sub-mini russian 6n16b-v tubes instead of 12au7?

[aran.e666]

hi all, sorry for not posting for a while but I've been very busy. I was curious as to some mini 6n16b-v soviet tubes I acquired and since they are dual triodes, would I be able to in theory replace a 12ax7/au7 (and swap the pinout obviously). is this even possible to run these on 9/12v (and put a mosfet circuit to lower voltage to 6.3v for the heater) in the matsumin valve caster? or maybe make a small pre amp? sorry for very short description but I cant really describe it any better since all I need to know is will this work in place of a 12a-7 tube. any ideas would be much appreciated. thanks

p.s I've posted this in the 'building your own stompbox' page since im not sure what else this classifies as.

aran

[frequencycentral]

The 6n16b is somewhat similar in performance to the 6111 submini, which is somewhat similar in performance to the 12AU7....So, yes!

[aran.e666]

Thank you very much sir! Im basing the circuit off the sopht amp but that uses tubes that run on 12v. My main problem is I cant test it since im out of solder!  So basically I can sub out the tube for say a 12u7 NOT 12au7 and use the 6n16, and sub out the other tube (pentode) for a sub mini pentode and run it on say 12-30v? Thanks

Aran

[aran.e666]

Okay so I wired it up and tested it through a 10" speaker (10watt) so im not surprised that it didnt work, any ideas if it was just the speaker since im sure I need an output transformer.  If anyone needs il try and send a pic and the schematic and also one of the tubes dosent light up (heater) so it might be broken.

Aran

[aran.e666]

[tonyharker]

Definitely won't work without an output transformer.  What pentode are you using?

[aran.e666]

The pentode is 6j5b-v. It is also a subminiature but it dosrnt light up but non of my other 6j5b-vs light up so I think I neef an output transformer. Do you think it would work on 12v? Cheers

Aran

[tonyharker]

Are you sure the 6j5b-v. is connected the right way round? Some datasheets show heater connections on pins 3 & 4 but some show them on 4 & 5 instead.
My 6j5b-v s light up if you look at the lead end you can see a glow.

[aran.e666]

Ahh I will try then. I know the orientation is correct since the anode is a pin that runs up to the top from pin 1. If I do this correct, could it work of for sure would I need higher voltage and an output transformer?   Thanks

P.s I am now using a small  0.8watt speaker.

Aran

[tonyharker]

You will still need a transformer!
There is insufficient load on the pentode to develop any gain with just a speaker.
The wattage of the speaker is irrelevant.

[aran.e666]

Thank you.  What would you recommend for a transformer like the winding etc. Also if pin 4 and 5 on the 6j5b-v are the heaters, what would the grid be. I would like to know the pinout if possible. Thanks.

Aran

[aran.e666]

So I have probed a 6j5b tube with 6.3v and I am getting no heater glowing, I must be doing something wrong. Does thia tube require a secial wiring? I have tried with 5 of them. Sorry to keep 'asking' but this means alot since ive never built an amp. Thanks

Aran

[tonyharker]

There appears to be two types of these tubes.  One with the base with the wires all in line and one with the wires in a circle.  Which ones do you have. 
I would suggest that the tansformer has a primary impedance of about 1k.  However from 12 volts you are not going to get much sound out into a speaker. Just a few milliwatts.
A better result would be to use at least 90v B+.

[aran.e666]

The pins are in a straight line, running the heaters of 6 v battery. I would agree but 1. My caps are rated 50v 2. I dont usually work with high voltages but I think it could work if I used 12v tubes but I cant get any. Soon I might get some qqe03/12 tubes for a serious amp project,  but I would like to make this one. It is all wired up however I dont have an output transformer yet so.. thanks

Aran

[tonyharker]

On the base of the tube you should find an arrow, moulded into the glass on one side.  The arrow points in the direction you should read the connections. The arrow points away from pin 1, which is the Anode (Plate), then comes 2 - Screen Grid, 3 - Heater, 4 - Heater, 5 - Suppressor Grid, 6 - Cathode & 7 - (Control) Grid.
Applying 6.3v to 3 & 4, should show a glow after a few seconds just visible in the centre if the tube is held upside down. 
If no glow is observed, then it appears the tubes are defective.

[aran.e666]

Yeah I know the pinout ec and I have tried it anyways but still no lighting up so I informed the seller and she said if I order more,  she will throw in 3 qqe03/12's which is nice. Also is it safe to take say a 6v battery and directly pit it onto pins 3 & 4 or would I need a low ohm resistor etc. Thanks

Aran