• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

information needed...Antique Sound USA PA-3 preamp

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Gentlemen

I purchased but haven't received as yet a PA-3 preamp. According to what I have been told it has 3 5814A tubes. It is non-working and I would like to find some information before I tear into it to either gut it and start over or to repair it.

Frank

It looks like I may have to draw up yet another schematic. OH GOD!:bawling: :bawling: :bawling:

Any help or information would be much appreciated.


Joe
 
I got my preamp today and half the transformer is trashed. I had to disconnect one side of it to remove the short. The reading I took are as follows: orange pair of wires 51volts ac, blue pair of wires 3.2 volts ac, purple pair of wires 121volts ac. I assume I need a transformer with secondaries of 6.3 volts, 100volts, and 240 volts. If this is correct where do I find one?

Joe
 
diyAudio Senior Member
Joined 2002
Hi,

Does this sound ample to run 3 5814A's? The listing of tubes says: 12AX7, 12AU7, 6sn7 X 4

The entire tubelisting looks odd to me...

3 x5814 which are just 12Au7S + what? a 12AX7, yet another
12AU7 and than 4 6SN7s?

For a linestage this is rather hard to believe unless some (say 3/4) of the valves are used as regulators...which I somehow feel is quite unlikely...

Back to the drawing board I'd say,;)
 
Frank

Sorry to confuse you. The information on the transformer states that it can run 12AX7,12AU7, and 6sn7 times four. I would assume it means it has enough guts to run 4 12AX7's or 4 12AU7's or 4 6sn7's.

The preamp I purchased has only 3 5814A's in it so I would assume the transformer should be ample to run it.

Joe
 
I ran across another preamp with the same schematic as the Antique Sound USA. I will try to attach a schematic.
 

Attachments

  • radii-scan.jpg
    radii-scan.jpg
    52.9 KB · Views: 158
I am still looking for a schematic for a Antique Sound USA PA-2 Line Preamplifier. I’m tying to confirm the correct designation (4ea) tubes for this Preamp. I found this Preamp for a fair price and I think a rookie tube guy just put whatever tubes he could find and I want to roll the correct tubes into this gear. Your thoughts, experiences and or Docs would be much appreciated, thank you.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.