My experience with the 6080 variants is that the Winged C 6N13 are the best sounding of the lot. They beat RCA's and Mullards by a very long mile. Anti-soviet prejudice is grossly unfounded in the field of NOS valves.
Shoog
By trade I'm a mechanic. 4th vertebrae is slipped forward 5mm on 5th. My back always hurts!
Check this out; 500 Watts Step UP & Down Voltage Converter Transformer, THG-500 220-240 Volts to 110-120 volts, 110220Volts.com
When was the last time you paid $19.99 for a power transformer?
Check this out; 500 Watts Step UP & Down Voltage Converter Transformer, THG-500 220-240 Volts to 110-120 volts, 110220Volts.com
When was the last time you paid $19.99 for a power transformer?
Agree completely! Soviet tubes can be excellent! The 6P3S is another example of a great 6L6 for cheap (NOT GC) where I get almost 20W in class A tetrode push pull. Sure I run them a bit past the maximum ratings, but I had one set running for 2 years straight except for power failures and they were still pretty strong.
The 6N13S isn't very linear but neither is the average tetrode/pentode... Could make a good sounding amp if you're not expecting miracles.
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From what I've read the average pentode when triode wired can be darn good. The 6AS7 and similar are fun because they are big and they glow nicely. However, I've become of the opinion that they have no other benefits over many other choices. They prefer lower than usual B+, lower than usual output transformer ratios and cook the chassis when run with cathode self bias. There are better choices I think, as already mentioned. Nevertheless, I do like their appearance.
I found this from John Broskie in a Tube Cad article on parafeed.
"Does this make any difference? Sonically, I doubt it. In terms of safety, I prefer the original setup up, as any short between primary winding and the case would be far less dangerous. On the other hand, if there is anything to polarized interconnects, which I certainly believe there is, perhaps having the primary charged up to the B+ voltage is a good idea. More testing is required."
In the first drawing the parafeed cap is between the center tap and ground. This has some advantages. First there isn't any AC signal at the center tap, I think. And second, while it will still block DC current the primary is exposed to DC. And while no DC current is flowing the potential is there. As Broskie writes this might be a good thing. In the second drawing there are two caps between the plates and the primary. This is obviously safer. But it also puts the caps directly in the signal path and removes the DC potential from the primary.
I am inclined to the first example. And I think if the case is insulated from the chassis, it would be safe?
"Does this make any difference? Sonically, I doubt it. In terms of safety, I prefer the original setup up, as any short between primary winding and the case would be far less dangerous. On the other hand, if there is anything to polarized interconnects, which I certainly believe there is, perhaps having the primary charged up to the B+ voltage is a good idea. More testing is required."
In the first drawing the parafeed cap is between the center tap and ground. This has some advantages. First there isn't any AC signal at the center tap, I think. And second, while it will still block DC current the primary is exposed to DC. And while no DC current is flowing the potential is there. As Broskie writes this might be a good thing. In the second drawing there are two caps between the plates and the primary. This is obviously safer. But it also puts the caps directly in the signal path and removes the DC potential from the primary.
I am inclined to the first example. And I think if the case is insulated from the chassis, it would be safe?
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For simple voltage conversion it would work fine, but it provides no isolation if it's an autoformer which makes it dangerous to use as a power supply for an amp.
As for a short to case that's what the fuse is for, right?
> They don't identify it as an autoformer.
It is described for ignorant users. It converts voltage. The "how?" is not relevant to the buyers.
It is clearly a transformer and probably an autotransformer. It looks like a transformer, with extra deep bells for connectors; not some kind of switcher. The cost/weight are a bit low for 500 Watts full transformer but not wrong for 250 Watts (the amount actually converted by a 1:2 autotransformer).
Which is NO good for audio amp power, unless there is another isolation transformer in the line. (Such as powering 240V transformer gear from a 120V line, and a few unlikely side-cases.)
It won't provide extra drama in a power surge. Short-to-case is already too much drama for me; ideally it is well jointed and insulated inside. (But at this price, I would open it to see.)
An interesting option for a non-problem I have. My lights flicker when my well-pump starts. I somehow have a 120V pump on a 120/240V line 500 feet long. The start-up surge is 44 Amps, which causes about 16V drop one side and 8V rise on the other, for a split second. Their 2,000W 240-to-120 job would easily carry the start surge and the 11A run current, wired across the 240V legs, with 4V drop on the 240 and 2V drop on each 120V leg, insignificant. At $74 delivered it is much cheaper than industrial transformers.
It is described for ignorant users. It converts voltage. The "how?" is not relevant to the buyers.
It is clearly a transformer and probably an autotransformer. It looks like a transformer, with extra deep bells for connectors; not some kind of switcher. The cost/weight are a bit low for 500 Watts full transformer but not wrong for 250 Watts (the amount actually converted by a 1:2 autotransformer).
Which is NO good for audio amp power, unless there is another isolation transformer in the line. (Such as powering 240V transformer gear from a 120V line, and a few unlikely side-cases.)
It won't provide extra drama in a power surge. Short-to-case is already too much drama for me; ideally it is well jointed and insulated inside. (But at this price, I would open it to see.)
An interesting option for a non-problem I have. My lights flicker when my well-pump starts. I somehow have a 120V pump on a 120/240V line 500 feet long. The start-up surge is 44 Amps, which causes about 16V drop one side and 8V rise on the other, for a split second. Their 2,000W 240-to-120 job would easily carry the start surge and the 11A run current, wired across the 240V legs, with 4V drop on the 240 and 2V drop on each 120V leg, insignificant. At $74 delivered it is much cheaper than industrial transformers.
I operated my experimental PPP 6AS7 amp in class AB2 with 180V anode supply and 1KCT OPT. Bias current is 80mA per tube (2 triodes) at about -75V fixed bias. Cathode ballast resistors are only 22R. One triode in each bottle typically operates near cutoff at idle, but it's no problem because they share load current nicely when it counts. Overall performance of this amp (breadboard) was exemplary when operating on lab power supplies.
Found this and I think it should work fine. Use the 120 volt secondary as a primary and set if for 240 volt secondary at about 1 amp. I'll have to insulate the connections. I've also found a military surplus 6.3 volt 12 amp filament transformer. I'm thinking with separate B+ and filament transformers I can use two power switches enabling me to power up the filaments first and then the B+.
And I would like to reiterate, I bought four Winged 'C' power triodes for ten bucks each! I think even with the drawbacks of the tube this is a huge advantage.
And I would like to reiterate, I bought four Winged 'C' power triodes for ten bucks each! I think even with the drawbacks of the tube this is a huge advantage.
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I use the similar type of control transformer by Hammond, same 2 x 120 secondaries connected as a 120 primary, and 240V primary serving as secondary in my Lab setup.
I must tell that in this way the trafo gets pretty hot after a day of breadboarding joy, up to 55-65 C though the most of time it stays idle or little-loaded.
I would not recommend to use the control trafos for the amp PSU.
So far the AnTek toroids are unbeatable for a combination of staying cool and having the filaments and a bias tap extras vs the price. You can get them even nicely potted. For your purpose I'd just get 2 x 50Watters, and either parallel them or make it the separate PSU for each channel aka 2 monoblocks in one chassis.
I must tell that in this way the trafo gets pretty hot after a day of breadboarding joy, up to 55-65 C though the most of time it stays idle or little-loaded.
I would not recommend to use the control trafos for the amp PSU.
So far the AnTek toroids are unbeatable for a combination of staying cool and having the filaments and a bias tap extras vs the price. You can get them even nicely potted. For your purpose I'd just get 2 x 50Watters, and either parallel them or make it the separate PSU for each channel aka 2 monoblocks in one chassis.
Thanks for saving me from buying that transformer. I've used many Antek transformers over the years. I've looked through their list and don't seem to be able to find anything that would work. I did find a Hammond toroid the 182J240. Dual primaries and single 240 volt secondary at 940ma. Newark and Mouser have it for less than $80. Heyboer wants $125 for an E core. I like the idea of a separate filament transformer and was planning to use cathode bias.
I'm quite puzzled, as I wouldn't have expected that. Usually a secondary winding has a little bit (some percent) more turns per volts than the primary, in order to compensate for transformer losses. Thus, magnetization current should be expexted to be lower. Perhaps your transformer was faulty?
Best regards!
It seems true about some more turns on secondaries as in the opposite way it gave slightly less than 240V. But, the trafo was brand new when I bought it, and some electrician friend confirmed the Control transformers prone to get that hot. .. industrial application. I later found the detailed specs on it where the high exciting current was mentioned, like 80-100 mA - compare to 5 mA on AnTek toroids.
But that is a concern if you run it straight on 120V, in the Lab Setup most of time it is connected through the variac with less input so not a big deal.
In opposite, the Hammond 266 filament trafos stay almost cold if not loaded.
But that is a concern if you run it straight on 120V, in the Lab Setup most of time it is connected through the variac with less input so not a big deal.
In opposite, the Hammond 266 filament trafos stay almost cold if not loaded.
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