BrownBox - A new toy ?

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Dr-Joned
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BrownBox - A new toy ?

Post by Dr-Joned »

Has anyone tried one of these?

http://www.amprx.net/
I Think I Think Too Much !
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lord preset
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Re: BrownBox - A new toy ?

Post by lord preset »

They say it's not a variac but it sure seems like one.
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martin manning
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Re: BrownBox - A new toy ?

Post by martin manning »

My guess is it's a bucking transformer.
R.G.
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Re: BrownBox - A new toy ?

Post by R.G. »

You could certainly do it with a bucker, but I think they probably did a tapped autotransformer - which a bucking transformer is, in a way.

Using what amounts to a fixed-tap variac is simple. I think I could draw up a workable schematic from the advertising blurbs. The transformer only needs to process at most about 5A at 12V, or 60VA, which is a pretty small chunk of iron.

From the features list:
Easy to read, back-lit L.C.D. display enabling real-time voltage and amperage monitoring, also useful for diagnostics.
Integrated AC volts/amps meters are pretty easy to find. Here's one:
http://www.mpja.com/Panel-Meter-LCD-Sna ... 1496%20ME/
Tough road rugged construction.
Cast metal box.
Filament soft-start in full reduction mode.
Not sure exactly, other than filaments start slower at lower voltage. Maybe this switches in an inrush limiter, or an alternate inrush limiter.
A powder coated EMF neutral housing.
All non-metallic powder coating is plastic, and is "EMF neutral". If they mean the housing is EMF neutral, it's plastic and not metal. Can't tell from the blurb.
Fully integrated in-rush current and transient protection, as well as over-load protection .
There's a MOV, an NTC inrush limiter, and a fuse or circuit breaker in there.
Silent operation.
Our transformer doesn't make noise.
Custom wound 5 amp transformer.
Had these wound up to our specs.

The controls show two rotary switches, one for "primary voltage select" and % reduction. I'm not sure what primary voltage select does. But the % reduction is something you get automagically from selecting taps on the auto.

It may be that the primary voltage select picks input points on the autotransformer, and the % reduction picks other taps for outputs.

I don't seen anything about UL or CE certification, so it may be a USA only product.
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Reeltarded
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Re: BrownBox - A new toy ?

Post by Reeltarded »

I think the only thing brown about it is the stinking hyperbole

By the way.. we all know what a starved amp sounds like.. pretty much like it does at normal voltage without pushing the speakers as hard. A variac works like the best master volume.

I'd rather buy new brown slacks.

RG, I love that breakdown. The truth is out there somewhere and if we ever find out what it is there will be bruises and many abrasions.
Signatures have a 255 character limit that I could abuse, but I am not Cecil B. DeMille.
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Reeltarded
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Re: BrownBox - A new toy ?

Post by Reeltarded »

And everyone with a vintage amp should be matching voltages.. so.

But the variac is the wtg.
Signatures have a 255 character limit that I could abuse, but I am not Cecil B. DeMille.
tele_player
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Re: BrownBox - A new toy ?

Post by tele_player »

What advantage would a variac have over a variable bucking transformer?

Robert
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