Hi,
I'm just wondering if anyone might know if both these models share the same power transformers and block capacitors?
I've had a look at the schematics but drew a blank - I wonder if anyone here might know?
Many thanks.
I'm just wondering if anyone might know if both these models share the same power transformers and block capacitors?
I've had a look at the schematics but drew a blank - I wonder if anyone here might know?
Many thanks.
Maybe this helps:
You can download the parts list for the AA-903 from here: Pilot AA-903 - Radiomuseum
The parts list says about the power transformer:
Primary:
117 Vac / 0.67 A
Secondaries:
333-0-333 Vac / 82 mA
5 Vac / 2 A
6.3 Vac / 2 A
Pilot part number: 55-38
Stancor part number: PC-8409
Halldorson part number: P9310
The biggest difference between the AA-902 and AA-903 is that the AA-902 draws 1.2 A / 6.3 Vac, while the AA-903 draws 1.95 A / 6 Vac.
You can download the parts list for the AA-903 from here: Pilot AA-903 - Radiomuseum
The parts list says about the power transformer:
Primary:
117 Vac / 0.67 A
Secondaries:
333-0-333 Vac / 82 mA
5 Vac / 2 A
6.3 Vac / 2 A
Pilot part number: 55-38
Stancor part number: PC-8409
Halldorson part number: P9310
The biggest difference between the AA-902 and AA-903 is that the AA-902 draws 1.2 A / 6.3 Vac, while the AA-903 draws 1.95 A / 6 Vac.
Correction:
The biggest difference between the AA-902 and AA-903 is that the AA-902 draws 1.2 A / 6.3 Vac, while the AA-903 draws 1.95 A / 6.3 Vac.
The biggest difference between the AA-902 and AA-903 is that the AA-902 draws 1.2 A / 6.3 Vac, while the AA-903 draws 1.95 A / 6.3 Vac.
AA-902 uses 6L6GB vs. 6V6 in AA-903, so it likely has a larger power transformer (higher voltage and current) and larger output transformer (higher power rating, lower primary impedance). It's in Sams 222-9, maybe in my basement in the bottom box of the stack...
Thank you for correcting my mistake. I wrongly based what I wrote about the AA-902 on this schematic: https://www.ampslab.com/vintage_pilot_aa902.htm
Thanks to everyone who replied to this - especially to PFL200, the information was very useful - much appreciated.
I have recently found the original factory service information on the Pilot AA-902 in the AWA archives, and I was mistaken - the AA-902 uses 6V6 output tubes (Later AA-902A uses 6L6). Power transformer is Pilot part number 55-31B. It's 335V-0-335, 6.3 and 5.0V, and the transformers should be electrically interchangeable between AA902 and AA903B, though I can't be certain they're the same physical size (both are vertical mount).
I've posted the AA-902 service info on my web page: http://www.audiophool.com/hifistuff.html
I've posted the AA-902 service info on my web page: http://www.audiophool.com/hifistuff.html
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Hi Tom, I've made scans of the operating instructions that came with my Pilot AA-903.
It might come in handy for someone in the future if you'd give it a place in that treasure trove of a website which you've so kindly made.
Thank you and all best.
It might come in handy for someone in the future if you'd give it a place in that treasure trove of a website which you've so kindly made.
Thank you and all best.
Yes, I can add it to my web page. The second file is partly cut off (amp layout) - if you could re-scan (even upside down), I can separate and rotate the pages to make a complete pdf.
The Sams folder is at Radiomuseum.org, no need for me to scan that.
The Sams folder is at Radiomuseum.org, no need for me to scan that.