Amp build with 400v @ 3 amps of HT available?

4114Effects

Watching a couple of power transformers on eBay at the moment.  One has HT of 400v at 3 amps the other 350v at 2 amps ...They look bigger than my head and weigh 18kg each.

 The sensible person in me is saying that's too much current and voltage for anything practical. The mad professor is imagining some Goliath of a bass amp with 4x KT88 or something silly ... Not that I'd find a suitable OT anywhere.

 Out of interest any idea what such big transformers would have been originally used for?

ecc83

4114Effects said:

Watching a couple of power transformers on eBay at the moment.  One has HT of 400v at 3 amps the other 350v at 2 amps ...They look bigger than my head and weigh 18kg each.

 The sensible person in me is saying that's too much current and voltage for anything practical. The mad professor is imagining some Goliath of a bass amp with 4x KT88 or something silly ... Not that I'd find a suitable OT anywhere.

 Out of interest any idea what such big transformers would have been originally used for?

Oh I don't know! Maybe Blackstar will flog you an S1 200 OPT? Mind you, that HT is fused at 1A so the 3A traff would still be overkill (200W STEREO! ? "Get thee behind me!) .

There were some pretty big mother amps made for hospital headphone distribution and factory PA. I worked on one with EL31s and about an 800V anode supply.

Dave.

Sporky

If the mains transformer along weighs 18kgf then the finished amp will be what, a seventh of a tonne or so?

Might as well add a seat and build in a small engine to move it about.

ICBM

If the 400V is AC that will indeed be suitable for a monster KT88/6550-type bass amp - they typically use a B+ of around 600V, so that's quite likely what they're for. If they're not from audio amps they might be for a radio transmitter or something.

olafgarten

Do a huge quad channel amp with all 4 channels at the same time. 

jpfamps

The Hammond 1650W will easily do 400W in the mid band.