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View Full Version : 4 ohm speaker in Fender Princeton Reverb


pics2050
01-18-2011, 10:15 AM
Hello, I have a nice 4 ohm Weber speaker that I would like to install in my mid 70s Princeton Reverb. I have read Fender amps can take some speaker impedance mismatch but is it perfectly safe to the amp in long run?

Also, if the chassis is hooked to an internal 4 ohm speaker can you still plug an external cabs to the amp at the same time?

guitarcapo
01-18-2011, 10:22 AM
If it has a external speaker jack (I'm not sure) it's usually wired in parallel so you are reducing the impedence even more. I would think the 4 ohm load would be o.k. but I wouldn't push it by adding other speakers in parallel too.

Personally I've never had a problem going one step away with the amp handling things. Some opinions on here might differ from mine though

pics2050
01-18-2011, 10:30 AM
Thanks capo for your quick response, yes the amp has two speaker jacks. I probably wouldn't use the ext speaker jack but it's good to know it wouldn't be very safe.

Anyone warning against having 4 ohms speaker load in this amp?

guitarcapo
01-18-2011, 10:42 AM
For example, the Fender Blues Junior has an "8 ohm output transformer" but it usues the same exact internals for another custom shop amp that uses two 8 ohm speakers wired in parallel for a total load of 4 ohms. I believe it's called the "Two-Tone"

Fender doesn't seem to have a problem with it.

pics2050
01-18-2011, 11:13 AM
I see. I hope older Fenders like mine work the same way, I guess they do.

gzerninplatz
01-20-2011, 12:49 PM
I called Fender and spoke to an engineer there about simply adding a speaker to my Deluxe Reverb...there are two jacks, one internal speaker wire looped out to the back panel and plugged into on of them, and no impedance selector...and I'm sure that impedance-challenged folks over the years took that as "permission" to plug in a parallel external cabinet..it seems odd that they would even have two jacks just sitting there with the internal plugged into one of them

Two speakers would, of course, drop the impedance to 4 ohms with the spec still at 8 ohms....he said no problem "as long as you don't run it all the way up all the time"

guitarcapo
01-21-2011, 08:21 AM
Well if you plug in an extension cabinet in my Super Reverb AND also disconnect the internal speaker, the thing sounds horrible...like "probably damaging your amp" horrible. You have to have the internal one hooked up too.

As a matter of fact, if Fender intended you to unplug the internal speaker before plugging in the extension speaker...there would be no need at all for a second jack wired in parallel to the "internal jack". Having one jack would not only save them production costs, but it would also insure that no one ran the internal and an extra speaker simultaneously. Personally I think the whole idea was to get a second speaker going along with the one inside the amp...and Fender pretty much knew what some people don't what to admit, that the load doesn't have to be exact....just close. No harm done.

pics2050
01-26-2011, 11:21 AM
Guys, I just installed the 4 ohm Weber in the Princeton Reverb, sounds great...cranked with JJ 6V6 power tubes now!! Cranked means more current thru the output transformer...should I just keep checking that the transformer does not get too hot?

Guitarcapo, what you say above makes sense, so does what Fender told to gzerninplatz above...can I really damage the OT if run the amp at full volume all the time? Or has anyone heard that a Princeton Reverb OT failed having 4 ohms load?