Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: plexi50 on June 02, 2011, 02:42:18 pm
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Guys my brain has froze up. I am 2 wires away from firing up my new 18 watt 6V6/EL84 Rebel 20 build
Below is the diagram for the PT primary and secondary wiring. I am finished with the secondary wiring
I am confused on the two primary wires that will be going to the mains fuse and then over to the On switch
I would think they are the Black and Brown 120V wires on the diagram
But i also see a Brown wire with a White tracer at the bottom of this diagram also labled 120V
I am ready to hear this puppy! :help:
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I think you're supposed to wire the two 120 windings parallel:
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So would that be the Black & Black/White together and the Brown & Brown/White together? One pair going to PT and one pair going to the Switch?
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no,one pair is hot and one is neutral.(so yes,one pair to PT an one to switch)
Hammond does that silly wiring too.
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So would that be the Black & Black/White together and the Brown & Brown/White together? One pair going to PT and one pair going to the Switch?
Yes and yes.
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Right and ON! Thanks alot guys. Voltage is good on rectifier and all tube sockets. Putting in the tubes now and will post the results later.
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This appears to be a method to use the entire primary windings in either a 120or 240 VAC config?
rob
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This appears to be a method to use the entire primary windings in either a 120or 240 VAC config?
rob
Ran in series, brown to neutral, brown/white to black/white, black to line. the primaries will be rated at 2x's the voltage and half the current draw.
Ran in parallel, brown/white and black/white to neutral and brown and black to line, the primaries will be at the rated voltage and current draw.
Ray
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Hammond does that silly wiring too.
I'd rather say that it's good engineering. You can set the primary for any worldwide mains voltage and still use all or most of the windings/core/etc. A tap is much less efficient (and less elegant, too).
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Silly for a guitar amp is what I mean.We don't need that stuff and the manufacturer should make two versions;one domestic and one export version.It simplifies our lives.
Why Hammond came out with a guitar line of transformers.And look at Marshall power transformers.Easy wiring for multiple voltages.Now THAT is good engineering.
A common lead for all voltages and a secondary voltage lead easily wired into a voltage selector switch.
Why not build ALL PT's that way?
Ever try and do multiple voltages on the Classic Tone PT? Now that would be difficult.
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It works! This is the first PT i have used from Classic Tones. I have used 6 different OT's and they were all simple enough to wire as usual. So now i know from here on what i am looking at when i use one of these PT's.
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Hey plexi, details? Sound?
Thanks, Brad :icon_biggrin:
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Silly for a guitar amp is what I mean.We don't need that stuff and the manufacturer should make two versions;one domestic and one export version.It simplifies our lives.
Let me kindly disagree again. You need 50 Hz-sized cores and multiple primaries as soon as you stop thinking local. The Euro is very strong at this time, a lot of European customers buy US-made stuff - of course including amps - and you need to ship the right version, with 220 to 240V primaries, 50 Hz-sized cores as well as self-certified compliance with what the eurocrats have decided this week. Ditto for Japan, China or the Far-East : lots of customers there with deep pockets lusting for real US-made stuff.
And look at Marshall power transformers.Easy wiring for multiple voltages.Now THAT is good engineering.
Easy if you've got the right switch. A more than $30 proposition for the Marshall part if bought at retail (and 1/3 or so if you go for the original version by Schurter).
Ever try and do multiple voltages on the Classic Tone PT? Now that would be difficult.
Piece of cake with the right switch - Schurter to the rescue, again, or other manufacturers.
http://www.schurterinc.com/Home (http://www.schurterinc.com/Home)
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Ok,lets agree to disagree here.The OP is not in Europe and Canadians and US buyers don't need 230v.
Two markets.
Then the switch thing.Sure if you use the 'Marshall' switch it's expensive,but eas to use and wire.The Shurterinc switch ain't cheap either.
So you don't want to shell out 30 bones for a Marshall AC switch? Buy a 3TDP switch and swap the two most popular voltages.
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I have decided to use the 5 volt tap and put a rectifier tube in this amp. What are the two correct wires to use? One is 5 volt and the other 6 volt. Wires are / Yellow / Yellow/White & White
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Yellow - Yellow/White should give you the 5v
G
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Thats what i was thinking. Thanks Geez for your input. Will try it now that i have the rest of my combobulation here sorted out. I would love to build your Carolina Special when i get the time. It looks and has great reviews
Wired up and sounds great. Using a 5AR4 recto tube. Plate voltages and bias spot on
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I really like the Mag Comp Classic Tone trannys.
Very reliable, good price and the OT's sound great (opinion)
The few extra leads are likely to reduce mfging cost so that 1 tranny can "fit" quite a few designs.
While this may be frustrating at fist encounter, Those coiled up, unused taps can be VERY handy down the line for things like switching relays and such.
Kudos to you on your success!
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Thanks Stingray65. I just ordered a Classic Tones 40 watt OT for my Windsor Studio 20. The Windsor is too compressed with the tiny OT it has from the factory. It's trying to breath but can. I bet it will sound great with the OT change and also be able to get some nice clean tones out of it. Needs some full blossoming headroom for sure in that amp