Email Weber and ask; they can recone JBL speakers and can also change the impedance. they may say they're fine.

Article comparing them to the D120:
http://www.vintageamps.com/plexiboard/viewtopic.php?f=12&t=26806

'65 Fender Tremolux, '74 Princeton; 77 Vibrolux Reverb; '81 Princeton Reverb
'65-66 Hilgen Basso Grande
Dr. Z MAZ 18 Jr. + 1x12 Cab
Various Telecasters and noise-making pedals
Farfisa Compact Duo

Thanks guys!

Cats 'n' Strats, 'cause that's how I roll - I eat reverb for breakfast!

Fenderus Collecticus
Strat Blender Pot Modification HERE

The old D series impedance ratings were reclassified in later series by JBL. What they called 16 ohms in the D series they now call 8 ohms. So no need to re one to change impedance.

If the K-120's are labeled 16 ohm, they most likely are. They will not be quite as loud in your amp's 8ohm output circuit as a pair of 8 ohm JBL speakers would be (wired in parallel).

I would not re-cone good originals. I'd just use them and your twin operating into an 8 ohm speaker load is no problem for the amp. Aspen Pittman at Groove Tubes wrote that it could reduce your tube's life a bit but probably no real issue on your output tranny. The best overall insurance would be to install a boxer fan on the inside of your cabinet blowing upwards toward the output tubes. I've done this and it reduces the operating temp of the amp by an astounding amount. Both the tubes and the transformers will love you for it.

If you are worried about it, I'd have Mercury make me an 8 ohm output transformer, swap it out and keep the original if you want to change the JBL's out at a later time.

I have a K-120 that has been in and out of a lot of amps over the years. It was especially good in an early 90's single 12 Concert amp that I had for a while. It brightened up that printed circuit board amp which made for a good combination. I have a number of E-120's and never have liked them in anything except for PA cabinets. They are heavy as hell and nobody likes to lug my cabinets around when loaded with those things.

A pair of pristine K-120's? Snarf 'em!

ed

Traditional........speak softly and play through a big blonde amp. Did I mention that I still like big blonde amps?

I believe the main difference between the D's and the K's are that the K's have ceramic magnets.

I'm no longer that big a JBL user as I have been on the EV (15L) bandwagon for years, but at the time I got that Concert amp, I didn't have any 12" EV's. My one K-120 did a fine job in that as well as briefly, in a home brewed 12" tone ring cab that I played around with. I have several 2-12 small Fender cabs (see below) and over the years had a number of different speakers in and out of them several times each. The asterisks indicate what they are currently loaded with.

I need to put that K-120 in something.

JO, I think you'd like the MM with the K-120.

Best reverbs,

ed

12" Cletron C-12NR from a home organ
12" JBL D-131F these sound amazing but I am afraid of blowing them
12" EV 12L Currently in the 62 blonde Bandmaster cab. Wild Bill plays bass out of this cab at small venues
12" JBL E-120's weigh a ton and are just OK to me but WoodyJ liked them
12" Fender Stock* current speaker used in the Twin Reverb and sound really nice in the small Bandmaster cabinet.
12" Peavy Black Widow rare 8 ohm with the aluminum cap, best sounding and loudest of all the speakers. Too lazy to swap a pair of the others out for these (again). We seldom use the blackface amps and cabs a shows.

Traditional........speak softly and play through a big blonde amp. Did I mention that I still like big blonde amps?

Thanks, Ig & Ed!
The Peavey Black Widow - you mean the 1203-8, right? What can be said about its performance? Sounds like it's in the same arena as JBL and EVM 12L. Any impresdsions of the Jensen Neodymium 100?

Squink Out!

Last edited: Jan 27, 2015 14:43:05

Ed,
I thought the 1201s were for sound reinforcement and the 1203s for guitar. I guess it really do't matter - f'rinstance Altec 417s are high-end audio drivers for cryin' out loud.
I think we are on to something here: vintage guitar amplification was closely related to high-end audio. Example: I just bought a pair of D130s from a local audio enthisiast who has outrageously complex systems for playback. A lot of his gear would be at home in a recording studio if not a stage.
Since the advent of Randal Prune and amplification aiming for distortion and added coloration, we diverge from the world of sound that is the native place of surf/instro. We are rooted in a pre-rock world of music that aimed at fidelity.
The reverb unit is the single most problematic part of a surf guitar rig - it's where all the real distortion and attenuation occur. The rest of the system has to work extra hard to 'rescue' the sound and keep it coherent. Thus single coil pickups that don't round off the edges already obscured by the little transducers in the tank, amps that don't compress or add harmonic to the already tweaked reverb signal of plucked string, and speaker that renders the whole thing without boosting the mids at the cost of (what's left of ) the high end.

Squink Out!