specialidiot Posted March 11, 2009 Share Posted March 11, 2009 I'm building a 245 powered SET and I just want a reality check. It seems that my '78 Cornwalls (Crites tweets, updated XO's) should mate up well. I'm pleased with how they sound with my Bottlehead SEX amp. Has anyone experienced this combination? Quote Link to comment Share on other sites More sharing options...
hammertop Posted March 11, 2009 Share Posted March 11, 2009 Not really, as far as set-up, but i have not heard anything that was bad on a corn Enjoy! Quote Link to comment Share on other sites More sharing options...
Dflip Posted March 11, 2009 Share Posted March 11, 2009 4 watts on a K-horn should work, on a Cornwall? I guess it depends on how load you want to listen to your music. It should sound very good at low to mid volumes, if you want to crank it up, well... 15 - 20 watts would make it more than loud. Quote Link to comment Share on other sites More sharing options...
db101 Posted March 12, 2009 Share Posted March 12, 2009 I never run out of steam with my 2A3 monoblocks on my vintage Cornwalls, and way prefer the sound of the 2A3's over my 100 watt KT88 PP mono's. Quote Link to comment Share on other sites More sharing options...
Coytee Posted March 13, 2009 Share Posted March 13, 2009 heh heh.... it's all about perspective and what your end game is. I recently tried a pair of Quad II's on my HF horn alone (biamping). I think the Quad II's have about 15 watts? and they were pulling duty from 450hz on up. Quickly ran out of steam for me. I had some 4 watt SE-OTL's on my Khorns and though they're probably the sweetest amps I've yet heard, 4 watts simply didn't cut the mustard. Was 100% fantastic though for what I'd call 'dinner music' levels. Perhaps even a bit toe tapping volume, but certainly not 'loud'. So, it's all about your final goal and how you listen to them. Quote Link to comment Share on other sites More sharing options...
mike stehr Posted March 13, 2009 Share Posted March 13, 2009 heh heh.... it's all about perspective and what your end game is. I recently tried a pair of Quad II's on my HF horn alone (biamping). I think the Quad II's have about 15 watts? and they were pulling duty from 450hz on up. Quickly ran out of steam for me. I had some 4 watt SE-OTL's on my Khorns and though they're probably the sweetest amps I've yet heard, 4 watts simply didn't cut the mustard. Was 100% fantastic though for what I'd call 'dinner music' levels. Perhaps even a bit toe tapping volume, but certainly not 'loud'. So, it's all about your final goal and how you listen to them. Well, it's obvious that the OP isn't too concerned about loudness factor, because he seems happy with the SEX amp. It's around a 2 watt per channel amp, which uses 6DN7/6EM7/6EA7. Television tubes for vertical or horizontal amplifier uses, I suppose. A 45 single-ended triode amp would be about the same wattage. But a 45 tube has a euphonic sound to it, which may be more enjoyable....one would have to find out...... My 2A3 SET amp sounds great on my Cornwalls, which uses 6EA7 for driver tubes. I'm currently breadboarding a circuit, to try 71A. It'll be about 3/4th's a watt per channel.........might be a little light for Cornwall, but shouldn't be bad for LaScala.... Quote Link to comment Share on other sites More sharing options...
specialidiot Posted March 13, 2009 Author Share Posted March 13, 2009 Thanks all, for your comments and insight. Yes I'm running my Cornwalls with my SEX amp, flea powered as it may be. I think the combination is stunning. I've been wanting to build a SET using 300b's or 45's, or maybe even 2A3's for quite a while. So when a nice pair of 45's became available I thought I'd go for it. I think I'm going to like it fine, what's the worse that can happen, right? Quote Link to comment Share on other sites More sharing options...
mike stehr Posted March 15, 2009 Share Posted March 15, 2009 A rather elaborate breadboard with DC heating for the 71A's. 6SL7's driving 71A's. Sounds rather good with the junk midranges running 140 volts on the DC supply, at 30 milliamps. A National Union and a RCA/Cunningham 71A. The NU 71A was saved from the garbage, and tests over 100%. The RCA/Cunningham is around 90%. The tag on the tube shows date sold, 12/4/35...... Quote Link to comment Share on other sites More sharing options...
JL Sargent Posted March 15, 2009 Share Posted March 15, 2009 Hey Mike, as dad would say "looks like something you put together from the midnight autoparts" Absolutely, the 45 Set should sound great with the high eff. Corns. Im running my little Maggie 5wattish SET into the top half of an active 2 way. Sounds fantastic. Quote Link to comment Share on other sites More sharing options...
mike stehr Posted March 15, 2009 Share Posted March 15, 2009 Hey Mike, as dad would say "looks like something you put together from the midnight autoparts" Absolutely, the 45 Set should sound great with the high eff. Corns. Im running my little Maggie 5wattish SET into the top half of an active 2 way. Sounds fantastic. Yeah, breadboarding makes for quite a homely mess. But it's a quick way to listen to a circuit of interest. I had a pair of nice GE JAN-CG-6SL7's. I found this schematic: http://www2u.biglobe.ne.jp/~tossie/71ASE-E.html#circuit-fig And a couple days and I'm up and running. I'm using a Heathkit tube PS, for B+ and heater voltage for 6SL7. The 71A's are heated with these little Xentec brand DC power supplies. 2-4 volts @ 3amps. They seem to be nice and stable at 5 volts heating the 71A's, which is only 25 milliamps per tube, IIRC. The 71A bypass caps are a 22uF Solen metal poly strapped across some NOS Sprague "Chlorinal" 10uF 600 volt oil caps. I just lashed this mess up to my LaScalas. It sounds rather nice, and rather interesting what three fourths of a watt tube can do. With no filament growl.......a triode with no fridge growl in the background.....I'm not used to that.... Big and lush, good deep bass, and excellent midrange. It may not get as loud as a Magnavox single-ended pentode amp, but we're talking single-ended triode sound. While single-ended 6BQ5 can sound great to me on my LaScalas, there is a certain sharpness with SEP 6BQ5. I don't find it objectionable, but there is more of a larger open sound with triodes, even the lowly 71A. But I live small place, and it does run out of steam. I do get to rather good moderate levels, good enough for me. The tone with LaScala is nice.... Quote Link to comment Share on other sites More sharing options...
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