Using the effects loop as an antenuator

[kjrocks]

2 t's I know ^^^^
I remember reading something about this back on the old Rivera board but thats gone now. I think some said if your effects loop has send and return level controls you can loop it and use it as some kind of attenuator. You can crank up your volume or master volume and throttle it in the loop.Does is really work this simply or is not really the same thing? Any dangers?

 

[JammerMatt]

Re: Using the effects loop as an antenuator

You can use a volume pedal, or effects unit that has a volume control. Yes it works (I use a volume pedal), and no it shouldn't hurt your amp (at least it won't hurt mine). You will go through power tubes faster since you're cranking them up. It will alter the tone, but so does everything.

 

[ErikH]

Re: Using the effects loop as an antenuator

It will not be an attenuator. You'll still be choking the volume down before the power amp stage. An attenuator goes between the amp and speakers and chokes the volume down AFTER the amp.

Think of the Master Volume as a water valve. You crank it up and more water flows. Now, you put something in the effects loop to choke the volume down, guess what, that's another valve and you just cut back the water flow to the same spot that it was before opening up the MV. Silly analogy, but it's easily understood.

If you want to attenuate, get an attenuator. Plain and simple.

 

[Tor]

Re: Using the effects loop as an antenuator

I take it you have a parallel loop, so you can adjust the presence of the loop?

Take a look at this thread, you'll soon find a (cheap!) loop attenuator trick by a user named hal9000... I've tried it myself, and it works wonders, but:

1) is your amp's signature mostly from the preamp- or the poweramp section? Because if you attenuate through the loop, you will only push the preamp. The Mesa F-50 has a lot of its sound from the preamp, so this mod works very well for these amps...
2) If you use your FX loop, this will not help you.. You need to have the patch cable directly from the send to receive..

 

[rainsong86]

Re: Using the effects loop as an antenuator

It will not be an attenuator. You'll still be choking the volume down before the power amp stage. An attenuator goes between the amp and speakers and chokes the volume down AFTER the amp.

Think of the Master Volume as a water valve. You crank it up and more water flows. Now, you put something in the effects loop to choke the volume down, guess what, that's another valve and you just cut back the water flow to the same spot that it was before opening up the MV. Silly analogy, but it's easily understood.

If you want to attenuate, get an attenuator. Plain and simple.

so say we have a non-master volume amp with a parallel effects loop... if you enable the loop and try to use the MIX knob as a sort of attenuator it will basically just be ANOTHER volume knob.. meaning it will alter not only the loudness of the amp, but also the amount of overdrive

I was also wondering if putting a volume pedal in front of a non-master volume tube amp with no effects loop will basically serve the same purpose as the single volume knob on the amp itself.. I'm thinking that a volume pedal is just another potentiometer and will alter the signal almost just the same as the volume knob on the amp.. soo basically you have the volume on the amp dimed and you're enjoying some good power tube saturation; when you lower the volume pedal in your signal towards the heel position not only will the volume decrease, but the amount of overdrive will decrease as well

so it seems the only way to get that cranked-tube-amp sound out of a master volume amp at low volumes is to buy a good attenuator.. on a side note, isn't the "output" on Mesa Rectifiers an attenuator of sorts or is it the same thing is utilizing the "effects send" of the loop?

 

[ErikH]

Re: Using the effects loop as an antenuator

so say we have a non-master volume amp with a parallel effects loop... if you enable the loop and try to use the MIX knob as a sort of attenuator it will basically just be ANOTHER volume knob.. meaning it will alter not only the loudness of the amp, but also the amount of overdrive

In a way, yes. However, if you are getting all of your overdrive from the preamp and/or pedals, that will remain the same and only the volume will change. The overdrive that will change is how hard the power amps tubes are being hit with the preamp signal.

Also, parallel effects loops work differently than series effects loops. With a parallel loop, the change in volume by using your method might be minimal, if any at all. The mix knob just mixes the original dry signal with the signal from the loop to form what you hear. By turning the mix down all the way, you're just choking off the effected signal without doing anything to the dry signal. In a series effects loop, your signal comes from the preamp, through the effects unit(s) and then onward to the power amp.

I was also wondering if putting a volume pedal in front of a non-master volume tube amp with no effects loop will basically serve the same purpose as the single volume knob on the amp itself.. I'm thinking that a volume pedal is just another potentiometer and will alter the signal almost just the same as the volume knob on the amp.. soo basically you have the volume on the amp dimed and you're enjoying some good power tube saturation; when you lower the volume pedal in your signal towards the heel position not only will the volume decrease, but the amount of overdrive will decrease as well

You could also lower the guitar volume and achieve the same thing. A volume pedal is just that, volume on the floor. In this case, the amount of overdrive will decrease no matter if you use pedals to get the OD and/or the preamp, because the signal is being limited or choked back before getting to the pedals and/or preamp.

so it seems the only way to get that cranked-tube-amp sound out of a master volume amp at low volumes is to buy a good attenuator..

Exactly.

on a side note, isn't the "output" on Mesa Rectifiers an attenuator of sorts or is it the same thing is utilizing the "effects send" of the loop?

Dunno for sure on that one. If it is a line out, then it's a line level signal before it even gets to the power amp, much like an effects send. The manual will say for sure.

 

[heavydutysg135]

Re: Using the effects loop as an antenuator

This is a very common misconception that will just not seem to die. A volume pedal in the effects loop absolutely does not do the same thing as a power attenuator. Using a volume pedal in the effects loop will absolutely not push your power tubes any harder because the effects loop is between the pre amp tubes and the power amp tubes. All you are really doing is adding another volume control between the two. The volume pedal in the loop will let you crank your "real" master volume, but will just take the power down again before the signal goes to the power amp section. Basically you are just canciling out the master volume pot on your amp with another master volume. This means that the power tubes will not be saturated any more. A power attenuator on the other hand dissopates the power AFTER the power amp section but before the speakers. This will allow you to saturate your power section but bring down the volume before the signal hits the speakers. By the way you cannot use a volume pedal after the power section because they only work with line level signals (I know that you know this, but I have also heard this question asked before). Power attenuators work with high power signals. If you would like to learn more information about this subject then I would recommend that you check out amptone.com. Have fun.

 

[OlinMusic]

Re: Using the effects loop as an antenuator

You can use many Serial FX loops to cut down volume by running into a processor and using the volume control in the A/D converter

My friend does this with his Budda and POD.

The Rivera does it better than any other bc you can control the FX loop and patch it!

 

[kjrocks]

Re: Using the effects loop as an antenuator

I get it now , of course its not the same as an attenuator. Its leaving out the power amp stage. I think maybe what I read was that jumping the loop added another gain stage or something like that whoops

 

[V!N]

Re: Using the effects loop as an antenuator

I get it now , of course its not the same as an attenuator. Its leaving out the power amp stage. I think maybe what I read was that jumping the loop added another gain stage or something like that whoops

That's what some Dual Rectifier users do around here ! It also works great on the Marshall silver jubs / Slash heads to make them a bit louder.


As for using the loop to add another volume, this is how the signal travels in a typical amp:

preamp gain stages > tonestack > effectsloop > master volume > power amp > speaker

To add a volume before the master volume ? Not very useful if you ask me.