50/50 export model's wiring of primary and varistor photos?

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joey_truelove
Mark II
Posts: 93
Joined: Tue Aug 01, 2006 5:31 pm

50/50 export model's wiring of primary and varistor photos?

Post by joey_truelove » Sat Sep 22, 2018 3:50 pm

I'm amidst of trying to sort out this converted american model Fifty/ Fifty. The PT seems to be the export version, so that checks out. But it doesn't have a varistor and the voltage is much higher than expected, unhealthily high if you're the screen grid of a 6L6GC.

As it were it didn't look very stock at all. Probably even the power-cord was replaced and the wiring of it and that of the switches was all over the place. Unfortunately the PCB is charred or has deposits on it which makes the traces difficult to see. I could measure the traces, though, to figure out which goes where. But some visual reference would really have been great here.

You wouldn't have photos of this portion of an export version Fifty/ Fifty, please? Or should you have one and find it in yourself to take some snap-shots of it? Preferably stock or at least in stock configuration, as reference.

Well, any and all in reference to the wiring of the primary and its components is of great help at this point.

MesaMad1378
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Posts: 59
Joined: Tue Sep 15, 2015 4:49 pm
Location: Gold Coast, Australia

Re: 50/50 export model's wiring of primary and varistor phot

Post by MesaMad1378 » Wed Oct 03, 2018 5:43 pm

Hi Joey,
I don’t have a 50/50 but I do have a diagram for one, it’s not that great but it is still one.
On it it says variations to voltage of 20% are normal. If you’d like it, I can email it to you.

Cheers Brett.
Mesa Dual Rectifier, TriAxis, Recto Recording,
2:90, 2:100, SUS-4 16ru Case,
Flux Five, Throttle Box EQ, 5 Band EQ,
Straight Traditional 4x12 Cabs.
And other stuff!!

MesaMad1378
Mark II
Posts: 59
Joined: Tue Sep 15, 2015 4:49 pm
Location: Gold Coast, Australia

Re: 50/50 export model's wiring of primary and varistor phot

Post by MesaMad1378 » Fri Oct 05, 2018 3:51 am

Hi Joey,
Here’s a pic that might be of some use to you. It’s on this webpage.

https://www.thegearpage.net/board/index ... s.1970104/
Mesa Dual Rectifier, TriAxis, Recto Recording,
2:90, 2:100, SUS-4 16ru Case,
Flux Five, Throttle Box EQ, 5 Band EQ,
Straight Traditional 4x12 Cabs.
And other stuff!!

joey_truelove
Mark II
Posts: 93
Joined: Tue Aug 01, 2006 5:31 pm

Re: 50/50 export model's wiring of primary and varistor phot

Post by joey_truelove » Tue Oct 16, 2018 5:22 pm

MesaMad1378 wrote:Hi Joey,
I don’t have a 50/50 but I do have a diagram for one, it’s not that great but it is still one.
On it it says variations to voltage of 20% are normal. If you’d like it, I can email it to you.

Cheers Brett.
Yes, you're quite correct about that. However + 20% does put the output valves in a bit of a hazard, particularly the screen grids are likely overtaxed by some margin.

Thank you that would be very kind of you.

joey_truelove
Mark II
Posts: 93
Joined: Tue Aug 01, 2006 5:31 pm

Re: 50/50 export model's wiring of primary and varistor phot

Post by joey_truelove » Tue Oct 16, 2018 5:24 pm

MesaMad1378 wrote:Hi Joey,
Here’s a pic that might be of some use to you. It’s on this webpage.

https://www.thegearpage.net/board/index ... s.1970104/
Thanx, mate! That's all good, but it seems the OP of that thread also enquires about the section farthest to the left, which in this photo is partially obscured.

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