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Author Topic: Kelmar amp repair anyone? Eric Robinson Jedi Master Film Handler Posts: 538 From: Santa Rosa, CA Registered: Jan 2005 posted 03-06-2007 01:23 AM                     I have the following amps which I would like to have repaired. Does anyone know who or where I could send them to? And...hopefully I'm not posting in the wrong forum. Tell me if I am and I'll move this somewhere else. Quantity 1 - Kelmar - Model AA-7700 Serial 521 - 50 watt amplifier Quantity 1 - Kelmar - Model AA-7700 Serial 522 - 50 watt amplifier Quantity 1 - Kelmar - Model AA-7700 Serial 523 - 50 watt amplifier Quantity 1 - Kelmar - Model AA-1200 Serial 922 - 120 plus Thanks...ERIC  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 03-06-2007 07:24 AM                     To Kelmar... or we can also do it. I carry a rebuild kit in the van. I will also say that replacing all the electrolytics will restore 90% of them to good working order. Mark  |  IP: Logged Louis Bornwasser Film God Posts: 4441 From: prospect ky usa Registered: Mar 2005 posted 03-06-2007 08:09 AM                        We also do this work. Kelmar apparently will no longer repair the 26 watt module...but we will. Louis at Hadden.  |  IP: Logged Marin Zorica Jedi Master Film Handler Posts: 671 From: Biograd na Moru, Croatia Registered: May 2003 posted 03-06-2007 11:42 AM                     This repair stuff gives me think about....where to use 25W or 50W amp?  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 03-06-2007 02:46 PM                     We have been known to repair them too (even with the Christie badge). The reason replacing the electrolytics often fixes the problem is that I've found them incorrectly installed and reverse biased. That is, when they use them as blocking caps, they have the polarity wrong for the circuit...which kills the cap. Of course, they could have chosen a better type of cap for this purpose than electrolytics. Steve  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 03-06-2007 03:01 PM                     Steve, These amps are not really good enough quality to justify good mylar or film coupling caps... class B output stages and some used darlington O.P. devices, very old stuff but reliable. I normally use non polorized caps for the input stage positions though. in these amps it is usually justnthe input caps that fail fomr what Steve mentions.... but replace them all! Also use good quality electrolytics rated at 105 deg C. and they will last the rest of the time you will be using these amps. Mark  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 03-06-2007 04:45 PM                     I was mainly referring to using the better caps for the input stages to have avoided the failures rather than any dramatic sonic improvement. Then again...why is anyone running mono nowadays.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 03-06-2007 04:51 PM                     quote: Steve Guttag Then again...why is anyone running mono nowadays. They are all Woody Allen fans......  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 03-06-2007 05:55 PM                     Yeah, but even Woody uses Dolby Digital Mono!  |  IP: Logged Eric Robinson Jedi Master Film Handler Posts: 538 From: Santa Rosa, CA Registered: Jan 2005 posted 03-07-2007 05:18 PM                     Hi Mark, If I did send these amps to your company, might you be able to give me an average repair cost? I will need this to provide to the higher ups. These are typical units, no visible signs or olfactory suggestions of burning components.  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 03-07-2007 05:33 PM                     i question if with shipping cost and labour if it is not more prudent to replace these with better more modern amplifiers  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 03-08-2007 07:20 AM                     Eric, If the semiconductors are not blown in them then 1.5 hours plus parts. I sonewhat agree with Gord though... a more modern replacement is in order for them. Take a look at the least expensive QSC line available through music stores. They are VERY inexpensive and very reliable. Mark  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 03-08-2007 09:04 AM                     However, you will probably find that repairing them is the least expensive route and if you get a straight amplifier, you will still need a preamp and configure the other channel for a monitor amp.  |  IP: Logged Louis Bornwasser Film God Posts: 4441 From: prospect ky usa Registered: Mar 2005 posted 03-08-2007 02:49 PM                        We "take 'em home" and ups them back. This allows a 24 hour burn in with pink noise on the bench. Really not a bad amplifier for what it needs to do and for its times. Louis  |  IP: Logged

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