71A amp
Andre Jute wrote:
On May 4, 12:11 am, Raymond Koonce wrote:
Hi RATs,
I finally got my 71A amp up and running and in a proper chassis. It's a
push-pull design with transformer coupled 56s driving the 71As. It has
transformer input with a pair of Newcomb microphone transformers.
Really nice sound, zero hum in Klipsch Cornwalls. I used, at Al Marcy's
suggestion (thanks Al) Blumlein Garters. I found the bass to much
improved over a standard bias method. Nine tubes and sixteen
transformers for 2 watts/channel :-). I posted a photo on
alt.binaries.pictures.radio. I will have a web page up tomorrow.
Happy listening!
Raymond
That's a thing of beauty, Raymond. Congratulations! It must have a
very high Dunker Factor (weight/power ratio).
Andre Jute
Mo' iron is betta iron!
Hi Andre,
Thanks! It was a lot of work getting the chassis built. To me, that's
the most challenging part of a project. The wiring is easy. The
breadboard that I built this on was made from the cases of old computer
power supplies with appropriate holes punched to mount the sockets. I
haven't weighed it yet, but I'll estimate 35 pounds, so 4 watts (2 per
side) divided into 35 pounds gives a Dunker of 8.75. Not too bad, I get
about 6 wpc from my SE 300Bs which weigh in at 60 pounds, a DF of 5 :-)
Raymond
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