« previous next »
Pages: « 1 2 3 4 5 6 7 8 9 »

Author Topic: Ming Da MC34-AB  (Read 116982 times)

Offline kajak12

  • Hero Member
  • *****
  • Posts: 2468
  • Liked: 78
    • http://killerdac.com/forum/index.php
Re: Ming Da MC34-AB
« Reply #60 on: May 12, 2011, 09:26:37 PM »
Quote from: mcb on May 12, 2011, 09:22:08 PM
Mario, are any specific 6SL7's that you recommend.
i have running right now in flemos 5691 black plate rca's
http://www.ebay.com.au/itm/2-NIB-RCA-JAN-CRC-5691-6SL7-Red-Base-Tubes-1-/110686315394?pt=Vintage_Electronics_R2&hash=item19c56b2382

only the ones with WHITE WRITING NOT THE YELLOW WRITING
Report to moderator   Logged
still discovering the link between electronics and audio reproduction.so much to learn and so little time

Offline kajak12

  • Hero Member
  • *****
  • Posts: 2468
  • Liked: 78
    • http://killerdac.com/forum/index.php
Re: Ming Da MC34-AB
« Reply #61 on: May 12, 2011, 11:14:59 PM »
since i have flemo's amp on loan i decided to change some wires from the input rca's to the volume pot.WHAT a pain in the arse job 4 hours of fcuking around,wire used is vintage copper carefully cleaned inserted through teflon.the original wire was silver plated      multi strand bullsh!t.
the sound is much better smoother not finished yet with this amp more to come.
Report to moderator   Logged
still discovering the link between electronics and audio reproduction.so much to learn and so little time

Offline flemo

  • Sr. Member
  • ****
  • Posts: 472
  • Liked: 22
Re: Ming Da MC34-AB
« Reply #62 on: May 13, 2011, 12:16:35 AM »
Good stuff Mario.   :o

I gues with your amp it was pretty much finished and having the Ming Da has given something play with!!  8)
Report to moderator   Logged

Offline donberry

  • Newbie
  • *
  • Posts: 32
  • Liked: 0
Re: Ming Da MC34-AB
« Reply #63 on: May 13, 2011, 05:50:51 AM »
couple of questions -
first, using the 6SL7. I was reading where the 6SL7 had a MU factor of 70 where the 6SN7 is only 20 - so is it just a plug and play switch and not knowing a whole lot about tubes, it won't hurt anything ?

Second - I am just curious on this one. My amp came from pacific valve. Besides the 4 .22 film caps made by Jinvina or whoever, the rest of the caps in my amp were Multicaps (caps 5, 6, 7 and 8 in mcb's diagram) - were these caps specific to pacific valve or did all MC34AB's come with these ?
Thanks
Report to moderator   Logged

Offline kajak12

  • Hero Member
  • *****
  • Posts: 2468
  • Liked: 78
    • http://killerdac.com/forum/index.php
Re: Ming Da MC34-AB
« Reply #64 on: May 13, 2011, 10:36:07 AM »
Quote from: donberry on May 13, 2011, 05:50:51 AM
couple of questions -
first, using the 6SL7. I was reading where the 6SL7 had a MU factor of 70 where the 6SN7 is only 20 - so is it just a plug and play switch and not knowing a whole lot about tubes, it won't hurt anything ?

Second - I am just curious on this one. My amp came from pacific valve. Besides the 4 .22 film caps made by Jinvina or whoever, the rest of the caps in my amp were Multicaps (caps 5, 6, 7 and 8 in mcb's diagram) - were these caps specific to pacific valve or did all MC34AB's come with these ?
Thanks
i have made no circuit changes to the amp for the 6sl7 its just plug and play working with no problems.regarding the caps in your mingda i have noticed a few pictures on the www of the mingda and they have different caps in them,maybe they changed what caps they use due to cost or supply.
Report to moderator   Logged
still discovering the link between electronics and audio reproduction.so much to learn and so little time

Offline kajak12

  • Hero Member
  • *****
  • Posts: 2468
  • Liked: 78
    • http://killerdac.com/forum/index.php
Re: Ming Da MC34-AB
« Reply #65 on: May 13, 2011, 11:22:51 AM »
future changes to be done to flemos mingda
Report to moderator   Logged
still discovering the link between electronics and audio reproduction.so much to learn and so little time

Offline kajak12

  • Hero Member
  • *****
  • Posts: 2468
  • Liked: 78
    • http://killerdac.com/forum/index.php
Re: Ming Da MC34-AB
« Reply #66 on: May 13, 2011, 11:41:42 AM »
more future changes to mingda
Report to moderator   Logged
still discovering the link between electronics and audio reproduction.so much to learn and so little time

Offline kajak12

  • Hero Member
  • *****
  • Posts: 2468
  • Liked: 78
    • http://killerdac.com/forum/index.php
Re: Ming Da MC34-AB
« Reply #67 on: May 13, 2011, 11:50:25 AM »
the 220k resistor challenge will require a lot of listening
Report to moderator   Logged
still discovering the link between electronics and audio reproduction.so much to learn and so little time

Offline ozcal

  • Sr. Member
  • ****
  • Posts: 466
  • Liked: 2
Re: Ming Da MC34-AB
« Reply #68 on: May 13, 2011, 01:01:27 PM »
Great read Mario , now all we need to do is get Pete to decide on A  pair of speakers  ;D
Report to moderator   Logged
Listening with my ears :)

Offline kajak12

  • Hero Member
  • *****
  • Posts: 2468
  • Liked: 78
    • http://killerdac.com/forum/index.php
Re: Ming Da MC34-AB
« Reply #69 on: May 13, 2011, 01:04:47 PM »
Quote from: ozcal on May 13, 2011, 01:01:27 PM
Great read Mario , now all we need to do is get Pete to decide on A  pair of speakers  ;D
he has the ml1's +R ;D
Report to moderator   Logged
still discovering the link between electronics and audio reproduction.so much to learn and so little time

Offline kajak12

  • Hero Member
  • *****
  • Posts: 2468
  • Liked: 78
    • http://killerdac.com/forum/index.php
Re: Ming Da MC34-AB
« Reply #70 on: May 13, 2011, 04:12:11 PM »
ok the bias 10r resistors are changed to jay car special 40cents each
yes they are staying much more natural presentation with out the metalic sheen that the metal oxide resistors have.
smoother beautiful but a lot more to go
Report to moderator   Logged
still discovering the link between electronics and audio reproduction.so much to learn and so little time

Offline kajak12

  • Hero Member
  • *****
  • Posts: 2468
  • Liked: 78
    • http://killerdac.com/forum/index.php
Re: Ming Da MC34-AB
« Reply #71 on: May 13, 2011, 04:20:32 PM »
my room is a mess working on the amp easy access to the amp is the major factor of quick changes
Report to moderator   Logged
still discovering the link between electronics and audio reproduction.so much to learn and so little time

Offline ozcal

  • Sr. Member
  • ****
  • Posts: 466
  • Liked: 2
Re: Ming Da MC34-AB
« Reply #72 on: May 13, 2011, 04:31:29 PM »
Quote from: kajak12 on May 13, 2011, 01:04:47 PM
Quote from: ozcal on May 13, 2011, 01:01:27 PM
Great read Mario , now all we need to do is get Pete to decide on A  pair of speakers  ;D
he has the ml1's +R ;D
What about some horns in the ht system  ;D
Report to moderator   Logged
Listening with my ears :)

Offline mcb

  • Full Member
  • ***
  • Posts: 235
  • Liked: 6
Re: Ming Da MC34-AB
« Reply #73 on: May 14, 2011, 06:07:18 PM »
Quote from: donberry on May 13, 2011, 05:50:51 AM
couple of questions -
first, using the 6SL7. I was reading where the 6SL7 had a MU factor of 70 where the 6SN7 is only 20 - so is it just a plug and play switch and not knowing a whole lot about tubes, it won't hurt anything ?

Second - I am just curious on this one. My amp came from pacific valve. Besides the 4 .22 film caps made by Jinvina or whoever, the rest of the caps in my amp were Multicaps (caps 5, 6, 7 and 8 in mcb's diagram) - were these caps specific to pacific valve or did all MC34AB's come with these ?
Thanks

Don,

In my amp, the 4 big caps at the back where EPCOS and the four smaller blue ones are marked BC.

Regards

Murray
Report to moderator   Logged

Offline mcb

  • Full Member
  • ***
  • Posts: 235
  • Liked: 6
Re: Ming Da MC34-AB
« Reply #74 on: May 14, 2011, 06:19:42 PM »
Mario,

Thanks for the posts. 

I look forward to reading about more of your findings.  Unfortunately, getting down into where some of those resistors and caps reside is well past my capability.  I will be interested to read what 1uf caps you use on the EL34's and what their impact is (these look like a real bugger to get at, and if the size is much bigger than the current ones, then mounting will also be a challenge.

I was planning on bypassing all the switches between the input RCA's and volume control, but looks way to daunting for me.  I can't even follow all the wiring.

PS With the 10R resistors that you upgraded, would you expect further improvement if you used takman or the like?

Murray
Report to moderator   Logged

Offline kajak12

  • Hero Member
  • *****
  • Posts: 2468
  • Liked: 78
    • http://killerdac.com/forum/index.php
Re: Ming Da MC34-AB
« Reply #75 on: May 14, 2011, 07:51:14 PM »
Quote from: mcb on May 14, 2011, 06:19:42 PM
Mario,


PS With the 10R resistors that you upgraded, would you expect further improvement if you used takman or the like?

Murray
the takman only comes in 1 watt i personally like using 5w for the bias you could get a el34 go troppo and it will blow your bias resistor.So at 40c each for wire wound resistors from jay car is no big deal as to the sound i have no idea
ps:jaycar wire wound resistors is what i use in my amp
Report to moderator   Logged
still discovering the link between electronics and audio reproduction.so much to learn and so little time

Offline donberry

  • Newbie
  • *
  • Posts: 32
  • Liked: 0
Re: Ming Da MC34-AB
« Reply #76 on: May 15, 2011, 01:06:56 PM »
great info. I am going to keep all of my multicaps and just replace the 4 Jinvina .22uf(I have never heard of Jinvina caps). Duelands are out of my price range so will probably just go with the Mundorf silver/oil. Replacing the 10R resistors will also be included.

What I would like to find are some trim pots that are more sturdy or figure out a way to "reinforce" them (some kind of bracket? ). Is not a huge deal, but I would just like to have a little more "heft" when I am in there adjusting the bias. Since you guys are so good at this, I'll hold on until you figure it out  ;D

Upgrades for me are sort of on hold now tho as I boat a boat in january and am spending my money getting it fixed up. Probably mid to late summer before i get serious about the upgrades. Gives you plenty of time to find me some better trim pots  ;)
Report to moderator   Logged

Offline zenelectro

  • Hero Member
  • *****
  • Posts: 825
  • Liked: 177
Re: Ming Da MC34-AB
« Reply #77 on: May 15, 2011, 02:41:57 PM »
Quote from: kajak12 on May 13, 2011, 04:12:11 PM
ok the bias 10r resistors are changed to jay car special 40cents each
yes they are staying much more natural presentation with out the metalic sheen that the metal oxide resistors have.
smoother beautiful but a lot more to go

Mario,

10 ohm bias resistors are, IMO kind of dumb!

I always use 1 ohm 1 watt (or 0.5watt) and:

a) you can read mV to mA without any x 10 conversion b) likely to have less impact on sound c)smaller size d) more available types.

cheers

T


Report to moderator   Logged

Offline zenelectro

  • Hero Member
  • *****
  • Posts: 825
  • Liked: 177
Re: Ming Da MC34-AB
« Reply #78 on: May 15, 2011, 02:45:39 PM »
Quote from: kajak12 on May 14, 2011, 07:51:14 PM
Quote from: mcb on May 14, 2011, 06:19:42 PM
Mario,


PS With the 10R resistors that you upgraded, would you expect further improvement if you used takman or the like?

Murray
the takman only comes in 1 watt i personally like using 5w for the bias you could get a el34 go troppo and it will blow your bias resistor.So at 40c each for wire wound resistors from jay car is no big deal as to the sound i have no idea
ps:jaycar wire wound resistors is what i use in my amp

WRT blowing bias R, that's not a bad thing - it can save your OP transformer.

T

Report to moderator   Logged

Offline kajak12

  • Hero Member
  • *****
  • Posts: 2468
  • Liked: 78
    • http://killerdac.com/forum/index.php
Re: Ming Da MC34-AB
« Reply #79 on: May 15, 2011, 07:25:36 PM »
Quote from: zenelectro on May 15, 2011, 02:41:57 PM
Quote from: kajak12 on May 13, 2011, 04:12:11 PM
ok the bias 10r resistors are changed to jay car special 40cents each
yes they are staying much more natural presentation with out the metalic sheen that the metal oxide resistors have.
smoother beautiful but a lot more to go

Mario,

10 ohm bias resistors are, IMO kind of dumb!

I always use 1 ohm 1 watt (or 0.5watt) and:

a) you can read mV to mA without any x 10 conversion b) likely to have less impact on sound c)smaller size d) more available types.

cheers

T



sound very good T with 10r ceramic resistors flemo can play around more with them if he likes
Report to moderator   Logged
still discovering the link between electronics and audio reproduction.so much to learn and so little time
Pages: « 1 2 3 4 5 6 7 8 9 »
« previous next »