Has anyone tried one of these?
http://www.amprx.net/
BrownBox - A new toy ?
Moderators: pompeiisneaks, Colossal
BrownBox - A new toy ?
I Think I Think Too Much !
- lord preset
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Re: BrownBox - A new toy ?
They say it's not a variac but it sure seems like one.
- martin manning
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Re: BrownBox - A new toy ?
My guess is it's a bucking transformer.
Re: BrownBox - A new toy ?
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:
http://www.mpja.com/Panel-Meter-LCD-Sna ... 1496%20ME/
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.
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:
Integrated AC volts/amps meters are pretty easy to find. Here's one:Easy to read, back-lit L.C.D. display enabling real-time voltage and amperage monitoring, also useful for diagnostics.
http://www.mpja.com/Panel-Meter-LCD-Sna ... 1496%20ME/
Cast metal box.Tough road rugged construction.
Not sure exactly, other than filaments start slower at lower voltage. Maybe this switches in an inrush limiter, or an alternate inrush limiter.Filament soft-start in full reduction mode.
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.A powder coated EMF neutral housing.
There's a MOV, an NTC inrush limiter, and a fuse or circuit breaker in there.Fully integrated in-rush current and transient protection, as well as over-load protection .
Our transformer doesn't make noise.Silent operation.
Had these wound up to our specs.Custom wound 5 amp transformer.
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.
- Reeltarded
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- Location: GA USA
Re: BrownBox - A new toy ?
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.
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.
- Reeltarded
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- Joined: Sat Feb 14, 2009 4:38 am
- Location: GA USA
Re: BrownBox - A new toy ?
And everyone with a vintage amp should be matching voltages.. so.
But the variac is the wtg.
But the variac is the wtg.
Signatures have a 255 character limit that I could abuse, but I am not Cecil B. DeMille.
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Re: BrownBox - A new toy ?
What advantage would a variac have over a variable bucking transformer?
Robert
Robert