JBL 6260 power amp

[Mr. Widget]

Give it a try. The forum MUST know EVERRRYthing about stuff JBL!

Give what a try?

[Zilch]

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]

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]

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]

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]

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

The only time I’ve 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 don’t 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!

[hjames]

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]

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. 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?

[hjames]

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. 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]

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.

[Rudy Kleimann]

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]

Rudy

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

XLR pin connections diagram.

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

[Fred Sanford]

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]

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]

'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!