So I build a lot of 6V6 amps with old organ power transformers. I like to use SS recto and lots of times there's an unused 5 volt winding tied off and tucked away.
I see from the GE 6V6GT data sheet that the 5V6GT is supposed to be identical except for the heater. NOS 5V6GTs appear to be pretty cheap. I'm pretty sure you all know where I'm going with this line of thought. Anyone have experience building for 5V6? Any advice/caveats?
5v6 in place of 6v6
Moderators: pompeiisneaks, Colossal
5v6 in place of 6v6
Thanks,
Roger
Roger
Re: 5v6 in place of 6v6
At 6.3v on the heaters, you are going to burn them out faster. How fast? I have no idea. Figure out how to supply the heaters with 5V!
For personal use, why not? Don't expect someone else to realize the difference between 5V6 and 6V6 when attempting to retube.
How cheap is cheap? You should be able to buy used old stock 6V6's for cheap and with plenty of remaining useful life. If you will be running plate voltage under 300V, you might consider 6AQ5, which is plentiful, cheap, and identical spec to 6V6.
For personal use, why not? Don't expect someone else to realize the difference between 5V6 and 6V6 when attempting to retube.
How cheap is cheap? You should be able to buy used old stock 6V6's for cheap and with plenty of remaining useful life. If you will be running plate voltage under 300V, you might consider 6AQ5, which is plentiful, cheap, and identical spec to 6V6.
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sluckey
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1 others liked this
Re: 5v6 in place of 6v6
No experience with a 5V6 but I like your idea. I predict that the price is about to increase! 
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Tony Bones
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Re: 5v6 in place of 6v6
I've been eyeballing 5V6's with the intention of reducing the filament voltage somehow, but your idea of using an (otherwise unused) 5V heater winding is way better. Major points for you!
Re: 5v6 in place of 6v6
I guess I wasn't clear. I plan to use the unused 5 volt winding on the power transformer to power the 5V6s.Phil_S wrote: ↑Fri Mar 08, 2019 9:09 pm At 6.3v on the heaters, you are going to burn them out faster. How fast? I have no idea. Figure out how to supply the heaters with 5V!
For personal use, why not? Don't expect someone else to realize the difference between 5V6 and 6V6 when attempting to retube.
How cheap is cheap? You should be able to buy used old stock 6V6's for cheap and with plenty of remaining useful life. If you will be running plate voltage under 300V, you might consider 6AQ5, which is plentiful, cheap, and identical spec to 6V6.
Last edited by darefugee on Sat Mar 09, 2019 12:52 pm, edited 2 times in total.
Thanks,
Roger
Roger
Re: 5v6 in place of 6v6
I think it's a great idea. I had to look on ebay after reading your post. NOS 5v6's are going for $2.99 to $9.99. The 6AQ5 tubes are also pretty cheap and easy to find. I just built an amp using 6AQ5's and it sounds awesome.
Mike
Mike
Re: 5v6 in place of 6v6
Should be able to run 4 of them off a 5V 3A winding
https://frank.pocnet.net/sheets/049/5/5V6GT.pdf
(Or add a 5th one as a reverb driver)
Or you could use 6V6s (or, depending on the 6V winding current draw rating, maybe even 6L6s?) off the 6.3V winding, and use the 5V winding for a 5V6 employed as a screen current regulator. The maximum heater-cathode voltage is 100V, so the 5V winding would need to be elevated to 320V or so if you were going to aim for a regulated screen voltage of (say) 350. The maximum screen grid current of a 6V6 is around 6mA each, so the 5V6 should easily be able to supply enough juice to get excellent regulation on the 6V6 screens (or even on 6L6 screens)
Edit: Unprototyped schematic of 5V6 g2 regulator attached (no guarantees implied, but I'm pretty sure it will work
)
https://frank.pocnet.net/sheets/049/5/5V6GT.pdf
(Or add a 5th one as a reverb driver)
Or you could use 6V6s (or, depending on the 6V winding current draw rating, maybe even 6L6s?) off the 6.3V winding, and use the 5V winding for a 5V6 employed as a screen current regulator. The maximum heater-cathode voltage is 100V, so the 5V winding would need to be elevated to 320V or so if you were going to aim for a regulated screen voltage of (say) 350. The maximum screen grid current of a 6V6 is around 6mA each, so the 5V6 should easily be able to supply enough juice to get excellent regulation on the 6V6 screens (or even on 6L6 screens)
Edit: Unprototyped schematic of 5V6 g2 regulator attached (no guarantees implied, but I'm pretty sure it will work
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Last edited by tubeswell on Sat Mar 09, 2019 6:39 pm, edited 3 times in total.
He who dies with the most tubes... wins
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Stevem
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Re: 5v6 in place of 6v6
You might want to check this out.
The diodes do the bulk of the rectifing but you still get sag when / if your loading the tube hard and if you simply yank the tube the amp just runs on the SS diodes.
Just remember that your filters need to be rated for the higher V+ when the amp is on the diodes only.
This arrangement also greatly extends the life of the tube!
The diodes do the bulk of the rectifing but you still get sag when / if your loading the tube hard and if you simply yank the tube the amp just runs on the SS diodes.
Just remember that your filters need to be rated for the higher V+ when the amp is on the diodes only.
This arrangement also greatly extends the life of the tube!
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Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!