Help identifying OT on 1960 Fender Pro

[six el six]

Has anyone seen this OT before?

It's on a 60' Pro I just got.

Pics attached.

[DummyLoad]

stepping out on a limb...

manufactured by: better coil and transformer 1974 - 12th week.


http://www.triodeel.com/eiacode.htm

--DL

[eleventeen]

I woulda thought that took a fully enclosed output transformer, but evidently not...


http://www.ebay.com/itm/1960-Fender-Pro-Amp-Vintage-Brown-tube-amplifier-5G5-Tweed-Killer-Brownface-NR-/320790440428?_trksid=p4340.m1374&_trkparms=algo%3DPI.WATCH%26its%3DC%252BS%26itu%3DUCC%26otn%3D5%26ps%3D63%26clkid%3D4183242127552919703

[stratele52]

It look to me it is a non original transformer for this amp

[gldtp99]

That OT is used in the Bogen CHB50 tube PA head, see schematic under Audio/PA in Doug's library of amp schematics.
I've converted several Bogen CHB50's to guitar amp use----- the CHB50 is a 6L6GC x 2 output amp and they sound very good with typical Fender and Marshall preamps installed in place of the orig Bogen preamp circuit. I just sold a CHB50 with a Marshall 2204-type preamp to a young player last week---useful, cheap tone for a young musician short on $$$.
This OT is perfectly suitable replacement but it isn't orig---- but it does have 4/8/16 ohm output taps, as well as 25V and 70V.
If you paid full price for the '60 Fender and you were led to believe that it had all original iron, then you have an issue with the seller---if the amp was sold as non-orig "Player Grade" then, IMO, the Bogen (Better Coil and Transformer) OT in there now would sound as good or better than any other OT--- orig Schumacher or modern replacement.
The 6G5A Fender Pro schematic lists a 125A7A OT----- which is an 8 ohm OT of the same physical size as the Bogen OT you have now........................gldtp99

PS--- your OT has the 16 ohm (green) tap connected to the speaker jacks----- this may not match the speaker load

[stratele52]

Very good information gldtp99 ,

Which wire he should use for 8 ohms  ? brown , yellow ?

[gldtp99]

Black-- common
Orange-- 4 ohm
Yellow--- 8 ohm
Green--- 16 ohm
Gray-- 70V

This is according to the schematic--- same part # OT---- it's always best to confirm this with DMM because Bogen sourced their iron from different suppliers and there may be some differences compared to the schematic--- or Bogen's specs changed during the yrs that this product was made.

[HotBluePlates]

It's odd that the OT was replaced when everything else in the amp looks bone-stock.

[six el six]

Thanks everybody and especially gldtp99 for the positive i.d. on the OT.

The original filter caps are still were as well.

Speaker codes match as do choke and power T.

Check out the tubes that were in it!

I got it for peanuts so no complaints on the OT not being original.

Any comments/thoughts on restoration as I'm going to try to keep this one as close to original as possible. I usually just put new ones in across the board.

I'm definitely going to change the OT secondary to the correct one.

One question: What are the 70v and 25v taps on the OT for?

[six el six]

Original speaker reads normal for 8 ohms and it hummed a little (the owner had it on).

[PRR]

> What are the 70v and 25v taps on the OT for?

Long multiple-speaker systems found in schools and supermarkets.

For your use: insulate the ends and tuck them out of trouble.

If you are very brave, and hungry: wire the 70V leads to a hot-dog. Play real loud for some minutes. The hot-dog may cook. (So use long wires so the grease does not splatter the vintage cabinet.)

[stratele52]

70 and 25 volts help to drive sound to very long wire like PRR write.
Without this you'll loose volume

[stratele52]

Original speaker reads normal for 8 ohms and it hummed a little (the owner had it on).
_____ SIX el SIX

Speaker hum or is the amp ?

[six el six]

@stratele52

I don't know yet. The owner was just trying to show me that the pilot light lit up.

I was just happy that the PT was in all likelihood working. I tested the OT on site with a variac.

The amp definitely doesn't work now.

Almost all of the filters are bubbled and as you can see in the gut shot, every component in this thing appears to be original w/the exception of the OT.