Replacement Output Transformer with different mouting dimensions

[SoulFetish]

The solution was a convenient and easy one, but it took me a while to come up with it.
The problem was that not only did the new transformer have different mounting dimensions, but they were REALLY close! This, IMO, was the real challenge in retrofitting an already build amp. I had space constraints, as well as mechanical, noise, and aesthetic concerns. Here is what I'm talking about:
The dimensions drawn in black are the existing mounting holes, and the newer transformer is in the red. It has been scaled for 72dpi/screen res, and should show actual size on your screen.

This was cutting it close and it was going to be a tight fit. I looked into seeing if there were any EI mounting adapters from one standard to another with no success.
Anyway, the solution was so simple, I should have thought of it sooner. It's cheap, readily available, covered up the unsightly older mounting holes and resulted in a stronger mechanical connection than I had previously. The solution? Good old #8 fender washers.
While having to swap a transformer is not ideal, I'm really happy with the results.

[Leo_Gnardo]

The solution? Good old #8 fender washers.

Right on! And the photos look good too. Good solution all around.

[g1]

Looking at the drawing, washers are what I was thinking too.
Now looking at the finished pic, I'm assuming it hangs upside down. If not, a strap that goes under the lams may be preferable (to take the weight).

[SoulFetish]

Looking at the drawing, washers are what I was thinking too.
Now looking at the finished pic, I'm assuming it hangs upside down. If not, a strap that goes under the lams may be preferable (to take the weight).

It's actually a head unit and mounts Transformers/Tubes topside. I'm not a fan of upside down chassis because of the heat. But, in a combo amp, sometimes it's a trade off for efficient use of space and a nice user interface.
Can you show me an illustration of what you were suggesting with the strap? I'm having a hard time visualizing it.

But looking at it again. I will end up putting smaller washers under the screw heads to reinforce the top of the mounting feet as well. I've been seeing some amps come in lately that look like someone went bowling with them. Whatever the hell happened, the torque caused the transformers to now look like they are trying to escape they are so warped.

[g1]

For a strap, I meant rather than having 2 washers per side, have (per side) 1 long strap with a hole at each end.
The bulk of the strap would sit under the lams. This is instead of adding shims under the lams. I think without shims or straps, eventually the weight will push the transformer down til the lams bottom out on the chassis, deforming the mounting ears a little.


But maybe the washers are already going under the lams a bit and supporting the weight. In that case it's probably fine.

[SoulFetish]

For a strap, I meant rather than having 2 washers per side, have (per side) 1 long strap with a hole at each end.
The bulk of the strap would sit under the lams. This is instead of adding shims under the lams. I think without shims or straps, eventually the weight will push the transformer down til the lams bottom out on the chassis, deforming the mounting ears a little.
[ATTACH=CONFIG]49783[/ATTACH]

But maybe the washers are already going under the lams a bit and supporting the weight. In that case it's probably fine.

The Fenders seem to have a large enough diameter to support the transformer under the four corners.
I see what you mean now with the strap, it's a good idea and arguably stronger. Along similar lines, I was toying with fabricating an entire base plate for the top of the chassis. The bitch of it was how to secure the underside of the chassis. I mean, I was trying to come up with an elaborate adapter to utilize the same mounting holes. The straps would be great inside the chassis too if I could plan a layout around them first. If fact I had to file the two washers flat near the back of the chassis about ³/₁₆" to center to fit them. It doesn't show up in the photo because they are obscured by the twisted wiring.

[g1]

Yes, a base plate would be even better. If memory serves, I think Peavey sometimes used base plates for the TX's.

[Enzo]

Yes, PV welded base plates on a number of them.