PDA

View Full Version : Jubal vs L65 have both wondering which to restore ?



PPstereo
09-06-2010, 10:37 AM
New to the site. Had some amazing and informative reading on and searching the forums.

The past 6 months of hunting for nice vintage gear has been unusually good. Had some great JBL scores. In the bunch was a perfect pair of original L65s and perfect pair of Jubals (branded as such for both, you get the idea). I have to thin the herd of equipment (NO MORE ROOM!!!) and decide what to keep and sell. I know I most likely will never have such a local find in the future so I want to keep and restore one of the pairs. I believe these both are 1st gen of their production. Both were bought from their original owners. Both needed re foaming when I got them. I just got a large batch of woofers from being re foamed professionally by a local known store. So now ready to pick what to keep.

To help ID these they are configured as such

L65s have
128H-1 woofers (owner sent originals to JBL and they sent him back these in their place)
Xover mounted on bottom of cabinet
Port on bottom left
Controls on upper left side
Terminals on mid back cabinet
Brown cloth grills

Jubals have
122A woofers
Xover mounted mid back of cabinet
Port on upper right
Controls on upper right
Terminals on bottom back mount
Blue cloth grills

Will happily post pics if anyone would like further IDs.

Its my understanding the original L65 had 126A and was rated for 75watts. I dont know if this was the original 122As that came with the Jubals but I think they are. Im 99% sure the cones are original on both. Coils test perfect on both and now they have been re foamed are ready for action.

Im looking for advice on which to focus on? Condition wise they are both excellent! I plan to have the Xovers rebuilt on "my pair". And from my reading here it seems the 128H-1 are the woofers of choice??? Anyone here who rebuilds Xovers?

FTR the other pair that Im keeping is a perfect pair of original JBL 4430s 1st gen. Have a pair of TAD 2001s I want to implement in them. Guido's article has more than piqued my interest. And a pair of perfect L200T3s may likely never leave me. I love these old JBLs!

Any help / advice would be appreciated.

Thanks so much

Dave

speakerdave
09-06-2010, 01:07 PM
The L65's are further divided into a,b, and I think c. Changes in woofer was part of that sequence, and refinement of the crossover. Do searches here; this has been written up before.

When speaking of 12" JBL woofers in general, the preference among many here is for the 128-1, but I'm not sure that was ever in an L65. If you are doing a restoration, including all original parts, you may want to research that here also.

As for upgrading the crossover, as part of a restoration, I would suggest you pull your originals, put them in a clearly labelled box and set them on a shelf to preserve originality. Then watch ebay for a correct pair for your model and charge couple the circuit on a larger board, using the original inductors. You should not need to wait very long for them to show up on ebay, as the L65 often gets mined for its 077's and the rest parted out. You may also want to replace the L-pads and get high quality resistors (Mills, etc). Read up here about charge coupling.

PPstereo
09-06-2010, 07:11 PM
is simply bringing the speakers Xover up to spec/improved. And using the better of the 2 pairs of 12s in the chosen speaker pair.

I certainly want to keep the drivers and cabinets as close to original as possible. But I dont mind using updated / improved parts in the Xovers. I suppose I shouldnt have said rebuild, more like build new ones based on the originals.

If the original inductors are essential so be it. Otherwise I dont mind spending some decent money on a ground up build. Im really hoping to find someone here who has done this many times and has first hand knowledge to do the work. Otherwise Madisound is only a few hour drive from me.

And yeah if anyone knows any major differences in the L65 and Jubal? I know everyone always says listen and find what you like. Which is always a good idea. However with a network re-work who knows the sound difference... Just hoping someone might have some first hand knowledge of the voicing differences and porting changes between the two as far as sound goes.

Pretty sure my L65s are Ver A and or pre revisions.

Thanks again

Dave