Serial or Parallel FX loop?

[Danster]

You out there James? :)

I have a multi-effects unit which tells me to set the mix on the unit one way if my amp has a parallel FX loop and another way if the amp has a series FX loop. My amp manual doesn't specify which it is. How can you tell? In my simple minded way of thinking, if it were a series loop, then there would have to be something hooked up to the loop always or you would get no signal. How far from right is that?

Thanks,
Dan

[szulc]

Most amps have a serial effects loop. Now I have heard Eric mention his Laney has both types, this is new and unusual.

The jacks in a serial loop are switched so when you have nothing plugged into the return, the loop is bypassed. You can tell by plugging one end of a cable that is connected to nothing at the other end into the return and listening for sound, my bet is you will hear nothing, which means your loop is serial. In general if you play with a band and have a decent PA system you will not use effects on your amp at all. Use them in the effects loop of the mixer (which is parallel) or in series with the signal to the board from your line out or efx send. Make sure to use a direct box with a ground lift to isolate your ground from the PA ground, otherwise you will experience noise. I also suggest miking your cabinet and mixing the signals at the board. If your band is big enough you will have a separate monitor mixer for mixing the stage volume, a lot of the time you can use effects on your monitor mix the never get heard out front. This is useful for you to get that warm fuzzy feeling and be able to be inspired and also out front you rarely need reverb or lots of delay.

[Danster]

Originally posted by szulc
[B]Most amps have a serial effects loop. Now I have heard Eric mention his Laney has both types, this is new and unusual.

The jacks in a serial loop are switched so when you have nothing plugged into the return, the loop is bypassed. You can tell by plugging one end of a cable that is connected to nothing at the other end into the return and listening for sound, my bet is you will hear nothing, which means your loop is serial.OK, I did this, and I still had guitar coming through the amp, very crackly though. Does that mean its parallel?

In general if you play with a band and have a decent PA system ...Dude, I'm a living room player. I went ahead and got my 100W amp so I'd be arena ready when I get my chops in order. :D

[szulc]

Try the same trick again with a cable plugged into the efx send and nothing at the other end and also one plugged into the efx return and nothing at the other end.
The other easier test is to hook up your efx unit in the loop and move the slider or switch to parallel and set you efx to a long delay if all you hear it the delayed signal then it is serial if you hear both the original and delayed (at about the same volume ) it is parallel.
No one needs a 100w amp for any gig! (Except maybe a bass player)
I have played very large venues with a 35 watt amp and was probably only using 20w. Your stage volume is never very loud when you have a good PA system. The sound man wants to control your sound, so he wants as little stage volume as possible. You get your sound to the other players via the monitor system. In General the amp just needs to sound good, you can even use a load box (Eddie did on the first Van Halen Album), and have no stage volume. I did a couple of gigs with a rockman and headphones after the guys gave me s#$% about stage volume, they did ask me to use my tube amp the next night! The other problem with high stage volume is the guitar bleeding through the drum and vocal mics. I highly recommend using a lower wattage amp or removing the outside two power tubes, and also using a hot plate or similar device. The other thing is when you play smaller clubs the owners/managers get upset if you are loud.

[Danster]

Try the same trick again with a cable plugged into the efx send and nothing at the other end and also one plugged into the efx return and nothing at the other end.OK, I did this, and I got the same result as the previous test. That is, I still got guitar through the amp.
The other easier test is to hook up your efx unit in the loop and move the slider or switch to parallel and set you efx to a long delay if all you hear it the delayed signal then it is serial if you hear both the original and delayed (at about the same volume ) it is parallel.To be a little more complete, I want to describe things a little more thoroughly. The mix switch on the FX unit is labeled "Dry" on one end and "Wet" on the other (perhaps you knew that, but I don't know if "Mix" always means that). The manual says to set the mix level at 12 o'clock (50%) for a serial type FX loop, and to 100% (all wet) for a parallel FX loop. According to the delayed signal test you mentioned, mine is a serial loop. That is, I set the mix at 100%, and I only heard the delayed signal. With the mix at 50%, I get the original and the delayed signal.

So now maybe you can help me a little more (pleeze!). I don't quite get why the FX manual says to set the mix at 50% for a serial FX loop. It is my understanding that 50% mix means that the sound you'll hear coming from the amp is 50% the pre-effects signal, and 50% the signal with effects. This is borne out by the test you had me do. While it does make sense for delay to have the mix set at 50%, wouldn't one typically want 100% wet for most other effects? I can control the intensity (for lack of knowledge of the correct term to use here) of the effect by controls on the FX unit other than the mix control. I'm guessing the mix just gives one more way of controlling that "intensity"??

Incidentally, my amp also has a mix control. I paused earlier while writing this, and went to my amp, and found that if I set the FX unit mix to 100%, and set the amp mix to 50%, I get the same result as the other way around (fx mix @ 50% and amp mix to 100%), hearing both the original and delayed signal. So are these two mix controls interchangeable such that I could set one on 100%, and the other to 50% (or whatever), and it wouldn't matter which was which?
No one needs a 100w amp for any gig! (Except maybe a bass player)As I said earlier, I'm a living room player. The 16w amp I was using earlier was only loud enough to blow out my own windows. I wanted to be able to blow out my neigbors windows also. :) Joking aside, I know I didn't need that much power. I didn't buy the amp for its power rating. I was really looking for something in more a 30w range, but this one came along (I bought it used), and it had the other features I wanted and the price was right.

I appreciate all your help James. My goal in life is to someday be able to help you with a music-related problem. :D

[szulc]

It is rare to have an amp with a mix setting, what brand of amp is this, and is it a tube amp?
This really means that when your amp is set to mix at 50% you have a parallel loop but when iti is set to wet it is a serial loop.
Most amps that have this feature give you just a switch. Chorus/flanging won't work with only wet actually phasing shouldn't either (but most phasors have the signal mixed internally). The only things I can think of that you want in your loop that are serial are a noise gate and compressor/limiter. If you use a wah, use it before your amp, the same with a phasor or distortion stompbox. Now you could use all of these in a serial path to your mixer, but phasing and wah sound much different after the distortion of your preamp than before. In the case of having both methods use your ears to decide. But if you use a noise gate or compressor limiter, set your amp to wet and use the mix control on your efx unit.
What brand (make ) of efx unit do you have?

[Danster]

It is rare to have an amp with a mix setting, what brand of amp is this, and is it a tube amp?It is a Tubeworks RT2100. It is a hybrid amp with tubes in the pre-amp stage and a ss power amp stage. This model is not made anymore. I think I recall reading somewhere that they were made in the early 90's.
This really means that when your amp is set to mix at 50% you have a parallel loop but when iti is set to wet it is a serial loop.OK, that makes sense.
Most amps that have this feature give you just a switch. Chorus/flanging won't work with only wet actually phasing shouldn't either (but most phasors have the signal mixed internally). The only things I can think of that you want in your loop that are serial are a noise gate and compressor/limiter. The FX unit has a compressor, but I don't want to use that (for practicing at least), cuz I think learning to play the proper dynamics is important. Would you suggest then that I set the amp mix to 50% so that I have in effect (lil pun there :)) a parallel FX loop? I'm new to all this stuff in case ya couldn't tell. :)
What brand (make ) of efx unit do you have?Its a TC-Electronics M300. I actually won this in a Berklee Music Press Internet contest about a year or so ago. I originally thought this thing was a piece of junk, because it hissed like crazy with my old amp any time I had just a little gain dialed into my amp. With my new amp, the fx unit adds no hiss. So I'm really just now learning how to use it.

[szulc]

I'll bet the pot is less noisey on the TC so I would set the amp to 100% ans use the tc unit to mix, besides when you want to use the noise gate or compressor function this will be how you will have to set it anyway. Eventually you will want to use the noise gate and compressor, using a compressor , especially on clean sounds helps keep the note sustaining. The trick is not to set the ratio too high or the threshold too low, that way you won't lose much of your dynamics and only effect the release of the note. The noise gate is similar in that you want to set the threshold high enough to get soft passages through, but low enough to eliminate the hum and other noise.