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Old 4th January 2013, 01:06 PM   #11
frank2 is offline frank2  Canada
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I have deal with tube depot, it is a good place to deal with, imao. The 170 V transfo i was looking for was this one:
110V 30W Transformer 170V 6.3V for 6N3 PRE AMPLIFIER | eBay
chinese shitty transformer probably made by beated children

For using 120V, i would use two of these :
VPS12-2000 Triad Magnetics | 237-1256-ND | DigiKey

Since i am ordering other thing from digikey, all would come in a box with the second option... The only fear i have is hum, i hate them so much. For now my project have work with mercury magnetic and hammond transformer so i have never had any problem with transfo, i hope this is not the begginning of hell...

What do you think?
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Old 8th January 2013, 09:39 PM   #12
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Quote:
Originally Posted by Stormrider View Post
Stancor PS-8415 which was used in the Alembic F2B preamp with two 12AX7's.
Leeds Radio in NY still has the PS-8415 for $22.
Cool! Of course the Alembic used a ladder of caps and resistors to get the exact voltage they wanted. But that's a great transformer source for me! I have two really old "footwitch" tube chassis, each with a fender-circuit preamp channel but then a small output transformer and teensie speaker as a 'speaker emulator'... I'd rather just convert them both to the exact Alembic schematic. They have decent pots, but inferior power supplies. I might just bolt the two stompboxes together, externalize the power supply with the real Alembic transformer and even better chokes and caps, convert to DC heaters or raise the AC with with some DC offset bias like Weber, and make a great little Alembic preamp that could be positioned closer to the guitar and both channels in series, so I could use one, the other, or both via the footswitches.
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Old 8th January 2013, 10:08 PM   #13
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I bet if you just used a 115v output transformer in the 50 to 200VA output range
you would realy get close to 135 v out if not higher in your case. Rember small power transformers don't have good regulation. That is a 50va 115 v output transformer will have about 115v out when loaded to about 400ma but at a much lower load the output will be substantialy higher.
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Old 8th January 2013, 11:58 PM   #14
JMFahey is offline JMFahey  Argentina
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Location: Buenos Aires - Argentina
Quote:
I bet if you just used a 115v output transformer in the 50 to 200VA output range
you would realy get close to 135 v out if not higher in your case. Rember small power transformers don't have good regulation. That is a 50va 115 v output transformer will have about 115v out when loaded to about 400ma but at a much lower load the output will be substantialy higher.
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