When sending a unit into the effects return what is it doing exactly?

TUEP · #1 02-20-2013, 02:13 PM

I ran my Behringer BDI-21 into the effects return on the B2R Amp and noticed it was considerably different in a cool way. But I also noticed none of the knobs on the amp work. Like the gain, and EQ knobs. I will I know if I am sending to strong a signal to the power amp? I have never done anything like this before I learned about it reading these boards.

Its pretty damn cool...I bet my Digitech BP-50 would sound a lot better into the effects return than straight into the front end of this amp. But will pushing the Behringer cause any damage to the power amp unit itself? I kind of rely on the blinking light by the Amps gain switch to make sure I am not pushing anything to hard.

Also this Amp has a power amp in. How does that work?

will33 · #2 02-20-2013, 02:24 PM

Going in the effects return bypasses your amps preamp/tone controls and goes right to the power amp section. It's like replacing your ampeg "front end" with a different one, but still using it's power.

Got2SadowskyNYC · #3 02-20-2013, 02:32 PM

This is NOT true for all loops. They can be in different circuit locations and send/return voltages.

Depending on the output voltage of the 21 you MAY not be driveing the amp with the proper voltage. Although this will not hurt anything, it will sound different.

The 21 isn't really designed to push a power amp so I would try it both ways, in the return and in the front with the EQ set flat, and see which you like better.

(A note about Ampeg's EQ: Flat is not 100% flat. It will color a bit. You'll also get a litte color from the power amp alone because Ampegs are designed to sound like Ampegs.)

Downunderwonder · #4 02-20-2013, 02:35 PM

If you send too strong a signal your speakers will blow up, or the amp will clip harshly and sound like ass.

JimmyM · #5 02-20-2013, 05:03 PM

Quote:

Originally Posted by Got2SadowskyNYC

This is NOT true for all loops. They can be in different circuit locations and send/return voltages.

Depending on the output voltage of the 21 you MAY not be driveing the amp with the proper voltage. Although this will not hurt anything, it will sound different.

The 21 isn't really designed to push a power amp so I would try it both ways, in the return and in the front with the EQ set flat, and see which you like better.

(A note about Ampeg's EQ: Flat is not 100% flat. It will color a bit. You'll also get a litte color from the power amp alone because Ampegs are designed to sound like Ampegs.)

Not so much with the B2R and that series of amps. They were designed to attract players who don't traditionally want "Ampeg voicing" and are way flatter than their other amps.

But you are right that not all effects loops do that. Markbass is one glaring example...you can't bypass their amps' preamp by plugging another preamp into the effects return on them. Ampegs, however, allow it.

Got2SadowskyNYC · #6 02-20-2013, 05:15 PM

I didn't notice the power amp in option. This is what you want to use. This bypasses the internal pre completely, including the effects loop.

It works by interrupting the signal coming from the internal pre and replacing it with what ever is plugged into that jack.

Keep in mind that you will be bypassing the internal pre COMPLETELY, so you can plug something in the front of the amp all you want but it will not get to the power amp if there is something plugged in at the power amp in.

TUEP · #7 02-20-2013, 07:59 PM

So what should I use? The effects return jack or the power amp in jack?

Jim C · #8 02-20-2013, 08:08 PM

Whatever sounds best
For your application you are either inserting the effect before the pre-amp (and pre-EQ), or, between the pre-amp and the power amp (post amp EQ).

chaosMK · #9 02-20-2013, 09:25 PM

That's essentially what it does. I can depend on the amp, sometimes the graphic EQ is post FX loop (it is on my Bass 400/D180).

If you are using a tube amp sometimes running stuff in the FX loop can help you control whatever gain staging is going on. For example... running your pedal in front may hit the front end of the amp hard and cause overdrive (which can be wanted or unwanted), and running it in the FX loop may allow it to stay cleaner (or the inverse- slam a tube power section) for example.

For me getting to know how my FX loops worked on my various amps was a major step in improving my tone. If you have a tube driven FX loop you can play with that too. Sometimes I use them as an extra gain stage to either add gain or keep the preamp hot but send a small signal to the power section (if you have send/return volume), or manipulate them with a certain type of tube (EC 5751 for example).

Nephilymbass · #10 02-23-2013, 05:43 PM

I run my sans amp RBI into the effects return of my swr 750x to use it as a power amp. The limiter and master volume contols of the 750 still work the same the fx mix knob is basically turned into another volume control but none of the other controls do anything. So I would assume in most amps going into the effects return is bypassing the preamp all together. Btw this has been my set up since the RBI first came out and it hasn't don't any harm and is much louder than using the inboard swr pre

B-string · #11 02-23-2013, 05:52 PM

No harm. Most effects loops are series loops (preamp signal gets isolated). There are parallel effects loops out there.