Erik Mandaville Posted October 24, 2006 Share Posted October 24, 2006 Sure, the words 'high power' and '2A3s' are like oil and water and shouldn't be mentioned in the same sentence. That's okay, I'm going to anyway. I had made some modifications to my Moondogs in order to use them with 300Bs, and the result was better than expected. This past Saturday morning I decided to rewire the filaments for 2.5 volts, and make some other adjustment in order to run my pair of KR2A3s at a higher operating point than I would ever think of doing with our vintage RCAs (which I also like very much). KR2A3 = Transistor in a bottle..........................to some ears, not mine. I had been using the Moth with AVVT meshplates, which is an integrated amp. For the Moondog KR experiment (using my own input/driver modification), I used my quad 6SN7 line-stage. With the new crossovers I built for the Heresies also just installed, the first CD I tried with this was Yo Yo Ma's Bach Cello suites (double CD). The sound brought my wife out of the kitchen, the same way the minibox experiment caught her attention. Having someone who can provide perhaps a little more objectivity is important for me, and I am someone who would rather take advice from a serious music listener for whom electronics and capacitors and resistors is essentially irrelevant -- what matters is the sound and nothing more. I think these amps, with the linestage show below is among the very best two channel sound we have had here. I need to point out I'm far more interested in sound quality at moderate volume levels than I am in driving amps and speakers at auditorium SPLs, and the listening space with have this system in is perfect for it. Fabulous music! Strings are always an important test for me, but every kind of music we played sounded fantastic. Erik Quote Link to comment Share on other sites More sharing options...
Erik Mandaville Posted October 24, 2006 Author Share Posted October 24, 2006 And my preamp: Quote Link to comment Share on other sites More sharing options...
Erik Mandaville Posted October 24, 2006 Author Share Posted October 24, 2006 ...what I need to get is a good rack. The preamp is at the very bottom, with the amps on top (which to me look cool that way, and probably run cooler, too). It's hard for me to bend right now, so I really need to get something where the preamp controls are within easier reach. The one issue I have with my particular Moondogs, is that the epoxy that was originally used to glue down the solder terminal boards inside was either old or incorrectly mixed. I've used old epoxy in the past that didn't set up properly. So, the last boards have now pulled up. I'm going to do this the right way and drill holes for them and use machine screws to hold them down. Fortunately, Welborne Labs now does this (uses screws instead of epoxy) for the terminal boards. Bye, Erik Quote Link to comment Share on other sites More sharing options...
Cody_Mack Posted October 24, 2006 Share Posted October 24, 2006 ..... some modifications to my Moondogs..... ......With the new crossovers I built for the Heresies also just installed..... ......The sound brought my wife out of the kitchen, the same way the minibox experiment caught her attention. Having someone who can provide perhaps a little more objectivity is important for me, and I am someone who would rather take advice from a serious music listener for whom electronics and capacitors and resistors is essentially irrelevant -- what matters is the sound and nothing more. Erik, I am a few steps behind you on the upgrades, but I can relate. 2A3 and Heresy do make beautiful music! What I wants to know is, how do you get your wife interested? Mine is more interested in, who is leading the 'Amazing Race' or who is the latest 'American Idol' Lucky Man! Rick Quote Link to comment Share on other sites More sharing options...
Daddy Dee Posted October 24, 2006 Share Posted October 24, 2006 Erik, The Moondogs look cool and your preamp, too. Thanks for the story about Yo Yo Ma's cello. I bet that is a sweet sound on your setup. Quote Link to comment Share on other sites More sharing options...
jt1stcav Posted October 25, 2006 Share Posted October 25, 2006 A few quick fixes and your Moondogs are back to 2A3 duty...sweet! I'm so glad converting your monoblocks from 300B back to 2A3 was not a permanent thing. Quote Link to comment Share on other sites More sharing options...
Erik Mandaville Posted October 25, 2006 Author Share Posted October 25, 2006 Rick: We have those same shows on here, and just share in each other's hobbies'. She likes tube amps (and good transistor or digital amps) when they make good music; I've hung out with her at hand-made teddy-bear shows, and enjoy seeing the work of people who really enjoy whatever craft they might be interested in. Dee: Thanks! They are still in good shape after all these years. Welborne Labs stuff was built to last. Jim: The back and forth between 300B and 2A3 involves about 20 minutes of work on each amp. That input/driver arrangement I've wanted to try (and eventually did) was just so good with the 300B, I decided to try it with the KR tube, as well. It would actually be straightforward to add a toggle switch to make the change that simple. An amp built around a 5687 driver would probably sound very similar. Erik Quote Link to comment Share on other sites More sharing options...
jt1stcav Posted October 25, 2006 Share Posted October 25, 2006 Jim: The back and forth between 300B and 2A3 involves about 20 minutes of work on each amp. That input/driver arrangement I've wanted to try (and eventually did) was just so good with the 300B, I decided to try it with the KR tube, as well. It would actually be straightforward to add a toggle switch to make the change that simple. An amp built around a 5687 driver would probably sound very similar. That would make for an interesting amp (or monoblocks)...a switch between using higher powered 300Bs and lower powered 2A3s. Has anyone ever made this sort of amp arrangement before? Quote Link to comment Share on other sites More sharing options...
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