Date code on Schumacher/Fender Transformer

[jborders5]

I just found this old Fender output transformer that has been stored in one of my parts bins for a number of years..... Does anyone have an idea what era this is from? I assume it's a 1975??? I wonder how close it is to the xformer in Robben's #102 (EIA code 606 144). Thanks.

[img960]http://img198.imageshack.us/img198/5893/ztpv.JPG[/img]

[talbany]

33rd week of 75 would be my guess..
Jason
Honestly as long as the transformer is not ultralinear (standard Twin) it's not going to be much different than one made 44th week of 71 on Robbens amp
Since most of the design changes to transformers (if any)on Silverfaces would have been made right after the CBS sale..

A Good Transformer

Good Luck!

Tony

[jborders5]

Thanks Tony. It's a standard OT. Not sure if it's ideal for me as I don't have any 4 ohm cabs. I use an attenuator pretty much 100% of the time live (Faustine Phantom) to knock off a few dBs and I don't know how it will behave with a mismatched load.

[talbany]

Thanks Tony. It's a standard OT. Not sure if it's ideal for me as I don't have any 4 ohm cabs. I use an attenuator pretty much 100% of the time live (Faustine Phantom) to knock off a few dBs and I don't know how it will behave with a mismatched load.

Jason
I thought most of those attenuators have an impedance switch??...It Should..
Sure!!..I think I remember hearing (from a reputable source) that Robben likes the sound of a slightly mismatched load.. 4 ohm tap into 8 ohm load.
Dumble also built several combos (#05) ferris amp that too had a mismatched load..It's pretty funny that pretty much all of the old time and generally very experienced tube amp and guitar guy's are not really two concerned with slightly mismatching loads..They generally say an amp with a well made (beefie) output transformer if you like the tone knock yourself out..Many of the newer less experienced amp builders seemed to be more concerned with a matched load.. I've run mismatched loads for years with some of my old BF Fenders and still have these amps today..So I look at impedance matching as a kind of guideline than a rule (impedance being frequency dependant).. Now I would never run a 4 ohm load in a 16 ohm cabinet or visa versa and I don't recommend the use of an attenuator (set real low driving the crap out of the OPT Section)..However I don't see it being much of an issue if your shaving off a few dB's..Knock yourself out!!..(If your really worried about it you can install some spike protect diodes from the plates to gnd..Back EMF)
Let's NOT discuss impedance mismatching PLEASE!!..

Tony

[dreric]

Jason,

Seriously, that transformer is a dog, you know how bad 70"s Fenders were. The best thing to do is to upgrade, you're a nice guy, I'll take it off your hands....................