LucasB Posted April 21 Share Posted April 21 Another pick up of mine from this weekend was just something I couldn't resist! This gorgeous Trio W-45 amplifier was just too good looking to pass up. I do not have any experience with tube amps either so for the price (and expected repair costs) I want to get it back up and running. They also go under the Hamlin brand. It currently turns on and all tubes glow aside from one - the 5AR4 which looks a bit trashed and has white flakes inside the tube - but does not produce any sound other than a bit of a hum through the speakers. The speakers definitely work with other amps. I have tried all manner of speaker wiring configurations and have tested what I could understand with a multimeter but that's about the limit of my very very basic electrical knowledge. I have all the tube model numbers but don't know if I should go ahead and order all new tubes and see if that helps or just send the whole unit into a specialist. I am in way over my head. Can anyone recommend someone who could take a look at this in the Melbourne area without me having to sell a kidney? Thanks! 2 1 Link to comment Share on other sites More sharing options...
muon* Posted April 21 Share Posted April 21 The 5AR4 is a valve rectifier. Best to have someone knowledgeable look it over before playing with it. 1 Link to comment Share on other sites More sharing options...
LucasB Posted April 21 Author Share Posted April 21 Absolutely - as soon as I opened it up I knew I was in over my head! Thanks. 1 Link to comment Share on other sites More sharing options...
muon* Posted April 21 Share Posted April 21 Inside underneath there are likely caps that need to be replaced, along with the electrolytic caps doing PS duties. 1 Link to comment Share on other sites More sharing options...
xlr8or Posted April 21 Share Posted April 21 (edited) I have 2 Trio W45A's. Your one looks in mint condition. As @muon* shared it's best to have the caps inside changed. Also, just letting you know that you can still get parts for these from Yahoo Aleado in Japan. The tube configuration is 4 x EL84 tubes in PP configuration. 2 EL84 tubes per channel. 4 x 12AX7 and 2 x 12AU7 tubes. I think from memory 2 of the 12AX7 tubes are used in the phono stage section of the amp. DC B+ to the EL84 is provided by the 5AR4/GZ34 tube. Edit: The 12AU7 tube is the input tube which then goes to the 12AX7 tube as the driver tube for each EL84 PP pair. This tube configuration is repeated in the other channel. Edited April 21 by xlr8or 2 1 Link to comment Share on other sites More sharing options...
LucasB Posted April 21 Author Share Posted April 21 11 hours ago, xlr8or said: I have 2 Trio W45A's. Your one looks in mint condition. As @muon* shared it's best to have the caps inside changed. Also, just letting you know that you can still get parts for these from Yahoo Aleado in Japan. The tube configuration is 4 x EL84 tubes in PP configuration. 2 EL84 tubes per channel. 4 x 12AX7 and 2 x 12AU7 tubes. I think from memory 2 of the 12AX7 tubes are used in the phono stage section of the amp. DC B+ to the EL84 is provided by the 5AR4/GZ34 tube. Edit: The 12AU7 tube is the input tube which then goes to the 12AX7 tube as the driver tube for each EL84 PP pair. This tube configuration is repeated in the other channel. Thanks mate! If the tubes are glowing, is that any indication whatsoever that they’re still good or can they glow and still need replacing? I presume it’s the latter. It’s in pretty damn good shape - there is a bit of rust on the top lid but not much at all. Link to comment Share on other sites More sharing options...
xlr8or Posted April 21 Share Posted April 21 37 minutes ago, LucasB said: Thanks mate! If the tubes are glowing, is that any indication whatsoever that they’re still good or can they glow and still need replacing? I presume it’s the latter. If all the tubes are glowing then the heaters are working for each tube, which is a good sign. I'd be inclined to not change them until I've heard the unit and am sure they need changing. You can always get the tubes tested to be sure. Is the rectifier working with those small internal white flakes you mentioned previously? Are you able to share any close up photos of the rectifier and the white flakes? 1 Link to comment Share on other sites More sharing options...
muon* Posted April 21 Share Posted April 21 1 Link to comment Share on other sites More sharing options...
LucasB Posted April 21 Author Share Posted April 21 1 hour ago, xlr8or said: If all the tubes are glowing then the heaters are working for each tube, which is a good sign. I'd be inclined to not change them until I've heard the unit and am sure they need changing. You can always get the tubes tested to be sure. Is the rectifier working with those small internal white flakes you mentioned previously? Are you able to share any close up photos of the rectifier and the white flakes? I don’t believe that it is glowing but I’ll have another look at it after work and get some better photos. The white flakes appear to be chunks of the white powder at the top of the tube. Excuse my dirty tradie fingernails! Link to comment Share on other sites More sharing options...
ENIGMA Posted April 21 Share Posted April 21 42 minutes ago, LucasB said: I don’t believe that it is glowing but I’ll have another look at it after work and get some better photos. The white flakes appear to be chunks of the white powder at the top of the tube. Excuse my dirty tradie fingernails! The getter has changed colour which shows the tube is finished as air has gotten in. The Trio is a nice amp. 1 1 Link to comment Share on other sites More sharing options...
LucasB Posted April 22 Author Share Posted April 22 2 hours ago, ENIGMA said: The getter has changed colour which shows the tube is finished as air has gotten in. The Trio is a nice amp. Thank you! Is it worth getting a replacement and seeing if the unit outputs sound or is there no point unless the caps are all changed? I would love to hear it through my Toshiba s30’s! Link to comment Share on other sites More sharing options...
RCAJack Posted April 22 Share Posted April 22 I’d suggest you don’t chance it by replacing that dead rectifier valve. A tech will likely use a dim bulb tester and variac to bring the amp to life gently. Just plugging it can cause damage and smoke if there are shorts or other issues. What a great looking amp though! 1 Link to comment Share on other sites More sharing options...
LucasB Posted April 22 Author Share Posted April 22 37 minutes ago, RCAJack said: I’d suggest you don’t chance it by replacing that dead rectifier valve. A tech will likely use a dim bulb tester and variac to bring the amp to life gently. Just plugging it can cause damage and smoke if there are shorts or other issues. What a great looking amp though! Thanks. I don’t think watching the Fallout series on tv helped me resist the styling of it, at all! It’s very cool. I’ve read good things about Open Ear Audio so might get in touch with them to take a look at it and give me a quote. Thanks everyone for your help! I’ll be sure to update. 2 Link to comment Share on other sites More sharing options...
ENIGMA Posted April 22 Share Posted April 22 I saw one of these amps about 20 years ago, very nice sound. 2 Link to comment Share on other sites More sharing options...
xlr8or Posted April 22 Share Posted April 22 9 hours ago, LucasB said: Thank you! Is it worth getting a replacement and seeing if the unit outputs sound or is there no point unless the caps are all changed? I would love to hear it through my Toshiba s30’s! Yes, buy this and give it a go. My 2 were in a far worse condition than yours and they appeared to work. They just need some TLC to bring them up to speed. https://www.ebay.com.au/itm/196342306750 1 Link to comment Share on other sites More sharing options...
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