seti Posted September 7, 2020 Share Posted September 7, 2020 Just finished this one. My friend drew up the schematic based on what we had on hand. The rectifiers are RCA 816 mercury vapors, power tubes triode wired 1625, and driven by 6J5GT. The 6J5 are half a 6SN7 and I've been collecting them for years... I'll do distortion and power ratings soon. The meters need a little tweaking but sounds ok so far. joined_video_c8d5860632994b51984cb95326861299.MP4 8 1 Quote Link to comment Share on other sites More sharing options...
David Evans Posted September 7, 2020 Share Posted September 7, 2020 Wow. Very nice. Sounds great. 1 Quote Link to comment Share on other sites More sharing options...
OO1 Posted September 7, 2020 Share Posted September 7, 2020 cool amplifier -----really looks like one of a kind ---great work Seti 1 Quote Link to comment Share on other sites More sharing options...
seti Posted September 8, 2020 Author Share Posted September 8, 2020 Just tested the power on this one and it is a little over 1.5wpc. Amazing how little you need with 107db 1w1m horns. 1 Quote Link to comment Share on other sites More sharing options...
jcmusic Posted September 12, 2020 Share Posted September 12, 2020 Hey Seti, Glad to see someone running the 6J5GT tubes. I been running them for a couple years now as a replacement for the 6SN7 tubes in my pre amp. I also run the 6F8G tubes in my amp as drivers for the 45 tubes in my Korneff amp. I would love to talk with you more about the 6J5 tubes... 1 Quote Link to comment Share on other sites More sharing options...
seti Posted September 22, 2020 Author Share Posted September 22, 2020 On 9/12/2020 at 5:28 AM, jcmusic said: Hey Seti, Glad to see someone running the 6J5GT tubes. I been running them for a couple years now as a replacement for the 6SN7 tubes in my pre amp. I also run the 6F8G tubes in my amp as drivers for the 45 tubes in my Korneff amp. I would love to talk with you more about the 6J5 tubes... I buy 6j5gt tubes often. One day I'll make a preamp with 6j5 insteadof 6sn7 preamp. There are lots of 6sn7 schematics out there. Quote Link to comment Share on other sites More sharing options...
henry4841 Posted September 22, 2020 Share Posted September 22, 2020 Wow! Be sure and post picture in my topic of pictures of tube amplifiers. Let more see what excellent work you have done. Also I would like to know more about your build, choice of transformers and what kind of PS section did you choose. Is some of that iron chokes on the PS? Are those big caps motor run ones. Quote Link to comment Share on other sites More sharing options...
seti Posted September 22, 2020 Author Share Posted September 22, 2020 3 hours ago, henry4841 said: Wow! Be sure and post picture in my topic of pictures of tube amplifiers. Let more see what excellent work you have done. Also I would like to know more about your build, choice of transformers and what kind of PS section did you choose. Is some of that iron chokes on the PS? Are those big caps motor run ones. I ain't no expert but I have a friend with 40 year build experience who is helping me. I use big motor run caps in power supplies as I don't want to replace lytics ever. I only use them when I have to. The power transformers and chokes are usually potted. I buy vintage and then painted. The power transformer was from tektronix or paeco as were the chokes. I use two chokes and two big caps. These were pretty high guality. I use PS Designer to dial in power supplies. Then we build to see how close we are. The only thing I'll be changing is adding a 30 second solid state relay so the mercury gets a bit of a warm up instead of manually doing it every time. thanks Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted September 22, 2020 Share Posted September 22, 2020 Very high on the cool meter. Quote Link to comment Share on other sites More sharing options...
henry4841 Posted September 22, 2020 Share Posted September 22, 2020 17 minutes ago, seti said: I ain't no expert but I have a friend with 40 year build experience who is helping me. I use big motor run caps in power supplies as I don't want to replace lytics ever. I only use them when I have to. The power transformers and chokes are usually potted. I buy vintage and then painted. The power transformer was from tektronix or paeco as were the chokes. I use two chokes and two big caps. These were pretty high guality. I use PS Designer to dial in power supplies. Then we build to see how close we are. The only thing I'll be changing is adding a 30 second solid state relay so the mercury gets a bit of a warm up instead of manually doing it every time. thanks I thought that is what the PS section looked like. Old school and it worked in the past so should work now. I have done the same thing on some of my builds years ago. Many say that way improves the sound. Using motor run caps, excellent quality film caps, instead of electrolytic's is always a good thing in my book. Quote Link to comment Share on other sites More sharing options...
seti Posted September 22, 2020 Author Share Posted September 22, 2020 10 minutes ago, henry4841 said: I thought that is what the PS section looked like. Old school and it worked in the past so should work now. I have done the same thing on some of my builds years ago. Many say that way improves the sound. Using motor run caps, excellent quality film caps, instead of electrolytic's is always a good thing in my book. The down side of motor run is size but the upside is they likely won't need to be replaced in our lifetime. I am restoring a Fisher X1000 and it has a few lytics but it is the only thing that fits so that is what I'll use the JJ are pretty good. Quote Link to comment Share on other sites More sharing options...
jcmusic Posted September 23, 2020 Share Posted September 23, 2020 On 9/21/2020 at 10:07 PM, seti said: I buy 6j5gt tubes often. One day I'll make a preamp with 6j5 insteadof 6sn7 preamp. There are lots of 6sn7 schematics out there. Ok great I am curious where do you buy your 6j5 tubes from? I use an adapter with my 6j5 tubes in my pre amp and also with the 6F8G tubes in my amp, works and sounds fantastic!!! Quote Link to comment Share on other sites More sharing options...
seti Posted September 25, 2020 Author Share Posted September 25, 2020 On 9/23/2020 at 5:36 AM, jcmusic said: Ok great I am curious where do you buy your 6j5 tubes from? I use an adapter with my 6j5 tubes in my pre amp and also with the 6F8G tubes in my amp, works and sounds fantastic!!! Various places. I play russian roulett on ebay. I've bought some from Brent Jessie. Then found some in random boxes of tubes. Quote Link to comment Share on other sites More sharing options...
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