensive.

The one-spot is a good alternative. Most people find that the cause of hum is the pedal power supply they are using.

 

[Brennen]

I have 3 pedals in my loop (EQ, Delay and Sonic Maximizer) with isolated power and have not noticed additional noise and or volume decrease. One thing I was unable to find online (when I was looking) was whether or not the FX loop on these is actually buffered. I agree with the above comment that a buffer might really help out, I have a JHS one on my pedal board and seems to keep things tight.

 

[elvis]

Even when they say the loop is buffered, it often is not buffered enough. 10k or more output resistance is common, but too high for a proper buffer.

 

[jak3af3r]

One thing I was unable to find online (when I was looking) was whether or not the FX loop on these is actually buffered.

Don't have this amp but do have a D-stlyle clone with an unbuffered FX loop. It doesn't buzz with a pedal in the loop but the volume does go in and out without a designated FX loop buffer.

 

[ibanezfan1]

I just received my MT15 a couple weeks ago and so far, I have had no issues with my effects loop; it's very quite and I don't detect any desegregation in signal and/or volume.

My signal path is guitar > Audio Technica wireless > TC electronics 3 tuner > CAE wah > front of amp
Effects loop > Boss DD3 > Mooer King Chorus > Boss BF3

All powered by Voodoo Lap Pedal Power 2

Bodie