arthur63 Posted October 27, 2013 Posted October 27, 2013 I'm a newbie here and have a question about the ME 550 series 1 power amp. Just purchased a second hand one from ebay and have been testing it this weekend. It's going to be used with my ME25 / ME550 which I purchased in 1994 and is the same vintage as my own ME550. I have made several observations: - The filter looks as though it's never been cleaned, the layer of dust was blocking any air circulation into the amp. - The fan seems to be running faster than my original ME550, even at cool temperature. - The warm up cycle takes less time as the operting temp light comes on minutes earlier than than my ME550. - Sound from the left channel distorts and the severity varies depending on the type of music and volume. Right channel appears to be ok. I don't think the amp has ever been serviced and it's probably 20 years old - to give you an idea of age the serial number is 550452F. Looks like it desparately needs a service, will it be something straight forward as replacement of the caps or something major?
cheekyboy Posted October 27, 2013 Posted October 27, 2013 Send it up to Zaph in Sydney to take a look at it for you. Cheers, Keith 1
arthur63 Posted October 27, 2013 Author Posted October 27, 2013 Thanks, I'm in Melbourne so I was thinking of Winovate. They serviced my ME25 pre amp about two years ago. 1
Winter Posted October 27, 2013 Posted October 27, 2013 Try clarke audio in glen waverley. (Dallas) . I think he's on holiday atm.
Zaphod Beeblebrox Posted October 27, 2013 Posted October 27, 2013 Thanks, I'm in Melbourne so I was thinking of Winovate. They serviced my ME25 pre amp about two years ago. Yep. Winovate are the guys to see in Victoria for your ME550. It will be more than just caps. It sounds like your amp may have an old style fan controller. If so, it will need to be updated to the new style type. Hard to say about the other issues, but certainly new caps should be high on the list.
oceangreen17 Posted October 27, 2013 Posted October 27, 2013 Out curiosity is Dallas Clarke (Clarke Audio) also an approved ME amp service person? I have had him work on other gear in the past but never an ME Thanks Steve
Zaphod Beeblebrox Posted October 27, 2013 Posted October 27, 2013 Out curiosity is Dallas Clarke (Clarke Audio) also an approved ME amp service person? I have had him work on other gear in the past but never an ME Thanks Steve Not to the best of my knowledge.
arthur63 Posted October 27, 2013 Author Posted October 27, 2013 (edited) Yep. Winovate are the guys to see in Victoria for your ME550. It will be more than just caps. It sounds like your amp may have an old style fan controller. If so, it will need to be updated to the new style type. Hard to say about the other issues, but certainly new caps should be high on the list. Thanks Trevor, if I was in Sydney I'd look you up. From all the posts I've read from you, you're passionate about ME. BTW, do you have any updates on the proposed upgrades for original ME amp range? Are they still going to happen and will they include ME550 series 1? Edited October 27, 2013 by arthur63
oceangreen17 Posted October 27, 2013 Posted October 27, 2013 Not to the best of my knowledge. Thanks for the update Zaph - If anyone on this forum would know it would be you. Useful info for the future.
Zaphod Beeblebrox Posted October 27, 2013 Posted October 27, 2013 Thanks Trevor, if I was in Sydney I'd look you up. From all the posts I've read from you, you're passionate about ME. BTW, do you have any updates on the proposed upgrades for original ME amp range? Are they still going to happen and will they include ME550 series 1? Things have been held up (again!) in that area, due to a recent injury to Peter's hand. He's OK now and proceeding on the design for the upgrades. The ME750, ME850 and ME1400/1500 amps will be the first models to be addressed. If there is sufficient interest, then the ME500 should follow. I don't see a problem with addressing the ME550 (though Peter needs to confirm), since it is very similar to the ME750. Earlier models (ME75, ME150) are unknown quantities ATM. If I had to guess, I think that we should see something by the middle of 2014. I've been wrong before though.
Jake Posted October 27, 2013 Posted October 27, 2013 Things have been held up (again!) in that area, due to a recent injury to Peter's hand. He's OK now and proceeding on the design for the upgrades. The ME750, ME850 and ME1400/1500 amps will be the first models to be addressed. If there is sufficient interest, then the ME500 should follow. I don't see a problem with addressing the ME550 (though Peter needs to confirm), since it is very similar to the ME750. Earlier models (ME75, ME150) are unknown quantities ATM. If I had to guess, I think that we should see something by the middle of 2014. I've been wrong before though. He's going to upgrade the 1500? How is this possible?
Zaphod Beeblebrox Posted October 27, 2013 Posted October 27, 2013 He's going to upgrade the 1500? How is this possible? Mechanically, or because it already sounds so damned good? The upgrade will be substantial and will include: * Double the number of output devices (from 12 per channel to 24 per channel). * The new output devices are more linear (lower distortion) at all current levels, notably at very low currents and high currents. * The new output devices are much faster (4MHz for the old to 30MHz for the new devices). * An auto bias scheme, which will accelerate warm-up time and ensure that bias adjustments will never be required (though I don't know what Peter has worked out with the ME1500 switching system). The upshot will be: * Approximately half the distortion (particularly at HF). * Approximately half the output impedance. * Periodic bias adjustments are eliminated. * Faster warm-up time. * Double the output current capacity (from 100 Amps to 200 Amps).
Jake Posted October 27, 2013 Posted October 27, 2013 Mechanically, or because it already sounds so damned good? The upgrade will be substantial and will include: * Double the number of output devices (from 12 per channel to 24 per channel). * The new output devices are more linear (lower distortion) at all current levels, notably at very low currents and high currents. * The new output devices are much faster (4MHz for the old to 30MHz for the new devices). * An auto bias scheme, which will accelerate warm-up time and ensure that bias adjustments will never be required (though I don't know what Peter has worked out with the ME1500 switching system). The upshot will be: * Approximately half the distortion (particularly at HF). * Approximately half the output impedance. * Periodic bias adjustments are eliminated. * Faster warm-up time. * Double the output current capacity (from 100 Amps to 200 Amps). Please let me know when this is available Zaph.
Zaphod Beeblebrox Posted October 27, 2013 Posted October 27, 2013 (edited) Please let me know when this is available Zaph. Of course. I will be shouting it from the roof-tops. Edited October 27, 2013 by Zaphod Beeblebrox 2
Guest kab Posted October 27, 2013 Posted October 27, 2013 My ME1400 is chafing at the bits......bring it on i say!
arthur63 Posted November 9, 2013 Author Posted November 9, 2013 I'm please to advise that my ME550 has been repaired and is in tip top shape again. As I expected the left channel amp was faulty. Replaced were failed output transistors, all driver transistors and miscellaneous resistors. The same driver transistors were replaced in the right channel amp as well as the electrolytic capacitors on the power supply control board. Been using it since Wednesday and sounds just as an ME550 should, thanks to Ron from Winovate for the quick turnaround. Next step will be bridge both ME550s and run them as two mono amps - probably get around to doing this next weekend. 1
Phantom Posted November 9, 2013 Posted November 9, 2013 Of course. I will be shouting it from the roof-tops. No schit eh? Who would have thought 1
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