JBL D120f

Steel guitar amplifiers, effects, etc.

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Greg Readling
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JBL D120f

Post by Greg Readling »

I'm considering buying an amp loaded with jbl d120's. I'm not too interested in the amp--just the speakers. Other than checking for the original cone stamp (I don't want re-coned speakers), what should I do to ensure the speakers work great before I buy?

Thanks,
Greg
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Eric Philippsen
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Post by Eric Philippsen »

Well, play through the amp and listen VERY carefully for any buzzing and/or odd speaker noises. You’ll hear them if they’re there but make sure any noise or odd sound is coming from a speaker and not from the amp cabinet itself.

Also, and it’s usually not possible when trying an amp out, it would be nice to actually remove the speakers to see if the any of the cones have been repaired. I’ve run across repairs a lot of times which are undetectable when viewed from a speaker’s rear. Had that happen to a JBL myself! Some cone repairs don’t affect a speaker’s performance but it depends on the extent of the repair. Either way it’s a disappointment to discover it later. Sometimes an amp’s grill is attached via velcro, such as found on later Fenders. When you remove the grill it allows you to examine the speakers from the front.

Look at the amp and think about how it’s been stored. I mean, has it sat in a garage or damp basement for 20 years? Well, then so have those JBL’s and that can be a warning sign. Or maybe the amp has sat unused for decades which means those voice coils have sat dormant for the same length of time. If so, be careful to first run low level signals through the amp to get the speakers moving. Don’t run dimed-out, death-metal volumes at first. I made that mistake last week. Repaired a little vibro-champ style amp that had sat unused for 10-15 years. Played through it at a low level for a minute or two and then turned it up. Dumb. Now the speaker has a buzz where it didn’t before.

Original JBLs with no issues are a nice find.
Last edited by Eric Philippsen on 26 Aug 2019 5:36 am, edited 1 time in total.
Steve Sycamore
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Post by Steve Sycamore »

Even if you do get lucky and happen upon a nice find, with use and a new environment the original cones may deteriorate very quickly. Drying and cracking is probably much more common than moisture caused damage.

There are recone kits available that correspond to the vintage design and materials. They are not difficult to install and after breaking in will sound virtually indistinguishable from the originals. Of course there are variations in the originals depending on use and date of construction. So I wouldn't be at all afraid of reconing yourself or using an expert recone service.
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Chris Willingham
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Post by Chris Willingham »

I just lucked into a very clean 1968 d120f with original cone which I bought here on the forum. Got it in my Milkman mini today and MAN, is it glorious! Bass is tighter, mids are great and the highs are just sparkly and gorgeous. I'm gonna have to put in some more seat time tho, because this speaker will tell on you. It expresses every little nuance of my playing. The tone tho!

Like prob the majority of us steelers, I've always had the JBL curiosity, if it was real or just hype. Not hype at all, it's creamy, buttery, clean tone, IMO.

Good luck with your d120 hunt. I think they're well worth seeking out if you can find a decent one.
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Bob Hoffnar
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Post by Bob Hoffnar »

I'm a JBL D120 guy myself. They are special. I have had a couple reconed and they sound great also. So don't worry about them being perfect. They are at least 50 years old after all.
Bob
Steven Paris
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Post by Steven Paris »

D-120 vs. D-130:
What do you guys think?
Emmons & Peavey
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Bob Hoffnar
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Post by Bob Hoffnar »

Steven Paris wrote:D-120 vs. D-130:
What do you guys think?
I prefer the 12" JBLs. There is a dip in the mids in the 15" s that doesn't work for me. It gets that classic twang sound if you are looking for that. Old JBL's are in a class of there own.
Bob
Bob Carlucci
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Post by Bob Carlucci »

Nothing sounds better than a JBL D 120/D130.. For years every speaker under the sun has been touted as a "great" speaker for steel.. To my ears nothing is even close to the old JBL.. however, trying to find a used one with original cone??... Best of luck with that..
Even when you do, chances are it will need to be reconed within a month of regular use anyway.. Even when new, the damn things just blew left and right.. The recones aren't quite as good as the originals to my ears, but when done by a good speaker service, they are very close and still sound better than anything else out there at ANY price... bob
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Steve Hinson
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Post by Steve Hinson »

I used a d130 every day in the studio for years...

...now I'm using an Eminence EPS-15c...

...ain't a nickel's worth of difference...

...my opinion...and should be yours...

SH
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Ken Pippus
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Post by Ken Pippus »

Not at all true Steve! I’d pay way more than a nickel to drop those 8 or 9 lbs.
Greg Readling
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Post by Greg Readling »

Thanks for all the response. The amp I was looking at is a 1969 Fender Capricorn with 3 12” JBL’s all original cone for $500. I passed b/c they are all 4 ohm speakers and I want 8 ohm. Anyway, if anyone is interested, it’s on the Raleigh Craigslist now.

Greg
Steve Hinson
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Post by Steve Hinson »

Greg Readling wrote:Thanks for all the response. The amp I was looking at is a 1969 Fender Capricorn with 3 12” JBL’s all original cone for $500. I passed b/c they are all 4 ohm speakers and I want 8 ohm. Anyway, if anyone is interested, it’s on the Raleigh Craigslist now.

Greg
I have NEVER seen a 4ohm d120...are you sure?
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Bill A. Moore
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Post by Bill A. Moore »

I think he means the amp is listed for a 4 ohm output, but it is driving 3 speakers. 3 8 ohm speakers would be a little less than 3 ohms paralleled.
Greg Readling
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Post by Greg Readling »

The seller said that each individual speaker info plate listed 4 ohms.
I have seen an old fender catalog that showed a 4 ohm option for d120s

That Capricorn amp is one weird amp and over 100 lbs.

Greg
Greg Readling
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Post by Greg Readling »

This is a screen shot of part of a 1969 fender catalog

Note the asterisk 4 ohm special order option


Image
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Bill A. Moore
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Post by Bill A. Moore »

If 3 4 ohm speakers are paralleled you would only have 1.3 ohms. 3 4 ohm speakers in series is 12 ohms.
I found a schematic, lists the Capricorn 105 watts @ 4 ohm.
Greg Readling
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Post by Greg Readling »

So, 3 speakers need to be 12 ohms each or 1.33 for the math to work out?
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Bill A. Moore
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Post by Bill A. Moore »

3 8 ohms paralleled would work for an expected 4 ohm load. Remember that they are rated for impedance, which varies with frequency, not DCR.
Greg Readling
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Post by Greg Readling »

Ok, I may go look at this amp after all—or at least get a pic of the speaker back. I wanted to use 2 of the 3 jbl’s for a twin reverb—but when he said the speakers were all 4 ohm, I thought it better to use 2 8 ohm 12’s in a twin.

Greg
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Bill A. Moore
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Post by Bill A. Moore »

I like the D120's, and have a Twin with a couple, but I sure hate to move it!
I also had one in a 57 Deluxe that too sounded great, but replaced it with a Weber alnico to make it more portable.
Steve Hinson
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Post by Steve Hinson »

Greg Readling wrote:Ok, I may go look at this amp after all—or at least get a pic of the speaker back. I wanted to use 2 of the 3 jbl’s for a twin reverb—but when he said the speakers were all 4 ohm, I thought it better to use 2 8 ohm 12’s in a twin.

Greg
It WOULD be better to use 2 8ohm speakers in a Twin...

I don't think you wanna run a 2 ohm load...
Steve Hinson
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Post by Steve Hinson »

4 ohm d120s!I've seen it all now!

One of those would be great in a Nashville 112!
Greg Readling
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Post by Greg Readling »

The owner of the Capricorn amp wrote back to me and said he inspected the speaker tags further and all three d120f’s are 16 ohm. I guess trying to use 2 of these in a fender twin is a no go still?

Greg
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Bill A. Moore
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Post by Bill A. Moore »

I have a D120F that is tagged 8-16. A knowledgeable friend said that they went out with the intent to work with either requirement, and the ones he's measured have about 12 ohms DCR. Mine is about 7.2 ohms, when I first got it, before use it measured about 10 ohms. 2 16 ohm paralleled would give the 100% mismatch that many claim is fine with Fender circuits.
Steve Hinson
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Post by Steve Hinson »

Greg Readling wrote:The owner of the Capricorn amp wrote back to me and said he inspected the speaker tags further and all three d120f’s are 16 ohm. I guess trying to use 2 of these in a fender twin is a no go still?

Greg
Acccording to what I've always heard(?),a Fender amp will accept a 100% mismatch...a Twin wants to see 4 ohms,so two 16 ohm speakers=8 ohms will work-I used an 8 ohm D-130 with a Twin in a head cab for years with no problem-just puts out about 1 notch less volume...

SH
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