I wound up attaching a 24 pound regulated linear power supply to my little project. Linear power supply wound up being an ancient Lambda LQ 532. I suppose a 3 amp version might have worked just as well.
Amp is already quite wonderful with wall wart. I was a bit skeptical that the linear power supply would improve things, but it did. Some grain lost in upper midrange, better layering, more reveal in the nuances bigger soundstage(it was already quite large and well defined). Surprising things emerge from well trodden musics, even compressed digital. The SK60 is a remarkably liquid and analog performer. I think I might commit heresy and say with the linear power supply, I prefer it to the original SIT 1 and 2 amps I heard, but that's going on memory.
Whouda thought. Sony VFET harvested from blown chassis, put back into an old VFET chassis, with an old linear power supply, and it is my favorite amp now for the midrange ribbon (300Hz to 7Khz). Crazy, since I have a couple of other Pass designs to compete with it.
Since this is my first amplifier build with many strange screw ups along the way, it is an odd journey of beginner's luck. I only burned my fingers about ten times and thought I blew it up about ten times.
Amp is already quite wonderful with wall wart. I was a bit skeptical that the linear power supply would improve things, but it did. Some grain lost in upper midrange, better layering, more reveal in the nuances bigger soundstage(it was already quite large and well defined). Surprising things emerge from well trodden musics, even compressed digital. The SK60 is a remarkably liquid and analog performer. I think I might commit heresy and say with the linear power supply, I prefer it to the original SIT 1 and 2 amps I heard, but that's going on memory.
Whouda thought. Sony VFET harvested from blown chassis, put back into an old VFET chassis, with an old linear power supply, and it is my favorite amp now for the midrange ribbon (300Hz to 7Khz). Crazy, since I have a couple of other Pass designs to compete with it.
Since this is my first amplifier build with many strange screw ups along the way, it is an odd journey of beginner's luck. I only burned my fingers about ten times and thought I blew it up about ten times.
LOL! Looks like junk from an old sci fi movie. Sounds sublime. I'll have to get it organized, solder attachments, and get the top back on the TA4650 chassis. I hope it lasts, been going strong for a couple of months now, seems stable to heat and performance.
Attachments
I closed it up as a finished project. Here it is with its antique linear power supply. A bit of an aberrant monster, but it has some appeal as an antiquarian Phoenix.
It has been working flawlessly for a couple of months now and I haven't not been able to break it with my incompetency. I transferred the power supply SMPS noise card to the little SMPS powering the internal TA 4650 preamp, which itself performs competently as a 15 to 20 db booster, though I prefer to operate it as a current amp for external voltage preamps.
Not many thing you can say decisively in audio that are outside the realm of wishful hearing and superstition, but the linear power supply made the already great SMPS 8 to 10 Nelson Pass watts grainless and ultra dimensional. The SK60 is a liquid and analog performer. I thought this would be a 'nice amp', never remotely expected it would be a giant killer. It is now my preferred amp for my 6 ohm, flat impedance 75 inch midrange ribbons. It has the dimensionality and 'reveal' of 45 or 2A3 flea amps, but with real specular highlights and intensity which those fleas tend to lack.
It has been working flawlessly for a couple of months now and I haven't not been able to break it with my incompetency. I transferred the power supply SMPS noise card to the little SMPS powering the internal TA 4650 preamp, which itself performs competently as a 15 to 20 db booster, though I prefer to operate it as a current amp for external voltage preamps.
Not many thing you can say decisively in audio that are outside the realm of wishful hearing and superstition, but the linear power supply made the already great SMPS 8 to 10 Nelson Pass watts grainless and ultra dimensional. The SK60 is a liquid and analog performer. I thought this would be a 'nice amp', never remotely expected it would be a giant killer. It is now my preferred amp for my 6 ohm, flat impedance 75 inch midrange ribbons. It has the dimensionality and 'reveal' of 45 or 2A3 flea amps, but with real specular highlights and intensity which those fleas tend to lack.
Attachments
I have had my Sony VFET J2S18 amp running flawlessly for a few weeks now and the amp is just sublime. I have a hard time tearing myself away from listening. I am using the Ship of Theseus PS filter into the Ship of Theseus Missouri Front Ends. This gives me a XLR input from my MiniDSP preamp. Driving a pair of ZU Soul speakers, 96 db and an Aperion Sub. The resulting music is transparent, dynamic, with excellent sound stage and separation of the channels. Clarity is amazing. It even sounds great at evening wife approved listening levels. I am in awe of the generosity of Nelson Pass, Mark Johnson, 6L6, Zen Mod, and the whole DYI community for offering this experience into audiophile heaven.
It's fantastic to hear that Missouri + Sony Pch VFET OPS are a joyful combination that gives enormous delight. Good on ya!
Channel separation in that particular arrangement will be excellent, thanks to heavy filtering and dual outputs in the PSFILT, followed by additional (ridiculously heavy) supply filtering per channel on Missouri, followed by textbook ideal supply rejection in the Pch output stage, whose follower has a grounded drain and constant current load.
And on top of all that, you also get the noise rejection bliss of balanced inputs. Very nice.
Channel separation in that particular arrangement will be excellent, thanks to heavy filtering and dual outputs in the PSFILT, followed by additional (ridiculously heavy) supply filtering per channel on Missouri, followed by textbook ideal supply rejection in the Pch output stage, whose follower has a grounded drain and constant current load.
And on top of all that, you also get the noise rejection bliss of balanced inputs. Very nice.
Hey guys, I see where the some are using the dual die and changing P1 R8 back to the ealier VFET build and also changing R1&R2 doubling R1 and shorting R2. All for the P channel. To be clear 2SJ28 and 2SK82 with OS2 boards.
Can I get some confirmation on how to handle this on the N version using dual die? I think I have it, but want to be sure.
Thanks,
JT
Can I get some confirmation on how to handle this on the N version using dual die? I think I have it, but want to be sure.
Thanks,
JT
My P VFET OS2 is working and playing great sound. Some connections are bit precarius because the amp is waiting for the FE (Kitty Hawk). The FE is now my Luminaria. The amp's output is inverted the polarity for negative H2. The absolute phase of the signal is ensured by the inverting output of the Luminaria. When the ZTX957s arrive, the VFET will finally be able to take off.
Thanks to Nelson Pass and everyone who collaborated to make this wonderful project possible.
Thanks to Nelson Pass and everyone who collaborated to make this wonderful project possible.