2. amps-preamps
  3. 1106508342

Need advice...driving some vintage JBL's

Welcome to my first post!

Flashback - after getting out of college in '86 and securing a job and apartment, it was time for a decent sound system. At that time the absolute best sounding speakers I had ever heard were the JBL L100T. A friend had an uncle working for JBL and I managed to get pair through him for $550 shipped to my door (they listed at like $600 each at the time). I promptly took the cash I saved and put it into a Hafler DH220 amp and DH100 preamp. I then got my hands on a DBX DX5 cd player and Onkyo TA2090 tape deck at an insurance salvage sale (water damaged boxes). When all was said and done I had less than $1500 in my system and life was pretty darn good. I was very pleased with this system. So pleased in fact that I bought a second pair of JBL's at an out of business sale for $400. It was a couple of days before I could get a truck and pick them up. As luck would have it, in between that time I was broken into and lost the Haflers and what little CD collection I had at the time. Needless to say, I moved shortly thereafter.

Flash forward to the present - believe it or not the JBL's remained in storage since the summer of '87. I've been living since with a Halfler SE120/100 amp/pre, the DBX cd player and a pair of Ohm H speakers. Well I've finally moved into my OWN home, I was ready to resurrect my JBL's and start looking at a new system. In anticipation of this I pulled out a pair of the JBL's this spring. The foams were rotted. I found a refoam kit on the net and refoamed them (all four). I tested them with the present Haflers and put them in back in the box (perhaps a little uninspired).

Last weekend I pulled the JBL's out and set them up in the living room for fitting purposes - they look absolutely wonderful with the current furniture scheme - OK, 5 stars for aesthetics. A friend brought over an Adcom system he's looking to sell ($700) and loaned it to me for a test drive. So here's what I have hooked up right now:

Adcom GFA-5500 amp
Adcom GFP-565 preamp
Adcom GCD-600 cd player

I've only got enough speaker cable (monster) to hook up one pair of JBL's so far. Nothing special on the interconnects - gold plated. This could very well be the reason however I am not too impressed. I did notice that things sounded a bit better after a couple of hours once things got warmed up. The following test discs were used as a good cross section of my listening tastes:

Dave Weckl - Synergy
Cassandra Wilson - New Moon Daughter
Steve Tibbets - Yr
Chris Whitley - Hotel Vast Horizon
Wes Montgomery - Far Wes
Jeff Beck - Guitar Shop

I guess anyone familiar with these artists would understand the range I intended to explore. Forgive me for not knowing all of the audio "porn" terms, but all I can say is that the highs were just too harsh and the bass was just too muddied and lacked punch. I know for a fact that these speakers are capable of sounding much better than this.

OK, so here is my situation: I'm rather attached to the JBL's and am not convinced that they are the worst sounding speakers going for me right now. The Adcom demo was convenient but I'm not impressed and do not believe that better interconnects are going to remedy that. I'm thinking if anything it's the amp but all I've known has been Hafler products.

As a novice audiophile, I'm looking for any recommendations one might have on getting me some decent sound out of these JBL's (all four of them). Perhaps someone has some experience getting decent sound out of a similar speaker.

I'm still working on my house so unfortunately I'm going to have to settle on a budget of $2000 for a decent amp, preamp and cd player. This is just an interim system so that I may be able to enjoy my music somewhat passionately in my new home. Maybe some suggestions on equipment that may later transition well into a home theater setup until I can afford to get serious with my primary audio again.

The listening room is 16' by 24' with 9' ceilings. The specs on my JBL's are as follows:

Recommended Power Amplifier Range: 200 watts
• Nominal Impedance: 8 ohms
• Woofer: 12" aquaplas
• Midrange Driver: 5" high polymer laminate
• Tweeter: 1" pure titanium dome
• Frequency Response: 35Hz - 32kHz
• Crossover Frequency(ies): 800Hz, 4.5kHz
• Sensitivity: 91dB (1 watt/1 meter)

Looking forward to some reasonable suggestions. Thanks.
slothman

Showing 3 responses by slothman

slothman OP
311 posts
 
Again, thanks for the advice guys.

I did a bunch of research in here as well as on a lot of the review boards/forums, etc. Hiend2 - you'll be pleased to find that I happened across a pair of Rogue M120's on the bay for $1200. Didn't seem too bad a price. They reportedly have less than 100 hrs on them. Probably not even broke in yet. I really would like to explore tubes and this solution seems to be a reasonable place to start. From what I have read, at least my power reservations are somewhat diminished. Any recommendations on a preamp? Should I try and match it with a Rogue or are there some reasonable alternatives (lighter?, grin).
slothman OP
311 posts
 
Thanks for all of the responses guys.

Some interesting proposals here. I would have though that a good beefy solid state amp would give those 12" woofers what they're asking for. I guess maybe it's time I take a good look at tubes. What about integrated tube amps? I guess at 91db, I probably would need to be looking at something in the 6 to 8 Watt range?

I going to play around with this Adcom setup more. From what I can tell the 565 preamp is respectable - maybe the CD player is the culprit. I talked to another buddy that's got a couple of DAC's and some decent cables I can borrow. In the meantime I'm going to explore the tube thing - plenty of information in here.

Thanks again guys.
slothman OP
311 posts
 
Updated!!

Managed to come in under budget at just under $2,000.

• Rogue M-120's (non-Magnum) $1300 shipped
• Adcom GFP-565 $175
• Adcom GCD-700 $175
• New interconnects/speaker wire $300

While waiting for my M-120's to arrive, I decided to refoam my woofers and bought some better interconnects. With that done, the GFA-5500 did sound markedly better, especially when using the silver reference speaker wire - refoaming the woofers didn't hurt either. Bass was improved - kind of boomy, no punch, however the highs were still somewhat intolerable. Tried the bypass outputs in the preamp but things sounded slightly dark and muddy.

Finally got the M-120's hooked up last weekend. All I can say is that these badboys deliver!. Started out in ultralinear mode (lab connects on the pre, contour and tone in depressed) and the bass and punch I was looking for was just right there, the highs were much more tamed and crisp and the mids were absolutely clean and smooth. I stuck with this setup through the weekend -listening to a lot of rock and pop and enjoying the delivery that I just was not getting before. Sunday evening came and I started dipping into the jazz and ambient acoustic stuff - music that I don't necessarily want to crank. I decided that this might be a good time to try the triode option on the amps. WOW! For the second time in as many days I was floored. This mode seemed to give me the utmost power at the lower listening levels that I am most comfortable with. Most notable however is the improved mids which were much more dynamic along with a more defined placement of vocals and lead instruments. I might also like to add that the listening couch is more comfortable and that 12 year old Macallan is tasting a little smoother...

Thanks Hiend2 for your recommendation! This has been the largest jump for me in terms of sound quality of any audio purchase I have ever made. Perhaps I got a little lucky with the synergy of these components. I love these old JBL's and don't think I'll ever part with them. Just sent my buddy home with that GFA-5500 tucked under his arm and $350 for the preamp and CD player. He just could not get over the sound I was getting out of the M-120's - got him thinking tubes now himself. At this point I'm afraid to listen to anything else. I tend to believe that any future improvements will most likely be less in leaps of improvement and most likely greater in cost. Think I'll coast for a while...
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