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Modifying amp to accept different tubes (Newbie alert!)

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Pickledcreeky

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Joined 2005
#1
Hello,

I have recently ordered a Bada ph-1 headphone amplifier. It uses two 6N16B valves. Having looked around the internet for replacements or equivalents I only turned up one site that is based in Russia.

The 6N16B is a small dual triode tube and it's soldered to the board of the headphone amp. My question is would it be possible to install a socket for a different valve on the chassis of the amplifier and install a different dual triode eg 12AX7 or ECC82? I understand the pin layout is different between valves so the heater, grids, plates etc.. would have to be wired up correctly but would this be possible assuming the new valve were to be wired up correctly or would I have to change resistor/capacitor values for the new valve?

Sorry for the possibly stupid questions but I am pretty new to Valves/tubes (Past experience is replacing caps and resistors in an old GEC radio) :clown:

Thanks.
 
#2
Pickledcreeky said:
Hello,

...would it be possible to install a socket for a different valve on the chassis of the amplifier and install a different dual triode eg 12AX7 or ECC82? I understand the pin layout is different between valves so the heater, grids, plates etc.. would have to be wired up correctly but would this be possible assuming the new valve were to be wired up correctly or would I have to change resistor/capacitor values for the new valve?

...Thanks.
Click to expand...


Don't worry about the question! It is something everyone new to valves faces.

Unless the tube you are replacing the original with has the same values (max plate voltage, current etc.) you will most definitely have to make changes other than just soldering in a valve socket. What exactly you have to change depends on a few factors.

More than just voltage differences you need to know if the rest of the circuit can handle the output from your new tube or if your new tube is capable of driving the next stage. There are some amazingly knowledgeable people here so if you can post a schematic it is likely someone can give you the answers you need.
 
#6
Thanks all for your replys!

andyjevans said:
why replace it? If it ain't broke, don't fix it. Just because it's the fashion to 'tube roll' doesn't mean that original equipment has to be torn out on principle. If you want to be able to replece it at some point, speak to Edicron. www.edicron.com. Bear in mind there are some really excellent russian tubes, and they may well be better than your average ECC83
Click to expand...

Hello Andy,

I am not about to replace the tubes just yet dont worry :angel: I have just heard a rumor that these tubes do not last that long (750 hours I was quoted) so just thinking ahead a little. As for the ECC83s the only reason I suggested those is someone I know has a few of them and has said I could have them.

Btw The link you gave me doesn't seem to be working.


Originally posted by Sch3mat1c I'd look for a place in the case/chassis to mount a tube socket on a bracket and run pigtails. Takes care of any pinout variations, too!
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Thats a very good idea also as the case is very small so it would take care o9f space issues with the sockets mounted on a seperate bracket

Originally posted by Colt45 Here is a datasheet: http://frank.pocnet.net/sheets/113/6/6N16B.pdf

Now go look around for something with similar curves, I'm too damn lazy.

I forget the numbers of some of the common domestic submini twin triodes. but- i wouldnt bother. I'm sure you can hunt down 6N16B for next to nothing, if you know the right people..
Click to expand...

Cheers for that!

Thanks all for taking the time to reply. 🙂
 
#7
Pickledcreeky said:
I have just heard a rumor that these tubes do not last that long (750 hours I was quoted) so just thinking ahead a little.
Click to expand...

Umm... usually valves last longer than that. It isn't uncommon for small signal types to last for a few decades under normal use.

The 750 hours is quoted in the datasheet linked earlier in this thread by Mark. It might be that the valve is guaranteed to last at least 750 hours, but may last very much longer. These sort of guarantees are important in military service where the machine must be working, so the valves will probably be replaced anyway, just to make sure they don't fail at some other critical time.
 
#8
Yes, I agree with audiousername.

the 750h is conservative rating, I think it applies to *minimum* life at *maximum* ratings.

since small signal tubes are usually run at a small amount of their ratings, they usually last a few decades..
 
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