What type of FX loop does the MT-15 have?

[Yzerman]

I get a huge volume jump when using my Boss BF-2 flanger in the loop and i'm thinking the loop might be line level? If so, this is disappointing... most people are using pedals these days and the amp should have been built around that.

 

[elvis]

Actually, a huge number of users have multi FX. There are a variety of FX levels, so usually the channel master or amp master volume controls the send volume.

If your pedal is not being overdriven, then the loop level is not actually line level. Also, a jump in volume when inserting a pedal is also not about the send level.

Either the pedal is not unity gain, so turn down the pedal output level, or the loop adds gain when you plug into it. You can check if the loop is adding gain by plugging a patch cable from fx send to fx return. If that causes a volume bump, then the loop has gain. If not, it's your pedal.

 

[László]

Elvis is exactly right.

Though he forgot to mention that effects loops are the spawn of satan.

 

[Yzerman]

Actually, a huge number of users have multi FX. There are a variety of FX levels, so usually the channel master or amp master volume controls the send volume.

If your pedal is not being overdriven, then the loop level is not actually line level. Also, a jump in volume when inserting a pedal is also not about the send level.

Either the pedal is not unity gain, so turn down the pedal output level, or the loop adds gain when you plug into it. You can check if the loop is adding gain by plugging a patch cable from fx send to fx return. If that causes a volume bump, then the loop has gain. If not, it's your pedal.

These pedals worked fine with Marshall, Mesa and Orange amps.... somethings off with the FX loop on the MT-15. Is it Parallel or serial?

 

[andy474x]

Elvis is exactly right.

Though he forgot to mention that effects loops are the spawn of satan.

Runnin’ with the devil!

Yzerman, have you tried any other pedals in the loop? I’ve run delays and reverbs, a noise gate, and a Boss LS2, and not had any issues. Perhaps it’s something particular to this amp and pedal combination? Also, have you tried replacing the driver tube for the effects loop? Just a thought.

 

[Falcon1]

The fx loop is wired in series according to the owners manual. Hope this helps. Does your flanger have an internal volume pot? I know my flanger has one..as well as my tremolo..not to be mistaken with the level knob on the pedal.

 

[elvis]

These pedals worked fine with Marshall, Mesa and Orange amps.... somethings off with the FX loop on the MT-15. Is it Parallel or serial?

Parallel vs serial won't give you a volume jump like that unless the pedal has gain.

Divide and conquer.

Pull the pedals out off the loop.
Play with nothing in the loop.
Put a patch cable between FX send and return. Same?
Add ONE pedal at a time.

When you find a volume jump, stop. That thing is the cause. Then you have to figure out why.

Does the BF2 cause a volume jump between on and bypass? Does it do the same if you plug into the front of the amp on the clean channel?

 

[Yzerman]

Parallel vs serial won't give you a volume jump like that unless the pedal has gain.

Divide and conquer.

Pull the pedals out off the loop.
Play with nothing in the loop.
Put a patch cable between FX send and return. Same?
Add ONE pedal at a time.

When you find a volume jump, stop. That thing is the cause. Then you have to figure out why.

Does the BF2 cause a volume jump between on and bypass? Does it do the same if you plug into the front of the amp on the clean channel?

Update

I've messed around with my setup on the weekend and i can isolate it to the Flanger. For some reason the loop doesn't agree with it so i might need to run it out front or look at another brand.

 

[andy474x]

Update

I've messed around with my setup on the weekend and i can isolate it to the Flanger. For some reason the loop doesn't agree with it so i might need to run it out front or look at another brand.

I did some reading on loops and flangers after your original post, and learned some new things. Apparently this issue is fairly common. Flangers work by passing the signal through, and then passing some back through again, phase delayed, for the flange effect. Amps with a “hot” loop throw off the gain ratio especially when stacking signal in this way.

 

[Deleted member 5962]

Yes, plus, I like flanger in front even when I'm running delays, verbs and chorus in the loop. So try it in front before you go Flanger shopping.

 

[elvis]

You can also use a loop attenuator like an Ebtech LLS to get the loop level down to instrument level before your pedal effects and back up to line level after the effects.

 

[watelessness]

I cant run my flanger in loops either

 

[Paul Bouthiller]

I tried running my BOSS NS2 and a few effects in the effects loop to no avail. Buzzing, hiss etc. Sounds worse then running in simple mode. I don't get it.

Also, I like my Phaser or Flanger in front of the NS2.

 

[shimmilou]

Have you tried what elvis suggested above?

"Pull the pedals out of the loop.
Play with nothing in the loop.
Put a patch cable between FX send and return. Same?
Add ONE pedal at a time."

 

[Goran Lorencin]

I`ve also had birth cramps when I bought my MT15 (although secondhand), FX loop as well ... then I tested and tested and tried and searched ... then a few week later I swapped some tubes (one JJ was faulty, and two were swapped because I wanted a different sound and also used one frame grid JJ) and it all got much better ... sort of kinda magic