"Andy Evans" wrote in message
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On Dec 17, 6:08?pm, "Iain Churches" wrote:
"Andy Evans" wrote in message
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For me, I want a couple of really good sounding 1:1 interstages, SE so
gapped, and in nickel and sounding fabulous - to link a 10Y to a 300b.
I haven't found anything better than these two valves, so I just need
the best handshake possible!!!
Speak to Santa Sowter. He and his team of industrious
elves fulfill such wishes on a daily basis:-)
I hear contradictory things about Sowter, except for the universal
fact that his stuff is expensive. There's a cheap nickel Hammond
transformer but it's stepdown - as previously mentioned 1:1
interstages date from the period where DHTs were low mu - up to 15 -
and stepdowns are really only useful for medium and high mu valves,
which ain't my cup of tea. Dave Slagle will build a nickel one, so
that's once possibility. Another is Lundahl amorphous core, like the
LL1660. I'm bracing myself to let go of some money here. I built a 10Y
preamp for a friend, output was the usual LL1660/5mA. Sounded so
utterly wonderful I can't wait to build another!!! But has to be 1:1 -
can't sacrifice any of my hard won gain with these DHTs.
Sowter may not be the cheapest, but their transformers *are* superb. I've
used their transformers professionally since 1971, and have always had good
results. Some years ago, I designed and built a 100watt pc. stereo ULPP
amplifier using 6550A valves, and they wound the output and mains
transformers and smoothing chokes.
In the early 70s, I met Dr Sowter, who at the time was over 80, long since
retired from the day-to-day of his company, but still the main design
authority. I was fresh out of University and needed help with some
transformers for the Broadcast Audio routing switchers I was designing. A
most illuminating day, one I shall never forget. Real experts, with a deep
and detailed knowledge of their subject were a delight for a young engineer.
Similar impressions were made by Peter Walker and Angus Mackenzie, who's
eyes I was for one memorable AES meeting, where he needed someone to read
the 'scope for him.
S.
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