Ultimate Attenuator???

[Bryan Q.]

Anyone using this or have opinions on this brand of attenuator? I have the opportunity to buy one for less than half price used slightly and was wondering about you guys opinions. Thanks in advance!

[KevinOConnor]

Hi Guys

As detailed in TUT4, the UA is far from "ultimate".

It was designed by Ho in Vancouver, BC, a repair tech who modifies amps and custom builds odd items. The UA guys copied it and made no improvements despite adding a "voice" switch.

The unit provides a 30R load to the tone amp - a common value used by many attenuators. A pot samples the signal and drives a complimentary Darlington follower - a solid-state output stage without a front-end circuit. The follower drives the speaker to whatever level is dictated by the pot. Being an output stage itself, the follower requires a power supply sufficient to provide 100W+ - whatever the maximum input power may be.

So, your tone amp is cranking out its full 50W or wooW or whatever. The UA wastes all of that audio power as heat and drives the speaker while wasting more power in its own circuitry.

Sonically, the sound is changed going through the UA at any attenuation including no-attenuation. The output impedance of the UA is lower than any tube guitar amp, so the speaker is better damped - you might actually prefer this. The speaker is isolated from the tone amp by the very high current gain of the follower. This means any tone variation you had from the tone amp interacting with the speaker is lost.

Technically, it is an interesting concept but it needs a lot of refinement to be universally applicable.

Have fun
Kevin O'Connor

[MDD]

I've got one that I use with the VM. It works well and allows me to crank the VM in HDR in the house without anyone killing me or me killing my ears. At half price i would pick it up. Sorry Surf (doing my Jedi mind trick wave) there is no UA talk here go on to the next topic :nope

[TubeStack]

They certainly were the "bees knees" around the forums last year. So much hype and excitement everywhere. I bought one to use with my JCM800 2204 and did not like it at all. Couldn't stand it, really. Paid $500+ for something that sounded like total ass and then sold it for probably a little over half that. Maybe it depends on the amp, I know some love it for older, non-master volume Marshalls. With the 2204 it was pure shite.

[MKB]

FWIW, Doyle Bramhall had one atop his Marshall in the second Clapton Crossroads video. That's the only time I can recall seeing one used by a big name player.

[Mats A]

Hi Guys

As detailed in TUT4, the UA is far from "ultimate".

It was designed by Ho in Vancouver, BC, a repair tech who modifies amps and custom builds odd items. The UA guys copied it and made no improvements despite adding a "voice" switch.

The unit provides a 30R load to the tone amp - a common value used by many attenuators. A pot samples the signal and drives a complimentary Darlington follower - a solid-state output stage without a front-end circuit. The follower drives the speaker to whatever level is dictated by the pot. Being an output stage itself, the follower requires a power supply sufficient to provide 100W+ - whatever the maximum input power may be.

So, your tone amp is cranking out its full 50W or wooW or whatever. The UA wastes all of that audio power as heat and drives the speaker while wasting more power in its own circuitry.

Sonically, the sound is changed going through the UA at any attenuation including no-attenuation. The output impedance of the UA is lower than any tube guitar amp, so the speaker is better damped - you might actually prefer this. The speaker is isolated from the tone amp by the very high current gain of the follower. This means any tone variation you had from the tone amp interacting with the speaker is lost.

Technically, it is an interesting concept but it needs a lot of refinement to be universally applicable.

Have fun
Kevin O'Connor

So what do you think of the Marshall Power Brake? Is it any better?