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4344
07-15-2005, 06:48 AM
Hello!

Anybody has the JBL/Urei 6260/6290 power amp ?

Which one is better, if use to drive 4344...

thx

Robh3606
07-15-2005, 07:07 AM
Are you biamping or running full passive?? I would run them with the larger amp. I biamp mine and have 325 watts starpped Crown 150 series 2's on the 2235's and 100 watt's up top a Crowm PS-200. Occasionally I can get the clipping/distortion light to flash on the top end. On the low end they never come on so I would run them with the larger amp if I had a choice. They can certainly handle the power.

Rob:)

grumpy
07-15-2005, 08:15 AM
If you decide to go with the 6290, keep in mind that the fan (on mine, at least)
isn't the quietest, but does keep the amp from melting.

Oh...and bend at the knees, keep your back straight. :D

-grumpy

GordonW
07-15-2005, 09:17 AM
That's easy. Bi-amp the 4344s, with the 6260 on the high end, AND the 6290 on the bass. :bouncy:

See, problem solved! :D

Regards,
Gordon.

Zilch
07-15-2005, 01:12 PM
I use 6260's for LF and 6230's for HF routinely here, on a variety of systems.

Though I also have bigger amps (Mackie), I rarely use them at home.

I also keep the trusty Radio Shack SPL meter at hand at all times.

6230 actually has plenty of power for most uses here, big subs being an exception.... :D

I've always considered 6290 as gross overkill here. Two power switches? If I REALLY need more power, I can run 6260's in bridge mode.

Just bought another 6230 on eBay for $100, and another good one sold for $105 yesterday. At those prices, nobody should be without such decent amps.

Mr. Widget has one of my 6260's for evaluation. I anxiously await hearing how it plays his new speakers.... :p

Tom Loizeaux
07-16-2005, 10:50 AM
I have 2 rack boxes set up with the combination of a JBL Urei 6260 and 6230 amp configuration. I use them with my 4320s and 4333Bs. I also use the JBL Urei 5235 crossover in each to divide the signals.
I find the 6260 has enough power to push the 2231s in each cabinet and the 6230s are plenty for the 2420 compression drivers and 2405 slots. I have trouble getting these amps all the way up while still in the room!

On the 4344, because they added a 10" to the upper end, you're pushing 3 componants from the "high" amp and crossing that amp in around 275 to 300Hz. This will need a little more power then my bi-amp setup for the 4320s and 4333s.
If you can find two 6260s, one for low and the other for highs, you'll probably be fine.

Tom

johnaec
07-18-2005, 07:31 PM
Red X ??

John

Zilch
07-19-2005, 02:26 PM
Tom's case:

Tom Loizeaux
07-19-2005, 04:44 PM
Thanks Zilch!

Tom

4344
07-20-2005, 04:31 AM
Dear all,

Thanks for all of your valuable inputs.

My final decision is.....YES...to have both 6260 & 6290

will keep you all updated.... :)

4344
08-01-2005, 08:04 AM
:applaud:

Finally, I have both 6260 & 6290 and the sound is too harsh....maybe takes times to burn-in!!

GordonW
08-01-2005, 08:54 PM
Have either the amplifiers or speakers been sitting, stored away without being used for a while? If so, then yes... it may be a matter of needing to run the equipment for a while, so that capacitors re-form, driver suspensions "limber up", and the like.

It's like an old car- you shouldn't expect it to run perfectly, the minute it's started up after a long storage period. But, unless something is broken, it should "settle in" shortly...

Regards,
Gordon.

Guido
08-02-2005, 03:32 AM
Those AMPS look like new :)

4344
08-02-2005, 05:50 AM
Yes..you are right. What can I expect for amps that had been sleep for more than 10 years! I will be patience to await for the wake up moment. ;)

Yes...good on you...it is new old stock and seems like never been used or even tested! :o:

pelly3s
08-02-2005, 06:07 AM
they look great. i think i want to get a 6260 to compliment my 6230

Tom Loizeaux
08-02-2005, 07:16 PM
My guess is that there's not going to be much change in the way these amps sound over time. They have "burned in" way back when. You might want to adjust your L Pads to help get the balance you like.
Keep us posted.

Attached is a photo of my other JBL Urei amp box, sitting on top of my 4333s.

Tom

GordonW
08-02-2005, 07:30 PM
Well, if they've been sitting for over 10 years, then the electrolytic caps and such have probably oxidized and unevenly dried out inside. They will need to be re-formed (by being used at voltage for a period), before they'll work at 100% performance. Could make a very slight difference in the sound... enough to make a perceptable 'graininess', sometimes.

Regards,
Gordon.

4344
08-03-2005, 06:30 AM
i am working hard to run the amp :o:

and one thing.....
per as grumpy say : the fan isn't the quietest :( , but does keep the amp from melting :)

4344
08-05-2005, 08:10 PM
OMG!

I turn the power off of both channel A & B, the clipping indicator "ON"! :( How come...why's that??? It can just be "OFF" after I plug out the socket?

Zilch
08-05-2005, 08:36 PM
There is enough energy stored in those amps for the indicator LED's to remain illuminated for a minute or so after you turn them off. Consider it a "lamp" test. The relay you heard has long since disconnected the speakers....

Tom Loizeaux
08-06-2005, 08:06 AM
OMG!

I turn the power off of both channel A & B, the clipping indicator "ON"! :( How come...why's that??? It can just be "OFF" after I plug out the socket?

It might be good for you to read the owner's manual for the 6260 amp. Understanding how to operate these does help prevent problems and reduce anxiety.

Tom

Jakob
08-13-2005, 02:30 AM
Hi all,

I don't know if You experienced this, but on my 6290 it's not the fan that is the big problem, it's mechanichal noice from those big transformers! They rattle the whole amp. To reduce this I've removed the top-lid, that helps a bit to get rid of the box-resonance. However, I use them to drive a pair of 18" and never felt I needed more power. At my listeninglevel that is a remarcable thing, and then You don't hear nor the fan or the transformers:D

speakerdave
08-13-2005, 10:19 AM
Yeah, the vibration noise can be a problem even with the smaller amps, the 6230 and 6260 (which I now have on my 4333A's--the 6230 is nice, but too small by itself). The top of the case seems to be the usual culprit--a reminder that these amps were not designed for livingroom use. I leave it on, though, for safety, etc.; I use an old paper back to dampen it, careful not to block the venting slots. A beanbag of shot would work even better.

David

GordonW
08-15-2005, 02:13 PM
Hey, one caveat to those who have these 6260 amps (and will probably apply to the 6230 and 6290 as well):

There are some "power resistors" (1 watt resistors) in the amp, that seem to be a bit under-sized, power-handling wise. I started to have a weird "clicking" distortion out of mine (like the output relay was "dropping out" momentarily on high-power transients), and when I went inside to inspect, I noticed about 4-5 of these resistors that had gotten hot enough to brown the circuit board!

The 6260 is now at a very competant repair tech, to have all those resistors replaced (with 5 watt resistors, spaced off of the board about 1/4" to enhance airflow and miminize heat transfer to the board), and for a general checkout. I'd recommend you all look inside your amps too, to make sure you're not having problems with these "mini-space-heaters"...

Regards,
Gordon.

speakerdave
08-15-2005, 02:17 PM
Thanks, Gordon.

Zilch
08-15-2005, 03:19 PM
Another tip:

One of the used 6260's I received had a problem with the standby relay buzzing and being intermittant. It was obvious that a technician had struggled with the temperature sensor and capacitors in the circuit to make it half-assedly work.

Had he bothered to look at the +/- 15V supplies on an oscilloscope (an old-school ANALOG test and measurement device ;) ,) he would have seen substantial ripple there. The culprit? Small electrolytic filter capacitors located too close to the three-terminal regulators had dried out over time. I replaced them and restored the standby/overload circuit to factory values, which worked to perfection.

On loan to Mr. Widget for audition, he's been driving his Sub1500's with that amp without complaint for a while now.... :applaud:

GordonW
08-15-2005, 06:46 PM
Another tip:

One of the used 6260's I received had a problem with the standby relay buzzing and being intermittant. It was obvious that a technician had struggled with the temperature sensor and capacitors in the circuit to make it half-assedly work.

Had he bothered to look at the +/- 15V supplies on an oscilloscope (an old-school ANALOG test and measurement device ;) ,) he would have seen substantial ripple there. The culprit? Small electrolytic filter capacitors located too close to the three-terminal regulators had dried out over time. I replaced them and restored the standby/overload circuit to factory values, which worked to perfection.


That may be at least part of the problem with mine. Same symptom, sort-of... the relay will momentarily "drop out" on high-power transients.

I'll make sure that the tech checks that +- 15V supply... though, knowing him, he's probably already on the case, WAY before I mention it...

Mr. Widget
08-15-2005, 07:19 PM
On loan to Mr. Widget for audition, he's been driving his Sub1500's with that amp without complaint for a while now.... :applaud:

I am using it in my music only configuration... even when pushing it to see how crazy loud the system could go the peak indicators have not come on with these 4 ohm woofers. I am crossing them over at 50Hz, so with musical program there isn't a lot of content.

I doubt it would work in my HT application where I have seen certain explosions clip my 660 watt JBL MPA 600 driving the same speakers!


Widget

GordonW
08-15-2005, 08:03 PM
I dunno. Even in it's "semi-crippled" condition (the relay dropping out), my 6260 was still strong enough to make an entire storage unit building RATTLE, on just a pair of Eminence 15" drivers in 3.7 cubic foot vented cabinets. I mean, loud enough that the storage unit bays on the OTHER side of the driveway were rattling!

IME, those 6260s and 6290s had power, quite beyond what would normally be expected for their ratings. I'd expect, though they're rated at the same power, that the 6260 has close to TWICE the "usable" power of my QSC 1400... it'll easily drive subs to near-destruction, that the '1400 would not even begin to stress...

Regards,
Gordon.

Zilch
08-15-2005, 09:53 PM
Give it a try. The forum MUST know EVERRRYthing about stuff JBL! :D

Mr. Widget
08-15-2005, 10:09 PM
Give it a try. The forum MUST know EVERRRYthing about stuff JBL! :DGive what a try?

Zilch
08-15-2005, 11:12 PM
I doubt it would work in my HT application....Give the 6260 a try in your HT!

Actually, we'd like to know how it stands up to critical listening in other than sub duty, as well....

speakerdave
08-17-2005, 02:49 PM
Just for the record, listening to the CD of Miles Davis in Tokyo with the 6260 driving the 4333A's--the way the muted trumpet is miked so close-- has sent me scrambling for the winter amp, the Audio Research VT60, with the bonus that everything is opened up, more natural sounding, instruments more distinct spatially and tonally, etc. To be fair, perhaps the 6260 is not up to original spec, but the VT60 sure is. Within its power limits this is a very listenable amp for those speakers.

David

Figge
10-05-2005, 03:43 PM
would 2 jbl 6260 in bridged mode be a good amp for 4430:s? have a yamaha p2201 now....really dont need more power but i can buy 2 6260 for a good price.

silly question maybe....

Zilch
10-05-2005, 04:35 PM
A single will work just fine.

Again, I use 6230 on the HF and 6260 LF when biamping.

So, buy both just in case.... :)

JBL 4645
06-15-2007, 06:37 PM
:applaud:

Finally, I have both 6260 & 6290 and the sound is too harsh....maybe takes times to burn-in!!


The only time Iíve seen the JBL 6290, was at the EMPIRE Leicester square cinema back on Friday February 14th 1992, when I popped up into booth WOW! That is a rack system wall to wall of power 13KW of brut forcing THX!

Thou they are good I donít know if I could deal with the noisy fan blowing during quite moments in a film. Sue you can place the amplifiers in a different room to isolate the sound of the fan.

Wish I had the money for at least x11 of them!

The EMPIRE was using around 15 for there JBL THX sound system!:applaud:

hjames
06-15-2007, 08:27 PM
Thou they are good I don’t know if I could deal with the noisy fan blowing during quite moments in a film.
Sure you can place the amplifiers in a different room to isolate the sound of the fan.


The Model 6230 and 6260 don't have fans - only the Model 6290 does - but its a monster (well over 1200 w/ch in bridged mode!!)

I'm pretty new to the biamping, but the amps sound good with my gear (4341s).
I have a 6230 for the highpass; lowpass feeds a 6260 running just the 2234s - a nice firm bass.
I played parts of Prince's "Musicology" today for a test - very nice snap to the bass, the guitar and keyboards crisp and in your face.

JBL 4645
06-15-2007, 10:22 PM
Heather

I think itís the (dampening factor) specifications that count that makes for tighter bass response, the higher the number the better the bass will sound.:applaud: Yes your right about the 6290 having the fan system Iíve seen a picture of them from the rear nice amplifier so how much did the JBL Urei amps set you back second-hand then?

hjames
06-16-2007, 05:31 AM
Heather

I think it’s the (dampening factor) specifications that count that makes for tighter bass response, the higher the number the better the bass will sound.:applaud: Yes your right about the 6290 having the fan system I’ve seen a picture of them from the rear nice amplifier so how much did the JBL/Urei amps set you back second-hand then?


I got a real deal on the JBL/UREI crossover - about $125 shipped.
Price varies a bit, but I'm on a budget so I did ebay and bid on the low priced gear (its all I can justify).
They cost around $180 each - but that includes shipping, which ran around $50 each - quite pricey as these are Real Heavy! My little rack is over 100 lbs.

And, back on topic, your favorite, the 6290, they're over 70 lbs each!!!.

JBL 4645
06-16-2007, 03:13 PM
Still I think you got a bargain, I think they would cost around $800.00 to $900.00 new, but the 6260 is discounted now. Still lovely looking amplifier.:)

The Alesis RA300 are a mere 19 pounds in weight, so I can imagine lifting one of those mighty THX approved 6290 up.:blink:

Rudy Kleimann
06-17-2007, 08:50 AM
I own a 6290 myself, and it IS a brute: rock-solid soundstage, powerful, -and HEAVY.

A couple of things worth noting on these amps:

Pin THREE is HOT and pin TWO is COLD on the XLR input -opposite of AES convention and most other mfg. conventions. The TRS input is "normal" i.e. tip is HOT and ring is COLD. gotta watch this when mixin' 'n' matchin' up with other amps, or you'll have part of your speaker systems playing out of phase with one another.

Check the " JBL 62xx Specifications" page that hjames posted previously for proof positive about the phase issue.

I also own a Urei 5234A crossover, and it employs 12dB/octave slopes. The outputs are out of phase with each other at the crossover frequency. Bear in mind when using these, lest you end up with a big suckout at the crossover frequency due to phase cancellation between the two drivers.

I read on the QSC website some time ago the QSC was contracted by JBL to build amplifiers for them at one time. Never confirmed what models were produced for JBL, but I always suspected the Urei 62xx amps were the ones, for the following reasons:

1: Unlike virtually all other amplifier designs, the output transistors are mounted directly to the heatsinks with no electrical insulating washers in a "grounded collector" circuit configuration (IIRC) for better heat transfer to the heatsinks. QSC adopted this same design around the same time in their own line of amps.

2: the cooling fan and heatsink arrangement is very similar to the QSC's of the time.

3: QSC MX series amps had a similar polarity reversal issue, only it was on the TRS inputs. QSC stated it was an an amp safety issue, in that if you accidentally plugged in a 1/4" speaker output cable into an input (or something along that line), it would not cause the amp to run away into oscillation mode. The MX series amps did not come standard with XLR inputs: a separate XLR input module had to be purchased and installed if required.

A sound company I once worked for was stunned to learn of this phase anomaly when I worked over their amp racks and cables and demonstrated to them what was wrong with their systems sound. I made up one side of their FOH system with cables that got polarity right in all the cabinets at Lows, mids, and highs (triamped), and left the other side like they had been doing it. Even from behind the stack, standing inside the trailer, the sound quality improverment was obvious.

JBL 4645
06-17-2007, 09:28 AM
Rudy

Reversing the phase at the HF loudspeaker terminal end this would put it, in-phase.

XLR pin connections diagram.

Also Iíve noted with the DCX2496 that changing the phase of the left or right though 0ļ to 180ļ you can see the input with pink noise on the spectrum analyzer dipping down due to the cancellation of the phase.

Fred Sanford
03-08-2008, 02:09 PM
Hey, one caveat to those who have these 6260 amps (and will probably apply to the 6230 and 6290 as well):

There are some "power resistors" (1 watt resistors) in the amp, that seem to be a bit under-sized, power-handling wise. I started to have a weird "clicking" distortion out of mine (like the output relay was "dropping out" momentarily on high-power transients), and when I went inside to inspect, I noticed about 4-5 of these resistors that had gotten hot enough to brown the circuit board!

The 6260 is now at a very competant repair tech, to have all those resistors replaced (with 5 watt resistors, spaced off of the board about 1/4" to enhance airflow and miminize heat transfer to the board), and for a general checkout. I'd recommend you all look inside your amps too, to make sure you're not having problems with these "mini-space-heaters"...

Regards,
Gordon.

Reviving an old thread here- anybody have more details on these resistors? I'm visiting my tech in a couple weeks, and would love to have better details to give him. My 6260s working fine, but will soon be in use pretty regularly, if this is a logical pre-emptive repair to do, I'd like to do it now.

I've got the manual, which includes a schematic on p31.

Thanks in advance,

je

scott fitlin
03-08-2008, 10:34 PM
Rudy, QSC DID build amps for JBL. THEY WERE THE JBL MPX series of amps from the 90,s, into the early 21st century.

They are good amps, too!

johnaec
03-09-2008, 07:23 AM
'Not positive about the MPX series, but I've got a bunch of the JBL MPA series, and they were definitely made by QSC. Nice amps!

John


Rudy, QSC DID build amps for JBL. THEY WERE THE JBL MPX series of amps from the 90,s, into the early 21st century.

They are good amps, too!

scott fitlin
03-10-2008, 01:52 AM
'Not positive about the MPX series, but I've got a bunch of the JBL MPA series, and they were definitely made by QSC. Nice amps!

JohnYeah, I make a little mistake, MPA is correct, not MPX! They are the amps, QSC made, JBL badged, good quality, good sound, good reliability.

They were a good series of amps.