Noise in effects loop with analog stomp boxes, even when bypassed?

[russgoos]

My HD500X is producing a noticeable hiss when I try to add analog pedals via the effects loop, even if that loop is not active.  For example, I have the effects loop programmed into a block in front of the amp(s) block.  Even if I turn the effects loop off, I can still hear the noise AND a hissy version of the analog stomp pedal itself.  In this case, it's an EVH Phase 90 MXR pedal.  The same issue is present when I try the EVH 117 flanger pedal.

 

Using standard instrument cables, the HD500X's FX SEND connected to the input of the stomp box.  The stomp box output is connected to the FX RETURN L/MONO on the HD500X.  The FX level switch is set to STOMP.

 

Also, the stomp boxes sound better when NOT used in the FX Loop of the HD500X.  For example, if I plug my guitar directly into the stomp box itself, then connect the output of the stompbox to the GUITAR IN jack of the HD500X it sounds less noisy and more natural.

 

I use batteries to power the stomp boxes.

 

Any advice for solving the FX loop noise issue?  Thanks!

[radatats]

I don't have a clue why you should be hearing any noise whatsoever if the FX Loop is turned off.  That is not possible to my mind and I use pedals in my loop.  If I turn the Loop off there is nothing from the pedal at all.

 

Do you have the FX Loop mix set to 100%?  Make sure it is so your full signal goes out to the pedals and back.

 

As for the other question, try lowering the SEND level and see if that helps at all.  You can compensate volume by raising the RETURN levels.  You can also try setting the switch to LINE and adjusting levels to see what that does for you.

[spaceatl]

short circuit your FX Loop with a cable...Did you try one pedal at a time? Might help isolate where the issue is coming from...Odd you hear things with the loop off...

[russgoos]

Thanks for the advice!  Yep, this is a strange issue!  The concept is very simple so I was surprised with the noise problem.

 

radatats, I don't know what % the mix is for the FX loop.  I did leave it at whatever the default is when I added it to the block.  I'll check that next time I get to my rig.

 

spaceatl, I have tried one pedal at a time, same result.  I will definitely try isolating things one by one.

 

I'll try to report back my findings, but it might be a couple days until I get a chance to experiment.

[spaceatl]

Ok....I think I see hwat could be part of your problem here....It's the pedals together....A level and impedance mismatch Eddie did on purpose....This might be a case for a BOSS LS-2 for the buffer correction...anyhoo, this is what I see...

 

The HD Loop switch between +4 and -20 dbv....10K I/O impedance I think...

 

EVH-90 is a 1M input and 10K output with -20 dbv input and output...

 

EVH117 is 470K input and 1K output impedance with +5 dbv input and output...A loud tone sucker...

 

Needless to say, these pedals are completely different....EVH90 is high impedance input, so I think you want to put it before the 117....This is what Eddie did, but that line level was taken off a dummy load on the speaker output....The 117 is low impedance and going to suck the tone and make it turn brown....At least his is part of the recipe...

 

My suggestion: HD Loop set to Line Level

HDSend->EVH90->EVN117->HDReturn

 

The reason I say Line Level is because Eddie hit the phase 90 off a dummy load...Because it's 1M input, it will not overload very easily....This is probably where the tone is too...The flanger on the end is a no brainer...That's part of the tone bowning....Basically, I think if you are trying to approximate the sound of these pedals, you gotta slam some signal thru them....you might need extra buffers Like a BOSS LS-2 to drive the pedals like they need to be driven AND match the level and impedance back to the HD...Eddie was all about using a "house of cards" in impedance mismatches all over his rigs getting that tone....Really cool stuff...

[russgoos]

spaceatl, thanks for that information.  It's a lot to take in!  I'll try them one by one first.  If I can get them to behave individually, I'll try pairing them up with the EVH90 first in the chain.  I'll try the Line Level switch too.  I should have some serious experimentation time this weekend.  I'll report back what happens.

 

Many thanks!

[phil_m]

If you have the trails parameter turned on in the setup menu, that effects return stays on even when the effects loop block is bypassed. That why the noise is there even with the block off.

[russgoos]

phil_m, that is very interesting.  I'll look at that trails setting too!  That logic seems to make sense... if that return remains on, the swooshing of the pedals (which are also left on) would be audible even with the loop turned off, one would think.  Very interesting - thanks for the tip!

[Brazzy]

If you have the trails parameter turned on in the setup menu, that effects return stays on even when the effects loop block is bypassed. That why the noise is there even with the block off.

 

Good Think'in! Thanks. I may've never thought of this.

[russgoos]

phil_m, the trails setting was the culprit.  Switching the trails to OFF fixed the issue right away.  Thanks very much for the tip!

[panaman]

if you like the trails you could use a footswitch to bypass  the loop and set the fx loop return level to zero with the same footswitch

[russgoos]

Hi panaman, the trails aren't a big concern for me but thanks for the tip!

[phil_m]

if you like the trails you could use a footswitch to bypass  the loop and set the fx loop return level to zero with the same footswitch

 

You can't tie parameters within an effect to a footswitch like that. You could have the FX loop return level controlled by one the expression pedals if you wanted to, I suppose.