MK7 - tube mic project

[ioaudio]

gus,

in my test-setup i experimented with the order (e.g. rc before the regulator)
i had the best result with the mod - schematics as shown, bridge into lm317 and the rc stages after that.


jeremy,

i´m working on it. i have two prototypes for the rev2 BV7 transformer with stock lamination from magmet usa, they do work, but still sound different.

-max

 

[bradb]

guys, sorry for the ignorance... but what tranny(s) should I get for Max's custom PSU design....

 

[Jeremy.Starseed]

gus,

in my test-setup i experimented with the order (e.g. rc before the regulator)
i had the best result with the mod - schematics as shown, bridge into lm317 and the rc stages after that.


jeremy,

i´m working on it. i have two prototypes for the rev2 BV7 transformer with stock lamination from magmet usa, they do work, but still sound different.

-max

So a couple of tweaks to the design of the trafo are still being made, then? Take your time, by all means, that is a vital part of the sound after all 

Is it the fact of the lamination being stock that makes for difficult matching? Sorry if that is totally off the mark...I don't know how much energy has gone into the trafo design, so far.

BTW. Today I had a listen to a comparison of different capsules for the U47, and was a little surprised at how big the differences were, and inspired by how good they sounded...http://www.nordicaudiolabs.com/

I'm glad that the build has become more and more ambitious as the thread develops. This is just one of those things that need to be done right.

Thankful for all the work you guys have put in.

 

[angryman]

hi patrick,

welcome!

all DIY projects here can be build for the varying mains voltages. just specify the primary of your power transformer accordingly.
maybe start with an easy project which uses cheaper parts - you will learn where to source standard parts, learn about voltage requirements for capacitors etc.

making your own mic housing is a good thing - you will have your very own mic, recognizable also from the outside 
the thomann mic body is ok, nothing special. not very pretty as-

Thanks for the reply, I will start with an easy project as that is true of most things .
Kind Regards

 

[Martin B. Kantola]

BTW. Today I had a listen to a comparison of different capsules for the U47, and was a little surprised at how big the differences were, and inspired by how good they sounded...http://www.nordicaudiolabs.com/

The correct link to my little test is here: http://www.panphonic.com/M7/

Martin

 

[Davo]

Thanks for the samples Martin... I'm looking to purchase a Thiersch blue line... do you have any experience
with these vs. any of Peluso's capsules??

On another note, I contacted Edcor about a Power tranny for Max's PSU, they wrote:

It would be a PWRC100 unit.  Cost would be $23.03 each plus a one time design and setup charge of $20.00.  You can see the dimensions at this link
http://www.audiotransformers.net/forum/tp-downloads/15000-EI075-100-PWC.pdf

dave

 

[Martin B. Kantola]

Have never heard Peluso capsules, except in his microphones. Was quite unimpressed. Mr. Thiersch is in another league if you ask me.

Martin

 

[Davo]

Cool, that's what I wanted to know  ;D
After listening to all the samples thoroughly, my favorite all around was the Blue line... with the Neumann
a close second (surprised me on that one)  I think all the capsules are really nice, and was impressed by the tone
that Dale was able to achieve with his... so once again, thanks for those tests.... a real eye opener!!

dave

 

[Arno]

I just noticed there's no value mentioned for the last filtercap in the heater supply, after the wire-wound pot (I'm referring to the "ground-up" psu schematic)

Is it also 10000mmF/25V ??

I hope I haven't over-read something

tnx
arno

 

[ioaudio]

i was contacted by a gentleman who stumbled across this thread, and he offered me some old/original lamination he has in stock. there are chances that i will have some more (~25) of the MK7 sets in the future.
again, there will be no list and a link to the BM will be posted here as soon as they are available.

Is it also 10000mmF/25V ??

yes.

 

[Jeremy.Starseed]

Excellent news!

How much money to set aside, per kit?

 

[Jim50hertz]

Hi Max

Thanks for all the hard work here, I don't suppose you have an idea where to source the power trafo for the beefier (your design) power supply in Europe?  Short of dropping £100+ per trafo on custom sowters I'm coming up empty.

Cheers

Jim

 

[ioaudio]

there are some places for scustom pwr transformers in europe.

e.g.
http://www.die-wuestens.de/dindex.htm?/t1.htm

 

[Gus]

Max
 
  Have you tried something like a LM1086  adjustable?

 

[Davo]

Hi Max

Thanks for all the hard work here, I don't suppose you have an idea where to source the power trafo for the beefier (your design) power supply in Europe?  Short of dropping £100+ per trafo on custom sowters I'm coming up empty.

Cheers

Jim

Jim, Edcor in the USA will make em for a lot cheaper... see my post above.... It looks like only $23.03 ea, after an initial setup charge.... I don't have the funds to cover any kind of group buy, but who knows, maybe something can be set up with edcor, where everybody pays seperately......

 

[bradb]

seems like alot of us would want this, so if he was guaranteed some buisness maybe that fee would be waived.

also does the edcor tranny have the heater and HT both in one transformer?

 

[Davo]

Yup... specs I gave em were straight from Max:
Dual secondaries w/ the first being 160vac @ 10ma and second 12vac @ 500ma....
of course, I don't know if there would be a separate setup charge for all those folks wanting 220v primaries

 

[bradb]

I just got off the phone with Edcor and followed up with Davo's conversation.

If we ordered 50 pieces the design charge would be dropped...

but i don't think we'll get to that because some of those 50 kits went overseas and there's a separate design charge for the 220V version.


SOOO... perhaps whats easiest is to figure out how many people want this power transformer, have someone just pay the design fee, and then just have other people who also order the transformer paypal that person a bit of money to cover it honor system-style?

what does everyone think?

Here's some shipping info:

USPS
$40 shipping overseas
$10 shipping US
$25 shipping canada


So... how about we just get a tally right now of how many people want these transformers

PWRC100-1 (120V version)
PWRC100-2 (240V version)


I want 2


EDIT:
Don't post here, lets deal with this Edcor tranny thing in a different thread:  http://www.groupdiy.com/index.php?topic=31306.0

 

[Davo]

Bradb, you work fast! ;D
One for me

 

[Jim50hertz]

Jim, Edcor in the USA will make em for a lot cheaper... see my post above.... It looks like only $23.03 ea, after an initial setup charge.... I don't have the funds to cover any kind of group buy, but who knows, maybe something can be set up with edcor, where everybody pays seperately......

Hi Davo, thanks! I missed that post  :

and thanks Max for your link!

So... how about we just get a tally right now of how many people want these transformers

PWRC100-1 (120V version)
PWRC100-2 (240V version)


I want 2

This is great Brad, sounds good, should we start another thread in the BM for this perhaps?  And keep this for project related posts?

I'd like two 240v versions anyhoo