In parallel push pull (PPP) how much power output would four of these tubes listed produce? I think the PPP 201 is only 1/4 watt- not enough power.
PPP= 8 output tube == 4 very closed pair tube.
Nowadays 10Y/VT25 (10 is rare as a hen's teeth) pair about 150 ... rather 200-250 USD.
So only tubes costs 800 USD.
Nowadays 10Y/VT25 (10 is rare as a hen's teeth) pair about 150 ... rather 200-250 USD.
So only tubes costs 800 USD.
Here is a Cornwall speaker quote from Steve Hoffman.
'Sensitivity of the Cornwall is insane so dynamics are amazing, and my 24 WPC Line Magnetic 219ia uses about 1/4 – 3/4 of a watt to run these to a nice volume for daytime listening. If I want to crank and shake the walls with clean sound, it uses about 2 watts.'
'Sensitivity of the Cornwall is insane so dynamics are amazing, and my 24 WPC Line Magnetic 219ia uses about 1/4 – 3/4 of a watt to run these to a nice volume for daytime listening. If I want to crank and shake the walls with clean sound, it uses about 2 watts.'
Thanks. 2 watts will work with the Cornwall speakers. 112 tubes would not make enough power per my calculations that are too generous. Perhaps 1 watt. at best.
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Despite its sensitivity I wouldn't dare to say that 2W is "enough" for 3 way speaker without a hearing.
I use 100dB sensitivity speaker with 10W SET ... but it's full range, without crossover.
I use 100dB sensitivity speaker with 10W SET ... but it's full range, without crossover.
Steve Hoffman stated 2 watts blasts the room with Cornwall speakers. Normal listening is 3/4 watt max per Steve Hoffman.
In his forum others use large variety of amplifiers for this speaker, from low (not 2W!) Watt SETs to beefy PP or SS amplifiers.
Other equipments, other rooms, other people with different taste.
The choice is yours.
Other equipments, other rooms, other people with different taste.
The choice is yours.
If you want to use DHTs I'd suggest putting them first, not last. 26 is still good value for instance and better than 112A. If you use a high gain output tube like EL12 or 7591 or a pair of EL84s you can use a number of DHT drivers like 26, 01A, 2P29L, 4P1L, 46, 47. The driver DHT will flavour the sound more than using DHTs in the output stage.
Hey Andy good to hear from you. You been on Audio Asylum for many years. The 26 tube is interesting. Could 26 tube low voltage filament use AC with hum pot? At 180 volts and -13.5 volt grid bias, easy to drive with lots of headroom.
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Never tried 26 with AC. I always use Rod Coleman regulators with DHTs. They sound really good and Rod gives great support.
Andy nailed the tube- 26 tube. It has everything going for it. I operate at 150 volts and push the plate current slightly at 7.5ma with 9 volts bias. It is in the most linear part of the plate curves. Four tubes draw 4.5 watts, I shoud get at least 2,5 watts out per channel. I will try AC filament with hum pots. If hum too much I will use voltage DC regulators. To find a 1.5 volt transformer I will have to buy 10 amp 2.5 volt and remove part of the secondary windings or 1.5 volt- no big deal. I will use JJ E83CC with cathodyne phase splitter and other half of JJ for the preamp. I will buy NOS RCA. The Dynaco Z-565 audio transformer is perfect for PPP 26 tubes. Thanks Andy.
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Choke input power supply for 26 tube. Antek 100va 175 volt transformer. Hammond 15HY choke. 400uF polypropylene filter motor run capacitor 250 volt AC- 350 volt DC. Cree 600 volt rectifier in bridge configuration. Unlike 1N4007 Cree make no noise. AC ripple at 150 VDC. is .05 volts. with all tubes drawing current.
You are very optimistic.
You didn't read my #3 post enough carefully:
"PPP= 8 output tube == 4 very closed pair tube."
I have few bunch of #26 tubes ... maybe I can pick 4 -enough closed- pairs ... but it's not sure.
Buying nowadays for very closed pair IMO is mission impossible.
PPP -if you want to use hundred years old tubes- is difficult course.
You didn't read my #3 post enough carefully:
"PPP= 8 output tube == 4 very closed pair tube."
I have few bunch of #26 tubes ... maybe I can pick 4 -enough closed- pairs ... but it's not sure.
Buying nowadays for very closed pair IMO is mission impossible.
PPP -if you want to use hundred years old tubes- is difficult course.