Need OT specs for 5F6A Bassman
Moderators: pompeiisneaks, Colossal
Re: Need OT specs for 5F6A Bassman
yep, that was a great post - thanks a lot!
In the interest of full disclosure, I am Animal Factory Amplification.
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martin manning
- Posts: 13208
- Joined: Sun Jul 06, 2008 12:43 am
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Re: Need OT specs for 5F6A Bassman
Hammond makes some pretty accurate replacement transformers. Here are their catalog specs for a Tweed Bassman OT:
Impedance
Pri 4K CT (447V)
Sec 2 Ohms (10V 5A) 50W
Turns 44.67:1
Inductance 42.44H @ 240V 50Hz, open circuit
Primary DC resistance 89.4 Ohms
Secondary DC resistance 0.18 Ohms
Core outside dimensions 3.5 x 4.06 in
The stack height is not given, but one can infer that it is 1.44 in from the drawing on the Hammond spec sheet. The attached pic is of a '59 5F6-A. I take each dark "stripe" on the stack to represent four laminations, and I count ~20. A 26 gauge sheet thickness (0.0179 in) times 80 would total 1.43 in.
MPM
Impedance
Pri 4K CT (447V)
Sec 2 Ohms (10V 5A) 50W
Turns 44.67:1
Inductance 42.44H @ 240V 50Hz, open circuit
Primary DC resistance 89.4 Ohms
Secondary DC resistance 0.18 Ohms
Core outside dimensions 3.5 x 4.06 in
The stack height is not given, but one can infer that it is 1.44 in from the drawing on the Hammond spec sheet. The attached pic is of a '59 5F6-A. I take each dark "stripe" on the stack to represent four laminations, and I count ~20. A 26 gauge sheet thickness (0.0179 in) times 80 would total 1.43 in.
MPM
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Last edited by martin manning on Sun Feb 07, 2010 12:14 am, edited 1 time in total.
Re: Need OT specs for 5F6A Bassman
Martin, this is informative. Just about the only critical bit of information missing is the width of the inside tongue of the E lamination (the core), which shouldn't be hard to guess at. With inductance and DCR, and the interleaving from the 18W information, an experienced winder ought to be able to come up with a credible copy of the transformer, though maybe not exact. Certainly, it should sound decent.
I maintain, there isn't a person alive on the planet who can actually recall accurately what a '59 Bassman sounded like in 1959, so there's no problem throwing caution to the wind.
I maintain, there isn't a person alive on the planet who can actually recall accurately what a '59 Bassman sounded like in 1959, so there's no problem throwing caution to the wind.
Re: Need OT specs for 5F6A Bassman
ok...i live in neuquen...patagonia..argentina. so i know how you guys feel. I have to handwire my ots, and don't have that kind of information that you request. But...i have the specs for a 50 watts recto boogie, a 100watts ul fender, and a very interesting book by babani on how to make your own output transformers. drop me a p.m if you want them. cheers from the south!!