Author Topic: Ming Da MC34-AB (Read 116967 times)

Jehuty · « **Reply #100 on:** September 30, 2011, 10:03:41 PM »

Yeah I agree, it's hit and miss. I'll get one soon and hopefully it works well. Cheers.

mcb · « **Reply #101 on:** October 01, 2011, 01:05:51 PM »

Quote from: data on September 30, 2011, 04:17:42 AM

Murry is it?
I'm just wondering about the improvement from the Ampohm aluminum foil & oil caps?

They are coupling the first two stages, are they not? hmm..three stage amp huh?

Just wondering what they are like, what they sound like?

Also, what (1uf) caps are you using between the second and final stages ?

Hi Data, my knowledge of the technicalities of amps is near non-existent. All my mods have been based on proven mods made by others, primarily those initially made by crazikid, to the amp now owned by flemo. This means I can't comment on first stage, second stage etc. Also, I am not too flash at describing what I hear (and I am not a critical listener). I basically like the change or I don't. To that end, the adding the 0.22 ampohms, was a good step forward. How they sound, compared to other caps, I can't comment on. Also, ampohms are now fairly hard to get, though i have not checked their availability for a while.

As to the 1 uf caps, if you are referring to the white ones that are commented on by Mario at post 66 of this thread, then, mine are still the original MingDa caps. Way to fiddly for me to get down into there.

Regard

Murray

data · « **Reply #102 on:** October 01, 2011, 09:12:13 PM »

Yeah I'm not all that knowledgeable myself compared to many.

Thanks for the comment of how much better it sounds now, says a lot for the caps

rab · « **Reply #103 on:** January 22, 2012, 05:34:23 PM »

.... annnnnnddd, as of this afternoon, mcb's amp is going to be rab's amp!

I will be collecting it in person on Feb 6 or thereabouts! Can't wait!

The plan will be to continue mcb's project to replicate flemo's mods and hopefully bring it to the same level (sadly, without flemo's skirt bling).

treblid · « **Reply #104 on:** January 22, 2012, 05:48:17 PM »

Quote from: rab on January 22, 2012, 05:34:23 PM

.... annnnnnddd, as of this afternoon, mcb's amp is going to be rab's amp! I will be collecting it in person on Feb 6 or thereabouts! Can't wait!

Carry on hand luggage? :p

mcb · « **Reply #105 on:** January 23, 2012, 05:24:34 PM »

Quote from: rab on January 22, 2012, 05:34:23 PM

.... annnnnnddd, as of this afternoon, mcb's amp is going to be rab's amp! I will be collecting it in person on Feb 6 or thereabouts! Can't wait!

The plan will be to continue mcb's project to replicate flemo's mods and hopefully bring it to the same level (sadly, without flemo's skirt bling).

I am looking forward to meeting you in a couple of weeks rab. Your post in the other thread last week was indeed very timely.

New amps for both of us, though the changes for one of us is not quite as big as for the other.

mcb · « **Reply #106 on:** January 23, 2012, 05:26:04 PM »

Quote from: treblid on January 22, 2012, 05:48:17 PM

Quote from: rab on January 22, 2012, 05:34:23 PM
.... annnnnnddd, as of this afternoon, mcb's amp is going to be rab's amp! I will be collecting it in person on Feb 6 or thereabouts! Can't wait!
Carry on hand luggage? :p

Only if he as spent a lot of hours in the gym

treblid · « **Reply #107 on:** January 23, 2012, 06:19:40 PM »

Quote from: mcb on January 23, 2012, 05:26:04 PM

Only if he as sent a lot of hours in the gym

Two weeks to train..

IIRC this amp is pretty heavy. So what new amp are you getting?

rab · « **Reply #108 on:** January 23, 2012, 07:18:13 PM »

Incidentally, I just saw on the weekend for the first time that a US company has commissioned MingDa to make a souped up version they call the MD75 for the US market - or at least are the exclusive dealer. There is an upgrade version running KT88's! Does that mean we can run KT88's in our 'standard' versions with appropriate bias adjustment, or is more required?

http://www.pacificvalve.us/MingDaMD75.html.

Close-up of the innards is here:
http://www.pacificvalve.us/images/_DSC4118.jpg

One nice feature in the new version is the provision of bias adjustment trimpots accessible from the top of the amp - through RCA female sockets!
See here: http://www.hometheaterhifi.com/integrated-amplifiers/1447-ming-da-md-75-integrated-stereo-tube-amplifier.html?start=1.

data · « **Reply #109 on:** January 23, 2012, 07:39:49 PM »

To run KT88's I think the only thing ya' need to change is the filament current....but even that may be OK, you would need to check.

Running KT88's will just change the sound, no extra power to be had running in the same amp.

rab · « **Reply #110 on:** January 24, 2012, 07:28:18 AM »

Thanks, data. I confess i have no idea how these different valves would change the sound. flemo is running SED Winged C's, mcb has been running Genelex KT77's,... at this stage I have yet to decide what valves to buy... I have some bias towards the Winged C's because the reports of flemo's amp are so positive, and the cost for a matched quad is only A$150 delivered .

Any opinions?

data · « **Reply #111 on:** January 24, 2012, 05:09:43 PM »

I know folk that prefer the sound of KT88's but for myself I like the EL34's, and so far my preference is for the Winged C's also.

KT88's have a cleaner, less warm sound compared to EL34's.

I suck at describing the sound of things

kajak12 · « **Reply #112 on:** January 24, 2012, 08:38:53 PM »

Quote from: rab on January 24, 2012, 07:28:18 AM

Thanks, data. I confess i have no idea how these different valves would change the sound. flemo is running SED Winged C's, mcb has been running Genelex KT77's,... at this stage I have yet to decide what valves to buy... I have some bias towards the Winged C's because the reports of flemo's amp are so positive, and the cost for a matched quad is only A$150 delivered .

Any opinions?

The mingda your buying is made for el34 tubes others will work but not to full potential stick with el34 (svetlana el34 winged c) or the big bucks el34 philips double dd getter
)

rab · « **Reply #113 on:** January 25, 2012, 07:33:07 AM »

ah, i was wondering when you would show up...!

thanks, Mario - sounds like i should buy those SED valves.

What would you recommend for the other (small) valves?

zenelectro · « **Reply #114 on:** January 25, 2012, 10:06:30 AM »

Quote from: data on January 24, 2012, 05:09:43 PM

I know folk that prefer the sound of KT88's but for myself I like the EL34's, and so far my preference is for the Winged C's also.

KT88's have a cleaner, less warm sound compared to EL34's.

I suck at describing the sound of things

One thing that hasn't been mentioned here is that despite the KT88 offering little more absolute max power, they can be biased much higher.

KT88's have a max anode dissipation of 42W so for a 500V HT and a 75% of max dissipation bias point, you will get much higher class A operation.

So the short of it is just changing tubes is one thing, but finding their best bias / operating point is another.

IME, plenty of bias for KT's is a good thing and they can handle it.

Same goes for 6L6's. I've been using JJ's, which are not the worlds best sounding tubes, but you can bias them to >40mA easily and it really helps the sound.

EL34's tend to be less robust and can be more finicky about bias. I think this might be the Pentode versus Beam Power construction - they are very different tubes.

T

rab · « **Reply #115 on:** January 26, 2012, 07:35:10 AM »

Thanks, Terry. Interesting, but do you have an opinion on the relative sound quality of the two?

Incidentally, this may be a dumb question, but are the 6SN7 and 12AT7 valves only used in the preamp section? The reason i ask is that i will mainly use this (at least initially) with my PDX DAC which has an SRPP output stage and a built-in lightspeed-type attenuator, so I could use the MingDa either with or without the preamp section... i suspect without the preamp may be better... has anyone done a similar comparison?

zenelectro · « **Reply #116 on:** January 26, 2012, 11:02:27 AM »

Quote from: rab on January 26, 2012, 07:35:10 AM

Thanks, Terry. Interesting, but do you have an opinion on the relative sound quality of the two?

IME both tubes can sound fantastic, it depends on circuit / bias / brand.

I've had amps come through for repair with both with great variance.

If I were to make a huge generalization which I hate to do

EL = more complex harmonics, sweet midrange
KT = bigger / cleaner

For hifi, I think if circuit is optimized, KT's are a great tube but much harder to get right.

[/quote]

Incidentally, this may be a dumb question, but are the 6SN7 and 12AT7 valves only used in the preamp section? The reason i ask is that i will mainly use this (at least initially) with my PDX DAC which has an SRPP output stage and a built-in lightspeed-type attenuator, so I could use the MingDa either with or without the preamp section... i suspect without the preamp may be better... has anyone done a similar comparison?
[/quote]

AFAIK, you need all the tubes in your Mingda

cheers

T

kajak12 · « **Reply #117 on:** January 26, 2012, 12:41:04 PM »

Quote from: rab on January 26, 2012, 07:35:10 AM

Thanks, Terry. Interesting, but do you have an opinion on the relative sound quality of the two?

Incidentally, this may be a dumb question, but are the 6SN7 and 12AT7 valves only used in the preamp section? The reason i ask is that i will mainly use this (at least initially) with my PDX DAC which has an SRPP output stage and a built-in lightspeed-type attenuator, so I could use the MingDa either with or without the preamp section... i suspect without the preamp may be better... has anyone done a similar comparison?

Mr.Rab the mingda runs a whole lot better using the integrated mode due to the way its wired up just for amplification duties,all of this can get changed i can tell you how to do it.You will have a handful of parts left over i know that mcb's amp is good much more needed to make it great.

rab · « **Reply #118 on:** January 26, 2012, 12:49:05 PM »

Thanks T and Mario.

It sounds like i should stick to the SED Winged C EL34's.

Incidentally, at http://www.tubedepot.com/sv-el34.html it seems i can get an octet delivered FedeX for A$300. Similar price at http://thetubestore.com/el341.html.

Has anyone had good or bad experiences with either of these sites?

mcb · « **Reply #119 on:** January 26, 2012, 01:18:49 PM »

Quote from: treblid on January 23, 2012, 06:19:40 PM

Quote from: mcb on January 23, 2012, 05:26:04 PM
Only if he as sent a lot of hours in the gym
Two weeks to train.. IIRC this amp is pretty heavy. So what new amp are you getting?

Hi Treblid,

I have bought flemo's MingDa

.

We (flemo & I) started talking about it a few days before rab made his timely post about looking for one,
thus a good arrangement for all of us.

The other good thing for rab is that he will get to hear the difference between the two and what the next round of upgrades will deliver.