Mercury Magnetics Wiring

[pxpx83]

Hi All,

I've got a Mercury Magnetics Power Transformer (FTDP) for my 5E3. I'm not sure how to wire it up. Here is what I've got so far:

Green: to 6v6 Pin 2
Green: to 6v6 Pin 7
Yellow: to 5Y3GT Pin 2
Yellow: to 5Y3GT Pin 8
Red: to 5Y3GT Pin 4
Red: to 5Y3GT Pin 6
Red/Yellow: ?
Green/Yellow: ?
Black: On/Off AC Switch
Black: ?

Any ideas? Thanks!

-Mike

[stokes]

Red/yellow should be the CT for the high voltage winding,green/yellow is likely the CT for your 6.3v heater winding.This should be verified with an ohmmeter,measure the CT to either end of the winding and it should read close.The CT's then get connected to ground.The 2 black leads are your primaries.One to the switch,the other to the mains fuse.

[Tom Phillips]

Mike,
Do you have a real 5E3 or a repro/kit/home build? Also tell us what you have for documentation. (Schematic? Layout diagram? Kit instructions? Etc.)
That will determine what you do with the green/yellow which is the 6.3V heater winding center tap. The 6.3V CT is not used in the real, stock 5E3. Usually is used in new builds AND you may have a modified original Fender unit.
The red/yellow is the high voltage winding center tap and it is grounded by connecting it to the chassis near the power transformer.
The black wires are the 120V primary. Wiring will depend on if you have an old 2 wire power cord or a three wire with ground which is preferred.
Tom

[Tom Phillips]

Opps. I was going too fast and didn't pay attention to the fact that you were posting in Tweed Builders / 5E3 so I'd now assume that you are rolling your own. I that case I'm a little surprized that you are asking those particular questions.

I'd recommend that you wire the primary circit to current manufacturing standars with a grounded power cord and the fuse and the ON/OFF switch both in the hot side of the circuit.
Are you in the USA using a 120V AC line?

Tom

[pxpx83]

Thanks for the quick responses. I'm located in the USA, and I'm building my 5E3 from a Mission Amps kit. I've built a few projects (preamps, compressors, stompboxes), but this is my first tube/high voltage project.

Thanks for the help.

[Tom Phillips]

OK. Mission has a reputation for supplying good instructions. So... just use the information that Stokes provided and follow the Mission instructions to hook up the wires.
Have Fun,
Tom

[TD_Madden]

Just curious...why'd you spring for the MM? Bruce's iron is pretty dang good!

[pxpx83]

I purchased the MM transformers before I decided to get Bruce's kit. I've heard nothing but good things about Bruce's trafos. Guess I'll have to try them on my next build

[AG Amps]

You cannot wire current Mercury Magnetics power transformers in this manner.

If you ground both center taps you will fry the transformer or cause severe damage to it. You cannot use it to bias at the cathode either. Snip the green/yellow wire and cover it. It will still be noisy however. The current MM iron is way over hyped/ over priced, but YMMV. I received a batch of severely flawed transformers and they will not honor any warranty.

[bob p]

if you want a definitive answer about the MM transformer, contact technical support/sales at Mercury. Paul Patronete and Sergio have always been helpful, and I'm sure that they'd provide you with a wiring diagram if you asked them. I would think that a wiring diagram would be available on their web site.

Unfortunately, they do have those ridiculously high prices which has kept me from buying from them for several years. It used to be that you could buy Mercurty iron for less than it cost to buy hammond. not any more.