Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: olgoat on July 10, 2012, 09:52:35 am
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I am replacing the PT in my working 5E3 build with this "more complex" power transformer. I am baffled by the comment on the spec sheet for secondary wiring.
"Use RED-RED/Yel-RED for 355-0-355, Use ORN-RED/Yel_ORN for 330-0-330"
I have 2 red and 2 orange wires. There are no Yel-Red or Yel-ORN wires. Any idea what they are talking about? I have an email into them but they are a bit slow in responding.
Also on page 2 for the primary wiring. For 120V. I assume I need to connect the brn and blk to the power switch and the blk/wht and brn/wht to the power cord hot lead?
The transformer I am replacing was a straight forward 120V single secondary voltage which is was much simpler compared to this beast.
Thanks
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(http://)
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Attaching jpg incase pdf is not viewable
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Call off the dogs. Just heard back from Magnetic Components. Pasting the reply.
"You are correct for the primary connections.
For the HV secondary, use the RED, RED/YEL, and RED leads for the 5E3 Deluxe. Use the ORN, RED/YEL, and ORN leads for later Deluxe amps. The 5E3 had higher plate voltages than the newer amps.
If you want plate voltages like the P-TF22772, then use the ORN, RED/YEL, and ORN leads."
The comments about the other colors must be for another variation of the transformer I guess.
TWC
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There are no Yel-Red or Yel-ORN wires.
Come on ! Does that mean you don't have the center tap on that PT ?
I've used a 40-18078 PT in my 5E3 (240 VAC ; 660 VCT) & everything was OK.
There's something I can't figure out yet : why Magnetic Components don't say a word about the lack of the center tap in their answer ? What did you ask them actually ?
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He mentioned the center tap. That was pretty clear from the spec. "For the HV secondary, use the RED, RED/YEL, and RED leads for the 5E3 Deluxe. Use the ORN, RED/YEL, and ORN " CT is the Red/Yel and I was clear about that early on. What I did not see was a Yel-Red or a Yel-Org which they reference in the spec. That's what was confusing me.
There are no Yel-Red or Yel-ORN wires.
Come on ! Does that mean you don't have the center tap on that PT ?
I've used a 40-18078 PT in my 5E3 (240 VAC ; 660 VCT) & everything was OK.
There's something I can't figure out yet : why Magnetic Components don't say a word about the lack of the center tap in their answer ? What did you ask them actually ?
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What I did not see was a Yel-Red or a Yel-Org which they reference in the spec.
Look at the spec sheet again. There's no mention of a "Yel-Red" or "Yel-Orn" wire.
What they say is Red-Red/Yel-Red. The dash is the separator between the three wires, ie, you have a Red wire, then a Red/Yel wire, then another Red wire. Red/Yel is the red wire with yellow stripe.
Red - Red/Yel - Red
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I was about to say yer wacked! but went back and looked again. In the software business we would call that "precedence of operators" :) I was seeing the / as the separator not the dash. Thanks
What I did not see was a Yel-Red or a Yel-Org which they reference in the spec.
Look at the spec sheet again. There's no mention of a "Yel-Red" or "Yel-Orn" wire.
What they say is Red-Red/Yel-Red. The dash is the separator between the three wires, ie, you have a Red wire, then a Red/Yel wire, then another Red wire. Red/Yel is the red wire with yellow stripe.
Red - Red/Yel - Red
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I'm curious, why not go with Magnetic Compenents 14-18021 and no extra wires or hookup matrix - and $20 less?
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Honestly I am concerned about how the circuit is going to react to a 710V secondary. It is running with a 650V secondary right now. If I don't like it, this PT gives me the option of easily change it to a 660V secondary.
It sounds pretty good now. Just seeing if I can get it to sound a bit better.
I did not intend on changing the PT at all. I originally was going with the multitap OT but then saw the dual secondary and thought I'd give it a try while I was tearing the chassis apart. The PT change is taking a lot more effort than the OT change. Probably a bad idea over all.
I am so far beyond "Saving $20" with this chassis it is ridiculous..
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I am so far beyond "Saving $20" with this chassis it is ridiculous..
:laugh:
For sure, we don't do this to save money!
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I surely know what you guys mean. But, it's not as bad as a boat is it? :rolleyes: lol
thanks , I was just wondering what you were up to with all the wires on that beast.. I saw they do have one with lower voltage too.