Sorry no,
Have you heard of the 6EU7? I have loads of them.
They were specially optimised by spacing the sensitive pins differently and superior cathode materials.
Nobody seems to want them, while prices of mullard ECC83/'AX7 are getting stupid.
This has 6V heater on 1 & 2, grids on 5 & 8, - a significant improvement.
Compare 12AX7 heater 4 & 5 ct on 9, grids on 2 & 7.
The submins have no theoretical advantage at all.
They were made for military guidance systems which have no interest in hum optimisation whatsoever.
Hence, the tendency to pick up parasitic hum even thru the tiny glass is noticeable.
I found it impossible to get rid of hum unless DC heated, and even then one side or a CT between a pair has to be grounded.
I think it's simply the ultra close proximity of all the tiny bits causes this. (g1 next to heater pins)
6111/6112 has heater 3&6 grid = 2 & 7
6Н16b has heater 4 & 8 grid = 3 & 7
Again all a bit too close for comfort.
Hi Sarcastic1
I guess there is a missunderstanding, perhaps I didn't write it clear enough:
I see an advantage of the 6N16B in comparison to the other subminiature twin triodes only.
This is because the 6N16B has its both heaters connected in parallel. Hence, the capacitive caused amount of hum is able to be reduced by use of a center-tap-grounded heater transformer (as done succesfully in the 12A?7 series in thousands of amps).
In my subminiature tube amp, I replaced a 6021 by the 6N16B (socket removed, tube wires direct soldered in the pcb to solve the different pin assignent), and the hum got reduced.
However, some hum is still present in my amp, which I suppose is now the magnetically induced amount of hum.
And yes I agree, in terms of magnetically induced hum, the subminis are clearly worse compared to the standard miniature twin triodes. 😉
all the best, Adrian
I guess there is a missunderstanding, perhaps I didn't write it clear enough:
I see an advantage of the 6N16B in comparison to the other subminiature twin triodes only.
This is because the 6N16B has its both heaters connected in parallel. Hence, the capacitive caused amount of hum is able to be reduced by use of a center-tap-grounded heater transformer (as done succesfully in the 12A?7 series in thousands of amps).
In my subminiature tube amp, I replaced a 6021 by the 6N16B (socket removed, tube wires direct soldered in the pcb to solve the different pin assignent), and the hum got reduced.
However, some hum is still present in my amp, which I suppose is now the magnetically induced amount of hum.
And yes I agree, in terms of magnetically induced hum, the subminis are clearly worse compared to the standard miniature twin triodes. 😉
all the best, Adrian
Hi Adrian,
By the end, do you think it would be better to use sub-minis or miniature valves?
Cheers,
Pedro
By the end, do you think it would be better to use sub-minis or miniature valves?
Cheers,
Pedro
Hi Petro
From a hum point of view, the miniature tubes are cleary better then the Subminis.
But it is possible to design a submini amp with sufficient low hum, at least for clean to crunchy amps. Just use the 6N16B as the first stage. For HiGain Amps, I would dare it only with DC heated Subminis.
All the best, Adrian
From a hum point of view, the miniature tubes are cleary better then the Subminis.
But it is possible to design a submini amp with sufficient low hum, at least for clean to crunchy amps. Just use the 6N16B as the first stage. For HiGain Amps, I would dare it only with DC heated Subminis.
All the best, Adrian
Hi Adrian,
Thanks for your reply.
So, are you saying to use 6N16B in both pre-amp and power amp?
Cheers,
Pedro
Thanks for your reply.
So, are you saying to use 6N16B in both pre-amp and power amp?
Cheers,
Pedro
The 6N17B doesn't provide internal paralleled heaters, so this tube is only a good option for the very first stage when it is DC heated (and this DC voltage must be grounded).
If you do not intend to introduce a DC heater (which makes your design a bit more complex) then I recommend the 6N16B. It has less gain, but is uncritical to parasitic-cap related hum, so offering the possibility of centertap-grounded AC heating.
The 5902 is the only subminiature power pentode which is able to deliver several Watts in Pushpull configuration.
If you do not intend to introduce a DC heater (which makes your design a bit more complex) then I recommend the 6N16B. It has less gain, but is uncritical to parasitic-cap related hum, so offering the possibility of centertap-grounded AC heating.
The 5902 is the only subminiature power pentode which is able to deliver several Watts in Pushpull configuration.
Well, no direct equivalent soviet type to the 5902, unfortuately...
There is the 6J5B pentode, which copes 1W or so in pushpull. Quite cheap.
6J5B-V / 6Zh5B-V Orel HF pentode tube → MINIATURE tubes → Tubes-Store.com
perhaps this is the right for your needs?
cheers, Adrian
There is the 6J5B pentode, which copes 1W or so in pushpull. Quite cheap.
6J5B-V / 6Zh5B-V Orel HF pentode tube → MINIATURE tubes → Tubes-Store.com
perhaps this is the right for your needs?
cheers, Adrian
Eh? are you joking??
Haven't you heard of this??
It makes the 5902 look real weak,- A 6W pentode with roughly the gain of a 6V6.
You want the one on the left which can be had for about 2-3 EURO.
Put them pairs in PPP and they can conduct 120m/a knocking out a good solid low distortion 15W
Some people use them for voltage stabilisers.
6П30Б-Р
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Hi sarcastic1,
thanks for that hint - super interesting russian submini tubes!
Quite impressing output power the russian tube designers achieved, out of a submini with 6.3V/400mA heater!
I realy didn't know the 6П30Б and 6П30Б-Р... That totally change the game!!
regards, Adrian
thanks for that hint - super interesting russian submini tubes!
Quite impressing output power the russian tube designers achieved, out of a submini with 6.3V/400mA heater!
I realy didn't know the 6П30Б and 6П30Б-Р... That totally change the game!!
regards, Adrian
Actually, I knew about those because once, when I was googling, I came across this webpage.
RuSubMin-Tubes
It has a nice summary and data sheets of the most common subminiature Russian tubes for guitar amplifiers.
So, would it be better to go for the combination 6N17B + 6N30B (pre + power) or 6N16B + 6N30B?
Cheers,
Pedro
RuSubMin-Tubes
It has a nice summary and data sheets of the most common subminiature Russian tubes for guitar amplifiers.
So, would it be better to go for the combination 6N17B + 6N30B (pre + power) or 6N16B + 6N30B?
Cheers,
Pedro
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6П30Б-Р = 6p30b-R not "N30B". P in cyrillic = pentode,
although that one is like the 6V6 - a beam tetrode.
Actually TBQH, the 6V6 is the perfect example of minimal thinking and miniaturisation, going from the giant bulb 6V6G of the 1930s (actually a transmitting valve)
Vf 6.3 Volts / If 0.45 Ampere
to the small 6BW6 or 9BW6 for TVs...
And then the 6П1П and of course the 6AQ5.
If you think of the 6p30b-R as the inevitable outcome of the 6V6 saga you won't be far out.
Most people don't realise like most transmitting devices they really like being run into grid current, the 6V6 being a perfect device hammered into Ab2, even better in parallel push-pull.
I would not be suprised to see PPP amps using this soviet valve at 300V (people do), putting out an easy 30W.
Submin valves = *loads of extra space to put more in parallel.
"just saying". 😀
hint hint......I have something similar putting out a massive 50W per channel and because they are "mil spec" can be abused to death without even breaking a sweat...
although that one is like the 6V6 - a beam tetrode.
Actually TBQH, the 6V6 is the perfect example of minimal thinking and miniaturisation, going from the giant bulb 6V6G of the 1930s (actually a transmitting valve)
Vf 6.3 Volts / If 0.45 Ampere
to the small 6BW6 or 9BW6 for TVs...
And then the 6П1П and of course the 6AQ5.
If you think of the 6p30b-R as the inevitable outcome of the 6V6 saga you won't be far out.
Most people don't realise like most transmitting devices they really like being run into grid current, the 6V6 being a perfect device hammered into Ab2, even better in parallel push-pull.
I would not be suprised to see PPP amps using this soviet valve at 300V (people do), putting out an easy 30W.
Submin valves = *loads of extra space to put more in parallel.
"just saying". 😀
hint hint......I have something similar putting out a massive 50W per channel and because they are "mil spec" can be abused to death without even breaking a sweat...
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What do you think of buying a radio like this?
I comes with valves, transformer,heatsink for the valves, etc
Vintage radio modules,Vulcan, Lighting aircraft radio 5840 and 6021 mini tubes | eBay
Cheers,
Pedro
I comes with valves, transformer,heatsink for the valves, etc
Vintage radio modules,Vulcan, Lighting aircraft radio 5840 and 6021 mini tubes | eBay
Cheers,
Pedro
In Russia of course.
Most of the English and Ukraine >English vendors are a con.
They are out to make loads of bucks from obsolete old rubbish, which you can get for peanuts.
In the ex-USSR there are zillions and zillions of submins 'cos nobody want them.
I'm surprised they haven't already ended up in the crusher or landfill.
As for Vulcan and ex-mil UK bits.
Radios are for fun, now look where those Vulcans are all sitting, rotting away, -
soon to be followed by Harriers and lots of other museum pieces for people to get nostalgic about.
- was once an industry to be proud of.
Dead as a dodo now.
Most of the English and Ukraine >English vendors are a con.
They are out to make loads of bucks from obsolete old rubbish, which you can get for peanuts.
In the ex-USSR there are zillions and zillions of submins 'cos nobody want them.
I'm surprised they haven't already ended up in the crusher or landfill.
As for Vulcan and ex-mil UK bits.
Radios are for fun, now look where those Vulcans are all sitting, rotting away, -
soon to be followed by Harriers and lots of other museum pieces for people to get nostalgic about.
- was once an industry to be proud of.
Dead as a dodo now.
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Hi,
I've started simulating the amplifier in LTspice however, after the first stage, the wave form suffers severe clipping.
I am applying an input of 1V. Is this too much?
Best regards,
Pedro
I've started simulating the amplifier in LTspice however, after the first stage, the wave form suffers severe clipping.
I am applying an input of 1V. Is this too much?
Best regards,
Pedro