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Date: Tue, 22 May 2001 20:08:42 -0700
From: "IronMan Mike Curtis"
Subject: Re: Amp Question

(Vincent asked this off list - I tried to reply but it bounced, so
I'm posting to the list).

On 23 May 2001, at 12:00, Vincent Daliessio wrote:

> The amp was custom made by Walter Woods in CA. 500w per side. Its
> the size and weight of a ream of laser paper. The cabinets are: Bag
> End 2-10 and Bag End 1-18 sub. I tried going into both inputs with a
> Y cable but all I got was a crazy feedback sound. It just doesn't
> work like you'd think. So, we're continuing to work on it.

Hi Vince;

I tried doing a lookup for Walter Woods on the web. Couldn't find
any reference to a dual 500 watt amp. I found one site in France (in
English) with some very general info on some smaller amps,
http://persoweb.francenet.fr/~liegeois/ww.html

Basically, it's just a lot of amp jammed into the smallest possible
enclosure. It uses a switching power supply (no big surprise) to cut
the size and weight. Apparently, at least on some WW amps, the
frequency of the power supply varies with load. It operates around
100 kHz, which dramatically reduces the size of the transformer. The
transformer operates at magnetic saturation, and gets hot during
operation. In later models, shielding was added between channels,
and this might be your problem - needing shielding.

What controls does it have? Knobs, switches, jacks, the works. This
might give us a hint as to its operation. Do you know the year of
manufacture? Is there any documentation with it? A schematic
diagram, or even a simple block diagram, would be most helpful.

Also, can you describe the "crazy feedback sound" a little more in
detail? Is it a single pitch, or does it vary and in what manner?
Does it happen when the volume and gain controls are ALL set to zero?

It's also possible that the amp is defective.

You could use it in either single channel or bridged mono with the
two speakers, although you need to make sure the amp will safely
handle 2.6 ohms (e.g. it's rated for 2 ohm operation).

Another option is to rewire the 2x10 cab in series (16 ohms) and use
bridged mono.

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