guitar amp power soakers

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pucho812

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Oct 4, 2004
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third stone from the sun
looking to build an adjustable power soak for my guitar player.
He cranks his amps up for tone but that 135 watt twin with master volume can get too loud in some clubs.
I am thinking of wiring  a l pad into a conduit box that he can put between amp and speaker.

anyone know where I can get a 150W 4Ohm variable lpad?  or if anyone has a better diy suggestion it's always appreciated.




 
According to the local Fender Amp Guru, the only safe way to do that is with something like the Weber Mass.

Here is the website page:  http://www.tedweber.com/atten.htm

 
Inline a couple of 100W light-bulbs in parallel for even more "lamp" compression?

Rrawwrrrrrr, baby !!
 
Arrigotti said:
According to the local Fender Amp Guru, the only safe way to do that is with something like the Weber Mass.

Here is the website page:  http://www.tedweber.com/atten.htm

I have seen those.... there are other companies that make stuff that I feel is better.  I have been going over all kinds of attenuator's for this purpose and there are many ways it is done.

to be honest ever since ted's passing, I feel the company has really gone down hill. A co-worker of mine recently built an amp kit of theirs. First they sent wrong chassis and parts, next their layout is incorrect and lastly I ended up having to fix his issues which were mostly in part to their paperwork on the amp.

 
What about a variac?  Same basic concept, although not much cheaper than commercial products.
 
it wouldn't work in this application as there is a tube rectifier. the variac would reduce the heater voltages as well and eventually cause the tubes to stop working.
 
try here on amp garage. you'll have to sign up to see the files, but the air brake is good. i made one for my tw clone, but have used it with various amps with good results. http://ampgarage.com/forum/index.php link amended to index page, it's in trainwreck files under Airbrake files.
 
Hi there,

Just be aware that when using a power soak, the amp is actually running hard even though the volume is reduced.
This means it gets hot, and it's life is shortened according to how attenuated the setting is.
With most soaks I have heard, the sound also becomes choked as you wind them up.
At my electronic service workplace I have seen quite a few of these where the owners have blown up their amps, sometimes relatively quickly, because of not understanding how hard they were actually driving.

It is like doing a 120 on the motorway with the brakes on.
Sooner or later something gives.

I would never use a power brake, because I don't like the sound, and it is too hard on the amp.
In my opinion it is better to have a smaller amp which you can drive into distortion without being too loud.
You can DI or mic it through the PA if more volume is required.

If it's a 100W valve amp with 4X output valves, you can also remove the 2X outer valves and reduce it to 50W.
If you do this, and have variable output impedance windings, select the output which is half the actual impedance of your speakers.

Bye now,
Aomahana


 
schmidlin said:
Pull 2 tubes.

pulling 2 of the 4 6l6's will reduce amp volume in half but also increase the impedance the output.

Yes, driving an amp with a power soak can  cause issues but no more then running an amp with out a power soak. An amp at full volume will die just as quickly as an amp at full volume with a power soak I have read all the info on that from the amp experts.  yes the ideal thing is an amp that is lower wattage but that is not my call. I am just trying to make things work and on the fly if shit is way too loud I can go use this and fix for the moment...
 
Aiken Amps has an interesting design for a speaker load emulator, but it's not adjustable.  It seems to be a theoretical design, so I don't know how hard it is to implement or how well it works.  I've thought about building one myself that's designed to run parallel with a cab for volume reduction.  Try http://www.aikenamps.com/  --> Tech Info --> Advanced --> Design of a reactive speaker load emulator.

Of course, if you haven't already, you could try to convince your guitar player to buy or let you build a smaller amp.  Great tone and obnoxious volume are easy to get at 15 or 30 watts.  It's a lot less weight to carry around, easier to achieve a wide-open tube sound and cheaper to replace the tubes.  Plus nobody's telling him to give up his Twin.  ;)

I ran into a similar situation with a friend using an Orange 120W.  It was simply too loud for any club.  So he let me build him an SEL design from the AX84 forum.  It's a 20W single ended output that rarely needs P.A. re-enforcement.  And it sounds really really good (... but not quite as good as the Orange).

Good luck.
 
yeah I thought about building the man an amp....  but still trying to work through other diy projects and clients so building an amp would be not in the near future unless I really had to.
 
So here is another approach.  I have a drummer who play for our church and when he gets excited he just beats the snot out of the drums.  He's very capable of playing quietly, but he gets in the moment and it's over with.  So I built a 2 1/2 foot pony wall that goes around the kit and found the thickest carpet I could find to put on the floor under the drums.  On the inside of the pony wall I put 2'x4'x2" mineral wool panels and cover the thing with burlap.

This has been the best solution to the whole "the drums are too loud" thing.  The drums actually now sound much tighter and the high frequency bashiness is attenuated.  We actually put the drums through the PA now and they sound great.

So, with all that said, I bet some version of that would work it he turned the amp to face him, and put some type of portable gobo around the back as sides of the amp as well as maybe something fluffy on the floor in front of the amp.  If this guy is playing at the same club, he can leave it there.

In my situtation, our guitar players actually stand near the drums and the "drum cage" actually absorbs some of their sound as well.  These guys play through AC30's, Marshall 50 watters, and Fender Bassman amps, although they are relatively considerate when it comes to volume.

Just another thought......
 
RyanC wrote:
What about a variac?  Same basic concept, although not much cheaper than commercial products.

Pucho812 wrote:
it wouldn't work in this application as there is a tube rectifier. the variac would reduce the heater voltages as well and eventually cause the tubes to stop working.

I'm not sure RyanC was refereing to this application... A variac is a BIG wirewound pot.
Consider a 500 Watts variac... 105V 5A... Must have about 20 Ohms resistance... And variable from 0 to 20... Could work if you set the amp to 16 Ohms. Or use a 1000 Watts, for 8 Ohms operation...

Axel
 
Pucho,

Have a check of these http://www.tubeampdoctor.com/english-store/TAD-Silencer-Power-Attenuator-RS-pid-385.htm

The guitarist in my band uses one of these, and they are great. It has a dummy voice coil, instead of a pile of high wattage resistors , so the 'impedance' is more closely matched.

A little expensive, but they work great.

Steve ;)
 
pucho812 said:
schmidlin said:
Pull 2 tubes.

pulling 2 of the 4 6l6's will reduce amp volume in half but also increase the impedance the output.

Yes, driving an amp with a power soak can  cause issues but no more then running an amp with out a power soak. An amp at full volume will die just as quickly as an amp at full volume with a power soak I have read all the info on that from the amp experts.  yes the ideal thing is an amp that is lower wattage but that is not my call. I am just trying to make things work and on the fly if shit is way too loud I can go use this and fix for the moment...

I didn't suggest telling him about it.

;D
 
I was thinking the variac goes where a power soak would go, on the power amp out, not on the power line.  Who knows what kind of frequency response those things have though, obviosly they are designed to pass a 60hz sine.

But I'd go with option C, put some sheet music in front of him.  That should bring his level way down.
 
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