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Effects Loop Attenuator vs Post-Amp Attenuator

Racehorse

Member
Messages
712
Hi all, apologies if this has been discussed before. Searching produced little results.

I'm trying to determine the main differences between a cheaper effects-loop attenuator like JHS Little Black Amp box, vs something like the more expensive Rivera RockCrusher.

I have been under the impression that volume pedals in the effects loop could tame volume, but would be detrimental to tone. Is the JHS product the same thing as a volume pedal?

I don't care about IR or speaker emulation features. I just want to be able to crank my amp, but tame the volume, while retaining tone as much as possible. Would the JHS be just fine for that, or is there something better or superior about the post-amp products like RockCrusher?

Thanks in advance.
 

dudu

Member
Messages
579
The FX loop "attenuator" is nothing more than a couple of jacks connected by a wire across a potentiometer. It is a solution that only works if 100% of your amp's tone comes from the preamp section. In which case you are effectively addding a second master volume. Which begs the question - what's wrong with the first one?
 

ripgtr

Member
Messages
8,869
I made one, like @dudu says, it is just a pot. I had a blackverb for a while, and at low volume, the master was awful fussy, so turn the loop down, problem solved. Also, I tried this amp, which does have a master, into a power station, with the master up, that was interesting. Opening up the amp was really nice. Not enough change for me to haul another piece of gear to a gig, but interesting.
How much volume are you talking about? Just a little off the top? Yea, that will work using a regular attenuation. Really crank it down, it effects the tone too much. I could hear the dif on a tone king, and that had a highly regarded one. Even just a little off the top, you lose some highs. The PS or similar - a load and then reamping with another amp - does have less effect on the tone.

The loop is before the master, if there is a master. So, in that case, it would only serve the purpose I talked about. If you get all of your OD from the preamp, it probably has a master.

There is however one advantage in doing a pot in the loop. The amp I have, a Bella, has a loop with send/receive. I like to turn the amp up, because I use the bright switch on, and the higher the volume, the bright being set, the less it is in the total mix. So it reduces how much of the bright cap you get. And the preamp does warm up a bit. But it is a tube driven loop, so you also have that - you now have another tube in line.

It is dead easy to try, just wire up a pot with a couple jacks on it.
 

splatt

david torn / splattercell
Platinum Supporting Member
Messages
24,968
The FX loop "attenuator" is nothing more than a couple of jacks connected by a wire across a potentiometer. It is a solution that only works if 100% of your amp's tone comes from the preamp section. In which case you are effectively addding a second master volume. Which begs the question - what's wrong with the first one?
yup.
 

8len8

Silver Supporting Member
Messages
13,269
Using a post amp attenuator will give your tone more “girth” at lower volumes often.
 

Axe-Man

Member
Messages
6,142
A post amp attenuator gets the power tubes involved ‘if you wish’. You can drive the crap out of the amp and really get the full sound vs (as mentioned above) just adding a second MV pre PI.

There is also the PPIMV too which drives the PI as well as the preamp.

Only the post amp attenuator drives the power tubes.
 

Racehorse

Member
Messages
712
Thanks all. I'm using an EVH 5150 III 50w, with a 2x12 Mesa cab. It doesn't have an MV, just channel volumes.

I can use the channel volumes to get fantastic lower-volume, bedroom type tones. But then when I go to adjust for louder band volumes, it requires significant EQ, presence, and resonance changes. And these controls are extremely sensitive. I'm not a fan of tweaking, love to find a good tone, set it and forget it. Make subtle changes as needed for different guitars.

So, ideally what I'm looking for is something that allows me to dial-in band volume settings. Then when I want to play more quietly at home, use the attenuator to achieve the quieter volume without re-adjusting all of the settings.

It sounds like the effects loop will not give me what I'm looking for, since bypassing the power tube section will affect the overall tone, requiring EQ changes. Am I understanding that correctly? Or will it sound roughly the same, just not as thick? I don't need it to be a perfect reproduction, just something close enough to be enjoyable at low volumes, without the frustration of dialing in the settings every time volume needs change.

Thanks again for the feedback.
 

8len8

Silver Supporting Member
Messages
13,269
Thanks all. I'm using an EVH 5150 III 50w, with a 2x12 Mesa cab. It doesn't have an MV, just channel volumes.

I can use the channel volumes to get fantastic lower-volume, bedroom type tones. But then when I go to adjust for louder band volumes, it requires significant EQ, presence, and resonance changes. And these controls are extremely sensitive. I'm not a fan of tweaking, love to find a good tone, set it and forget it. Make subtle changes as needed for different guitars.

So, ideally what I'm looking for is something that allows me to dial-in band volume settings. Then when I want to play more quietly at home, use the attenuator to achieve the quieter volume without re-adjusting all of the settings.

It sounds like the effects loop will not give me what I'm looking for, since bypassing the power tube section will affect the overall tone, requiring EQ changes. Am I understanding that correctly? Or will it sound roughly the same, just not as thick? I don't need it to be a perfect reproduction, just something close enough to be enjoyable at low volumes, without the frustration of dialing in the settings every time volume needs change.

Thanks again for the feedback.
Just an FYI, it’s common for a more mid scooped setting to sound better at home volume, and a mid boosted setting is needed to cut through a band mix. I’ve rarely been able to set an amp to a single setting for all circumstances.
 

Dave B

Exit... Dual Stage Left
Gold Supporting Member
Messages
1,750
Yes, the Little Black Box is the same as having a volume pedal in your efx loop, lowering the signal level headed off for the steroids injections from the power amp tubes. I use both an LBB and some VPs across a few different amps, for the same agenda as you - set the amp gain & tone at volume, with the capability to lower the signal for quieter evening and quietest late-night playing.

Main difference besides the real-time control of a VP? Late at night, for an amp having the VP, if you don't check your treadle position before you play the first note, if it was bumped it could be quite loud. That's not a problem with the LBB. (I'm getting clumsier as I age, as my glasses shrink my peripheral vision field!)

The lowered sound doesn't stink, for sure, but to me at that point the lower you go, the more the bounce attached to the both feel and the sound gets squashed out of the results of the 'picking/plucking + fretting + amplifying' equation.

This concept should save me time by not having to sift through the myriads of threads here involving the multiple, creative quieter amp and attenuating solutions, and their associated rabbit holes, though I sift anyway. :D
 

ronmail65

Gold Supporting Member
Messages
3,325
Thanks all. I'm using an EVH 5150 III 50w, with a 2x12 Mesa cab. It doesn't have an MV, just channel volumes.

I can use the channel volumes to get fantastic lower-volume, bedroom type tones. But then when I go to adjust for louder band volumes, it requires significant EQ, presence, and resonance changes. And these controls are extremely sensitive. I'm not a fan of tweaking, love to find a good tone, set it and forget it. Make subtle changes as needed for different guitars.

So, ideally what I'm looking for is something that allows me to dial-in band volume settings. Then when I want to play more quietly at home, use the attenuator to achieve the quieter volume without re-adjusting all of the settings.

It sounds like the effects loop will not give me what I'm looking for, since bypassing the power tube section will affect the overall tone, requiring EQ changes. Am I understanding that correctly? Or will it sound roughly the same, just not as thick? I don't need it to be a perfect reproduction, just something close enough to be enjoyable at low volumes, without the frustration of dialing in the settings every time volume needs change.

Thanks again for the feedback.
Personally, I think you should pass on these options and save your money...
  • First, I fully understand your dilemma - amp settings and EQ for bedroom volume are not the same for gig volume. A nice bright bedroom volume EQ can sound like a bee hive at gig volume.
  • Write down your bedroom vs gig settings if you can't remember them. Depending on the gig / room you're playing - you'll probably want to tweak the EQ anyway. I feel like adding an attenuator is an 'over the top' solution for just twisting a few knobs... like making toast with a blow torch.
  • A 5150 is a very high gain amp. Adding an attenuator to a manageable high gain MV amp seems a bit pointless. But that's just me...
  • Decent attenuators are expensive and are an additional component / potential point of failure in your signal chain.
  • I've had 120W and 100W amps where the volume goes from silent to ear-splitting between 0.0 and 0.5. In that instance I've used a volume pedal in the FX loop so that I have more graduated volume control. I always felt that worked well and did not mess with the tone. That won't necessarily address your problem...
If you're dying to spend the money and don't want to change your EQ settings, I recommend getting a small SS practice amp that does great high gain. There are lots available that do bedroom volume quite well and are inexpensive.
 

Racehorse

Member
Messages
712
  • A 5150 is a very high gain amp. Adding an attenuator to a manageable high gain MV amp seems a bit pointless. But that's just me...
If you're dying to spend the money and don't want to change your EQ settings, I recommend getting a small SS practice amp that does great high gain. There are lots available that do bedroom volume quite well and are inexpensive.
Like I said before, this amp does not have a MV. Only channel volumes. So setting up 3 channels, 2 of them being a shared EQ, plus adjusting resonance and presence, is not something I'm keen on doing every time I change playing environments. I know that sounds super lazy to some people, there are worse crimes.

I'm not dying to spend the money, but I'd much rather spend $50 trying the little JHS box then buying a completely new solid state amp lmao.

To all who have given their experience, thank you. I think the effects loop volume will be just fine for my needs. I just wanted to understand if there was something justifiably worthwhile to going the more expensive post-amp route. Cheers.
 

ronmail65

Gold Supporting Member
Messages
3,325
Like I said before, this amp does not have a MV. Only channel volumes. So setting up 3 channels, 2 of them being a shared EQ, plus adjusting resonance and presence, is not something I'm keen on doing every time I change playing environments....
Best of luck to you! And, not trying to give you a hard time on this... just sharing my developing thoughts on the matter FWIW.

I have been, and remain, quite loathe to change any of the settings on my amp. I feel like I have things dialed in 'just right' and I don't want to screw it up.

However, I'm coming to the conclusion that I should be more experimental with my amp settings. I need to trust my ears and, besides, my amp isn't that complicated (8 or 9 knobs?). I can change it all up - and I should. If I know what I like and it was there all along, then I'll end up back where I started or I'll be someplace better. Maybe I'm in a 'tone rut' and I don't even know it. I guess if I was gigging or recording all the time, I would feel more justified in keeping my tone as consistent as possible (I'd probably put marks on the panel just in case anything got disturbed).

But it's time for me to say WTF...
 
Messages
4,529
If there was a magic $50 box made from $8 in parts that would make an amp sound the same at bedroom volumes as it does on stage, the amp would have those parts in it from the factory. I think you're going to be disappointed with the outcome of this, after you get over thinking that your $50 outlay solved the problem.

Also, your amp does have a master volume. It has 2. You'll be placing an extra master volume that works on both channels, one gain stage after the existing master volumes. The only thing this will do is allow you to balance the master volumes as you like them balanced, and scale that volume relationship up and down. It's still before the negative feedback loop (presence / resonance), so that relationship will not change with respect to volume settings.

Physics is working against you. The way that tubes, speakers, and ears work, there's just no way to use an amp at vastly different volume levels and not re-adjust the settings in different environments. I'd recommend getting used to it. You should be readjusting settings in different venues anyways. Amps tend to sound different in different rooms.

I know it's not what you want to hear, but it's the reality of it.
 

drbob1

Gold Supporting Member
Messages
27,195
What I'd recommend you'd try is a graphic or parametric EQ in the loop. That allows you to set up a master volume with different EQ for home practice than for band practice (turn it on for one, off for the other). It might not solve the resonance adjustment but should fix the rest of it, and, because the EQ will have a "master volume" you can use it to both EQ and set levels. I'd recommend the WMD Parametric-great tones, hugely flexible. Another recommendation would be the Fuzzrocious Baxstabber-which is an Ampeg style EQ in a box with a huge range of adjustability!
 

Racehorse

Member
Messages
712
Also, your amp does have a master volume. It has 2. You'll be placing an extra master volume that works on both channels, one gain stage after the existing master volumes. The only thing this will do is allow you to balance the master volumes as you like them balanced, and scale that volume relationship up and down. It's still before the negative feedback loop (presence / resonance), so that relationship will not change with respect to volume settings.
Nope, the 5150 iii 50w does not have any MV.

Look at a PRS Archon, or most any ENGL amp, these amps include MV, which dictates power amp levels---across all channels---i.e. MASTER volume.

This amp only has channel volumes, not the same thing. But thanks for trying to help.
 
Messages
4,529
Nope, the 5150 iii 50w does not have any MV.

Look at a PRS Archon, or most any ENGL amp, these amps include MV, which dictates power amp levels---across all channels---i.e. MASTER volume.

This amp only has channel volumes, not the same thing. But thanks for trying to help.
So what do you call the master volume on a JCM800? That’s a “channel volume” too? Because it’s the exact same thing.
 

Racehorse

Member
Messages
712
So what do you call the master volume on a JCM800? That’s a “channel volume” too? Because it’s the exact same thing.
LOL well yeah on a single channel amp it's the same thing.

5150III is a 3 channel amp. 3 separate volumes for each channel.
 
Messages
4,529
LOL well yeah on a single channel amp it's the same thing.

5150III is a 3 channel amp. 3 separate volumes for each channel.
I guess I just don’t subscribe to the notion of changing the name of a circuit element just because you add another.

On a JCM800, it’s a master volume. On a 5150, that same exact circuit element suddenly becomes a “channel volume”, simply because you have 2? It’s the same potentiometer wired into the same place in the amp.

Anyways, the nomenclature isn’t important. My point was that the OP will not see any tonal benefit to adding another master volume to the amp when it already has a master, ahem, channel volume for each channel. The only thing it’s useful for is balancing the volumes. “I want to be able to crank my amp and tame the volume”. Adding another volume knob doesn’t give the amp any additional ability to do that.
 

HeavyCream

Member
Messages
3,286
Pedal builders and dealers have been calling FX loop volume pedals “Attenuators”. This is marketing hooplas. Technically, they are attenuating the signal but do so in the same manner a volume pot does, because that’s what they are. Those volume boxes are nothing like post amplifier attenuators. They should be called FX Loop Master Volume boxes, not attenuators. If your amp already has a MV, there is no benefit of putting another volume pot in the loop.
 




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