Telefunken ELA M 251 Clone Tube Microphone Build Thread (D-Ela M 251E)

[koki]

I went down to 680nF with the DC blocking capacitor because anything over 1µF was way too bass heavy in my opinion. Then I got the warm mids that were there into focus. As for the tube, I'll be honest - I've tried lot of tubes, built "triode switch" adapters between the tube and socket to test both triodes on the tubes, and burned them in for days. There are only two "available" NOS tubes that I think have that "expensive" sounding, direct character. They are the 5-star Mica GE6072 and the Siemens Halske ECC801S. There are a lot of noisy/crackly NOS GE6072s on the market though and they are all expensive. It can be an expensive and educational journey until you find the right one. All other tubes sounded dull, not detailed/washed out, lacked warmth, no character or were too loud. And the TF AC701 is more a expensive Lottery nowadays.The GE6072 has that sexy edge, is perfectly balanced, hard to explain. It's magical. The Siemens Halske mentioned is also excellent and more available, less noise, very proud sound. TF ECC801S were good but a bit too much noise.

Thanks, ill try that. What is yours grid resistor value ?

 

[HerbertR]

100M Ohm on the Grid to Ground, on the Kathode 22uF and 1.8k Ohm. Regards

 

[Delta Sigma]

I think it's time to cut the counterfeit discussion out of this thread. If someone feels the need to keep it going, another thread would be useful. It's starting to bury the build thread.

 

[TLRT]

I went down to 680nF with the DC blocking capacitor because anything over 1µF was way too bass heavy in my opinion. Then I got the warm mids that were there into focus. As for the tube, I'll be honest - I've tried lot of tubes, built "triode switch" adapters between the tube and socket to test both triodes on the tubes, and burned them in for days. There are only two "available" NOS tubes that I think have that "expensive" sounding, direct character. They are the 5-star Mica GE6072 and the Siemens Halske ECC801S. There are a lot of noisy/crackly NOS GE6072s on the market though and they are all expensive. It can be an expensive and educational journey until you find the right one. All other tubes sounded dull, not detailed/washed out, lacked warmth, no character or were too loud. And the TF AC701 is more a expensive Lottery nowadays.The GE6072 has that sexy edge, is perfectly balanced, hard to explain. It's magical. The Siemens Halske mentioned is also excellent and more available, less noise, very proud sound. TF ECC801S were good but a bit too much noise.

Siemens triple mica tubes usually sounds too dull/dark for mics, I use them for phase inverters only. Mullards are usually the opposite, too bright. Agree about the 6072/ac701 most of them are not mic grade on the market (luckily I still have many of them

 

[HerbertR]

Siemens triple mica tubes usually sounds too dull/dark for mics, I use them for phase inverters only. Mullards are usually the opposite, too bright. Agree about the 6072/ac701 most of them are not mic grade on the market (luckily I still have many of....

Yes, a couple of 701s would be really sexy. But I don't play the lottery, so I wouldn't try to buy from unknown sellers (not you....)

Personally, I think these "very rare" Siemens Halske triple Mica ECC801S with the brand/label sound pretty good (the ones with the two holes on the plate side and the round getter and the shield mica over the top/finger mica, I think it was the German Military Version). Most other Siemens ECC81s... are total junk, like the DDR models. In my opinion, these Siemens Halske ECCs sound a bit brighter and also have a bit more low end than the more roundly balanced GE6072s. I have 11 NOS GE6072s and 6 of them are unusable, both triodes of them. They crackle or have a higher noise floor. Of the 6 Siemens Halske ECC801S NOS tubes, 4 are excellent, two are also unusable for microphones, they also crackle. One thing is really great, the Siemens Halske clearly have a better background noise compared to the "good" GE6072. That's my opinion.