I just bought a heathkit AA32, I'm waiting to receive it.
it works but I do not know if it was restored or not and suddenly, if any of you know this amp well and has information to communicate to me about what is important to do and if there has possible improvements.
it's been a long time that I wanted to buy an amp with el84 or ecl86 and I do not want to do any nonsense.
it works but I do not know if it was restored or not and suddenly, if any of you know this amp well and has information to communicate to me about what is important to do and if there has possible improvements.
it's been a long time that I wanted to buy an amp with el84 or ecl86 and I do not want to do any nonsense.
I have an AA-32 and scanned the schematics.
If your amp is still original, you should exchange the electrolytics in the power supply and the cathode circuits as they might have dried out.
The coupling caps to the output stage might also need a replacement.
The output transformers are of very high quality and the amp sounds quite good.
The preamp circuit is typical for that era with the tuner and aux inputs being too snsitive for today´s high-level outputs, but paired with vintage equipment this should work fine.
You can always do further modifications like bypassing the tome controls etc but I prefer to keep it original.
Best regards
Philipp
If your amp is still original, you should exchange the electrolytics in the power supply and the cathode circuits as they might have dried out.
The coupling caps to the output stage might also need a replacement.
The output transformers are of very high quality and the amp sounds quite good.
The preamp circuit is typical for that era with the tuner and aux inputs being too snsitive for today´s high-level outputs, but paired with vintage equipment this should work fine.
You can always do further modifications like bypassing the tome controls etc but I prefer to keep it original.
Best regards
Philipp
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Be aware of possibly worn out ECL86's. They're rather expensive in these days (but may be replaced by the cheaper PCL86's with the addition of a suitable heater supply).
Best regards!
Best regards!
thank you for the info and the schematics.
as I planned to replace the 6eu7 ECC83 by adding a 12vdc power supply, I also thought to look for pcl86 like that I warm everyone in 12vdc with a single power supply.
I will keep you informed when I receive it.
thanks 😉
as I planned to replace the 6eu7 ECC83 by adding a 12vdc power supply, I also thought to look for pcl86 like that I warm everyone in 12vdc with a single power supply.
I will keep you informed when I receive it.
thanks 😉
You may prefer an adjustable heater supply, as the PCL86 demands for 13.5 V rather than 12 V. Insert a small series resistor into each ECC83's heater chain then.
Best regards!
Best regards!
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