JBL C40 Harkness Looking for Info and a Match

[Johnny_Law]

Hello all,

My name is Ryan and I am a new audiophile with a budding JBL passion. I started with a pair of L26s that I restored and recapped and love. I then picked up a pair of J220As which surprised me. But then I stumbled across something amazing - a Harkness. As far as I know, it sat untouched in a California garage for 50 years.

I am looking for any and all information I can find on it. History, specifications, finish, etc. How do I check out the health of the drivers & crossover? What's the best way to refinish the cabinet? Any other tips & tricks?

I've been searching and reading threads about these speakers and have found some good resources:

http://www.lansingheritage.org/image...kers/1957-c40/
http://www.lansingheritage.org/image...catalogs/1957/
http://www.audioheritage.org/vbullet...2600-crossover
http://www.jblproservice.com/pdf/Net...tics/N2600.pdf
http://audiokarma.org/forums/index.p...-score.208482/

Most importantly, I'm NOT looking to sell. I'm looking for a mirrored match to go with it.

I did look at the drivers, it is a two-way with the 15" woofer with the shiny metal dust cap and the bullet tweeter. I haven't yet pulled them to check serial #'s. The crossover is the N-2600. And they work!

I will take more detailed pictures, but here's what I brought home:









Thank you for all advice and/or thoughts in advance!

Best,
Ryan

P.S., I also found out we have a family friend close to JBL which is very cool. My girlfriend's mother is good friends with a daughter of John Edwards, http://www.audioheritage.org/html/people/edwards.htm.

[audiomagnate]

I have one but I don't want to sell it and mine is mahogany anyway. A perfect cosmetic match is going to be hard to find, maybe build a period mono system around it. It's no surprise that it works as nothing wears out on JBLs of this vintage, although the capacitors might be out of spec but if it sounds ok I would keep them stock. I love the look of that grill cloth. There is an upgrade path (add a potato masher mid/tweeter, there should be a spot for it on your baffle) if you want to make it sound even better. Enjoy, I think the Harkness is the coolest looking speaker ever made. A little Howard's restore a finish and some 0000 steel wool might bring the cabinets back, but as my dad used to say, "if it ain't broke don't fix it."

[BMWCCA]

P.S., I also found out we have a family friend close to JBL which is very cool. My girlfriend's mother is good friends with a daughter of John Edwards, http://www.audioheritage.org/html/people/edwards.htm.

Nice find and a good contact. Perhaps he can help determine if what you have is genuine JBL or a home-built cabinet. My guess from the chopped-up back is that it was either home-built or butchered at some point. Sounds like you have the 030 load. Even the D130 should sound great in the loaded horn enclosure.

[SEAWOLF97]

as my dad used to say, "if it ain't broke don't fix it."

as we used to say at Intel , "if it ain't broke , fix it ..till it is"

[Johnny_Law]

Thanks guys. Yes this seems like a mirrored match will likely be a hell of a white whale to track down but I'd love any leads if anyone has them!

This cabinet isn't bare wood, it seems to have a clear coat like a lacquer or shellac on it, which is chipped, spider webbed, and in rough condition, so maybe I'll strip it and decide whether to re-lacquer. I'd love to figure out of the lacquer was an original finish, but first I suppose I need to figure out of this is a kit.

How could I figure out whether or not it's a kit? It doesn't have any JBL Harkness badges anywhere, bare plywood on the back, and the inner baffles seem to be real wood or plywood and not particleboard. Another odd thing is that the 075 is in the upper right corner which doesn't seem like the correct orientation from what I've read - it seems like it should be in the upper left.

The 075 does have some kind of discoloring on it ... I'll need to see what it is and if I can clean it up easily. I had forgotten to mention in the first post, now edited, but the big cone has the aluminum dust cap which doesn't have any dents. Do the surrounds fail on these? I'm wondering if I'd hurt anything by pulling the mounting panel to look at the drivers from the back.

About John Edwards, at least if I got good info from my gf's mother, he has passed. I'm not sure how much his daughter knows, but I hope to meet her and ask.

[BMWCCA]

The 075 does have some kind of discoloring on it ... I'll need to see what it is and if I can clean it up easily. I had forgotten to mention in the first post, now edited, but the big cone has the aluminum dust cap which doesn't have any dents. Do the surrounds fail on these? I'm wondering if I'd hurt anything by pulling the mounting panel to look at the drivers from the back.

The aluminum on the 075 can corrode just as any aluminum in the elements will. The D130 has either no surround material or the folded pulp cone edge has black "dope" on it if it's a later version. No foam to worry about, at least. Sure, take it apart and get some pics. What I don't understand is the plywood back with the enlarged hole and then adapter plate to make the JBL crossover fit. That seems odd for a factory build.

[Horn Fanatic]

What I don't understand is the plywood back with the enlarged hole and then adapter plate to make the JBL crossover fit. That seems odd for a factory build.

I agree. There would also be the screws on the back used to capture the two small panels used to secure the N1200 style network. With the over sized hole such as it is, the two panels could never be attached. As we all know, the typical hole that allowed access to the old style network connections, was also the same size hole that accommodated the newer can, such as the one in the photo.


This is what a typical C40 rear panel looks like, although the 1958 C40 rear panel drawing detail I have does not show a separate removable network access panel. It does show two holes for a three way configuration. One for the newer can, and a detail of the hole and two panels for the N1200 network, as in the C40 technical note page.

http://www.hifido.co.jp/photo/09/319/31987/j.jpg

http://www.lansingheritage.org/images/jbl/specs/home-speakers/1957-c40/page1.jpg

[Wagner]

There were more than a few FACTORY builds of the C40
Some examples have a split back panel, some do not and some have a split back where only half of it is removable.
There was also more than one factory version of the front baffle and countless homemade versions as well.
All plywood construction was dropped around 1962 but I have seen exceptions (they used up the material on hand)
I have owned 5 C40 cabinets, all 5 where factory and all 5 were different (well 3 and 2 were, as 2 were a pair purchased at the same time) My other 3 were stray singles
I owned one all plywood pair and one half and half (plywood and particle/early style MDF board) The particle board versions seem to also have the thinner veneer when compared to the earlier all ply versions
The odd man out was an all plywood box as well, very early probably around 1957
There are some inconsistencies with internal bracing and glue blocks as well

Mirrored pairs are difficult to come by. The C40's introduction and production run coincided with and crossed over the MONO to STEREO era.
By the time STEREO was the firmly established form, the C40 was no longer a favorite in large format box style for domestic use (big ass low boys)
The standard version of the box places the drivers to the right when viewed from the front, with the 175DLH in the upper right corner of the baffle . The opposite placement (and box obviously) was a special order proposition.
Most folks making the transition from MONO to STEREO just bought a second "standard" cab and that is what you will find 99% of the time. (drivers to the right of the "scoop")

It took me 5 years to find a second single cab with left driver placement to make my last pair mirrored.

As for your finish, if it is factory, it will strip easily and the veneer underneath it is world class and cleans up extremely well (especially on the "blonde" boxes). I do suggest chemical stripping and clean up using acetone versus aggressive sanding as the veneer, although fairly substantial is still not especially thick although more so than much later Black American Walnut veneered cabs synonymous with the '70s and forward JBLs

A single strip with paint remover followed by a liberal acetone wash and you will be amazed at the smooth tight grained and hard veneer you will find underneath (if in fact your box is factory). I had one cabinet that after an acetone wash was so nice it was practically finish ready and required only the finest of sandings.

They were really beautifully made.

I find it intriguing all the current interest in the "001" system and the C40 as of late. Years ago, when I first started collecting and restoring them (and coming here to read), they were "pooh poohed" as being an under performing "budget" system. Nothing but negatives, comparisons to the big brother 375 and just generally dismissed as a speaker suited only for collectors.
It can't do this, it can't do that, it can't make bass etc etc etc ad nauseam
I knew then and I know now that those folks were full of shit (or had never actually heard a pair)
Maybe they don't measure well, but they sure as hell sound good
Now everyone seems to love them.

I regret selling my last pair but was forced to due to financial necessity.

From what little I can see of the joinery in your photos, your box is factory. The mounting plates, hole blocks, front baffles and back boards were often cut by the owners to facilitate whatever their particular loads may have been (what they could afford) at the time.
These boxes and speakers were NOT cheap (inexpensive) by any means!
That was the beauty of what I call the "real" JBLs. You could even have them cut a board to accommodate whatever driver you wished (JBL of course) if you could not or did not want to do it yourself.

Great speaker, one of the best, enjoy!

Thomas Wagner

[BMWCCA]

I find it intriguing all the current interest in the "001" system and the C40 as of late. Years ago, when I first started collecting and restoring them (and coming here to read), they were "pooh poohed" as being an under performing "budget" system. Nothing but negatives, comparisons to the big brother 375 and just generally dismissed as a speaker suited only for collectors.
It can't do this, it can't do that, it can't make bass etc etc etc ad nauseam
I knew then and I know now that those folks were full of shit (or had never actually heard a pair)
Maybe they don't measure well, but they sure as hell sound good
Now everyone seems to love them.

All duly noted, and agreed, but what the OP has is the 030 system.
I know that one well, including all its attributes and weaknesses. I've had 030s in the house for nearly sixty-years, though mine are in C37s, not C40s. Very capable system as long as you're not demanding a lot of low-end performance and you have an EQ to bend the hole in the mid-range. That's how I got started on Soundcraftsmen Pre-amp-EQs. I particularly love how they sound with acoustic guitar music. I've even played a Gibson EB-O bass through mine!

[audiomagnate]

If you're sure it's lacquer you may be able to bring it back with steel wool and some more lacquer.

[Wagner]

If you're sure it's lacquer you may be able to bring it back with steel wool and some more lacquer.

If it real nitrocellulose lacquer you can skip the steel wool..................that's the beauty of lacquer
Just wipe it down, smooth out any rough spots with fine sand paper and shoot it

PLEASE DON'T USE STEEL WOOL on anything related to or near and around speakers, speaker cabinets, PHONO cartridges or just "hi-fi" in general

You may get away with it for ages, but I can promise you that one day it will bite you in the ass

Aside from that, steel wool is not the best option for wood work anyway, especially with light finishes, use brass wool

[Johnny_Law]

Thank you all very much for offering advice here. Wagner, thank you especially for such a great response.

I am not sure which particular clear coating is on it, just that it is a clear hard coating. There appears to be wear down to and through the veneer in places, but I won't know for sure until I can strip the coating.

I looked underneath the cabinet and did find holes which I imagine were for feet at some point, although I didn't get any feet. But my suspicion was that if this was a kit, it may not have holes for the feet?

I will follow up this week with pictures of the drivers and of the inside of the folded horn, hopefully something will provide further clues regarding its origin.

Best,
Ryan

[Wagner]

Thank you all very much for offering advice here. Wagner, thank you especially for such a great response.

I am not sure which particular clear coating is on it, just that it is a clear hard coating. There appears to be wear down to and through the veneer in places, but I won't know for sure until I can strip the coating.

I looked underneath the cabinet and did find holes which I imagine were for feet at some point, although I didn't get any feet. But my suspicion was that if this was a kit, it may not have holes for the feet?

I will follow up this week with pictures of the drivers and of the inside of the folded horn, hopefully something will provide further clues regarding its origin.

Best,
Ryan

The holes should be backed by "T" nuts on a factory (or well built DIY) box. Hard wood legs are available that are ALMOST exactly the same dimensions as the originals first used by JBL. They were wood long before the cast aluminum "stiletto"s became available (assuming you even want those).
So, my point being that wood ones would be accurate and get the job done while you search for the ever hard to find cast legs.
There are some "work around" cast legs out there, but they are not as accurate as the off the shelf wooden ones you can still buy today AND they require that you put some additional holes in your boxes to mount. Some guys like them, I don't....................and, they are expensive.

If I am going to blow well over a $100 and up on legs, and stilettos to boot, I'll suck it up and hunt down an original set (hard to find and VERY expensive unless you are incredibly lucky) before I sub in a less than original looking set AND have to drill holes. The only issue other than cost(s) for the originals is that they are often pitted and discolored due to age and the minty ones have a habit of staying with their original boxes.

The only problem I have encountered (with the current production wood legs) was staining them to match as the wood used is very hard and doesn't take stain readily.
Any good hardware or wood working store will have them. The height is correct, only the OD at the top is slightly smaller (you'll never notice it unless you hold an original next to a new one)
You'll have to buy new threaded studs too, they're wood screw threads on one end and machine threads on the other for the "T" nuts (again, readily available at any good hardware store) as the thread type and pitch are different. Very inexpensive.
The brass end cap and disc that actually touches the floor is better made from back in the '50s but that is to be expected; the new ones are still a pretty damn good option and match.
The originals had a sooth metal disc, the new ones have the white nylon insert built into a metal shell to protect a wooden floor.
Once installed on the cabinets you'll never know the difference

Thomas

[audiomagnate]

Right, no steel wool, use a "swooge":

http://www.audioheritage.org/vbullet...hlight=lacquer

[Wagner]

Right, no steel wool, use a "swooge":

http://www.audioheritage.org/vbullet...hlight=lacquer

Nice work!
As for the steel wool, I was referring primarily to the use of it between coats, applying wax as well as for smoothing and burnishing lacquer (and other finishes) like the plastics, ie: "Varathane" and the like
It is also often suggested when using strippers
Just best (my opinion) to avoid it all together with anything audio and I try to avoid it in general although sometimes it's the only practical solution for removing paint etc from carved or figured pieces

It can also cause spotting later on when used with light or clear finishes on lighter colored wood; you can never remove 100% of the almost tiny microscopic specs of metal, even with the best of tack rags, and over time they can (and do) react and become visible; sometimes in an aesthetically pleasing way, sometimes not

And NEVER use steel wool during any step if you are using ANY water based finish product (with the possible exception of paint)

I love shellac too. Was the go to finish used by the furniture industry for ages until nitrocellulose came along. It's only weakness is alcohol. It will also craze and crack wildly after about 100 years! Makes for a beautiful patina if the wood has survived injury
I have two Victrolas and one old Grafonola, all originally finished in shellac. Two of the machines' cabinets I was able to restore by just touching them up with a thorough cleaning and a VERY LIGHT film wipe with a wiping varnish to just smooth things out.
The beauty of the worst one of the bunch (which I had to refinish as it needed many spot repairs) was that the all original shellac finish was easily removed with a rag wet with denatured alcohol

Amazingly effective and preferable to harsh strippers and a lot of fine sanding. My only message here being that if you do choose shellac (real shellac like you used, FANTASTIC! ) take care to avoid allowing your beautiful finish to come into contact with any product containing alcohol

You mixed and applied your flakes with denatured alcohol as the vehicle I assume, yes? I ask as I am curious if some chemist has come up with something new.

If you want a gloss finish, like many of the old Victrolas had (and furniture too) you can spray natural shellac easily, even with a modest gun or air brush.
It goes on and flows well; spraying it is a JOY