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I just got the Ming da mc3008-ab. Bought it directly from the factory in China. Paid around $ 680. However, it didn't come with any manual or info at all. So, is there anybody who got some biasing values for this amp or schematics? Is it just the 805 tubes who need biasing, or the 300b's as well?
And while I'm asking, is the biasing routine with this amp just like any other tube amp, or is it anything special to think about, how often should I need to bias ?
So far, I'm pretty satisfied with the amp, except that it has got a hum. I think it is coming from the amp, no ground loops. Hums while nothing connected. I have only tried it at my place where I havn't got any grounded outlets. Do you think a tech could do anything with this hum, or would I need to change the transformer? But I think I can live with it, because it is mainly audible when not playing music, during breaks in the music or playing at a very very soft volume.
I have read there has been problems with this amp, but I do think I have gotten the revised version, bought it just 2 weeks ago.
But I like the amp a lot, and it looks very good! I'm using the tubes that came along for now. If I should change any of the tubes for NOS, would I feel the biggeste change when changing the 805? Those aren't so expensive as 300b's
Thanks for any feedback,
i heard this amp recently and was quite impressed with the sound, but was mindful that there have been a few people who warned of problems. has anyone in this asylum had a problem-free unit? seems problems with this model is the common thread in the posts I've seen here.
they have a similar looking 6L6 driven 805 model - anyone have any experience with that one?
thanks in advance
I have a few of the MC805-AA integrated units (6L6 driving 805 tubes at 40 wpc). I have had no problems with these units. One of them has been heavily modified and converted into a power amp and used on a daily basis. I love it.
The 3008 has had problems in the past and I do not know if the issues have been addresses. Especially since the Meixing factory has been sold and now being run by someone else.
The quality control from this factory has been very inconsistant recently since the changing of hands.
Build your system for yourself, not the critics!
I think the MC3008-ab has been revised. I read on a german site a quote from a chinese dealer (can't remember which) saying somethink like "Ming Da is back with a new and improved version of the MC3008-AB"
But even if that's the case, mine still has got a hum (for now).
I have this amp too. I love the sound of it, but have had lots of problems. I always had a hum, which was not too bad during the day, but could be quite loud at night. You can read my previous threads about my experience with this amp.
Here is biasing info that I got from the seller in Hong Kong:
" hi just a little chat with mingda on the fone
they told me that there is no need to adjust the bias of the 300b
they know very well about the sofia tube and they response to me and told me it is a tube from TnJ
but pls adjust the bias of the 805 to 100mA"
Also, I have a schematic that I can send you if you email me. I had just bought some Sophia Electric 300bs and some Telefunken and Mullard 12ax7 and 12au7 and had the amp serviced and bias set. After a few days of listening, I started the amp up and heard a loud hum and saw smoke coming out of the tranformer box. So after that I had enough and bought a DK Design amp, which has been trouble free. However, COEM audio actually sent me a new transformer free of charge, so i have that sitting around now and will take it to my technician when I have a chance (he's about an hour away). So I hope to get this amp up and running again, and then decide to keep it or sell it, if I can get it running smoothly.
Good luck with your amp.
I had looked at the Ming da (Meixing) but ultimatly went in another direction. Nothing to do with the Ming da as I never had a chance to audition.
One thing that I was cautioned about the Ming da and many other Chinese tube amps is the same thing you have experienced. Many don't come with bias values and they are a little different then the Jolida I owned.
My understanding the Mingda requires a bias-burn in-then another bias. Internal biasing? I was cautioned that unless you have a good background in tube amps you might be better off letting a technician do the biasing which usually runs about $100.
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