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Sunn 1x15 cab

Discussion in 'Amps and Cabs [BG]' started by fender3x, Apr 14, 2006.

  1. fender3x


    Mar 12, 2006
    I am looking for advice about a Sunn cab that I have had for a LONG time. It's an 1x15 cab. It has handwriting inside that says it was built in December of 1968. It has its original, totally unmodified JBL 140F. Cone looks good...no tears or anything...amazing really given its age.
    This came with my a 40w Sunn head from 1965. This is the 2nd head they developed for bass at Sunn, basically within the first year of forming as a company.
    This was my first amplifyier, and I got it, well used, in 1972!

    This thing has lots of sentimental value to me...but facing facts, the JBL was designed to handle 150 watts. It has a beautiful voice at low volumes, but it distorts at whenever I turn the amp up much at all (I am using a GK 400RB with it now), even when paired with another cab. (the other cab is a beater Randal 2x10 upgraded with Eminence speakers...cab rates at 8 ohms/300w).

    I have been thinking of putting an Eminence Deltalite in the Sunn cab. The T/S specs (of course I am estimating) look good. I could keep the JBL in case I ever try to sell the cab to a collector. In the meantime, would this give me more headroom without distorting?

    Just as important...would I be committing a form of sacrilege? I mean...this is a classic cab, and a Deltalite is NOT classic. Of course, at 13, when I got the cab, my back was in better shape too;)

    Any advice would be appreciated!
  2. Throw the deltalite in it and keep the old speaker incase you want to sell it someday.
  3. herndonbassist

    herndonbassist Low Down Thumper Supporting Member

    Apr 7, 2005
    Herndon, VA - NoVa
    +1 I couldn't agree more. Replacing a speaker with a more suitable one, isn't really sacrilege especially if you keep the old one around. I am assuming that you're trying to keep costs low, and in this case the deltalite probably makes the most sense! I say go for it!
  4. fender3x


    Mar 12, 2006
    Thanks for the advice and the moral support. I am trying to save money...and a cab of this quality is pricy. Also, like I said, there is sentimental value, and I've only got room for so many 1x15 cabs in my small place. Since I can't bring myself to get rid of this one...
  5. 4Mal

    4Mal Supporting Member

    Jun 2, 2002
    Columbia River Gorge
    Sounds to me like your JBL is tired and needs a re-cone... You shouldn't hear any 'farting' from a D140 unless you are over driving it seriously. I've run a GK 400 decked but close to flat into a pair of 140's and it's pretty darned loud, especially when you consider that we're talking 200 to 50 watts depending on the age of the GK.

    The JBL was actually designed for maybe 100 clean watts. It also falls off fairly steeply on the low end so some folks boost the bass to make up for it. That speaker doesn't like that much. Better to cut back the mids a bit to get more apparent bass...

    You will be sad with most replacement 15's as they don't have the sweetness of the old Alnico JBL's. If you're hooked on that, there isn't much you can do except scour the used market for frames and recone.

    Best bet - scrap the 2x10, get another driver, recone this one build a replica of the Sunn. Seriously, If you like the sound of that speaker and that box, you could do worse then a pair.

    ANother vntage baox that really shines with the D140 is the Music Man 115rh which is a reflex horn design. Very efficient design that one.
  6. rllefebv


    Oct 17, 2000
    Newberg, Oregon
    There was one of these for $100 here on Craigslist yesterday... Don't know what kind of speaker... I was very tempted but my wife is being tough about it :mad:

  7. fender3x


    Mar 12, 2006
    I have a relatively late 400RB but don't know the exact date. I actually like the combination. Tighter mids with the 2x10s and a better bottom with the 1x15.

    It doesn't really fart, it just plain distorts...and nowhere near flat out. I have thought of re-coning, but thought the problem might actually be the power handling, in which case it would still distort, right?

    Also, there is the issue of my back. The JBL weighs a ton, and the cab itself is well enough made to have some heft as well. Thought Neo might be a good compromize...better power handling for sure + lighter weight.

    How much will the sound be negatively effected? Opinions?

    As usual, thanks for your 2 cents! ;) ;)
  8. The 0x

    The 0x

    Aug 24, 2003
    Timonium, MD
    Keep the JBL, I might buy the cab off of you later. ;)
  9. 4Mal

    4Mal Supporting Member

    Jun 2, 2002
    Columbia River Gorge
    As speakers go, the Alnico JBL's weren't all that heavy. D & K 140's are Alnico. The E140 has a ceramic magnet and different, although good tonality. Also more power handling and a whole lot more weight. Personally, I don't think you're going to find a 15, neo or not that will bring to the table what the JBL does sound quality wise. They have an extended high end that rolls of really smoothly and provides a sweet natural presence. They don't go very deep but in the correct cabinet they roll off smoothly with no artificial anomolies in the low end.

    Correct cabinet for that guy is a 4 cubic foot with 25 sq inches of 6 inch deep port as I recall. You might want to do a measurement of the internals of the Sunn and see if the cab is too big. The D140 is happier in a smaller box than spec rather than a larger one. If it is, then maybe you can figure out a way to reduce the apparent volume via sound deadening material or maybe a structural mod internal to the cab.

    A recone is still probably in order though, you shouldn't be hearing a whole lot of distortion unless you're flat out dumping too much signnal into the box.

    I recently sold off a Sunn Beta 2x15 cab. Ported and a little undersized for 2 D140's. That cab, when loaded with a healty D140 and a healty 2205 (very similar to a D140) and wired for 4 ohms, was sucking down my GK 1001 RB II. I ran the Master wide open and the input vol at say 9 to 10, boost up a bit. That's in loud gigging territory for me with my normal Bag Ends.

    It was punishingly loud... as long as I didn't EQ for any extended bass. ....and too large for me to deal with in the back of my Subaru along with the rest of the PA and bass rig stuff I carry...
  10. fender3x


    Mar 12, 2006
    No worries. Losing the JBL was never an option ;-)
  11. edbass


    Nov 8, 2004
    The D140 is only rated at about 75 watts continuous sine wave. It comes from an era where tube amplifiers were the norm, and 100 watts was a HUGE amp. The key to the D140 is its efficiency. It has an extremely efficient AlNiCo motor assembly. It runs very close voice coil tolerances and has a relatively supple surround and spider allowing it to utilize its massive (for its time, almost unheard of large) 4” voice coil to move prodigious amounts of air with relatively small amounts of power. In the mid 70’s, amps quickly got much more powerful, and JBL introduced the “K” series. The only real difference for the K140, besides its new crinkle black paint job, is the cone/voice coil assembly. By making the surround stiffer and increasing the voice coil clearance, the speaker got less efficient, but capable of sustaining substantially more continuous sine wave, rated at 150 watts. The E140 is its own animal, ceramic magnet, stiff surround, designed from Jump Street to handle modern SS power amps. All of the AlNiCo JBL’s are built very solidly, and can deal with program musical dynamics well in excess of rated capacity, but be advised; You CAN disembowel an AlNiCo JBL with a powerful SS amp. It’s far less likely that a tube amp will launch the cones, as the distortion is very smooth and gradual as compared to a transistor’s harsh “instant square wave” distortion.
    In any case, it should get real loud before it croaks though; if the surround and spider seem intact, you may have a voice coil rubbing, possibly even shorting out one of the leads at max/near max cone excursion..
    Reconing a D140 as a true D140 probably isn’t an option, JBL hasn’t made the kits in some time. I currently use factory D140’s, factory K140’s, as well as various other drivers in different tube and solid state bass rigs. I also have a Sunn 2X15 cabinet a pair of D140 frames and motors with E140 recone kits in them. Not as efficient as the factory D140’s, but still AlNiCo smooth and able to handle probably 175 or so watts easily; a great match with a big tube amp. The factory E140 recone kit is the most readily available factory kit that will drop into your D140, and is probably the way to go if you recone your D140.
    The original Sunn cabinets (sold with the 60 watt 200S) were designed for the D140, actually two D140’s in what they called a “folded horn” configuration, but that is in actuality a folded horn port configuration. They work well together but make a huge unwieldy package to tote around. The 1X15 is really a 2X15 cut in half for portability, half the volume, half the port, half the weight, etc... It was introduced in the late sixties to pair with their 40 watt tube amps (the first year Sunn amps, 1965, were actually 60 watt Dynakit Mark III power amps and PAS 1 preamps bolted in a box as two separate chassis, wired together with the controls on the top. It was used for either bass or guitar, kinda like Reeves or HiWatt amps are today. There are rumors that there was a 40 watt, two chassis Dynakit ST70 based amp as early as '65, but I think that's just an urban myth (Like the Loch Ness Monster) based on a misquote in a third party article. However, also like the Loch Ness Monster, if you are in possession of one it would be of "great interest" to myself and others.)
    But, I digress. I think, fender3x, that maybe you and I have had this mystical Sonic I discussion before. I believe it was in the Hamptons. Maybe not.
    In the early 70's, Sunn went to side ports with front loaded speakers and away from the original middle ported, rear loaded cabinet, probably for production reasons The later, side port Sunn 15” cabinets, 215S, Beta series, etc., were designed for the Sunn labeled Eminence built (later Sunn in-house built) 15” drivers, and don’t have the volume necessary for the JBLs to excel.
    If you have a D140 loaded Sunn 1X15, it is most likely the late 60's first generation cabinet.
    I would go ahead with your plan to load the cabinet with a substitute driver and save the old JBL, but I’m not real sure about the Deltalite. The D140 isn’t all that heavy in the first place, only 6-7 lbs more than a Deltalite, and going Neodymium from AlNiCo may sonically not be worth the weight savings. Maybe an EV SRO or EVM series would be a good compromise, about the same weight as the D series, but more defined and modern sounding than the D140, but most likely warmer, less expensive, and a better match with your Sunn cabinet than the Deltalite.

    Or.....you could just send me your cabinet and 40 watt head and stop fretting about it!
  12. The 0x

    The 0x

    Aug 24, 2003
    Timonium, MD
    Dude, I already called dibs on it!!! :mad::spit::rollno:
  13. fender3x


    Mar 12, 2006
    Thanks for the detailed responses. I got the advice about putting a E140 cone kit in the speaker from someone at JBL… Most of this is new to me. The fact that the speaker distorts at relatively low volumes means that there is something definitely wrong… and I should probably start with a re-cone

    I had never really considered selling the cab or the amp… They were the first I ever owned. I suspect that it would have to be a pretty serious collector to even know what this is.

    I have never heard of a Sunn amp based on the Dynakit ST70. Still, I might be able to shed a little light on the Loch Ness Monster. What I have is a 40 watt amp, based on the Dynakit Mark IV. I understand that the ST70 is sort of like two Mark IVs side by side, so it uses two EL34 power tubes rather than 4 like the ST70.

    Now for the fun stuff… It is two-piece, with the amp chasis bolted to the floor of the box, and the pre-amp chasis bolted to the top, so the controls are on the top. The amp is really clearly a Mark IV, but the pre-amp is a bit of a mystery. I read an interview with Norm Sundholm that said he rodded the PAS1 preamps to scoop the mids a bit, but I have never been able to find specs on the mod—and am not sure they exist.

    I figure it comes from late in 1965…perhaps early 1966. It has the well-known Sunn logo on the outside. On the inside, however, where the serial # is stamped on, it has the “smiley” Sunn logo, that I think they got rid of in the first year of the company.

    In any case, this is the 40 watt head with the controls on top that was paired with the 1x15 folding horn cab. I have never seen another head like this. It’s retired now. It is not reliable for playing out, and is not a quick as modern valve amps. It does have a beautiful warm tone, but would need a really thorough going-through in order to be reliable.

    The cab looks like exactly what Edbass called it—1/2 of a 2x15 folding horn. It’s a rear-loaded, front-ported cab. I have seen a few of them around, but the 2x15s are a lot more common. If anyone is interested, I can put up some pics.
  14. edbass


    Nov 8, 2004
    Yep, an ST70 is in essence a pair of Mark IV's. No doubt, in that era Mr. Sundholm would have shoved a Mark IV into the box. I was refering more to the circuit; I have experience with ST70's and the circuit is nearly identical to the 40 watt Sunns I've autopsied.

    Be still my heart! You actually HAVE a live Sasquatch in your possesion!

    I'd imagine late '65, I don't think the smiley face, or the Dynaco produced split chassis was used at all after that. However, I've never seen a top control head with anything except the smiley face on the front. (Of course, I was the one questioning the split chassis 40 watters even existed so, so much for MY opinions!)

    Obviously, I'm pretty fond of old Sunn gear, but the 40 watt bass rigs are probably only useful as studio gear. I would think that even in tip top shape, in that Dynaco circuit, the pair of EL34's are going to be screaming their guts out before you get enough volume to be heard over most drum kits. Of course, there are those that like their bass real snarling and nasty...

    Get some pics of that bad boy up!
    Or....like I said before, you could just send it to me.
    No, really!
    It would have a bunch of it's siblings to play with in my personal "Tube Sunn Retirement Village".
    Since it is near and dear to you, I'm sure you would want it to have a good home and the best of care in it's golden years!
  15. fender3x


    Mar 12, 2006
    here are a couple...

    Attached Files:

  16. fender3x


    Mar 12, 2006
    ...and a couple more...

    Attached Files:

  17. fender3x


    Mar 12, 2006
    Last set...

    Attached Files:

  18. edbass


    Nov 8, 2004
    Very nice piece. You truly have a part of RARE Bass Guitar history there!
  19. The 0x

    The 0x

    Aug 24, 2003
    Timonium, MD
  20. Blues Bass 2

    Blues Bass 2 Supporting Member

    Oct 3, 2001
    Davenport Iowa
    Wow.If I were you I would do the recone that JBL suggested,that will take care of your distortion problem and still keep the vintage look/sound.Also it will increase the cabinets power handling.I have a soft spot in my heart for the tone of the JBL 15s and looking at that rig I would change it as little as possible.Wow.

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