Started my poctop D49c build!!!

[achase4u]

Yep, U67 has the filter, too. Inside, S2 can be bridged or jumpered. Not to be confused with the  HPF on the body (200 Hz HPF).

I've never heard that the 5840 was anaemic in the lows, but ideally it may ask for a transformer with a different ratio? Wiser guys than I should be able to do the math.
Apart from ratio, size can play a part, too. Some say the big tranny in the first C12s goes a full octave lower than the later Haufe T14/1.
Anyway, no doubt Oliver had his reasons. But unfortunately, we can't ask him anymore.

And this brings me to another member who passed away recently. Kidvybes bought Dany's prototypes (thus in assembled state) of the M49b and the M269c. After that he had them fine tuned and among other things, the tubes were replaced for another type subminiature. Probably the 5703.  But we can't ask him anymore, either.

As for lows, it depends what you're after.  There's lows and there's deep lows.
If you'd want to capture the low note of a big pipe organ (16 Hz?) you  wouldn't want to use an LDC anyway. A true pressure microphone (omni SDC) would be needed.
Then there's the 20-40Hz range. Bass guitars used to be above that, but now often come with a low B (approx. 31 Hz). That said, if you miss the fundamental, you'll still hear the tone.
BTW, yes, a 40 HZ HPF will have audible consequences a little higher up, too. But as a matter of fact, the HPF in a U67 actually has a stated corner frequency of  30 Hz, not 40 Hz. But 40 Hz better represents the real world effect.

If you don't use instruments that go below 40 Hz, like vocals, acoustic guitars and many other instruments, you're often better off without the low end sensitivity. Full range mics are very sensitive to rumble. You can acyually see this when you look at the woofers of your speakers come play back time. You need great isolation to truly avoid that.

Then there's the usual lows as well as low mids. Let's say 40-400 Hz. This range is what actually in most cases gives that full and meaty sound. Think proximity effect etc. This sounds much more impressive than an SDC omni. But the latter goes lower.
If it's this kind of fullness and meat you're after, you should reconsider the -b version of the M49.

Ah.  So it's inside the u67.  Yes, it is sad about Oliver.  Gone too soon.  A guy who really loved electronics and microphones, and helped us all with his products.

I didn't know about Kidvybes.  That is also tragic. 

I don't really want deep lows.  Stuff that happens under 30hz isn't really my bag.  Often I hipass to 50hz or more.  Bass I might not hpf, but most mics I have work fairly well.  I am talking more about the 40-400hz range you speak of.

I think my plan is to make an m49 B and C version.  I think I will make B version first, as I like the thickness I have heard about some m49s.  So I ordered some more materials to complete the B version PCB.  Then I can use the C version I already soldered up for the second mic down the road.

I am going to use Dany's D7 in at least one, perhaps Eric's in the other.  Just to have two different animals to work with.  I like variety.

 

[ln76d]

Yes, one could question if it is at all important.
But you said the best cardioid setting is with completely disconnected back diaphragm.
I basically found the same, but questioned if it's completely disconnected when the M49 is in cardioid only.
Do I understand you agree it isn't?
Not to nitpick, but since this is an M49 thread, it seems sort of relevant.
Plus I find these matters fascinating to begin with, of course. 

Be nitpicker!!!!!
We need more nitpickers here!!!
What we can better here to do - talking about how mount pcb to the psu box or which color of lamp use?
I'll be happy if someone would came here and write that he disagree with my opinion! Really

There two things - maybe i didn't wrote this clearly.

First thing - i agree with Oliver about cardioid setting via internal switch - when polar pattern inside the box is set to the omni - there would be best cardioid option with disconnected both sides of the capsule. When disconnected backside is polarised it also can affect the response!

Second thing - it's about caomparison between U47 and M49. When we take all the differences in the designs, this polarised, disconnected backside - is a minor difference.
Is it clear now? I have problems with english, that's why am asking

 

[micaddict]

Clear as mud.

Nah, kidding, my friend.
Gotcha.

Thanks. 

 

[ln76d]

I don't really want deep lows.  Stuff that happens under 30hz isn't really my bag.  Often I hipass to 50hz or more.  Bass I might not hpf, but most mics I have work fairly well.  I am talking more about the 40-400hz range you speak of.

I think my plan is to make an m49 B and C version.  I think I will make B version first, as I like the thickness I have heard about some m49s.  So I ordered some more materials to complete the B version PCB.  Then I can use the C version I already soldered up for the second mic down the road.

I am going to use Dany's D7 in at least one, perhaps Eric's in the other.  Just to have two different animals to work with.  I like variety.

For the capsule i would make investment in Thiersch M7 - this is what you can get really close to the original and for really good money.
Try both! It's really good idea - more tests, more improvements - more knowledge, more fun
I can say only that the B arragement sound little bit worse than C - and this can be related to the different tube!
For HPF as i said - you can freely move response as you want to - it's a change of capacitor.
Only disadventage is that this feedback node affect overall response in not so kind way.
That's why i resigned from it - and i can use other stages for HPF.

 

[achase4u]

Here you have, for direct comparison with original schematic, this what am talking about!
Connection included

Ok I see at r7 you show your edit for the resistor there - this is the cathode resistor?  In my build I have a 5k trimmer resistor, so I should be able to set this where it needs to be, yes?

 

[ln76d]

Exactly!
Big plus for Dan, that he put here trimmer!
I didn't noticed that, because i wasn't interested in PCB build.
So now you need to make few turns and adjust proper value of voltage!
You can measure resistance value and use good resistor instead

 

[achase4u]

Exactly!
Big plus for Dan, that he put here trimmer!
I didn't noticed that, because i wasn't interested in PCB build.
So now you need to make few turns and adjust proper value of voltage!
You can measure resistance value and use good resistor instead

Excellent.  I will have to figure out how to measure these things.  So for cathode I am shooting for 6.3 volts, and plate 100v @7.5 mA.  Now I just need to find the points to measure these... because I am not smart  

That is down the road though.  I am assembling the PSU.  Marking where to attach the hardware inside. Making holes for machine screws.

Now you say a *good* resistor in place of the trimmer.  What constitutes good?  Tight tolerance of 1%?  Vishay brand?  Certain material?

 

[ln76d]

At least stay alive!

Neumann did job for you and they marked voltages and points to measure at the schematics.
Look again and i will confirm is it right, ok?
Do at least minimum of decent work
Cathode isn't heater so don't expect here 6.3V

http://sub.allaboutcircuits.com/images/03006.png
http://sub.allaboutcircuits.com/images/03012.png

This is my opinion of course - for me the best option is anything which is close to the original component in Neumann, AKG and other stuff. Carbon (not carbon composite) or wirewound resistor. Beyschlag, Siemens, Draloric, Piher etc.
Cathode resistor and plate resistors matters.

http://www.ebay.com/sch/i.html?_odkw=beyschlag+widerstand&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.Xbeyschlag+carbon.TRS0&_nkw=beyschlag+carbon&_sacat=0

http://www.ebay.com/sch/i.html?_odkw=beyschlag+carbon&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR1.TRC0.A0.H0.Xdraloric+lca.TRS0&_nkw=draloric+lca&_sacat=0

http://www.ebay.com/sch/i.html?_odkw=siemens+wirewound&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.Xsiemens+karbowid.TRS0&_nkw=siemens+karbowid&_sacat=0

Sometimes it can't have impact, sometimes small, sometimes bigger - all depends. Don't expect different capsule effect but it can be pleasant change.
Definately worth.
There's something with metal resistors - i found this "upgrading" some units for boutique parts.
It give me a while to understand that this is not always the better way.
Between boutique dale for example and chinese metal resistor (currently manufactured - not 10 years ago and not from a flea market) in my opinion there's no difference at all. All the noise specs are far away from things we mostly use - so this is the point when ams saying - not worth
For capacitors - you will get really big difference at the output - i would not use polypropylene (KP/MP) here.

 

[Phrazemaster]

And this brings me to another member who passed away recently. Kidvybes bought Dany's prototypes (thus in assembled state) of the M49b and the M269c. After that he had them fine tuned and among other things, the tubes were replaced for another type subminiature. Probably the 5703.  But we can't ask him anymore, either.

Wait, what? I knew about Oliver, but who else are you referring to who passed Henk?

:-[

 

[achase4u]

At least stay alive!

Neumann did job for you and they marked voltages and points to measure at the schematics.
Look again and i will confirm is it right, ok?
Do at least minimum of decent work
Cathode isn't heater so don't expect here 6.3V

http://sub.allaboutcircuits.com/images/03006.png
http://sub.allaboutcircuits.com/images/03012.png

This is my opinion of course - for me the best option is anything which is close to the original component in Neumann, AKG and other stuff. Carbon (not carbon composite) or wirewound resistor. Beyschlag, Siemens, Draloric, Piher etc.
Cathode resistor and plate resistors matters.

http://www.ebay.com/sch/i.html?_odkw=beyschlag+widerstand&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.Xbeyschlag+carbon.TRS0&_nkw=beyschlag+carbon&_sacat=0

http://www.ebay.com/sch/i.html?_odkw=beyschlag+carbon&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR1.TRC0.A0.H0.Xdraloric+lca.TRS0&_nkw=draloric+lca&_sacat=0

http://www.ebay.com/sch/i.html?_odkw=siemens+wirewound&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.Xsiemens+karbowid.TRS0&_nkw=siemens+karbowid&_sacat=0

Sometimes it can't have impact, sometimes small, sometimes bigger - all depends. Don't expect different capsule effect but it can be pleasant change.
Definately worth.
There's something with metal resistors - i found this "upgrading" some units for boutique parts.
It give me a while to understand that this is not always the better way.
Between boutique dale for example and chinese metal resistor (currently manufactured - not 10 years ago and not from a flea market) in my opinion there's no difference at all. All the noise specs are far away from things we mostly use - so this is the point when ams saying - not worth
For capacitors - you will get really big difference at the output - i would not use polypropylene (KP/MP) here.

Well, I will stay alive - thats no problem!  I will be careful!  I'd rather make a so so mic and be alive than screw around and die.

I will do it to the best of my ability.

I see now the points on the schematic where you should see certain voltages.  Very good.

I like very much what I have heard from Dans D7 capsule so far - so I'll try that one - maybe Thiersch next.  I wan't Eric's as well, probably for my u87 build.

Those are interesting looking resistors.  So these are the old equivalent to todays caps.  I assume in some places I can use any material resistor as long as it has the right resistance and voltage spec, yes?  A way of experimenting with sound?

 

[ln76d]

I like very much what I have heard from Dans D7 capsule so far - so I'll try that one - maybe Thiersch next.  I wan't Eric's as well, probably for my u87 build.

Those are interesting looking resistors.  So these are the old equivalent to todays caps.  I assume in some places I can use any material resistor as long as it has the right resistance and voltage spec, yes?  A way of experimenting with sound?

I believe that Dan capsule is good.
I was thinking that you want to build two m49
For U87 i would use Peluso capsule - you already have it  - then you could use in p67 Eric K47 capsule - it would be different beast and i think you will like it.

In many places you can use any kind of resistor - but be prepare that some are tricky - especially carbon composite.
You need to look for resistance and wattage. In most of tube microphones worth is to use at R10 and R7 some old school type.
Neumann even gived you information what power it need to be at some points.
For vintage resistors max what you want to find is 0.5W and mostly 0.25W. These resistors are much bigger than usual metal resistor, so with many types of vintage resistors you will probably have problem to fit 1W.
For example in P67 you have two plate resistors - not one as in m49.
For the rest use metal resistors and all should be fine.
All voltage measurements you need to make reffered to ground.
Polarisation voltage - between r8 and r9.

 

[achase4u]

I like very much what I have heard from Dans D7 capsule so far - so I'll try that one - maybe Thiersch next.  I wan't Eric's as well, probably for my u87 build.

Those are interesting looking resistors.  So these are the old equivalent to todays caps.  I assume in some places I can use any material resistor as long as it has the right resistance and voltage spec, yes?  A way of experimenting with sound?

I believe that Dan capsule is good.
I was thinking that you want to build two m49
For U87 i would use Peluso capsule - you already have it  - then you could use in p67 Eric K47 capsule - it would be different beast and i think you will like it.

In many places you can use any kind of resistor - but be prepare that some are tricky - especially carbon composite.
You need to look for resistance and wattage. In most of tube microphones worth is to use at R10 and R7 some old school type.
Neumann even gived you information what power it need to be at some points.
For vintage resistors max what you want to find is 0.5W and mostly 0.25W. These resistors are much bigger than usual metal resistor, so with many types of vintage resistors you will probably have problem to fit 1W.
For example in P67 you have two plate resistors - not one as in m49.
For the rest use metal resistors and all should be fine.
All voltage measurements you need to make reffered to ground.
Polarisation voltage - between r8 and r9.

Ah yes - I just mean for this current m49 but yes a second one perhaps I will use another capsule for a second flavor.  One B one C version etc.

It makes sense that older components are larger.  Newer tech is always smaller...

Thank you for the info...

K47 in the p67 would warm the top a bit yes?

 

[micaddict]

Wait, what? I knew about Oliver, but who else are you referring to who passed Henk?

:-[

Mike, if you didn't know, then I'm very sorry to tell you that Dennis Stone (kidvybes) died two months ago.

http://groupdiy.com/index.php?topic=62170.0

 

[ln76d]

K47 in the p67 would warm the top a bit yes?

Yes - of course, you will get type of sound like m49 or u47 - not mean exactly the same but k47 type capsules are very pleasant.
Usual there's better low end, little bump in hi midrange (more presence) and smooth top.
You will get completely different machine

 

[achase4u]

K47 in the p67 would warm the top a bit yes?

Yes - of course, you will get type of sound like m49 or u47 - not mean exactly the same but k47 type capsules are very pleasant.
Usual there's better low end, little bump in hi midrange (more presence) and smooth top.
You will get completely different machine

Very cool!  Sounds like something I may try in that mic to make a mongrel of sorts.

I am working on the PSU now.  I realize there are different wire gauge requirements for different parts here.  Is there a chart or information available on wire gauge and sizes required for certain voltages and ampres?

 

[ln76d]

For high voltage you don't need anything special - look on many microphones internal pictures - there you will see that mostly are used really thin wires. Current consumption is really marginal.
These short wires inside psu or microphone are negligible - you need to send all the stuff by long "microphone" cable were usual wires are also thin - but here distance matters.
I don't operate in gauge but anyway something like 28awg to 22awg should be enough where thicker is needed for heaters (there's current consumption). 
Always you can use thicker for both of course

 

[achase4u]

For high voltage you don't need anything special - look on many microphones internal pictures - there you will see that mostly are used really thin wires. Current consumption is really marginal.
These short wires inside psu or microphone are negligible - you need to send all the stuff by long "microphone" cable were usual wires are also thin - but here distance matters.
I don't operate in gauge but anyway something like 28awg to 22awg should be enough where thicker is needed for heaters (there's current consumption). 
Always you can use thicker for both of course

Ok very good thank you

You will be happy to know I have taken my late uncles electronics books so I can LEARN!

I use 28g currently, so I'll get some 24 or 22 for heaters...

 

[ln76d]

Great!

Now read more, build more and next year i want to see your own project here
Don't have to be geek to find fun in that

Here's something usefull:
http://www.calculator.net/voltage-drop-calculator.html

 

[ln76d]

BTW you have a luck
In my opinion US books about electronic or acoustic are great!
I understood many things after i read some positions in the language which i barely know
Oh man, i was so happy when i found paper version of radio amateur handbook from the 50's.
Especially i like these old books, despite great source of informations, fonts and graphics are totally amazing.
German books also are great but unfortunately that language is too "panzerfaust" for me
Anyway still trying

 

[achase4u]

BTW you have a luck
In my opinion US books about electronic or acoustic are great!
I understood many things after i read some positions in the language which i barely know
Oh man, i was so happy when i found paper version of radio amateur handbook from the 50's.
Especially i like these old books, despite great source of informations, fonts and graphics are totally amazing.
German books also are great but unfortunately that language is too "panzerfaust" for me
Anyway still trying

Wonderful! Here are the books... I will try to understand...atomic weight so far...