Parallel effects loop

[Wireneck]

I have been using a Tc Electronics m300 in my Mesa's effects loop for over a year without problems. I recently purchased a Framus Cobra http://rocksolidamps.com/index.php?contain=description&ii=64&mid=2 and I decided to put the m300 in its effects loop.
The manual states that it is a parallel effects loop. I have the mix on the m300 set to 100% wet. I have to turn the fx loop knob on my amp to almost 50% to really hear any effects. When I bypass the unit, The tone of the amp sounds really nasally like something is slightly out of phase. I never had this problem with my mesa or marshall. Any ideas what might be causing this and how to get around it?

 

[travelin travis]

have you tried using a patch cable in the effects loop?

 

[Wireneck]

Travis I am not understanding your question. How else would you put it in the fx loop? In other words, I always use patch cables, unless of course your referring to something else.

 

[ggunn]

I have been using a Tc Electronics m300 in my Mesa's effects loop for over a year without problems. I recently purchased a Framus Cobra http://rocksolidamps.com/index.php?contain=description&ii=64&mid=2 and I decided to put the m300 in its effects loop.
The manual states that it is a parallel effects loop. I have the mix on the m300 set to 100% wet. I have to turn the fx loop knob on my amp to almost 50% to really hear any effects. When I bypass the unit, The tone of the amp sounds really nasally like something is slightly out of phase. I never had this problem with my mesa or marshall. Any ideas what might be causing this and how to get around it?

Some effects invert the signal, and if you run one of those in parallel, you will get some destructive interference (cancellation) of your signal. Perhaps that is what you are hearing.

 

[Wireneck]

GGUN- I only hear the change when the effects unit is bypassed. The tone sounds almost like a phaser is on but not sweeping, if that makes any sense.

 

[ggunn]

GGUN- I only hear the change when the effects unit is bypassed. The tone sounds almost like a phaser is on but not sweeping, if that makes any sense.

Yes it does, and it very well could be cancellation. It could be that the loop is phase inverted to compensate for the phase inversion that an effect produces, and when the effect unit is bypassed, the loop return is then flipped.

 

[NRS]

A paralell effect loop means your final sound will be a combination of what your dry amp sounds like without any effecs, blended with the wet signal that is running through the effects loop. So with the effect loop set at 50%, half your sound is completely dry signal while the other half is whatever is in the loop. Turn it up to 100% and your entire signal will pass through the loop without the blended dry one. This should solve your phase issues if you cant do it from your effects unit (providing its a phase issue at all).

If you take that approach you will then have to adjust your desired effect level completely from the FX unit instead of with your effects loop level on the amp. You can then toggle your effects loop on/off with your amps footswitch (if it does that) instead of having to use your effect bypass if that is what is causing you problems.

 

[OhSh1rt]

Travis I am not understanding your question. How else would you put it in the fx loop? In other words, I always use patch cables, unless of course your referring to something else.

I think he means running a cable jumpering the FX Out -> FX In

 

[travelin travis]

I think he means running a cable jumpering the FX Out -> FX In

Yes, that's what I meant. When I owned a dual rec, I noticed a difference in the sound when running a patch cable in the loop and adjusting the efx loop level.

 

[ggunn]

Yes, that's what I meant. When I owned a dual rec, I noticed a difference in the sound when running a patch cable in the loop and adjusting the efx loop level.

I'm not familiar with that setup, but might that be because the FX send has one more gain stage than the passthrough and is therefore inverted, so that when you do that you get some cancellation?

 

[travelin travis]

I'm not familiar with that setup, but might that be because the FX send has one more gain stage than the passthrough and is therefore inverted, so that when you do that you get some cancellation?

I don't anything about how the dual recs are built but I know that with the send level up, it added a bit more gain.

 

[Wireneck]

Travis so how do you set it up with the patch your mentioning. Our other guitarist used a dual rec and now that you bring it up, he had a similar issue which he never resolved. I just remembered that.

 

[travelin travis]

Travis so how do you set it up with the patch your mentioning. Our other guitarist used a dual rec and now that you bring it up, he had a similar issue which he never resolved. I just remembered that.

Just stick a patch cable in the loop from the send to the return. Try adjusting the send level up/down. Take the cable out and compare with it in. Dial in some different sounds and try playing with the cable in/out and send level up/down. It just adds something a little different to the sound. It's not subtle but it's not extreme either.

 

[Wireneck]

but thats taking the effects unit completely out of the loop right? My point is that I want to use the m300 in conjunction with my head. If I am not using the unit, I just set the fx loop knob to full dry.

 

[travelin travis]

but thats taking the effects unit completely out of the loop right? My point is that I want to use the m300 in conjunction with my head. If I am not using the unit, I just set the fx loop knob to full dry.

So you're saying that with the efx unit in the loop, and the send level on the amp at 0, the amp sounds different than with the efx unit out of the loop?

What I was talking about is using the efx loop on a dual rec changes the sound of the amp. I think I missed your question.

 

[Wireneck]

Its probably my wording.

-Effects unit in the loop set to 100% wet
-Effects loop set to 50% on amp
-playing with effects on, amp sounds normal
-Bypass the fx unit and the amp suddenly sounds like something is out of phase

 

[Outlaws]

Doesn't a $3000+ amp have an effects loop you can footswitch on and off?

 

[boingoman]

Its probably my wording.

-Effects unit in the loop set to 100% wet
-Effects loop set to 50% on amp
-playing with effects on, amp sounds normal
-Bypass the fx unit and the amp suddenly sounds like something is out of phase

The problem is most likely latency in the M300. If it's not a true bypass, there will be enough latency from the AD/DA conversions to cause annoying phasing in a parallel effects loop. When the unit is in action, there is no original signal coming out of the FX loop, so you get no phasing.

Set the M300 to mute when bypassed.