How do you determine ohm rating without a speaker ?

[danielzink]

I've got an old Sears 10xl that was hacked and smashed when I got it 10 years ago. It works fine - I rigged in a speaker jack and I've plugged into a cabinet and it makes good noise. Problem is....I want to order a new speaker for it - but I don't know if I should order an 8 or 4ohm speaker .......it's not like there's a ton of old Sears amp schematics floating around the net...I know....I've looked.....any ideas ?

Thanks, Dan

[generic_user]

not sure if i know exactly what ohmage it is but i "heard" you can figure it out by testing the OT and doing some maths. but i assume that is only if you absolutely cant find the right schematic. i wonder why it wouldnt say on the back.

[generic_user]

did you look at the back of the speaker to see if it said it on there

[danielzink]

If I had the original speaker - I'd just put a meter on it and read that........buuuuuuuttt.........no speaker....

[Enzo]

Well, I just saw 27 SIlvertone schematics on the Schemastic Heaven site. And I know there are some in the Aspen Pitman book CDROM. You might looka nd see what the typical impedance was over the models.

I would try both 8 and 4 in your shop and see which seem to perform better. It won't hurt it if you chose the "wrong" one. Me, I'd default to 8 ohm in the absence of other data.

[Satamax]

http://www.radioremembered.org/outimp.htm