Hammond 1650H/P drop-through conversion?

[Steve Conner]

Hi all,

I'm fed up with only having a 16 ohm output on my Toaster guitar amp:
http://www.scopeboy.com/toastpix.html

and would like to change it. I also use it as a bass amp, so I thought a full bandwidth OT like the 1650H or 1650P would be more suitable. However, the Hammonds are all foot mounting, but the current OT is a drop-through type!

Does anyone know if these Hammond OTs can be easily converted to drop-through mounting, whether they're held together by 2 bolts or 4, where the bolts are actually located, etc?

If the worst comes to the worst I may get a custom one made, but the Hammonds seem much better value for money and I can get them from Bluebell Audio...

Thanks, Steve

[loudthud]

I've got a brand new 1650K sitting on my bench. The laminations are the same size as the H and P (based on Hammond's data). It has 4 bolts on what look like 2.5 x 3.1 (inch) centers. It's got wires coming off both sides, primary on one side and secondary on the other. Two of the screws have combo slotted/robertson heads and two are plain slotted heads. O.D of the threads is 0.156". There are red fibre washers on both ends.

[Steve Conner]

Thanks Loudthud!

It looks like the Hammond O.T. is a good bit smaller. My current one has its mounting holes on 72 x 88mm centres and the Hammond is 63.5 x 78.7 (sorry, I did my math in metric!)

I also checked out Sowter's range of custom transformers, and their nearest match is about 3/8" bigger than my current O.T. and nearly twice the price! I guess I could try the Hammond, since it only needs four new holes drilled and the lamination stack will cover up the old holes.

I wonder if the wires from one side could be poked through to get them all coming out the same side?

steve

[bob p]

I wonder if the wires from one side could be poked through to get them all coming out the same side?

i've done that with a Hammond PT. you might be able to do that with a Hammond OT. my guess is that you'd have to remove the endbells to re-orient the wires.

[black_labb]

Thanks Loudthud!

It looks like the Hammond O.T. is a good bit smaller. My current one has its mounting holes on 72 x 88mm centres and the Hammond is 63.5 x 78.7 (sorry, I did my math in metric!)

I also checked out Sowter's range of custom transformers, and their nearest match is about 3/8" bigger than my current O.T. and nearly twice the price! I guess I could try the Hammond, since it only needs four new holes drilled and the lamination stack will cover up the old holes.

I wonder if the wires from one side could be poked through to get them all coming out the same side?

steve

would that be nessisary? the secondary taps will be going to the speaker out (assuming it is a head) so they already need to be out (or are the outputs on the front) . you may need a wire going back in for feedback if the design uses it.

edit: just saw the photos, forgot that you had linked them. looks like you will probably have to move the wires across to the other side to get them into the chassis.