Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: olgoat on May 12, 2012, 01:38:47 pm
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I just completed my first 5e3 build. Ceriatone circuit, lots of parts from Doug and elsewhere. It is working and a friend who has played tweeds before said it sounded good so I got that much right.
I want to get the tube pin voltages both with and without the 5Y3 in the circuit. So I have a real newbie question.
- Is the voltage at the tube socket pins AC or DC? I have seen some comments that the heater pins are AC with no comment on the other pins.
- I have been looking around the forum for what the voltages should be for the 5E3. Any suggestions on where else to look for that info? (I guess that depends on the PT to some degree I used at P-TF22772 325-0-325 no center tap on heater. had to use the simulated center tap resistors.)
Thanks for any thoughts on the matter.
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There will be both AC and DC voltages here.
You will have 5 VAC or VDC (depends on what you prefer to use) on the 5y3's pins 2 and 8, this is the heater voltage. You also have VDC on these pins. It is the B+ voltage for your amp.
You will also have VAC on pins 4 and 6, which are the plates. They connect directly to the power transformer high voltage taps.
It's a rectifier tube so VAC goes in and VDC comes out.
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Tubegeek. A bit confused on the statement "5 VAC or VDC (depends on what you prefer to use)" Do you mean setting the meter for either AC or DC will have the same results for pins 2 and 8? Thanks
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Pins 2 and 8 are the filament or heaters. They can be operated with either 5 VAC or VDC. The way it is now you have 5 VAC going to pins 2 and 8 from the power transformer. The two yellow wires. If you preferred for whatever reason to use 5 VDC instead, the rectifier tube will still function this way but will require further rectification before the 5y3 if you were to do it this way.