Last weekend during the evening I had just turned my stereo on in order to let everything warm up before my listening session. All of a sudden, a big electrical storm hit. Before I could run downstairs to power down my gear, a big bolt of lightning lit up the sky and we lost power for a couple of seconds. I knew that meant that all of my gear had powered down and was now powering up. I ran downstairs and shut everything down. After the storm had passed through, I powered everything back up again. When I did, I noticed that my amp was making some popping noises through my right channel speaker.
The next day I flipped my Jadis on its side and removed the bottom cover in order to check the bias and health of my output tubes. When I was checking the bias, I found I had one dead output tube in the right channel. Bummer. I had just replaced all of the output tubes last June, and when you are buying 12 KT-88 tubes at once, that’s almost $800. Because of the wacky bias scheme that Jadis uses on the Defy 7 MKII, you only have one bias pot for each bank of 3 tubes. That means the tubes have to really be matched carefully. There are only two sources I really trust to match output tubes, and that is Upscale Audio and RAM Labs. Because of the bias scheme and the fact that the tubes had been in there since last June, I went ahead and bought 3 matched tubes from Upscale Audio so I would know they were all matched.
Not to get sidetracked here, but for anyone who owns or is contemplating owning a Defy 7, I will give you a little advice. When you are setting the bias, do not unplug your interconnects from your amp and leave the Jadis inputs un-terminated. I learned this lesson the hard way. I could not get the bias to adjust higher than 3.1v DC on any bank of tubes. When I turned the bias pot up to increase the voltage, my Fluke 77 meter would read “OL” which of course stands for overload and would normally mean you have your meter on the wrong range (set too low) or you have a short. I shot Tomex a PM to ask him what he thought was going on and he was as bum-fazzled as I was. Tom also commented on the wacky bias scheme that Jadis uses and I’m in total agreement. I like to see a bias pot for each output tube, and it should be easily accessed from the outside of the amp with test points that are also accessed from outside of the amp. I really don’t enjoy having to flip a 100lb amp on its side, remove the bottom cover, and then have to measure voltage from one side of a fuse on each output tube to ground and sticking a screwdriver into each of the bias pots while being careful not to come into contact with any high voltage. It’s not a job for the timid or weak. Anyway, the cause of my bias issue was I had unplugged the interconnects from the amp before I flipped it onto its side and left the inputs un-terminated and that was causing some instability in the amp. As soon as I plugged the interconnects back in and powered it back up, I was able to set the bias just fine.
Which now leads me to the next part of the story. While I was waiting for the tubes to show up, I got out my old trusty Phase Linear 400 Series II amp and hooked it up so I would have some music to listen to. I bought the Phase Linear from a local repair shop in Bloomington. It’s run by an older Greek gentleman who is really good at fixing any audio gear. I was in his shop to have my Teac 4 track worked on and I spotted the Phase Linear out of the corner of my eye. Thinking this could possibly make a nice back-up amp for emergency use, I bought it. He had just gone through it and replaced the main power supply filter caps with larger value caps which he assured me gave it better bass punch. I was just glad to know it had new filter caps because they are time bombs after 20 years.
So I hooked up the Phase Linear and powered on the system. I went ahead and fired up the digital music server/computer to let everything cook. Ever since I downloaded Foobar a couple of weeks ago, my digital has never sounded better as I commented on in another thread. Well, now it even sounded better still. The bottom end is much better which shouldn’t come as a surprise, but I wasn’t prepared for how good it sounded from top to bottom, and this was on digital no less. I just kept shaking my head and thinking there is no way an old SS amp should sound this good. Clean, quick, transparent, and with an overall purity I just didn’t think was possible from SS. This little amp is rated at a little over 200 watts at 8 ohms and it sounds like it has a 1000 watts. I previously owned a Pass Labs X-250 which is an impressive looking beast if you like audiophile approved thick face plates that are layered and have the Cyclops meter eyeball underneath all the layers. I hated that amp. Myles described it best in two words, “thin and wimpy.” The Pass Labs is a huge amp that weighs at least twice what the Phase Linear weighs and of course is a much newer design. If I didn’t know better, I would have sworn the Pass Labs had 25 watts per channel, not 250. I sold the Pass Labs amp because I thought it was a cruel joke and it made me think SS sounded worse than I had remembered.
So, even though I had my Jadis fixed and the bias set correctly, I didn’t bother to put it back into my system for last night’s listening session. That would normally never happen. I wanted to listen another night to the Phase Linear to see if I was dreaming about how good I thought the system sounded with the Phase Linear in it or did it really sound that good. The answer is, it really sounds that good and that is messing with my core belief system. With the addition of Foobar and the Phase Linear, my digital music sounds really good for the first time. I can accept it and appreciate it. Of course I still love my tapes and LPs.
The bottom line is that I’m feeling a little conflicted here at the moment. I need to put the Jadis back into the system, but it won’t be tonight. I still have more conclusions that need to be drawn.
The next day I flipped my Jadis on its side and removed the bottom cover in order to check the bias and health of my output tubes. When I was checking the bias, I found I had one dead output tube in the right channel. Bummer. I had just replaced all of the output tubes last June, and when you are buying 12 KT-88 tubes at once, that’s almost $800. Because of the wacky bias scheme that Jadis uses on the Defy 7 MKII, you only have one bias pot for each bank of 3 tubes. That means the tubes have to really be matched carefully. There are only two sources I really trust to match output tubes, and that is Upscale Audio and RAM Labs. Because of the bias scheme and the fact that the tubes had been in there since last June, I went ahead and bought 3 matched tubes from Upscale Audio so I would know they were all matched.
Not to get sidetracked here, but for anyone who owns or is contemplating owning a Defy 7, I will give you a little advice. When you are setting the bias, do not unplug your interconnects from your amp and leave the Jadis inputs un-terminated. I learned this lesson the hard way. I could not get the bias to adjust higher than 3.1v DC on any bank of tubes. When I turned the bias pot up to increase the voltage, my Fluke 77 meter would read “OL” which of course stands for overload and would normally mean you have your meter on the wrong range (set too low) or you have a short. I shot Tomex a PM to ask him what he thought was going on and he was as bum-fazzled as I was. Tom also commented on the wacky bias scheme that Jadis uses and I’m in total agreement. I like to see a bias pot for each output tube, and it should be easily accessed from the outside of the amp with test points that are also accessed from outside of the amp. I really don’t enjoy having to flip a 100lb amp on its side, remove the bottom cover, and then have to measure voltage from one side of a fuse on each output tube to ground and sticking a screwdriver into each of the bias pots while being careful not to come into contact with any high voltage. It’s not a job for the timid or weak. Anyway, the cause of my bias issue was I had unplugged the interconnects from the amp before I flipped it onto its side and left the inputs un-terminated and that was causing some instability in the amp. As soon as I plugged the interconnects back in and powered it back up, I was able to set the bias just fine.
Which now leads me to the next part of the story. While I was waiting for the tubes to show up, I got out my old trusty Phase Linear 400 Series II amp and hooked it up so I would have some music to listen to. I bought the Phase Linear from a local repair shop in Bloomington. It’s run by an older Greek gentleman who is really good at fixing any audio gear. I was in his shop to have my Teac 4 track worked on and I spotted the Phase Linear out of the corner of my eye. Thinking this could possibly make a nice back-up amp for emergency use, I bought it. He had just gone through it and replaced the main power supply filter caps with larger value caps which he assured me gave it better bass punch. I was just glad to know it had new filter caps because they are time bombs after 20 years.
So I hooked up the Phase Linear and powered on the system. I went ahead and fired up the digital music server/computer to let everything cook. Ever since I downloaded Foobar a couple of weeks ago, my digital has never sounded better as I commented on in another thread. Well, now it even sounded better still. The bottom end is much better which shouldn’t come as a surprise, but I wasn’t prepared for how good it sounded from top to bottom, and this was on digital no less. I just kept shaking my head and thinking there is no way an old SS amp should sound this good. Clean, quick, transparent, and with an overall purity I just didn’t think was possible from SS. This little amp is rated at a little over 200 watts at 8 ohms and it sounds like it has a 1000 watts. I previously owned a Pass Labs X-250 which is an impressive looking beast if you like audiophile approved thick face plates that are layered and have the Cyclops meter eyeball underneath all the layers. I hated that amp. Myles described it best in two words, “thin and wimpy.” The Pass Labs is a huge amp that weighs at least twice what the Phase Linear weighs and of course is a much newer design. If I didn’t know better, I would have sworn the Pass Labs had 25 watts per channel, not 250. I sold the Pass Labs amp because I thought it was a cruel joke and it made me think SS sounded worse than I had remembered.
So, even though I had my Jadis fixed and the bias set correctly, I didn’t bother to put it back into my system for last night’s listening session. That would normally never happen. I wanted to listen another night to the Phase Linear to see if I was dreaming about how good I thought the system sounded with the Phase Linear in it or did it really sound that good. The answer is, it really sounds that good and that is messing with my core belief system. With the addition of Foobar and the Phase Linear, my digital music sounds really good for the first time. I can accept it and appreciate it. Of course I still love my tapes and LPs.
The bottom line is that I’m feeling a little conflicted here at the moment. I need to put the Jadis back into the system, but it won’t be tonight. I still have more conclusions that need to be drawn.