lighting guy Posted November 20, 2008 Share Posted November 20, 2008 I 've had the good fortune of playing around a bit with Klipsch heritage speakers and tube amps and stumbled into some interesting observations that dispel some of my long-held views on amplification. But first, some back story.... I have a Khorn based stereo system and have been running some different tube amps on it for a couple of years now, with a Blueberry Extreme preamp, with very pleasing results. For amps, I have VRDs, Wright single ended Mono 3.5s and Mono 7s (direct heated 300Bs). Each amp pairing has yielded nice results. I listen mostly to rock/pop and jazz and each amp pairing has its strength and weakness. The VRDs give by far the biggest sound and the SET amps have more relaxed and detailed presentations. A couple of months ago I bought a pair of '78 Cornwalls and refreshed the crossovers with Sonicaps. I put them in my new (and still under construction) man cave, a 19x12 room that I've treated with sound deading materials and am using as a second room for more private listening purposes. At first I installed the BBX and VRDs on the Corns and was ROCKING, mainly using a Marantz 8260 as a source and using CDs. Nice BIG sound! Then I wondered what would happen if I ran the Wright 3.5s direct from the CDP into the speakers, "mainlining" the SET amps with no preamp or attenuation, someting similar to my first experience on my Khorn-based stereo setup in my main listening area. A glorious, pure SET sound poured out, full of tone, detail and image; not as commanding as with the push-pull amps, but sweet all the same. Some CDs were right in the pocket as far as volume, but some were too loud. I listened to this configuration for a couple of weeks, carefully picking out CDs to play, based on their output volume and general sound quality. Tonight I switched out the 2a3 based amps for the 300Bs, a little hesitant with an expectation that the volume and bass output would be too strong without any attenuation from a preamp. I decide to give it a go anyway. To my surprise, the volume was actually LOWER (3 to 6 db less in my estimation), and the attack of the mids and mid-bass was lower as well. Both of the SET monoblocks are from the same manufacturer (Wright), and each amp has premium tubes in it: the 300Bs are Western Electric with Sylvania chrome top 6sn7s and Mullard GZ34s; the 2a3s are RCA grey plates with Tung Sol 6sn7s, and JAN Phillips 5y3s, so the quality of the tubes doesn't seem to be a differentiating point in the amps as far as I can tell. I guess what I'm trying to say is that there are no absolutes in this game. We can only imagine what we will hear from different configurations and make assumptions based upon what we read. I really expected more clear results from the SET amp switching. I thought the 300Bs would be LOUDER, in fact too loud with no attenuation, with more bass. What I got was all little softer and just, well, DIFFERENT. Don't dismiss amps with out listening to them first. Whenever you can, try them in your own system. The results might surprise you! Darrell Quote Link to comment Share on other sites More sharing options...
Coytee Posted November 21, 2008 Share Posted November 21, 2008 Haven't you received the memo? Horns are honky, in your face, shrill, grating, congested and several other things. As for your experiment, [Y] When I had my Khorns, I (accidently) plumbed my cd player into my amps. I don't recall if it was the Wright 2A3's or the Transcendent SE-OTL's I had at the time BUT.... I couldn't figure out why my volume didn't work AND I thought it sounded even better. Maybe the input sensativities of your amps were different?? Quote Link to comment Share on other sites More sharing options...
jacksonbart Posted November 21, 2008 Share Posted November 21, 2008 Should I install high hats or just buy a lamp? Quote Link to comment Share on other sites More sharing options...
michael hurd Posted November 21, 2008 Share Posted November 21, 2008 Amplifiers have different gain structures: One may take 1.2V RMS input to produce full power, others over 2V. In your experiment, you tried two seperate amplifiers that have different gain structures, hence the notable increase in output. Quote Link to comment Share on other sites More sharing options...
NOSValves Posted November 21, 2008 Share Posted November 21, 2008 This is fairly simply to explain... The 2A3 amp has a different input signal voltage to full power spec (Lower) then the 300B amplifier my bet is neither amp was being driven to full power if they were it should of sounded like dung (serious compression). In other words the 300B amp definitely needs more then the output of your CD player to reach full power and so does the 2A3 amp to a lessor degree. The over all results I'm sorry to say are meaningless Don't do this with your VRD's you will get some ear awakening results fast.. The VRD's can be driven by a passive preamp to full power with most CD players without issue. But for reasonable and safe levels you need a preamps attentuation.... Quote Link to comment Share on other sites More sharing options...
lighting guy Posted November 22, 2008 Author Share Posted November 22, 2008 Thanks guys, for your responses. FWIW, I wrote to George Wright about what I'd experienced and he said the gain on the two amps is the same. He posited that the diffence in volume is in the tubes themselves. The 300B requires more drive, some Chinese makes are more sensitive and play louder (for a while). The WE 300Bs must need more gain. Craig, I NEVER would've tried this direct method with your amps! I only did this with the SET amps b/c very early on someone loaned me a pair of Wright 3.5s with a set of attenuators to audition on my Khorns. I figured with the lower sensitivity of the Cornwalls I couldn't be too far off trying this direct method. I like to shake things up sometimes, that's part of the fun of this hobby. Invalid test or not, I learned something. Darrell Quote Link to comment Share on other sites More sharing options...
fini Posted November 22, 2008 Share Posted November 22, 2008 Darrell, You've got some nice toys to play with! Hmm, maybe we should think about another Bay Area thang... Quote Link to comment Share on other sites More sharing options...
lighting guy Posted November 22, 2008 Author Share Posted November 22, 2008 Fini, absolutely! I was sad that the last get-together fell through. D Quote Link to comment Share on other sites More sharing options...
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