checking OT on 5e3

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acalan
Posts: 9
Joined: Fri Feb 17, 2012 11:34 pm

checking OT on 5e3

Post by acalan »

Hi ,I'm checking voltages on my Classic Tone 40-18022 output transformer.On the primary side of the transformer I'm reading 355dcv on the secondary I read 0 dcv that doesn't seem right. On the 40-18022 ot one secondary winding is grounded to the transformer frame the other goes to the speaker jack .Should I have a voltage on the secondary side? thanks
billc
Posts: 53
Joined: Wed Apr 02, 2014 4:33 pm
Location: Sonoma, Calif.

Re: checking OT on 5e3

Post by billc »

You are reading B+ on the primary side and it sounds about right....but you should not read any DC on the secondary so that sounds right too, as transformers only pass AC. If there was a signal to the speaker from your guitar, etc. you would read some AC voltage on the secondary.
acalan
Posts: 9
Joined: Fri Feb 17, 2012 11:34 pm

Re: checking OT on 5e3

Post by acalan »

thanks ,just not getting sound.I would like a chart that shows correct voltages for a 5e3.I always find people posting their voltages which are usually off,and that's why they are asking questions.(I'm fine with that)But I never see a post that shows what voltages are supposed to be.Maybe I'm just not looking in the right places.I tried doing a search ,but not finding what I was hoping to see.Thanks for any help
labb
Posts: 223
Joined: Sat Aug 02, 2008 2:03 am

Re: checking OT on 5e3

Post by labb »

Go over to the Hoffman site (EL 34 World) Under Tube Amp Building go down about 25 post to one that says 5E3 voltage chart. See Mr. Sluckey's chart of voltages from a re issue.
acalan
Posts: 9
Joined: Fri Feb 17, 2012 11:34 pm

5e3 voltages.

Post by acalan »

Thanks everybody.Now I think that I have what I was looking for.
Stevem
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Re: checking OT on 5e3

Post by Stevem »

Are you not getting any sound out of it at all, or low distorted sound?
Eitheir way if you are able to play thru the amp in a dark room and veiw inside the output tube(s) plate struture you should see a change in britness taking place inside the tube as you play.
If that happens then chances are very good that the OT is shorted as the change in briteness means that the tubes are getting input signal and trying to drive the OT priamary, but can not due to a shorted primary.
If you have another amp that works you can check that out first to be sure of what i discribe here.
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armillary
Posts: 76
Joined: Sat Jan 04, 2014 4:25 pm

Re: checking OT on 5e3

Post by armillary »

How are you wiring the speaker? I see on that transformer that (as you said) one secondary lead is attached to the frame. And as the spec sheet says, the mounting feet must make good electrical contact with the chassis so that the lead is grounded. And the other secondary lead goes to one side of your speaker (positive if it's marked for polarity). And the other side of your speaker must have a lead that comes back to chassis ground.
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