Why An Effects Loop Mod To Serial Needed???

[recto-robbie]

Hello all,,,I keep reading about people stating they want to change their effects loop to serial. Im wondering what this will bring?
I own a rectoverb series 2 combo, bought brand new with nothing changed on it so it leaves me wondering what people can expect from doing such a mod?
The reason I ask is because currently im running a delay pedal,chorus pedal and an EQ in the loop and they all sound nice and quiet.
I cant believe that my amp is any different than any other and im just not that lucky to have no problems.
I will say that I have owned another EQ pedal and chorus pedal and both seemed to create some deep thumping sound when I used to much bass from the pedals.
Could this be what people are talking about? I chalked it up to simply,possibly overloading the loop circuit? Just a guess on my part.
I also changed the v4 12ax7 from a high gain EH to a standard
jj 12ax7. I dont really know if that helped with the thumping problem because I already replaced the previous EQ and chorus pedals with pedals I liked better.
Anyways I havent had any problems using the effects loop with the new pedals....
Any ideas,,will be appreciated

 

[jbird]

A series loop sends the entire pre-amp signal through whatever you have in the loop! So, if you have signal degrading effects, it will degrade the entire signal! Parallel loops allow you to blend in a desired amount of the affected sound with the original signal, thus preserving some of the un-affected tone! I would imagine quality rack effects may benefit the user/amp of a series loop, where pedals may be better utilized in a parallel loop,as yours!

 

[recto-robbie]

Thanks for the responce jbird. I do understand what your saying there and it makes sence to me but just for the sake of knowledge here I had read my ROV owners manual the other day and it said the effects loop was designed for and better off used with a high quality rack unit.
So you can imagine why im a bit confused.
Any of you guys out there who did have your effects loop modded to serial, what did it make better? More quiet? Clearer? More pronounced?
Im not planning on doing the mod nor do I want to, but like I said,for a better understanding of the reason for the mod, because I keep seeing it posted.
Thanks again all

 

[jbird]

There may be instances in a parallel loop where your running a digital effect, your trying to blend the affected signal back in, but there's a weird oscillation going on? Possibly better off with a series loop then? :?

 

[dumeril7]

Series loops are better for "in-line" effects like compression and EQ where you want to process the entire signal.

Parallel loops are better for effects where you want to mix the effected sound with the uneffected sound -- such as delay, reverb, chorus, etc.

But there are other reasons that people want to go with serial loops.

To get the most performance from a parallel loop, you want to configure your effects so that they put out a 100% wet signal, then mix in the proper amount of wet signal using the FX loop mix control on the amp. But if you're using a programmable multi-effect, not every effect is going to require the same mix setting. At that point, it may make more sense to use a serial loop and then set the relative wet/dry mix as part of the effect program.

Now, for some people, setting the amp's mix control to 90% (which mean that 90% of what you're hearing is from the output of the effects and 10% is the dry signal from the amp) works well enough to not bother with a series mod. However, some effects devices put out a dry signal that is out of phase with the input signal. When you mix that with the 10% dry signal from the amp, you get a comb filtering effect that sounds terrible.

D7

 

[dumeril7]

Thanks for the responce jbird. I do understand what your saying there and it makes sence to me but just for the sake of knowledge here I had read my ROV owners manual the other day and it said the effects loop was designed for and better off used with a high quality rack unit.
So you can imagine why im a bit confused.
Any of you guys out there who did have your effects loop modded to serial, what did it make better? More quiet? Clearer? More pronounced?
Im not planning on doing the mod nor do I want to, but like I said,for a better understanding of the reason for the mod, because I keep seeing it posted.
Thanks again all

I think that the reason the manual recommends "high quality rack unit" for putting into the loop has to do with the loop being line level (as opposed to the instrument level input/output on a stompbox) and low impedance. However, a lot of stompboxes work just fine in the loop. Its one of those things where you just need to try it out to see if its going to work for you.

For myself anyway, having a serial loop isn't about improving the fidelity of the sound. Its more about wanting to put an in-line effect in the loop, or wanting to control the wet/dry mix from the effect devices rather than from the amp's mix control, as I described above.

D7

 

[Chad]

If you have level problems, try one of these:

I'm not using one with my DR, but am successfully using one with several pedals in the serial loop of my Randall RM50B.

 

[recto-robbie]

Man oh Man,,,you guys are good,,thanks much for all the info here.
Im beginning to understand some now.
I can assume from what one of you wrote is that with my effects loop level control on the back of the amp at 90%. The sound I am hearing is
90% affected by the pedals Im running through it, 10% is left untouched. Correct?
Thanks again all,,,Im going to mess with it a bit tonight,,maybe more understanding will result.. Thanks again

 

[pjrake]

i'm one of the one's that's in the process of getting my amp mod to serial (or is it series? hahahahaha)

anyway, i've tried for about a year with parallel loops, using pedals, and then the xpression unit and just could not for the life of me get a nice sound out of it.

i get my amp back from the shop tomorrow so i'll post an update on the sound. another thing i kinda wanted was to get rid of the master volume and just use the channel volumes. i feel that i can drive the tubes better that way. technically i can be wrong, but to my ears the amp sounded better when i bypassed the FX loop and used the channel masters for volume.

 

[dumeril7]

MI can assume from what one of you wrote is that with my effects loop level control on the back of the amp at 90%. The sound I am hearing is 90% affected by the pedals Im running through it, 10% is left untouched. Correct?

That's it, yes. Think of the mix knob as setting the balance between two sounds -- the sound from the pedals and the sound from the amp prior to the pedals.

The thing is, even when you set the mix knob at one extreme or the other, there is still some bleed from the other side into what you hear. If there were no bleed, then a serial mod would not be necessary because turning the knob all the way over to the "wet" side would effectively turn the loop into a serial loop.

D7

 

[ylo]

As explained in another thread on this topic, some effects introduce phase reversal. When used in a parallel effect loop, blending the effected back in with the straight sound can cause cancellation. This can sound like weird drops in volume, especially for the unaffected (initial) sound relative to delayed sound when using reverb and echo units, as I recall from the descriptions.

You can avoid this by keeping the mix at 100%.