Thanks!
I'm using a 12V 30A LED switching supply an 8200uf cap for the heaters and LEDs. It connects with 15 gauge speaker wire and banana plugs.
The high voltage is actually a voltage doubler off of a 120:62-0-62 300VA toroid. Runs through 2 6H chokes in parallel into 3500uf. Then it runs through a female to female 5.5/2.1mm DC power jack. The wire was rated to 300V anyway and so far everything is good. I'd prefer to use screw on DIN connectors though.
Perhaps I should start a thread about this.
I'm in a similar place actually
Mainly because they wire in just like the LM317 would so it's a simple drop in replacement. They're also about $1 CAD a piece on eBay at the moment
I also wire point to point so one heat sink is easier to work around.
Nice. I think you'll be pleased with the result.
Another reason I went with CCS was to try toroidal power transformers as outputs (and because there's no DC mismatch they actually sound damned good).
This was my first integrated amp attempt so it has an 6N1P/6N2P Aikido phono, 6N5P/6N6P Aikido headphone, 6N1P ACF buffer, 6N1P CCDA driver, and a 6N2P doing floating paraphase into the CCS loaded 6P1P tubes biased at 56 ma. 300V B+ in tetrode connection.
The power supply is external. And in this picture almost everything is wired except the RCA's and the switch. Thankfully ethernet cable is pre twisted, there were almost 100 connections to solder!
Oh and the chassis was reclaimed from scrap. That's why it's kind of rough.
Koda
Please start a thread on this! Too interesting and huge not to get it's own dedicated explanation...
What toroids, for instance, did you choose for your outputs?
Please start a thread on this! Too interesting and huge not to get it's own dedicated explanation...
What toroids, for instance, did you choose for your outputs?
Here it is --> http://www.diyaudio.com/forums/tubes-valves/304427-unconventional-integrated-tube-amp.html
I'm fuzzy on it but with a resistor in the cathode and the plate on a common cathode amp the max efficiency in class A is 12.5%, with a CCS it's about %25 and with a choke load it's about %50. I'll look for some technical papers on it and post them when I find them.
EDIT: This applies to single ended triode amplifiers only. If using a triode in push pull you can basically double the efficiency.
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I have fairly much abandoned any efforts with the 6080 family. They can make some really nice amps, but they have issues with resonant instability which seems relatively unsolvable (though unnoticeable unless you have really sensitive speakers).
The main reason though is that its really hard work and massively inefficient to drag a measly 6-7 watts out of them.
My current amp, which has taken pride of place in my main system, has taken all the best bits of my 6080 efforts and applied them to a very cheap double tetrode(QQ03-12). It uses power toroidals as OT but has the innovation of using a SMPS for the heaters and to supply a step up DC to DC booster for the B+. All in all the whole build matches the 6080 amps for less money and more efficiency and produces roughly the same power in a much more compact space.
Toroidals as OT's still rock my boat big time, but big hot low mu finals are just a dead end for me.
Shoog
The main reason though is that its really hard work and massively inefficient to drag a measly 6-7 watts out of them.
My current amp, which has taken pride of place in my main system, has taken all the best bits of my 6080 efforts and applied them to a very cheap double tetrode(QQ03-12). It uses power toroidals as OT but has the innovation of using a SMPS for the heaters and to supply a step up DC to DC booster for the B+. All in all the whole build matches the 6080 amps for less money and more efficiency and produces roughly the same power in a much more compact space.
Toroidals as OT's still rock my boat big time, but big hot low mu finals are just a dead end for me.
Shoog
My next experiment wil use a 12V to 220V 380V booster. I've already used DC-DC boards for a headphone and and line amp. Both have the elegance of running off of a 12V 10A plugin brick, and I've included a cheap Tripath output. Think class A tube OPT headphone with a cheap power stage. I hook it up to my TV because the speakers in it are unusable.
Booster work fantastically. I bought a nice compact 12V SMPS and booster board both for less than £20 direct from China and they have worked flawlessly. I have a large filter cap after them to isolate the power supply from the amp and offer masses of low end punch.
Shoog
The russian 6N13S became my favorite tube of all time, thanks to your threads and experiments regarding the 6080 and toroidal transformers in general. I scored a quad of them NOS for less than $20USD shipped from Ukraine, and I fell in love.
My tube of choice has changed to the 6V6 these days for almost any output stage that needs more than a couple watts, but in all of my comparisons, there was just something magical about the russian 6N13S that I had together, hard to explain. Very low THD, easy enough to drive, and they ROCK with efficient speakers. I could care less about the wasted heat, so long as I can supply the current and voltage that makes them work well. They may be big, hot, behemoths, but they work well.
I found the only issues I ever had with them was using the LM317 as individual bypassed CCS's. Once i went to garter bias and back-to-back bypass caps (with the junction referenced to ground via 1M resistor) they behaved very nicely. I think I was able to squeeze just at 10 watts out of a pair at 200 volts, and -50g1, but they measured poorly. I played with some of the other active biasing methods and never cared for them, either much worse THD, overload recovery issues, or just plain didn't track current worth a damn.
For what it's worth, my reference design for a pair of these guys in push-pull is 165 volt supply, 8k OPT with 4 ohm load on the 16 ohm tap, two stacked 10 watt 330r resistors (-33~ volts bias, 100mA )for the cathodes (remember, garter bias), 1M grid resistors cross coupled to the stacks, and 100nF PIO russian caps (the OD green ones all over ebay) with a 6SL7 concertina/voltage amp stage running off of a 300v supply. I'm planning up a five channel version for my home theater system next...
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My three current user amps are:
-QQ03-12 self splitter with plate to plate feedback from the 12L8GT driver. A nice three valve PP amp with a SE signature and a respectable 6 Watts of output.
-PL84 PP amp in a Tabor clone arrangement. Direct coupled 6AU6 drivers and CCS cathodes. A bit finicity but sounds really nice.
-EL55 SE parafeed spud giving around about 3watts. Very neutral performer and doing main duty on my bedroom system.
Of course all three use CCS bias and toroidals as OT.
Shoog
-QQ03-12 self splitter with plate to plate feedback from the 12L8GT driver. A nice three valve PP amp with a SE signature and a respectable 6 Watts of output.
-PL84 PP amp in a Tabor clone arrangement. Direct coupled 6AU6 drivers and CCS cathodes. A bit finicity but sounds really nice.
-EL55 SE parafeed spud giving around about 3watts. Very neutral performer and doing main duty on my bedroom system.
Of course all three use CCS bias and toroidals as OT.
Shoog
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