Guitar Power Attenuators...

[paulmurr]

Does anyone in PH land use an attenuator? My Marshall JCM800 is just too damned loud to crank and I'm getting cheesed off with not getting the tone I want.

A quick google throws up lots of attenuators such as...

Marshall Powerbrake
THD Hotplate
Koch Load Box
Weber MASS
Tom Scholz Power Soak
Dr Z Airbrake

and to be honest, i'm baffled.

Any advice greatly appreciated.

Cheers

P

[neilr]

Friend of mine uses a THD hotplate and is very happy with it... HTH.

[paulmurr]

Cheers Neil, only problem with the THD that I can see is that it is fixed impedence. I'm currently looking at the Weber MASS 100w because it seems to be a bit more adaptable.

[Bob Loblaw]

I used to gig with the THD, and it worked great with Marshalls and lower gain amps, but just did nothing for Mesa Boogies and the like.
I've only used the THD so I don't know if that applies to other attenuators or not...

[paulmurr]

Cheers Bob, my amp is a Marshall JCM800 from the mid 1980's so it needs cranking. At the moment its running a single 16ohm cabinet but I have plans to get another 4x12" later on, hence my reluctance to get a THD as the impedence is fixed.

Hmmmm

[loadblower]

Hi Guys,

I've used all of the above - heres my findings;

- Marshall Powerbreak; a bit fizzy to my ears.

- THD hot plate pretty faithful sound at medium levels. Major downside with only one impedance setting.

- Weber Mass; this is the best, most flexible.

BUT! And its a big but. I have dropped all of them.

Reason?

It seriosuly affects how your power amp interacts with your speakers. To my ears, it not just about pumping your power valves, its the whole thing. I have come up with a novel way of actually cranking your amp without the above even in smaller venues. Go to the facebook profile and have a look at the latest Beached fest photos and see if you can spot it! ;-)

Now my tone is seriously pumping, and I am using a minimum of two amps live.

http://www.facebook.com/album.php?aid=66452&id...

Cheers all, good luck with the tone-meistering. It is a truly wonderous thing...

[chevy-stu]

just pull the two outer main power valves out at smaller gigs/rehearsals etc., (presuming it's a 100 watt head) it'll run at 50 watt nicely !!!!

[paulmurr]

chevy-stu said:

just pull the two outer main power valves out at smaller gigs/rehearsals etc., (presuming it's a 100 watt head) it'll run at 50 watt nicely !!!!

It isn't as simple as that, a 50 watt amp isn't 'half as loud' as a 100 watt amp, even a 5 watt amp cranked up will be too loud for bedroom use. The formula is something like X% louder = 2^log10(P2/P1) * 100% so I think that a 50 watt amp is 81% as loud as a 100 watt amp. Yes, it is quieter, but still loud enough to cause hearing damage.

[chevy-stu]

paulmurr said:

chevy-stu said:

just pull the two outer main power valves out at smaller gigs/rehearsals etc., (presuming it's a 100 watt head) it'll run at 50 watt nicely !!!!

It isn't as simple as that, a 50 watt amp isn't 'half as loud' as a 100 watt amp, even a 5 watt amp cranked up will be too loud for bedroom use. The formula is something like X% louder = 2^log10(P2/P1) * 100% so I think that a 50 watt amp is 81% as loud as a 100 watt amp. Yes, it is quieter, but still loud enough to cause hearing damage.

Yes, it works about 7 x actual wattage for what we hear, so a 700 watt amp will only 'sound' twice as loud. In reality the valves will break up way earlier providing the sound you'd want from driving a lower power amp. Loads of people I know tried the attenuators, but no-ones stuck it it.. reason I suggested the pulled valve thing is it's relatively quick & easy and doesn't cost 'owt !!!!

paulmurr said:

...... a 5 watt amp cranked up will be too loud for bedroom use.

Why you'd want to even dream of using any valve head at home is beyond me.. !

[nevpugh308]

Rather than start a new thread, I'm going to resurrect this one

What do people think to something like this ?

GUITAR-AMP-ATTENUATOR on ebay

I'm GUESSING it's just a rheostat in a box (that you whack in the return/send loop) ... is this dangerous ? Is it going to cause problems with the amp ? (Fender Twin) What about ohm's etc for the speakers, does it bu**er all that up (sorry, no clue re. this kind of thing).

Cheers

[Stamp]

It is heading the attenuators way in this thread...
http://www.pistonheads.com/gassing/topic.asp?h=0&a...

[gingerpaul]

There's a review of a Bad Cat attenuator in this months Guitarist magazine if you're still looking.

I have a Marshall Powerbrake and it is my understanding that it simulates an inductive load rather than just being a variable resitior, hence the high price tags. I was lucky enough to get mine off ebay but I've seen that they run into may hundreds for a lot of them.