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Old 28th December 2006, 05:45 PM   #1
ghola is offline ghola  United States
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Question power supply for heath WA-P2

Hi all. I just bought an old Heathkit WA-P2 preamp, in unknown working/non condition. I want to pair it with an old Philco amp I pulled out of a console. Heathkit has no power supply, only an ?octal? plug which was to be connected to appropriate Heath power amp. My question is this: If I bring the pre to a tech, how much should I expect to pay for a new/mod power supply? (Assuming the unit doesnt need a major overhaul.) I will be using it as a front end to power my cut and spliced home made Philco guitar amp with original speaker (which works great, by the way, when connected to a modern pre amp)
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Old 28th December 2006, 08:58 PM   #2
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Default You could power it from your Philco amp...or...

You could build a power supply just for it. It only has three small tubes in it so the power demands are not high. I have the schematic somehwere of the WAP-2. It was made to be powered from one of the williamson amps that Heathkit sold. It's early 1953 so it's full of cathode follower inputs. Ray
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Old 28th December 2006, 11:53 PM   #3
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Default More on the WAP-2

It has it's own voltage divider and filter capacitor (4 section can) inside which I would recommend replacing as it is close to 60 years old. Also V3A (12ax7) has a 10ufd electrolytic in the cathode bypass which would need replacing. Voltage input is 320 volts DC and 6.3 volts AC filament. I could scan and send you the schematic if I had your email address. Ray
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Old 29th December 2006, 12:12 PM   #4
ghola is offline ghola  United States
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Thanks for the help. However, there are 2 problems:
1) I am not a tech. I decided to be bold and just pulled the amp from the Philco console (after plugging it in, turning it on and letting it warm up- I know, I know but it was practically free, so...) and spliced a 1/4 " cable to the wire from the ?mag/crys? to the amp. It worked, but guitar volume was very low, hence the need for a pre.
2) The Philco is in Maine, and I'm currently in Florida. I have some pics of it, but not many good ones, so I dont know about connecting Heath to it.
So it sounds like I would need to send pre off to a tech. Is what you describe a costly procedure? The heath cost less than $50, so I guess a little more would still be a reasonable price for a "vintage" unique guitar amp.
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Old 29th December 2006, 02:04 PM   #5
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Default It IS what it IS!

Hi-fi preamp intended to play RIAA equalized phonograph LPs. The post volume control circuits have tone control but not much gain. You would have to disable the feedback network that RIAA equalizes for phonograph records to use the front end gain block with your guitar. Yea, it would take a tek! I wouldn't spend too much time or money on it. It's small and cramped inside and full of ceramic capacitors and if you tried to replace with quality caps they will be MUCH larger you might run out of space. And you don't know the quality of the build. It may have been put together by a 10 year old just starting to learn how to solder. On the other hand it may be OK. Ray
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