Fender Pro Junior speaker impedence

[POWDOG]

Hi all. Just finished cleaning up my Pro Junior, bigger filter caps, new jacks and pots, re-biased. Now for the speaker. The original speaker is a 16 ohm Eminence, sounds like poo. I have alot of nice 8 ohm speakers. Any problem here? The schematic does not indicate the secondary impedence of the output transformer. Thanks alot!

[JazzGuitarGimp]

Is thie the correct schematic?
http://support.fender.com/schematics/gu ... _Rev-F.pdf

[POWDOG]

Thanks for the reply. No, the PJ I have is a first generation USA made amp with a 16 ohm speaker on the schematic.

[POWDOG]

Sorry man. After a second look, that is the right schematic. Thanks for the sanity check!

[JazzGuitarGimp]

And are you sure:

1 the internal speaker is the original?
2 the original speaker is 16 ohms?

The schematic and owner's manual I've found online indicate the original speaker is 8 ohms. If you really have an original, 16 ohm speaker in there, than I would not reccommend replacing it with an 8 ohm model.

But, it seems a bit unusual to see a one-speaker combo amp with a 16 ohm output. I think you need to take another look at what you've got. Are you the original owner, or is it possible a previous owner replaced the original speaker?

[POWDOG]

Not the original owner, but I know the original owner. The speaker code dates the speaker to the same year as the transformers, and I know they were using these blue label Eminence speakers in the early 80's. I guess assuming the primary is around 7k, I can just test it and know for sure. Nice Schumacher trannies.

[JazzGuitarGimp]

You could also unplug the speaker and measure its DC resistance (if you haven't already). 6.5-ish ohms indicates an 8 ohm driver and about 12.5-ish for a 16 ohm driver. I think it's a bit safer to put a 16 ohm speaker into an 8 ohm amp than the other way 'round. And I could perhaps understand someone doing just that in an effort to tame the amp, assuming it's a loud amp. Just thinking outloud....

[POWDOG]

Already checked the DC on the speaker ...as well as looked at the label on the speaker magnet, both indicating 16 ohms. And I'm with you on the speaker load, better more impedence than less. Fender has a good history of running 16 ohm speakers on an 8 ohm OT. I'd like to think that the engineers planned on guys running a 16 ohm extension cab into the amp, creating an 8 ohm load.

[JazzGuitarGimp]

Yes, that makes good sense too...