henry4841 Posted August 26, 2020 Share Posted August 26, 2020 (edited) My last tube amplifier build done a few years ago using some Soviet military NOS GU-50 pentode tubes run as SET's. Does not produce as good a square wave as good as some of my other tubes builds but sounds good to me. I do not know who the designer of schematic was. Edited August 26, 2020 by henry4841 1 Quote Link to comment Share on other sites More sharing options...
tube fanatic Posted August 26, 2020 Share Posted August 26, 2020 Those are cool looking tubes Henry! What kind of power are you getting from them? Maynard Quote Link to comment Share on other sites More sharing options...
henry4841 Posted August 26, 2020 Author Share Posted August 26, 2020 I honestly do not remember being it was a few years ago but I want to say in the neighborhood of 5 or 6 watts. Plenty enough for my speakers in my room for sure with good decent bass. Quote Link to comment Share on other sites More sharing options...
henry4841 Posted August 26, 2020 Author Share Posted August 26, 2020 (edited) For those that may be interested in the GU-50 tube. Others compare it to the 300b tube in SE mode. https://jacmusic.com/techcorner/ARTICLES/English/Portraits/GM50/index-GM50-Portraits.html#:~:text=GU50 is one of the most curious tubes to find.&text=Apart from the socket%2C and,you stay below 40Watt continuous. https://en.wikipedia.org/wiki/GU-50 Edited August 26, 2020 by henry4841 Quote Link to comment Share on other sites More sharing options...
MechEngVic Posted August 27, 2020 Share Posted August 27, 2020 They look like tall glass pots with the lids on! Are you going to try to improve the square wave? Quote Link to comment Share on other sites More sharing options...
henry4841 Posted August 27, 2020 Author Share Posted August 27, 2020 (edited) 5 hours ago, MechEngVic said: They look like tall glass pots with the lids on! Are you going to try to improve the square wave? The square wave does not have peaks or ring is just not as good as some of my other tube amplifiers. Using the distortion software Arta the distortion picture looks very good so I did not pursue it further. It may be something to pursue one day when I find the time. I just considered it an exercise in trying to hear what you measure. Edited August 27, 2020 by henry4841 1 Quote Link to comment Share on other sites More sharing options...
lberthelon Posted December 30, 2022 Share Posted December 30, 2022 Would you happen to have the schematic or a link to it? I'd like to build a SE GU5o myself. thank you Quote Link to comment Share on other sites More sharing options...
henry4841 Posted December 30, 2022 Author Share Posted December 30, 2022 Sorry for quality but it is the best I can do due to scanner not working. The schematic is from a Chinese kit I bought on Ebay that I liked so much I decided to build the one shown with better quality parts. Doing a quick google there are others out there. The called for 6N8P is the equivalent of the 6SN7. It has been years since I built it but there does still appear to be a kit and or finished version like the first one I built available on Ebay. Price has really increased over the years though. Defiantly not the same seller so buy at your own risk. The FU-50 is the Chinese clone of the Russian GU-50. https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2047675.m570.l1313&_nkw=Fu50+Vacuum+Tube+Amplifier+Diy+Kit+&_sacat=0 1 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.