by EWBrown » Fri Jun 19, 2009 10:23 am
You're right, I've not seen published technical specifications for the original Dynaco PA060 power trannie...
The new PA060s from Triode and Dynakitparts are rated thusly:
360-0-55-360 @ 300 mA (55 VAC bias tap)
2X 6.3VAC @ 5A
5VAC@ 4A
The original PA060s had somewhat smaller core stacks, and perhaps a somewhat lower I max (250 mA?) for the HV secondary. They tended to run quite hot.
The ST70 manual states that AC power consumption is 190 watts.
That agrees pretty much, if all the windings are "maxed out".
The main limiting B+ current factors are the GZ34 rectifier and the C354 choke, which is rated at 200 mA. In actual operation, with the EL34s properly biased (at 100 mA/channwel) and a few extra mA for teh 7199s, and the optional preamp connections, the actual DC current consumption could creep up ti around 220-230 mA.
The actrual 6.3VAC current consumption is 3.45 A for each channel, plus an additional Amp available at each of the front panel power take-ffs.
So that's 6.3VAC @ 4.45 A max per channel, so I'd believe the 5A rating for the 6.3V windings.
HTH
/ed B
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