SPECS FOR A MODEL T POWER TRANSFORMER

[Dave73]

Anyone here now the specs for a model t power transformer?
The one in my amp is burnt and I need to know the correct voltages
so I can have Heyboer either build me one to spec or re-wind the burnt one.
I do think it would be alot cheaper to have one built to spec than getting
the old one re-wound though. Any info is appreciated.

[inky]

i have used Mercury Magnetics in Cali for my SUNN AMPS, they are great!

[Dave73]

Cool I live in Cali so I shot them an email but no reply yet.

[Longmoor]

I have used this transformer successfully on a few 4 X6550 SUNNS I add a 120v/12.6v transformer and connect the 12.6v side to the 4 amp 6.3v of the bft1b to give 60v for the bias.


http://www.dezirae.com/dezzie/sunn/BFT1B_11.pdf
http://www.tubesandmore.com/new/scripts/silverware.exe/moreinfo@d:/dfs/elevclients/cemirror/ELEVATOR.FXP?item=P-TBFT-1B

[AdmiralB]

That transformer looks like a good choice - it'll be down on voltage, looks like it'll give about 490VDC with a SS recto, which is considerably off of the 550-560 that the originals do.  

I wouldn't bother with the extra transformer for bias, I'd tap off the HV a la 50W Marshalls, etc.

[Longmoor]

Voltages on the 2000s I did this week were 555vdc right after the solid state rectifiers (HEXFRED DIODES, 16A, 1200V, P-QHFA16P)
and 511vdc after the two chokes into the first cap. Line voltage around here is always 125vac to 128vac. I like the 6.3vac/9.6amp + 6.3vac/4.0amp windings. 9.6amps is plenty for a quad of 6550s. 1.6A X 4 = 6.4A. compared to Hammond trans with a filament winding of 6A. Mounting on SUNN chassis is a snap too.

[AdmiralB]

Right, and with SS rectification an original 2000S will be close to 600V on the plates.  So, like I said, down on voltage, enought to notice.  But probably the best cost-effective PT for this application.

[cromag]

not trying to hijack this thread.    but, i may need an output transformer for a 76 model T.   can anyone help me locate a replacement?  thanks in advance.

[AdmiralB]

Hammond probably has something that will work with some adaptation, but I don't know of anything that has four secondary taps and a Z-mount configuration.