Author Topic: Ming Da MC34-AB  (Read 116328 times)

Offline treblid

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Re: Ming Da MC34-AB
« Reply #120 on: January 26, 2012, 01:44:39 PM »
Hi Treblid,

I have bought flemo's MingDa :D.

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. 
LOL... The stars align so to speak.. Congrats to all ^_^...

Offline vitavoxdude

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Re: Ming Da MC34-AB
« Reply #121 on: January 26, 2012, 03:19:47 PM »
Struth Bruce.

Trying to change a Ford Escort into a Jaguar is going to be difficult at best and rearly works, you might be better buying the sound you want rather than blowing more money in trying to get the different valves to work in a circuit that was not designed for them.  This to my knowledge has only been pulled off once and it was with a Quad 2, I'll say that again ONCE it's only been done once by a batty old proffesor type who ended up in the nut house and knew intamately the in's and out's of valve design, he even had his own circle of listening cat's (the 70's term for the mondern 'Dude' ) and did not market until everyone said yes.  With all the tuning effort of Mario into geting the device sounding musical it's easily upset by changes.  Oh well, yer pays your money and makes your choice.

Best of luck and remember, tech's in Perth are REALLY expensive when bias and B+ currents draw more than the original design and the magic smoke rises.
We all like different things so lets all agree to disagree and if any common ground is found then worship it.  Mine is the KD hence being present on this forum.

Offline kajak12

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Re: Ming Da MC34-AB
« Reply #122 on: January 26, 2012, 03:54:44 PM »
Struth Bruce.

Trying to change a Ford Escort into a Jaguar is going to be difficult at best and rearly works, you might be better buying the sound you want rather than blowing more money in trying to get the different valves to work in a circuit that was not designed for them.  This to my knowledge has only been pulled off once and it was with a Quad 2, I'll say that again ONCE it's only been done once by a batty old proffesor type who ended up in the nut house and knew intamately the in's and out's of valve design, he even had his own circle of listening cat's (the 70's term for the mondern 'Dude' ) and did not market until everyone said yes.  With all the tuning effort of Mario into geting the device sounding musical it's easily upset by changes.  Oh well, yer pays your money and makes your choice.

Best of luck and remember, tech's in Perth are REALLY expensive when bias and B+ currents draw more than the original design and the magic smoke rises.
hey dude flemo's mingda tested by a perth tech ultra stable after kajak12 modds  :P :P lucky punt i guess
still discovering the link between electronics and audio reproduction.so much to learn and so little time

Offline flemo

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Re: Ming Da MC34-AB
« Reply #123 on: January 26, 2012, 07:12:42 PM »
Yepp MCB's amp was tested and measured before it changed ownership. 

The tests revealed the tubes were barely stressed and the amp worked effortlessly. All the tubes tested as almost brand new, and the EL34's could be 2 years old.

The techie commented on how well the amp functioned and sounded, and would easily out perform many hi-end, more expensive amplifiers.  I was happy with the techies findings because it was quite expensive to confirm what some of us already knew.  ???

 

Offline rab

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Re: Ming Da MC34-AB
« Reply #124 on: January 28, 2012, 01:26:01 PM »
blowing more money in trying to get the different valves to work in a circuit that was not designed for them.

? huh ? -- not sure what you are on about vv-dude. mcb has been using KT77's, which i understand is a commonly used drop-in replacement for the EL34.

As for me, as indicated in earlier posts I have followed flemos' lead and opted for Winged C EL34's - I ordered an octet yesterday and they are already on their way to me from the USA via FedEx.

Offline vitavoxdude

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Re: Ming Da MC34-AB
« Reply #125 on: January 28, 2012, 01:54:18 PM »
 ;D Easy really Rab, the whole amp would have been tuned around EL34's, by changing the valves the balance will be changed.  Kinkless Tetrodes are differnet in more ways than having the same pin outs but you will have to discover this for yourself.  IMV the EL34 has a denser sound with bold broad stroke colour palette, the KT's have a more delicate sound with a finer delinated colour palette.  You makes your choices.  Have you considered the 6550's as well?  These sound more muscular than either but it would be a yankie jobbie biggest - boldest approach. ;D

I would think that some of the more experianced valve heads here can chip in but as this is a personal prefference thing you pays your money and hope to receive a good set of valves.  I was not suggesting that the valve swap would not work, only that the sound and balence from top to bottom would change.  ;D ;D
V ;)
We all like different things so lets all agree to disagree and if any common ground is found then worship it.  Mine is the KD hence being present on this forum.

Offline rab

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Re: Ming Da MC34-AB
« Reply #126 on: January 28, 2012, 09:35:55 PM »
by changing the valves the balance will be changed.

... sure; i was just confused by your post because i am sticking to EL34's which, as you know, the amp was designed to use... so I suppose your comments are more relevant to mcb, who is using KT77's...

- r.

Offline vitavoxdude

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Re: Ming Da MC34-AB
« Reply #127 on: January 28, 2012, 09:42:22 PM »
by changing the valves the balance will be changed.

... sure; i was just confused by your post because i am sticking to EL34's which, as you know, the amp was designed to use... so I suppose your comments are more relevant to mcb, who is using KT77's...

- r.
Hey, no worries.  I will try to be clearer in future.
V
We all like different things so lets all agree to disagree and if any common ground is found then worship it.  Mine is the KD hence being present on this forum.

Offline rab

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Re: Ming Da MC34-AB
« Reply #128 on: February 01, 2012, 01:58:55 PM »
[ Winged C EL34's - I ordered an octet yesterday and they are already on their way to me from the USA via FedEx.

... and just arrived, apparently in good order, as 2 matched quartets  (4 x 40 and 4 x 39 mA).
Not bad, 5 days from placing the order to final delivery! Thank you Tube Depot and FedEx!

Offline vitavoxdude

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Re: Ming Da MC34-AB
« Reply #129 on: February 01, 2012, 04:05:01 PM »
[ Winged C EL34's - I ordered an octet yesterday and they are already on their way to me from the USA via FedEx.

... and just arrived, apparently in good order, as 2 matched quartets  (4 x 40 and 4 x 39 mA).
Not bad, 5 days from placing the order to final delivery! Thank you Tube Depot and FedEx!
;D Wow, 5 days from overseas, Oz post could learn a thing or two from fedex, I usually have to wait at least 10 days to have things arrive from the Eastern states.
Enjoy  V
We all like different things so lets all agree to disagree and if any common ground is found then worship it.  Mine is the KD hence being present on this forum.

Offline data

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Re: Ming Da MC34-AB
« Reply #130 on: February 01, 2012, 04:52:36 PM »
Then there are things nationally that never show up, bloody Aus Post  >:(

Offline kajak12

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Re: Ming Da MC34-AB
« Reply #131 on: February 01, 2012, 07:08:19 PM »
[ Winged C EL34's - I ordered an octet yesterday and they are already on their way to me from the USA via FedEx.

... and just arrived, apparently in good order, as 2 matched quartets  (4 x 40 and 4 x 39 mA).
Not bad, 5 days from placing the order to final delivery! Thank you Tube Depot and FedEx!
bring them with you i will test them and show you that matched tubes are just a marketing bullsh!!t,The mingda is manual biasing so no need for matched tubes food for thought.
still discovering the link between electronics and audio reproduction.so much to learn and so little time

Offline vitavoxdude

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Re: Ming Da MC34-AB
« Reply #132 on: February 01, 2012, 07:42:09 PM »
[ Winged C EL34's - I ordered an octet yesterday and they are already on their way to me from the USA via FedEx.

... and just arrived, apparently in good order, as 2 matched quartets  (4 x 40 and 4 x 39 mA).
Not bad, 5 days from placing the order to final delivery! Thank you Tube Depot and FedEx!
bring them with you i will test them and show you that matched tubes are just a marketing bullsh!!t,The mingda is manual biasing so no need for matched tubes food for thought.
Interesting Mario, they will always make a case for charging more for a matched quad etc so if this is a ploy discovered by actual testing then the various sellors need to be called to book. :o :o :o :o :o
Let us all know the actual readings from the tests please.
V ;D
We all like different things so lets all agree to disagree and if any common ground is found then worship it.  Mine is the KD hence being present on this forum.

Offline Jehuty

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Re: Ming Da MC34-AB
« Reply #133 on: February 01, 2012, 08:14:36 PM »
Then there are things nationally that never show up, bloody Aus Post  >:(

Can't do much data, not too mention poor handling by ANY courier in the world. Registered/trackable mail is an option but it's a LOT more expensive. Bought two RCA UX-250 globes from the US, one seller charged $12 (untrackable and uninsured) and the other seller charged $45 (trackable and insured)!!!

[ Winged C EL34's - I ordered an octet yesterday and they are already on their way to me from the USA via FedEx.

... and just arrived, apparently in good order, as 2 matched quartets  (4 x 40 and 4 x 39 mA).
Not bad, 5 days from placing the order to final delivery! Thank you Tube Depot and FedEx!
;D Wow, 5 days from overseas, Oz post could learn a thing or two from fedex, I usually have to wait at least 10 days to have things arrive from the Eastern states.
Enjoy  V

Agree, it's very quick, how much did you pay for the shipping rab?

Cheers,
William
Not all that matters can be measured, not all that can be measured matters.

Offline data

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Re: Ming Da MC34-AB
« Reply #134 on: February 02, 2012, 07:45:45 AM »
Then there are things nationally that never show up, bloody Aus Post  >:(

Can't do much data, not too mention poor handling by ANY courier in the world. Registered/trackable mail is an option but it's a LOT more expensive. Bought two RCA UX-250 globes from the US, one seller charged $12 (untrackable and uninsured) and the other seller charged $45 (trackable and insured)!!!


Cheers,
William
Very true, and as for couriers, I'm not going there......damn Toll!  ::)

Ooops! I went there  :D

Offline rab

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Re: Ming Da MC34-AB
« Reply #135 on: February 02, 2012, 06:34:41 PM »
how much did you pay for the shipping rab?

US$34.95 fixed price for FedEx shipping. The other site may have been cheaper for slower delivery (they estimate ~ US$20 for 4 EL34s), but i just wanted to get them here.

Offline rab

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Re: Ming Da MC34-AB
« Reply #136 on: February 02, 2012, 06:38:28 PM »
bring them with you i will test them and show you that matched tubes are just a marketing bullsh!!t
...they will always make a case for charging more for a matched quad etc...
Let us all know the actual readings from the tests please.

Tube Depot do not charge any extra for matching, they just do it automatically when you order multiples.

I would be extremely surprised if it is false given my positive experiences of North American service standards! Sorry Mario and VVD, but it's too much hassle to fly these tubes across the country twice just to confirm this...

Offline kajak12

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Re: Ming Da MC34-AB
« Reply #137 on: February 02, 2012, 10:35:19 PM »
bring them with you i will test them and show you that matched tubes are just a marketing bullsh!!t
...they will always make a case for charging more for a matched quad etc...
Let us all know the actual readings from the tests please.

Tube Depot do not charge any extra for matching, they just do it automatically when you order multiples.

I would be extremely surprised if it is false given my positive experiences of North American service standards! Sorry Mario and VVD, but it's too much hassle to fly these tubes across the country twice just to confirm this...
Tube depot oh i have some tubes from them rab the problem was when i measured them they where not very stable in fact 3 out of 8 where unstable should have been binned not sold.
still discovering the link between electronics and audio reproduction.so much to learn and so little time

Offline zenelectro

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Re: Ming Da MC34-AB
« Reply #138 on: February 03, 2012, 12:03:20 AM »
[ Winged C EL34's - I ordered an octet yesterday and they are already on their way to me from the USA via FedEx.

... and just arrived, apparently in good order, as 2 matched quartets  (4 x 40 and 4 x 39 mA).
Not bad, 5 days from placing the order to final delivery! Thank you Tube Depot and FedEx!
bring them with you i will test them and show you that matched tubes are just a marketing bullsh!!t,The mingda is manual biasing so no need for matched tubes food for thought.
Interesting Mario, they will always make a case for charging more for a matched quad etc so if this is a ploy discovered by actual testing then the various sellors need to be called to book. :o :o :o :o :o
Let us all know the actual readings from the tests please.
V ;D

Vita, some clarifications are in order.  :)

Tubes are burned in for 2 main reasons:

a) To stabilize them. Parameters drift over time but the biggest change is initially when first 'fired up' and then they slow down.

b) Weed out the 'infant mortality' rate'. IOW, if they are going to fail it is usually early in the life span.


They are matched for 2 parameters, a) current at a certain grid voltage (bias) and b) transconductance

I think burned in / matched tubes do sound better and it's a good idea from a reliability POV.

I've got boxes of (un burned in) tubes that failed just after new. Very frustrating.


Offline vitavoxdude

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Re: Ming Da MC34-AB
« Reply #139 on: February 03, 2012, 12:35:29 AM »
[ Winged C EL34's - I ordered an octet yesterday and they are already on their way to me from the USA via FedEx.

... and just arrived, apparently in good order, as 2 matched quartets  (4 x 40 and 4 x 39 mA).
Not bad, 5 days from placing the order to final delivery! Thank you Tube Depot and FedEx!
bring them with you i will test them and show you that matched tubes are just a marketing bullsh!!t,The mingda is manual biasing so no need for matched tubes food for thought.
Interesting Mario, they will always make a case for charging more for a matched quad etc so if this is a ploy discovered by actual testing then the various sellors need to be called to book. :o :o :o :o :o
Let us all know the actual readings from the tests please.
V ;D

Vita, some clarifications are in order.  :)

Tubes are burned in for 2 main reasons:

a) To stabilize them. Parameters drift over time but the biggest change is initially when first 'fired up' and then they slow down.

b) Weed out the 'infant mortality' rate'. IOW, if they are going to fail it is usually early in the life span.


They are matched for 2 parameters, a) current at a certain grid voltage (bias) and b) transconductance

I think burned in / matched tubes do sound better and it's a good idea from a reliability POV.

I've got boxes of (un burned in) tubes that failed just after new. Very frustrating.



Yup familiar with this as have own valve tester Mr. T   ;D although it's not as good as Mario's.  :(  Still a way to try and calm the public and make out that they are above the madding crowd.  ::)  Groove Tubes are the only company I know who burn in the valves properly before grading them and reselling them on, do you really think everyone 'burns in the tubes' before measuring them for sale???  ???  I would like thier contact details to avoid boxes of failed valves!

Any sign of a crystal finding a home in WA???  :-* :-* :-* :-* :-*
V
We all like different things so lets all agree to disagree and if any common ground is found then worship it.  Mine is the KD hence being present on this forum.