'72 SF Vibrosonic Reverb - Any experiences?

[Jeff R]

A guy on the local CL is selling what he IDs as a '72 Vibrosonic Reverb 1x15. No word of chassis hokeys, but it's loaded with an Eminence Big Ben. I had never heard of this model before, apparently they are somewhat rare, and all I can deduce at this point is its an even-higher-wattage SFTR (for no breakup at even excruciating volumes) that weighs as much as a compact car. I had a SFTR that adored ODs and assorted pedals out front, so this amp piqued my interest. His asking price also appears pretty cheap to me (currently at $680) and considering the ad's been through several CL cycles with no takers, I think I can get this thing for even cheaper with cash in hand and a hand cart and Tommy-Lift in tow LOL. Any of you guys have any experience? 

5 

[Lockbody]

"Tailless" Fender logo would be past '72.  More like '76 or '77.

What's the wattage,100w or 135w? 135w would mean a model with the Ultralinear transformer. I'd pass in that case.

[Jeff R]

Cut and paste from the ad ... 

This rare model has the same circuit as early 70's twin reverb, quad reverb, super 6 - this is the model with a single 15" speaker. 

includes original reverb tank, reissue chrome footswitch for reverb/trem.

handwired, no pcb, non-ultralinear
Real spring reverb and 100w tube power

[Lockbody]

Cool. Probably just a replaced logo, then.

Too bad about it not having the original speaker, which was a JBL D-130.

[Bloozguy]

1 hour ago, Lockbody said:

Too bad about it not having the original speaker, which was a JBL D-130.

Says "100 Watts R.M.S." on the back panel. Pretty certain it's not an ultra linear.

I had a Twin Reverb with factory JBLs from that era. Your ears would bleed long before it would break up but it loved pedals and sounded great.

I have quite a few D-130 and D-130F baskets that need reconing. If you snag the amp you're welcome to have one.

[zenmindbeginner]

Putting a 40-50 watt speaker (D130F) in a 100 watt combo seems weird... must have put out well below 100 watts

That said, most D130Fs were probably destroyed inside of these amps.

Would probably make a good platform for pedals though.

[cmatthes]

I had a '71 and a '72 Twin Reverb in the late '80s/early '90s.  I'm pretty sure my back (and ears) wouldn't be able to take it now, but it had a GLORIOUS clean sound.

[crunchee]

Somehow, this amp reminds me of a recent post here, where somebody left a very heavy amp in the back of a truck (I think it was an Ampeg), and thieves tried to steal it, but only managed to pull it out of the truck and go a few feet before abandoning it.  Unless this is your anti-theft plan, I'd recommend installing some casters, too.  I once had a blackface '67 Twin Reverb with casters already installed, and it made a ton of difference, literally.

[Bloozguy]

1 hour ago, zenmindbeginner said:

Putting a 40-50 watt speaker (D130F) in a 100 watt combo seems weird... must have put out well below 100 watts

That said, most D130Fs were probably destroyed inside of these amps.

Would probably make a good platform for pedals though.

D130 and D130F speakers were rated at 100 watts RMS power handling capability. Very old obsolete JBL literature occasionally shows up with 25 or 40 watt ratings but that was a carryover from hi-fi days.

[sonic1974]

Hi Jeff R, I had one of these amps, mine was a 73. I really liked it! I was in need of some cash at the time so I sold it but I really liked the sound of it. The only thing I didn't like was the weight! I have to admit it was a pain in the ass. The speaker had been changed for a lighter weight speaker, but still it was pretty heavy, in the 70 pound range I would estimate. 

The pluses, awesome clean sound and really great reverb. The trem was nice, but I'm not a big user so can't really evaluate it that much. Mine had a master volume, but I really can't remember if that was a mod or stock. You could use the master get some amp overdrive I guess, put it low and crank the volume. I tried that and the results were not too bad. 

But really, it worked awesome as a clean platform. 100 watts of power. Awesome awesome cleans. I had read that they were intended to be used for pedal steel players. I'm not really sure what the rational for using a 15 inch speaker vs. 2 12 inchs was, not sure why pedal steel guys would like it better, but sounded great to me. 

I really miss this amp actually, but not the weight, ha ha. 

If you don't have to move it around too much, man for $650 I would grab it for sure. If you do have to transport it a lot, how good of a buy it is I guess depends on your tolerance for lugging stuff around. 

I've had other Fenders like a Hot Rod deluxe, a SF Vibrochamp and Champ and a pawn shop Excelsior. This one was my favourite sounding. 

[cmatthes]

That would be a great, screamin' shop/demo amp!

 

[Bloozguy]

You might also take a look at the cabinet material. If you had a replacement made from solid pine rather than plywood you would likely save a few pounds.

Installing a Weber California AlNiCo 15 would give you a 12.6 pound speaker rather than the 19 pound JBL...and they sound pretty much identical.

[Caddie]

Mesa claimed that the Mark IV combo weighed 70lbs.   No freakin' way kids!  I put it on the bathroom scale with the foot switch mounted in it.  85lbs and the footswitch  DID NOT weigh 15lbs.  

Cheers!

caddie

ps- amps are like women, always heavier than advertised & louder than advertised & leave you wanting more headroom

[zenmindbeginner]

45 minutes ago, Bloozguy said:

D130 and D130F speakers were rated at 100 watts RMS power handling capability. Very old obsolete JBL literature occasionally shows up with 25 or 40 watt ratings but that was a carryover from hi-fi days.

The literature that states that the JBL D130 is rated at 25 watts wasn't erroneous or obsolete. Dual Showmans never blew a D130 or fried voice coils but Showmans did run the risk of blowing one or frying a voice coil even though they rarely did. The cleaner the amp, the lesser chance of damaging a D130 or D130F with a lot of power. The SF Vibrosonic Reverb above is a clean sounding amp, so that makes it safer... so were the Showmans. A lot of D130s were in those crystal clean Standel amps that Wes played and they probably never blew.

Harvey Gerst came up with the specs for the D130. Here's what Harvey had to say about the JBL D130 and D130F's power handling capability - "It's amazing about the variation in answers you'll get. Watts of what kind? RMS at 30 hertz? White noise? The question has almost no meaning without stating some parameters.
 
If you look at the original spec sheet for the speakers in that series you'll see that the D-130 is rated at 25 watts. Since this appears on the rear of the pamphlet that gives dimensions for recommended B/R enclosures, one should assume that it is 25 watts when mounted in the proper cabnet.
 
You should find that about 20 to 30 watts into one of these in proper sized enclsure will drive you out of the room. If you put it in an undersized and over damped box like a    Benson then the speaker will take more power, but it will need it to get the volume. The D-130 was/is an efficient speaker. It doesn't need a lot of input to get a lot out.

On the other hand, I saw a lot of D130's come through with fried voice coils that were running off a 12 Watt Williamson amp during the 50's and 60's. Integrated music from HiFi systems caused one kind of problem - using the D130 as a musical instrument speaker created other problems. 

That's why I suggested the D130F (which was a redesigned D130), made expressly for musical instrument amps, as were the D110F (a totally new design), the D120F                (a redesign of the D131), and the D140F (a new design using existing parts).

Power specifications for the F series were nominally 35 to about 60 Watts. How did I arrive at these figures? Pretty simple, I played guitar and bass through them and kept increasing the power till they blew. Then I downrated them from the power that fried them. Pretty hi-tech, huh? It seemed to work pretty well."

[Bloozguy]

I've talked with Harvey a number of times in the past and he told me that the only changes made to the speakers with the "F" designation (yes, it did stand for Fender) were to increase the clearance between the inner and outer pole pieces (the gap in which the voice coil rides) by approximately 0.005". I have disassembled both "F" and "non-F" versions and verified these measurements. The reason they did this was because both amp manufacturers and people out in the field were in the habit of using all eight screw holes to fasten the speaker to the baffle board and tightening them with an unnecessarily high amount of torque. This would, in many cases, warp the speaker frame and cause the voice coil to rub in the gap and eventually short out.

Here is the JBL literature I referred to:

[zenmindbeginner]

22 minutes ago, Bloozguy said:

I've talked with Harvey a number of times in the past and he told me that the only changes made to the speakers with the "F" designation (yes, it did stand for Fender) were to increase the clearance between the inner and outer pole pieces (the gap in which the voice coil rides) by approximately 0.005". I have disassembled both "F" and "non-F" versions and verified these measurements. The reason they did this was because both amp manufacturers and people out in the field were in the habit of using all eight screw holes to fasten the speaker to the baffle board and tightening them with an unnecessarily high amount of torque. This would, in many cases, warp the speaker frame and cause the voice coil to rub in the gap and eventually short out.

Here is the JBL literature I referred to:

Hey Ray a couple of questions... you know the sensitivity of the D130F, I know it's efficient, just not sure how much spec-wise as far as a db rating? 

and... How many screws are optimum for a D130F?

[Bloozguy]

I don't have the D-Series sensitivity specifications, but I believe they are the same as the K-Series in which case the 130 models are 103 dB.

Harvey told me to use 4 screws and a wrench with a short handle.