The KillerDAC Audio forum
General HIFI => Amplification (Pre/Power) => Topic started by: donberry on October 09, 2014, 08:53:35 AM
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I have the older version of the MC34AB - doesn't have the power meter on it, and it has made a scratchy noise for the longest time but I am just now getting around to working on it. Could be wrong and often am, but I have a feeling it is because of some loose tube sockets. None of the sockets could be said to fit like a glove, but 3 in particular are pretty loose. Even if it doesn't fix the noise, still needs done.
I have not examined the heck out of it yet but just did a cursory look - I didn't really see how the beauty rings are attached. I don't think there is access to them from inside the unit, so I am guessing they are just press fitted or screwed on ?
Figured as long as I am going to be doing that much soldering I may as well finally change the film caps. I didn't splurge on them, just picked up the Mundorf Supreme MKP for the .22uf, have not decided on the 1.0uf. As there are 8 of them it's not going to be too cheap so still trying to decide which way to go. Was looking at some obbligato gold, but couldn't make up my mind so still trying to decide. Wishing I had went with a better .22 cap already but figure I will give them a listen and see how they sound as they won't be hard to change
any info on the beauty rings appreciated
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Also on this topic does anyone have a schematic of the Ming Da MC34 they could possibly pm me?
I recently purchased the famous modded Ming Da and are very curious to research some possible ..... further mods.
The original schematic would be very helpful.
Will report back soon.
Thanks
Steve
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I have the older version of the MC34AB - doesn't have the power meter on it, and it has made a scratchy noise for the longest time but I am just now getting around to working on it. Could be wrong and often am, but I have a feeling it is because of some loose tube sockets. None of the sockets could be said to fit like a glove, but 3 in particular are pretty loose. Even if it doesn't fix the noise, still needs done.
I have not examined the heck out of it yet but just did a cursory look - I didn't really see how the beauty rings are attached. I don't think there is access to them from inside the unit, so I am guessing they are just press fitted or screwed on ?
Figured as long as I am going to be doing that much soldering I may as well finally change the film caps. I didn't splurge on them, just picked up the Mundorf Supreme MKP for the .22uf, have not decided on the 1.0uf. As there are 8 of them it's not going to be too cheap so still trying to decide which way to go. Was looking at some obbligato gold, but couldn't make up my mind so still trying to decide. Wishing I had went with a better .22 cap already but figure I will give them a listen and see how they sound as they won't be hard to change
any info on the beauty rings appreciated
obbligato gold, I think they are oil filled, generally oil caps have fuller, fatter, more weightier base than standard film caps of the same value, I find you can get away with running smaller caps than specified by the manufacturer. Are the Mundorf Supreme MKP for the .22uf oil filled.
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Also on this topic does anyone have a schematic of the Ming Da MC34 they could possibly pm me?
I recently purchased the famous modded Ming Da and are very curious to research some possible ..... further mods.
The original schematic would be very helpful.
Will report back soon.
Thanks
Steve
The WA crew may have one, they where really into these amps.
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I think I have the copy here somewhere, will have a quick look..
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Also on this topic does anyone have a schematic of the Ming Da MC34 they could possibly pm me?
I recently purchased the famous modded Ming Da and are very curious to research some possible ..... further mods.
The original schematic would be very helpful.
Will report back soon.
Thanks
Steve
pm me your email for a schematic...........
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obbligato gold, I think they are oil filled, generally oil caps have fuller, fatter, more weightier base than standard film caps of the same value, I find you can get away with running smaller caps than specified by the manufacturer. Are the Mundorf Supreme MKP for the .22uf oil filled.
I don't think the Mundorf MKP series are oil filled, neither are the obbligato gold... at least I don't think so. Although I'm confused my the use of MPK and the SUPREME notation, the SUPREME is a polypropylene, and the the MPK series are metalized polypropylene.
But the obbligato gold do have that sound you have described before, rich and full. A nice cap for not much $.
Edit: Damn....now I want to dissect an obbligato gold, I'm curious :)
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no, neither of those are oil filled. I have used the oil filled in speakers, pair of HPM-150, taming the midrange. Worked very well.
pm on the way kajak - thank you.
so no one knows how the beauty rings come off ?
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I'm still curious as to the construction of the obbligato gold caps, I have them in my crossovers.
The Mundorf line up of capacitors are very confusing, they used to have the SUPREME and then the oil impregnated SUPREME "silver & oils" and the silver/gold oils" Now with new lines including the MPK and the EVO range and some of those EVO range are oil impregnated.
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data - with the mundorf if it has oil in it, it will be in the name - i.e. silver in oil, Mcap evo oil, etc....with obbligato, same thing really tho they only make the one line of caps with oil in them if I am not mistaken.
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big THANK YOU to kajak12 for taking the time to get me the schematics for this amp.
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data - with the mundorf if it has oil in it, it will be in the name - i.e. silver in oil, Mcap evo oil, etc....with obbligato, same thing really tho they only make the one line of caps with oil in them if I am not mistaken.
Yup, that is what I was trying to point out when i was talking about the various Mundorf ranges, but they still make their cap designations confusing with so many ranges. And yeah, Obbligato just have the one and It's a power supply cap :)
All the best with the Ming Da, nice amps.
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BTW Don.
I'm still interested in what cap you are talking about when you said "Mundorf Supreme MKP" ?
The Mcap Supreme (polypropylene)?
Or one of the MKP range?
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OK, I'll guess that they are the Mcap Supreme (polypropylene).
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These are the caps I bought -- http://www.partsconnexion.com/capacitor_film_mundorf_suprm.html
Got them in and they are a lot bigger then I thought they would be, is what I get for not looking up the size. I'll find a way to squeeze them in tho. :)
Finishing up a project in the house then going to start on replacing the tube connectors if I can figure out how the beauty rings come off without scratching them all up.
On a side note - hooked the amp up, 1st time I have used it in a LONG time - forgot how good it was. Of course now that I ordered the tube connectors it isn't making that noise anymore.
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Cool, they are not a bad cap 8)
LOL, no noise now? isn't it always the way :)
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data - I used the obbligato oil filled in a speaker - worked out great.
Well, I now see how the beauty rings come off - they don't. To change the tube sockets I have to basically take off the vast majority of wiring and the sockets are attached to a "pan" that drops down.
What fun,.........
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I obviously have little experience with various sockets, as all the ones i have played with you need to unsolder the wires at the tags.
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I obviously have little experience with various sockets, as all the ones i have played with you need to unsolder the wires at the tags.
Rebuilding my Ming Da Mc300 pre and YEP! to remove the vanity rings you have to remove the sub plate which involves desoldering a lot of stuff.
What started out as a relatively simple transformer replacement has turned in to a complete rebuild. I have replaced all the standard valve sockets with better quality teflon , gold plated ones.
By the time I am finished the only standard parts will be the transformers , even the case has been enhanced to allow for better mounting of all the Deuland and Jensen caps , regulated heater supplies etc.
Hope it sound excellent as there has been a lot of time and money invested :D
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Rebuilding my Ming Da Mc300 pre and YEP! to remove the vanity rings you have to remove the sub plate which involves desoldering a lot of stuff.
What started out as a relatively simple transformer replacement has turned in to a complete rebuild. I have replaced all the standard valve sockets with better quality teflon , gold plated ones.
By the time I am finished the only standard parts will be the transformers , even the case has been enhanced to allow for better mounting of all the Deuland and Jensen caps , regulated heater supplies etc.
Hope it sound excellent as there has been a lot of time and money invested :D
Ozcal, That has always been a problem for me with the audio stuff. Like you when I stated replacing the parts inside them and virtually ended up with just the mains and output transformers, even then i was so temped to attack them. What to do to solve this problem.
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ozcal - would be interested in a report on your amp when all is said and done.
From just glancing at the work that needs done to get that sub-plate out, it doesn't seem difficult but I didn't realize it was going to be as involved as it will be.
I can't afford Dueland's, but as long as I am removing all of those wires, I am going to go over the schematic kajak12 sent me and see what else I can go ahead and swap in there.
I did just dry fit them and tho they are much bigger, the Mundorf caps won't be a problem fitting in there.
Got my tube sockets in and tried them out, putting a tube in one. It just showed me how loose the ones currently in the Mingda are.
This will be one amp upgrade where I really, really take my time tho
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Hi D , was pretty lucky that the previous owner had fitted the Deulands and the Jensens and some decent valves otherwise I couldn't have afforded them either.
The pre amp sounded very good when I got it and if it hadn't been for the transformer failure I would probably have run it as purchased for quite a while but once I started the rebuild I though I may as well try and get it to the next level.
Progress for me has been very slow too but I am lucky enough to have a spare valve pre to keep me going.
Good luck with your rebuild
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Also on this topic does anyone have a schematic of the Ming Da MC34 they could possibly pm me?
I recently purchased the famous modded Ming Da and are very curious to research some possible ..... further mods.
The original schematic would be very helpful.
Will report back soon.
Thanks
Steve
Did you get the schematic you are after
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Did you get the schematic you are after
Steven - Thanks for your enquiry.
I've had a crazy week with work and have only just got home late tonight. I will PM Mario and see if he can still send me the schematic.
This is a potentially superb amp.
However, it got a bit of a rough trip travelling over from Perth (thank you Pack and Send) and sustained some internal damage. One of the Audio Note caps dislodged itself from the chassis and launched itself into the main guts of the amp.
I believe James (Crazikid), possibly yourself?, Mario, and Pete all worked on this particular amp over a period of several months. It is a total labour of love!
It is now up and running but needs a few gentle tweaks to bring it back to it's former glory.
Steve
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Steven - Thanks for your enquiry.
I've had a crazy week with work and have only just got home late tonight. I will PM Mario and see if he can still send me the schematic.
This is a potentially superb amp.
However, it got a bit of a rough trip travelling over from Perth (thank you Pack and Send) and sustained some internal damage. One of the Audio Note caps dislodged itself from the chassis and launched itself into the main guts of the amp.
I believe James (Crazikid), possibly yourself?, Mario, and Pete all worked on this particular amp over a period of several months. It is a total labour of love!
It is now up and running but needs a few gentle tweaks to bring it back to it's former glory.
Steve