MT15 FX LOOP help

[Dekard2233]

Hey guys and gals. New here but definitely not new to the music scene lol

Just got my MT15 and absolutely love it. One thing i do miss from my Dual Rec Multi-watt tho, is the Solo button lol soooo that being said, I put a Tc Electronic Spark in the loop just before the fx return after all my time/modulation pedals to gimme that wee bit of volume for a solo.

Trouble is, at about 8 or 9oclock on the Spark (im assuming maybe only about 4 or 5db) the amp feeds back on me. Not during actually playing but when I stop. Any thoughts? Swap out the fx loop tube? Hit the front of amp with the Spark instead of the loop?
Much appreciated is anyone can help out

 

[László]

Hit the front of the amp.

 

[Ovibos]

Or swap the Spark out for a GE-7 with a mild bump on level, and maybe a small boost curve.

 

[Dekard2233]

Hit the front of the amp.

That was my next step. I had already done that but made the newb mistake of putting it before my Maxon lol

 

[Dekard2233]

Or swap the Spark out for a GE-7 with a mild bump on level, and maybe a small boost curve.

I was thinkin that too. Altho ive never really been a fan of Boss pedals. I know I know...im in the minority on that one lol

 

[Dekard2233]

Does the fx loop/circuit in the MT15 just have enough headroom?

 

[László]

Does the fx loop/circuit in the MT15 just have enough headroom?

The preamp may be hitting the output section differently than with other amps, and that's not at all unusual with amplifiers. Keep in mind that you have 5881 tubes putting out far lower than their rated power to operate at only 15 Watts. There may be some tricks in the circuit to make that happen that affect the interaction between preamp and power amp sections.

Or not. I have no inside info on this.

 

[Ovibos]

I was thinkin that too. Altho ive never really been a fan of Boss pedals. I know I know...im in the minority on that one lol

Well, replace with your favorite EQ.

 

[László]

I was thinkin that too. Altho ive never really been a fan of Boss pedals. I know I know...im in the minority on that one lol

I'm with ya. They have a certain sound quality that bugs me.

It's too bad Pettyjohn stopped making their excellent Filter EQ. It's truly a studio-quality box, and mine will never leave my board. There may be some out in the wild at dealers or on Reverb, haven't checked. It's not a graphic EQ like the boss, but damn, it sounds the business.

I run mine in front of my amps, and haven't tried in the the effects loops of the amps I own. I'm not much of an effect loop guy.

I like to joke and say that effects loops are the spawn of the devil! They always seem to generate noise, impedance mismatches, etc., so at some point I simply stopped using them.

 

[elvis]

Sounds like ground loop, especially if it's relatively high frequency. Make sure the pedal power supply is plugged into the same outlet as the amp, and use a good isolated supply like the VOODOO pedal power pro or the OneSpot.

 

[Deli6505]

mre6cXH.jpg
This is something that works for me. No additional noise, very smooth and bold boost.

 

[Jazzedout]

I have a TC Spark and it is the first thing after my guitar in the signal chain without an issue.
You could try running it on battery to see if it makes any difference.

 

[claythomas]

I use a Plethora X5 in the effects loop and engage a compressor for my leads. Obviously this isn't for everyone but if you wanna use this example I'm sure there's gear out there to do the same thing.

 

[Goran Lorencin]

I'm with ya. They have a certain sound quality that bugs me.

It's too bad Pettyjohn stopped making their excellent Filter EQ. It's truly a studio-quality box, and mine will never leave my board. There may be some out in the wild at dealers or on Reverb, haven't checked. It's not a graphic EQ like the boss, but damn, it sounds the business.

I run mine in front of my amps, and haven't tried in the the effects loops of the amps I own. I'm not much of an effect loop guy.

I like to joke and say that effects loops are the spawn of the devil! They always seem to generate noise, impedance mismatches, etc., so at some point I simply stopped using them.

Is it not weird that PRS gets away with it?! It is basically a faulty unit, FX loop is not usable, why the hell put it in in the first place, where was quality control?! It is like buying a cabriolet and not be able to lower the roof. I love the little beast, but this really put a new perspective on amps and the process of buying one. Any chance that there is someone who fixed this? Like the proper way, fixing the board or replacing other internal parts and removing the noise from the FX loop.

 

[László]

Is it not weird that PRS gets away with it?! It is basically a faulty unit, FX loop is not usable, why the hell put it in in the first place, where was quality control?! It is like buying a cabriolet and not be able to lower the roof. I love the little beast, but this really put a new perspective on amps and the process of buying one. Any chance that there is someone who fixed this? Like the proper way, fixing the board or replacing other internal parts and removing the noise from the FX loop.

Given the large numbers of mismatches between FX loops and external gear, no I don't think it's weird at all.

I had problems with the FX loops on my previous Mesas when I ran rack gear, and this is one reason why I don't use FX loops; the other reason is I don't care for the sound. I like running everything, including delays and other time based effects, into the front of the amp where I think it winds up sounding organic.

Not all that long ago, in order to use and FX loop in a custom built, five-figure Dumble amp, you had to buy an external box called a Dumbleator; assuming, of course that you were a good enough player that Dumble would have been interested enough in your playing to build you an amp.

Let me ask something, perhaps this was asked before and I've forgotten: Have you tried contacting PRS customer service ? After all, the amp is under warranty.

 

[vchizzle]

Maybe too late but if looking for actual volume boost on the high gain channel, thru the loop is the way you need to go. A boost in front of the amp will not raise the actual volume on high, only compress and make the gain more saturated. Clean channel is a different story. Any boost can increase volume in either place there. I’m assuming you want the high gain channel louder when you hit a solo. Some pedals work better than others with certain amps in the loop. Experimenting is the only way to find out.

 

[Goran Lorencin]

Given the large numbers of mismatches between FX loops and external gear, no I don't think it's weird at all.

I had problems with the FX loops on my previous Mesas when I ran rack gear, and this is one reason why I don't use FX loops; the other reason is I don't care for the sound. I like running everything, including delays and other time based effects, into the front of the amp where I think it winds up sounding organic.

Not all that long ago, in order to use and FX loop in a custom built, five-figure Dumble amp, you had to buy an external box called a Dumbleator; assuming, of course that you were a good enough player that Dumble would have been interested enough in your playing to build you an amp.

Let me ask something, perhaps this was asked before and I've forgotten: Have you tried contacting PRS customer service ? After all, the amp is under warranty.

Hey Schefman, thanks for the answer and your experience, and yes I wrote to PRS and am waiting for the answer as I got a mail that they have heavy mail traffic at the moment, so I am waiting to see if they can help me.

But ... as I am new to tube amps ... maybe the hum/hiss is always present and I just am not used to it. I have done some fiddling with different tubes (especially 12au7 in the PI - V6 position) and I think it does help a bit, but I think it takes a bit of grunt away as well. I must say that the second/third time I was doing tests, the Sentry actually took some noise away from the amps lead channel and it is much more to my liking. Will do some more testing and get back to you with my findings.

It's a process

 

[Goran Lorencin]

Maybe too late but if looking for actual volume boost on the high gain channel, thru the loop is the way you need to go. A boost in front of the amp will not raise the actual volume on high, only compress and make the gain more saturated. Clean channel is a different story. Any boost can increase volume in either place there. I’m assuming you want the high gain channel louder when you hit a solo. Some pedals work better than others with certain amps in the loop. Experimenting is the only way to find out.

Well I tried the FX loop with just one pedal between the cables and there was always the hum/hiss present ... will try some other pedals and see what that does. Looks like the impedance mismatch is a big thing.

Could it also be because of the power supply? I have a new HB AC10-pro with 10 isolated outputs and never daisy chain as I have only 5 or 6 pedals on the pedal board.

 

[vchizzle]

Well I tried the FX loop with just one pedal between the cables and there was always the hum/hiss present ... will try some other pedals and see what that does. Looks like the impedance mismatch is a big thing.

Could it also be because of the power supply? I have a new HB AC10-pro with 10 isolated outputs and never daisy chain as I have only 5 or 6 pedals on the pedal board.

Not familiar with the power supply but isolated outs should help. Yes, a pedal in the loop can certainly add some noise. Some pedals worse than others. I usually have an isp decimator in the loop to get rid of that if running my pedalboard.

 

[Goran Lorencin]

Not familiar with the power supply but isolated outs should help. Yes, a pedal in the loop can certainly add some noise. Some pedals worse than others. I usually have an isp decimator in the loop to get rid of that if running my pedalboard.

I really messed up that power supply naming ... it is a Harley Benton ISO-10AC pro, which I think is an awesome price/performance option to other known name brand supplies that offer the same or less functionalities for a lot more cha-ching. And as I have seen and heard it works like a charm for now.

So in regard to the hum/hiss/buzz ... I think I have to test some more and slowly get used to the fact that I come from solid state amps, where the noise is not that pronounced. Until then, I`ll be going in from the front of the amp.