my profile | my password | search | faq & rules | forum home

» Film-Tech Forum ARCHIVE   » Operations   » Film Handlers' Forum   » Hafler Amps, opinions? (Page 1)

This topic comprises 2 pages: 1  2

Author Topic: Hafler Amps, opinions? Bill Enos Film God Posts: 2081 From: Richmond, Virginia, USA Registered: Apr 2000 posted 09-21-2006 06:48 PM                     What about them, good? great? crap?something in the middle?  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 09-21-2006 08:38 PM                     Something in the middle regardless of the model... They can be made better by some simple modifications... Larger power supply caps/transformer, better wiring and replacing the dime store electrolytic caps on the driver boards with higher grade parts as is typically used in todays power amps. Haflers typically sound warm and its because of the very low odd harmonic distortion content they generate. Mark  |  IP: Logged Phil Hill I love my cootie bug Posts: 7595 From: Hollywood, CA USA Registered: Mar 2000 posted 09-21-2006 08:56 PM                  Mark, if one wanted to make all the changes you mention, I'd say those amps would then be "just" OK... but "As Is" from the factory they are CRAP (in my experience) The best amps by light years, are (most models of) QSC.  |  IP: Logged Fred Georges Master Film Handler Posts: 257 From: Lombard, IL, USA Registered: Jun 2000 posted 09-22-2006 01:06 PM                     The original products of the David Hafler (Mr.Dynaco) co. were Ok for the money. Always built to a low price point many compromises were made (Low quality parts, wimpy power supplies). In the early eighties they brought out the XL-280 (140 wpc) Touted as the "perfect" amplifier. It featured a user adjustable nulling circuit to cancel out all the remaining distortion leaving one with a "Perfect" amplifier. Much as I tried I couldn't get one to match the quality of the 25 watt Levinson Class A amps I was using at the time. The kindest comment I can say about Hafler is that of all the Solid state amplifiers that have passed through My hands in the last 30 years the Hafler was one of them!  |  IP: Logged Bruce McGee Phenomenal Film Handler Posts: 1776 From: Asheville, NC USA... Nowhere in Particular. Registered: Aug 1999 posted 09-22-2006 06:12 PM                     My theatre tech, as he aquires them, is replacing all of the KINTEK amps in my theatre with QSC power amps. We now have 4 of 7 theatres running the QSC's. I am very happy with them.  |  IP: Logged Kevin Raisler Film Handler Posts: 52 From: Warsaw, IN, USA Registered: Jun 2003 posted 09-22-2006 06:49 PM                    Bill, Hafflers are great sounding amps I once owned a DH200 years ago these things were clean, however like mark and others have said based on experience they don't hold up well in professional applications. cheers  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 09-22-2006 09:23 PM                     I have found that Hafler has terrible reliablity issues only slightly better than my experiences with BGW and Crown  |  IP: Logged Bruce McGee Phenomenal Film Handler Posts: 1776 From: Asheville, NC USA... Nowhere in Particular. Registered: Aug 1999 posted 09-23-2006 08:34 AM                     I have an XL-280 Hafler amp infront of me. Its not working. I see lots of caps with the plastic cooked off of them. No burned circuitry, other than lots of use. Is it worth my effort to recap it, and get it going?  |  IP: Logged Bill Enos Film God Posts: 2081 From: Richmond, Virginia, USA Registered: Apr 2000 posted 09-24-2006 05:58 PM                     The model number in question is DH500...how old is this model? Any model specific comments?  |  IP: Logged Fred Georges Master Film Handler Posts: 257 From: Lombard, IL, USA Registered: Jun 2000 posted 09-24-2006 08:28 PM                     "The model number in question is DH500...how old is this model?" Early 80's so at least over 20 years old. Caps have changed value for sure. Fan cooled 250 watt per channel. Could have been factory assembled or (ugh) a Kit. If your using it for home on easy to drive speakers you should be ok (For how long is anyones guess). Pro use? Forget it unless rebuilt.  |  IP: Logged Jon Miller Jedi Master Film Handler Posts: 973 From: San Diego, CA, USA Registered: Sep 1999 posted 09-25-2006 12:15 AM                     FWIW, in the four years I was a projectionist for a local museum (1991-94) one xenon lamp leaked and one exploded but not one of the three Hafler DH-500 amps in the sound rack even came close to crapping out. QSCs they aren't, but they did the job. As they say, your mileage may vary.  |  IP: Logged Bill Enos Film God Posts: 2081 From: Richmond, Virginia, USA Registered: Apr 2000 posted 09-25-2006 10:56 AM                     What are the issues, caps have been mentioned, do output transistors blow? power supplies? control circuits?  |  IP: Logged Jim Latendorf Film Handler Posts: 4 From: Sacramento, CA, USA Registered: Oct 2005 posted 09-25-2006 03:34 PM                     I remember those things. Worked as the bench tech at a local higher end stereo store that sold them when they came out. The first ones had a bad batch of main filter caps installed in them. Where quickly made good by the factory. Not a bad sounding amp, though. Those power MOSFETS gave the thing a "warm" tube sound and where very forgiving to weird speaker loads. An inherent thing with MOSFETS. Factory wired or kit form didn't make much difference. The main amplifier module on both was built and tested at the factory. The "kit" part was just assembling the chassis and doing all the interconnecting stuff which saved $100 off the purchase price. If yours is still running after all these years, I'd replace all the electrolytic capacitors and then you would be good to go for another ten years. Also, the main power switch on those things where junk. Just bypass it. David Halfler was trying to achieve "more bang for the buck" with his designs just as he did with the Dynaco line. Another note regarding the power MOSFETS. After opening the top cover and looking closely at the transistors you will note a single digit number stamped on the device. This is a test number. All of the output transistors on these things are "matched" sets for each channel so don't mix them up. Not bad for an amplifier that sold for about a buck a watt back then. Regards, Jim L.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 09-25-2006 04:30 PM                     Bill, It is not worth repairing or upgrading. The chassis is however a good chassis for the DIYer to build a real super amp. The Hitachi output devices on these amps have been long obsolete! When it dies just replace it.... Mark  |  IP: Logged Louis Bornwasser Film God Posts: 4441 From: prospect ky usa Registered: Mar 2005 posted 09-26-2006 04:26 PM                        Agreed: just OK in their day. That day passed about 20 years ago when David Hafler left the company. Louis  |  IP: Logged

All times are Central (GMT -6:00)

This topic comprises 2 pages: 1  2

Printer-friendly view of this topic

Hop To: Select a Forum: Category: Operations -------------------- Digital Cinema Forum Film Handlers' Forum Large Format Forum Ground Level Feature Info, Trailer Attachments & REAL Credit Offsets Category: Community -------------------- Film-Yak Film Handlers' Movie Reviews The Afterlife Bob Maar's Joke-A-Thon Category: Classified -------------------- Equipment and Supplies Wanted/For Sale Help Wanted/Seeking Employment Category: System -------------------- Software Beta Testing Forum

The Film-Tech Forums are designed for various members related to the cinema industry to express their opinions, viewpoints and testimonials on various products, services and events based upon speculation, personal knowledge and factual information through use, therefore all views represented here allow no liability upon the publishers of this web site and the owners of said views assume no liability for any ill will resulting from these postings. The posts made here are for educational as well as entertainment purposes and as such anyone viewing this portion of the website must accept these views as statements of the author of that opinion and agrees to release the authors from any and all liability.