AHT phono stage

[raeler]

Can anyone help me. I have a problem with my AHT (American hybrid technology) phono stage. I am getting a reading of 16 volts from both outputs. I have replaced the6 op-amps but still the same 16 volts is read with the supplied voltage tester. Anyone’s help would be much appreciated. Thanks.

 

[6L6]

Did it work before replacing the opamps?

 

[raeler]

Yes, it was fine for years, loved it.

 

[madis64]

Is this unit something similar to that listing?

https://www.ebay.com/itm/185735201101

 

[raeler]

Yes, exactly the same phono stage but I have the original psu. Mine was fine then one day it had the 16 volt reading on both channels, that’s when I replaced the opamps but it was not helpful in setting a m-volt reading, still 16 volts.

 

[triplej]

$12,000 USD? Wowser. Rail voltages OK on the Op Amps? If both channels failed at the same time could be power related.

 

[raeler]

Yes, a lot of money. I will get the new Op Amps checked.

 

[6L6]

Very unlikely that new opamps are causing any trouble.

Do you have the schematic?

 

[raeler]

No, I don’t have a schematic but would very much like one. I think Mr Fanny designed my AHT and then Loyd Walker brought the design but I don’t have any contact details for either of them. I believe Mr Walker sadly passed away last year.