Do these work? (valve amp vol. control)

[larry_emder]

http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&category=7266&item=7342722107

Not the biggest genious on amps myself........but do they have a similar effect as an attenuator? The idea sounds right to me, less gain going to the poweramp so you have to work the poweramp harder......your thoughts?

[Simon_F]

Re: Do these work? (valve amp vol. control)

I'd want to know a LOT more about that before I put it anywhere near my amp.

The description is ambiguous - it says it goes "between your guitar and amp", then it says it goes "through the FX loop".

If, as you say, it means less gain goes in to the power amp, then surely you would have to turn the amp up louder to get it to distort.

An attenuator goes between your power amp and your speaker. You can crank the power amp volume and the attenuator "soaks up" the power and only delivers as much as you want to the speaker. At least that's my simplistic understanding.

That item looks a bit fishy to me in the absence of a better description.

[larry_emder]

Re: Do these work? (valve amp vol. control)

Exactly what i thought mate.

[Chaos]

Re: Do these work? (valve amp vol. control)

It is a simple potentiometer. Just like the volume knob on your guitar. (A pot in a box w/ 2 jacks…) Like a volume pedal, it can be put in front of your amp or in the FX loop.

What it can not do is attenuate the output of your power amp. You are not going to get tube distortion from cranking your power tubes.

Output attenuators (i.e. Powerbrake, Hot Plate, etc) are designed to handle a significant load and dissipate most of it as heat. An attenuator is mostly a big heat sink with a few active & passive components to simulate a speaker’s response.

[ErikH]

Re: Do these work? (valve amp vol. control)

That thing is just a volume box to control the overall volume of the amp by way of the effects loop. I've built one. It is great for amps like the Fender Blues Deluxe or Deville where the master volume knob is really touchy (0 = off and 1 is still too damn loud). Throw this little bugger in your effects loop, get the amp's master volume up to where you want it, 3 or so, and then use the volume box to control the overall volume. It's just another master volume with better taper.

Like Chaos said, it's not an attenuator. DO NOT put it between your amp and speakers!

You can make one of these for under $10 using Radio Shack parts.

[kmcguitars]

Re: Do these work? (valve amp vol. control)

You can make one of these for under $10 using Radio Shack parts.

+1 A small project box, 2 1/4 inch jacks and a 100k audio tapered pot. Need a wiring diagram? Check the fender site. or if I can find it... I'll post it.

[ErikH]

Re: Do these work? (valve amp vol. control)

+1 A small project box, 2 1/4 inch jacks and a 100k audio tapered pot. Need a wiring diagram? Check the fender site. or if I can find it... I'll post it.

I've got one: http://diy.erikhansen.net/fxloopbox.htm

[shredaholic]

Re: Do these work? (valve amp vol. control)

if you really want to control your amp's volume AFTER the power amp, get a PPIMV (rich mod) - they're only $8 from metroamp.com

[ErikH]

Re: Do these work? (valve amp vol. control)

if you really want to control your amp's volume AFTER the power amp, get a PPIMV (rich mod) - they're only $8 from metroamp.com

That mod is more like $150.00. There's more to it than the switch, which costs more than $8.00 alone.

[Gearjoneser]

Re: Do these work? (valve amp vol. control)

Putting it in the FX loop is just like adding a global master volume to your preamp.

I do the same thing, using an Alesis Nanoverb, on my Marshall Jubilee, since it stays at home. Since the Nanoverb has a send, mix, and output, you simply get the input nudged up to the hottest point with no clipping. The output becomes your amp's main volume control.

You're not really overdriving the power tubes, but you are getting more juice out of the preamp section......no matter if the gain is low or high, you're still getting a cranked sound. It works great for making a Marshall halfstack useable at lower volumes, and retaining a good cranked tone. I don't think there's any chance of harming your amp either. If anything, you could heat up the FX unit, but only if the input isn't controllable. As long as the FX unit isn't running in the red, you're fine. It's best to use an FX unit that has an input and output knob.

[ErikH]

Re: Do these work? (valve amp vol. control)

Putting it in the FX loop is just like adding a global master volume to your preamp.

I do the same thing, using an Alesis Nanoverb, on my Marshall Jubilee, since it stays at home. Since the Nanoverb has a send, mix, and output, you simply get the input nudged up to the hottest point with no clipping. The output becomes your amp's main volume control.

You're not really overdriving the power tubes, but you are getting more juice out of the preamp section......no matter if the gain is low or high, you're still getting a cranked sound. It works great for making a Marshall halfstack useable at lower volumes, and retaining a good cranked Marshall tone. I don't think there's any chance of harming your amp either. If anything, you could heat up the FX unit, but only if the input isn't controllable. As long as the FX unit isn't running in the red, you're fine. It's best to use an FX unit that has a input and output knob.

The amount of juice you get out of the preamp has to do with the pre-amp volume and/or gain setting, which are controlling the level at the front end of the pre-amp. The amount of signal coming out of the preamp and in to the effects loop is the same whether this box is in the loop or not or if you use something else to achieve the same result or not. The master volume controls are after the effects loop, right before the phase inverter stage.

It will not allow the amp to have that cranked sound because that involves pushing the power tubes harder. Controlling the volume in the effects loop with the volume box or anything else, like an FX unit, will limit the amount of signal going to the power tubes so it's no different than keeping the master volume down low. Crank the pre-amp all you want, but unless that cranked pre-amp can use it's full force to push the power tubes, it's not going to sound cranked.

The entire purpose of the box, although it's advertised otherwise, is to help tame those amps with touchy master volumes (such as many Fenders).

[larry_emder]

Re: Do these work? (valve amp vol. control)

WHat a pos then!

Cheers.

[shredaholic]

Re: Do these work? (valve amp vol. control)

That mod is more like $150.00. There's more to it than the switch, which costs more than $8.00 alone.

eh - no there isn't, unless you pay an amp tech $142.00 extra to wire it up for you...

where/who from did you hear that?

[shredaholic]

Re: Do these work? (valve amp vol. control)

http://www.metroamp.com/store/product_info.php?manufacturers_id=12&products_id=254

[Imp]

Re: Do these work? (valve amp vol. control)

unless you pay an amp tech $142.00 extra to wire it up for you...

me! me me me!! i'll do it!

tom