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#1
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#2
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Are those pse's or pp?
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#3
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Very nice, good step up from the Quads Dave
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#4
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Thanks. Agreed.
My only reservation is 4mV of audible hum in zero feedback mode. DC heater has been applied by previous owner. any ideas for tackling this? Dave |
#5
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They're the PSEs then I take it.
It could still be the 300B heaters but further choices there are limited and involved. Look to other designs for a remedy. First stage is high gain pentode, second is a driver with no gain. OP is low gain. Chances are it's HT or heaters on the 6au6. HT looks decent enough so improve heaters. I found a good reduction in ripple and hence hum which was coming from just this source with Kit88 and that has a relatively low gain triode connected 6au6. You don't have enough volts for a reg so I'd do the passive shottky heater mod which gets an extra volt and burns it off in a pi filter, http://www.world-designs.co.uk/forum...read.php?t=573 |
#6
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Yes, mine were about the same. As Rich says, you won't better this without modding.
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