Ela M251 wet tantalum?

[ln76d]

That's why it looks so different!
Could you make more pictures of components?
First what i saw what is different  -  capacitor 23pF.
Looks like HF (even RF) damping.
Are there any other capacitors than this 23pf and 500nF output cap?
I don't see anything else (one 1nF is always hidden ).

 

[tonycamp]

such great info guys, thanx so much! i picked up some 3.3uf 75v's, and 3.0uf 300v's, one or the other should suffice, it's a bit unnerving reading the "open" failure possibility  of an underrated wet tantalum!

I managed to get an old pair of Haufe trannys for my builds, I have a pair of CT12's standing by, and a couple 5 star GE's lined up via a pal, please keep it coming if there is anything else anyone could suggest to get a little closer to the originals?

btw, since i started down this road a number of years ago, i started to believe the capsule was the vast majority of the sound, i've since come to believe it's about 50%, everything you do can have such an impact systemically, it's been fun, and continues to be fun learning, not to mention the unexpected honing of a completely different set of listening skills, it's actually made me a better musician.

 

[ding]

Where did you find the 300v 3uF tant? I looked all over for months and finally was able to find a single 3uF 150v on eBay but I got lucky and if I wanted to build a second one or this one ended up being shoddy I would be out of luck.

 

[ln76d]

such great info guys, thanx so much! i picked up some 3.3uf 75v's, and 3.0uf 300v's, one or the other should suffice, it's a bit unnerving reading the "open" failure possibility  of an underrated wet tantalum!

I managed to get an old pair of Haufe trannys for my builds, I have a pair of CT12's standing by, and a couple 5 star GE's lined up via a pal, please keep it coming if there is anything else anyone could suggest to get a little closer to the originals?

btw, since i started down this road a number of years ago, i started to believe the capsule was the vast majority of the sound, i've since come to believe it's about 50%, everything you do can have such an impact systemically, it's been fun, and continues to be fun learning, not to mention the unexpected honing of a completely different set of listening skills, it's actually made me a better musician.

Tony!
You really want to get Beyschlag resistors - trust me
Cathode and plate resistors are most important.
For rest of capacitors there were mostly used tubular ceramic capacitors (i'm not sure about these which were mounted in the "head") - ****** as hell but i think it's worth to try. If something better - Siemens styroflex like in later C12.
Cathode capacitor is also really important for the sound - and this was also tantalum ero/siemens.
Want to go even closer? Build psu close as possible  - use selenium rectifier for B+ and selenium diode for heaters.

 

[tonycamp]

such great info guys, thanx so much! i picked up some 3.3uf 75v's, and 3.0uf 300v's, one or the other should suffice, it's a bit unnerving reading the "open" failure possibility  of an underrated wet tantalum!

I managed to get an old pair of Haufe trannys for my builds, I have a pair of CT12's standing by, and a couple 5 star GE's lined up via a pal, please keep it coming if there is anything else anyone could suggest to get a little closer to the originals?

btw, since i started down this road a number of years ago, i started to believe the capsule was the vast majority of the sound, i've since come to believe it's about 50%, everything you do can have such an impact systemically, it's been fun, and continues to be fun learning, not to mention the unexpected honing of a completely different set of listening skills, it's actually made me a better musician.

Tony!
You really want to get Beyschlag resistors - trust me
Cathode and plate resistors are most important.
For rest of capacitors there were mostly used tubular ceramic capacitors (i'm not sure about these which were mounted in the "head") - sh*tty as hell but i think it's worth to try. If something better - Siemens styroflex like in later C12.
Cathode capacitor is also really important for the sound - and this was also tantalum ero/siemens.
Want to go even closer? Build psu close as possible  - use selenium rectifier for B+ and selenium diode for heaters.

Thanx In76d for more great info! I've been on the Beyschlag's since your first mentioning of it, not having much luck finding them though, are they carbon in the originals or did metal film even exist back then? Not sure if it's true, but from what i understand Vishay/dale bought Beyschlag, and the brown bean metal film resistors are the result? They do have the best sound of any in production resistor i've tried. I will hunt down the wet tantalum for the cathode as well, that is the 20uf/6v correct? As far as the PSU, i was thinking of going point to point on them, i will look for a selenium rectifier, and diodes...
thanx again for the great info!

 

[ln76d]

Brown/claret Beyschlag, from what i know, were out of production before Vishay bought it in 2002. From the mid 60's Philips was the owner. They made metal film from 1966, but these were looking little bit different.
This is how looking beyschlag resistors which you can find in many vintage mikes:
http://www.radiomuseum.org/forumdata/users/72/Beyschlag_Code.jpg
At least 100k you will find on ebay, but these are from newer production. I don't know is there any difference?!?
Bayschlag made really high quality resistors in the 50's/60's, standard was 5% tolerance but even in the 50's they made 1%!
Compare it to the Allen Bradley which were 10% and 20% and often noisy I like bradley carbon comps when i need some dirt

For 20uF tantal - yes, everything from 6V up. I would buy few and measure it. These tantals which i have from 251 and C28 have poor tolerance  - due to age probably.