5672, 5676, 5678 Telefunken subminiature tubes for tubemic

Hi,

does someone know if tubes above are suitable for tube microphone (instead of 5840 or any other submini) ?

I haven't used any of those, but as a side note I know I had problems using the 6021 at high impedances. I had quite a bit of sputtering noises until I replaced the tube. I talked with a few other people who had similar problems.

What was the 6021 used in? Did the problems come from the type of tube or the particular one you had? Lastly, what did you replace it with? My curiosity just gets the best of me, don't mean to be a pest.

I was trying out a dual triode for a microphone head amp. The first one was a voltage amp and the second was a follower. After talking with someone who had a similar problem with that tube in that application, I put a 5718 or 5719 with a mpsa42 follower. I don't remember which minature I used, but I think it was the 5718. I think the gain was closer to the 6021.

I had to replace an AC701 in an AKG C60 tube mike.  While researching this I came across a thread by Klaus Heyne. he recommended 5784WB miniature tube. I bought several NOS tubes on ebay. It was a perfect fit & I did not need to change the cathode resistor or the high value resistors & the mike sounded as good as with the AC701. In fairness, the tube is configured as a cathode follower, not an amplifier. The customer who bought the mike  is very happy with its performance. much better choice than the 5840.

5678 sounds killer!

https://groupdiy.com/index.php?topic=50731.0

CJ said:

5678 sounds killer!

https://groupdiy.com/index.php?topic=50731.0

Click to expand...

That was an exciting read. Now I want to build one!!