Weber Attenuator and a classic 30

[Oddjobmillionaire]

Hello all,
I recently picked up a weber attenuator load dump used for $20.00. It is the Brake Light type of unit that goes in the back of the amp and not the larger Mass or Mass Lite ones.
I have used his speakers and loved them but never any other products. This was too good a deal to pass up for the price
It is rated at 25 watts and 16 Ohms.

I have never used one of these on an amp and wanted to pick your brains before I did. I have a number of lower wattage amps that I could use this one no problem but was wondering if there were any thoughts on using it on a Cassic 30. The power rating is 25 on the attenuator and the amp is 30.
The amp will run at 16ohm so I figure I am good on that.
Let me konw what you think.

Will it hurt the amp? Will it overheat and blow all to hell? Will it sound like Ton Heaven? (in the ear of the beholder of course)
Thanks for any info or insight you may have.

RT

[Chuck H]

Without knowing the exact circuit of the Weber unit I can't say if it's overdesigned enough to handle it. Some resistive attenuators use the resistors in series/parallel for the different ohm load settings and the resistors often share the load with a large rheostat. So 25 watts is probably the minimum rating. It may be able to handle quite a bit more on some settings. Also, if you only need small amounts of attenuation your speaker will still be sharing the load with the attenuator so it wouldn't be stressed by the amps full wattage. Moderate or high levels of attenuation will.

Also, it's important to consider that your Classic 30 is 30 watts of clean power. And probably the main reason we use attenuators is so we can overdrive our amps. Your Classic 30 could well make over 40 watts fully overdriven.

Your best move would be to ask the guy that designed it. Ted will be able to help you better than anyone.

Chuck

[hasserl]

I've got a 50 watt Load Dump attenuator. These are purely resistive, though there is a small cap tp provide some treble bypass to help alleviate the squashed tone effect that attenuators tend to generate.

There is a large wattage rheostat in parallel with a couple of power resistors. Ted recommends with his attenuators that you use one that is rated at twice the power of the amp. In your case a 50 watter would probably suffice as long as you didn't crank the amp up to max output and try to attenuate the entire signal through it for long periods pf time. The 25 watter will be very iffy IMO. It might be OK as long as you don't try to push too much wattage thru it, i.e. crank the amp up and attenuate the volume down low, which of course is the whole idea behind using an attenuator in the first place. It might be effective at just knocking a few db's off the volume of the turned up amp, but don't expect it to handle continuous loading of full power. Worst case scenario, if you were to over dissipate it and burn it up, is possible loss of all loading of the output circuit which can cause damage to the output transformer and/or tube sockets & tubes, blown fuse, etc. I'd be careful if I were you.

Note that these things build a lot of heat when you use them that soaks thru the entire housing. You'll feel it getting warm to the touch, which is normal. However, if it gets too hot to hold your hand on it's way too hot; the components inside will be much hotter. Good luck, and be careful.