Siegmund Microtube Double Drive gut shots

bajaman · Post by **bajaman** » 14 Mar 2010, 12:26

Those tubes look like subminiature Russian tubes to me. Possibly 6N17B (6H17b) or 6N16B - they handle 200v easily and are similar two 12AX7 / ECC83.
They also have 8 leads just like the one in the pictures - they have 6.3v heaters though.
bajaman

culturejam · Post by **culturejam** » 14 Mar 2010, 21:45

Static, can we get a shot or two of the power supply board? That would be interesting to see.

Thanks!

bajaman · Post by **bajaman** » 14 Mar 2010, 22:39

yep - most probably 6N17B

bajaman

Urals shop in Siberia (on Ebay) has them at US$1.00 each or thereabouts.

deeleyer · Post by **deeleyer** » 15 Mar 2010, 09:30

I've never seen an unmarked 6n16b or 6n17b. And the shape of the bottle is different.
It could be a 6111 as Freq says.

Chrome Dinette · Post by **Chrome Dinette** » 15 Mar 2010, 10:55

staticinfinity wrote: in person they are pink/black/yellow. i'm gonna take a guess and say the pink ones are for brown since the cap is already brown. the resistor appears 4 places on the board. all the brown carbon comp resistors look like they came from the same manufacturer. The resistors under the 5 and 6th pots are yellow/violet/yellow. There is one with grey directly directly above the 3pdt (blue/grey/pink). There is one with orange in front of the third pot (orange/blue/orange) and one with red under the 47pf cap above the 3pdt (red/red/green).

If the stripe looks pink, it is actually violet, which makes them 700k resistors. This is a really odd value for this position and doesn't make much sense. Can you check them with a meter?

Honestly, I don't know if you can easily buy a 700k resistor, I can't find one at Mouser. Something weird is going on here.

Seeing as how the other tube had pretty low values for plate resistors, I am going to suggest you use a 6111. It has the lowest plate resistance of the 6111/6021/6112 types.

bajaman · Post by **bajaman** » 15 Mar 2010, 12:04

all the plate loads are 100k (for three tube sections) the other is a cathode follower to drive the tone stack. The 2k4 resistors are not plate loads, they are cathode resistors - also there is a 1k5 cathode resistor and of course another 100k for the cathode follower cathode resistor. Three dc supplies too - two ht supplies and a tube heater supply.
cheers
bajaman

staticinfinity · Post by **staticinfinity** » 15 Mar 2010, 14:18

If the stripe looks pink, it is actually violet, which makes them 700k resistors.

if pink=brown it's a 100k resistor. if pink=white it's a 900k. Do either of those values make more sense? If you look through all the resistors of that type, every color is there other than brown and white (including violet). The violet color on the other carbon resistors is not similar to the pink. What color would they use to indicate brown when the resistor is already brown? I'm not trying to be contrary, i honestly don't know.

staticinfinity · Post by **staticinfinity** » 15 Mar 2010, 14:48

staticinfinity wrote:
If the stripe looks pink, it is actually violet, which makes them 700k resistors.
if pink=brown it's a 100k resistor. if pink=white it's a 900k. Do either of those values make more sense? If you look through all the resistors of that type, every color is there other than brown and white (including violet). The violet color on the other carbon resistors is not similar to the pink. What color would they use to indicate brown when the resistor is already brown? I'm not trying to be contrary, i honestly don't know.

http://www.friday.com/bbum/2008/12/15/c ... code-time/ I realize it relates to a lamp, but I also feel like i've heard of pink being sub'd for brown another time and it was when the color of the resistor would make brown hard to read. The pink is actually a flesh tone.

staticinfinity · Post by **staticinfinity** » 15 Mar 2010, 15:07

bajaman wrote:all the plate loads are 100k (for three tube sections) the other is a cathode follower to drive the tone stack. The 2k4 resistors are not plate loads, they are cathode resistors - also there is a 1k5 cathode resistor and of course another 100k for the cathode follower cathode resistor. Three dc supplies too - two ht supplies and a tube heater supply.
cheers
bajaman

wow, you really know your stuff. Someone with you're level of expertize you could probably clone this thing.

staticinfinity · Post by **staticinfinity** » 15 Mar 2010, 15:12

culturejam wrote:Static, can we get a shot or two of the power supply board? That would be interesting to see.

Thanks!

I still have the PS apart and i will do this later today, but it only open up enough to see part of it because of the wiring.

Chrome Dinette · Post by **Chrome Dinette** » 15 Mar 2010, 20:28

bajaman wrote:all the plate loads are 100k (for three tube sections) the other is a cathode follower to drive the tone stack. The 2k4 resistors are not plate loads, they are cathode resistors - also there is a 1k5 cathode resistor and of course another 100k for the cathode follower cathode resistor. Three dc supplies too - two ht supplies and a tube heater supply.
cheers
bajaman

Aha, I had the tube backwards, makes much more sense.