joessportster Posted February 18, 2014 Share Posted February 18, 2014 Back injury at work in 2012 which led to: surgery, bankruptcy I was lucky to have all the gear I had, I was able to sell it all and it is what has supported my family till now. We are hoping the end is near Been outta work for 17 months dealing with this, worked for the company and paid into retirement for 8 years and they tell me i have no further benefits, They like to kick a dog when hes down, Things could sure be worse though, We have a roof, and we eat 3 a day, I get to listen to headphones Quote Link to comment Share on other sites More sharing options...
Deang Posted February 20, 2014 Author Share Posted February 20, 2014 Hang in there Joe, I'll check out the headphone section tomorrow night. Quote Link to comment Share on other sites More sharing options...
moray james Posted February 20, 2014 Share Posted February 20, 2014 They also sound pretty amazing with zero feedback. I have a single-ended EL84 (with 12aX7 driver -- the usual companion for this topology) that was among the first amps I used with La Scalas and then Klipschorns about 12 years ago. I am now listening to Lowther PM5A drivers on an open baffle with La Scala bass bins. This little amp is, as mentioned above, a very, very good performer. I also own a single-ended 6V6 stereo amplifier that is as nice, if a bit more bit more powerful. Have fun, these little amps are a blast! Amazing with my Grado headphones, too. gotta love the 6V6 but if you want less microphonics try the 6AQ5 which looks just like the 6BQ5 but which is a miniature 6V6 definitely one of the special audio tubes so is the 6BM8 and the wonderful EL34, SEP's have bass with balls. These ate all fine audio tubes. I love the 2A3 have not spent time with the 45 or 46 so far getting small. Good iron costs a lot. Good for Justin. Best regards Moray James. Quote Link to comment Share on other sites More sharing options...
Deang Posted February 23, 2014 Author Share Posted February 23, 2014 I just read my review again, so I could compare it to Joe's. I noticed that that the main reason I let Dave send it to me was because it had a supposedly nice headphone section. Guess who still hasn't listened to the headphone section. Quote Link to comment Share on other sites More sharing options...
Deang Posted February 23, 2014 Author Share Posted February 23, 2014 Justin's Music Maker, Beyerdynamic t5p, Stone Temple Pilots/Core = "Oh my" So Justin, tell me about the Kenzie. Quote Link to comment Share on other sites More sharing options...
justinsweber Posted February 23, 2014 Share Posted February 23, 2014 Kenzie was the brain child of Tom McNally... I think it goes back even further... Known wildly as the darling circuit. Tubes are 12SL7, 1626... "The US Government VT-137 is the commercial 1626. It was designed as an RF power oscillator for conditions where good frequency stability is important. The operating condition was class C and that explains the high negative grid bias. The valve was only designed to provide short pulses of power in the anode tuned circuit. The circuit itself would then ring and generate sine wave outputs." It was described to me as the baby 300b... I think its a much warmer sound... very akin to 6v6 warmth. As usual I want crazy with the power supply. I used to build this amp with Edcor XSE iron... Seemed nothing was lost... a true feat given the specs of the XSE iron. At this point, the Kenzie is a nice implementation of the Darling circuit with a lot of attention paid to the ground scheme and increased, increased filtering and good transformers. For the full range or Heritage crowd its where a lot of searching could end. My business partner didn't believe me or think it was worth building. We had completed his set of split cornscalas and I brought a DAC with vol control over and a kenzie I built for demoing. In his garage the sound was jaw dropping... and the although only 3/4watt it was loud enough to bring a neighbor and the discontent of his wife. Its not always how many watts, but the quality of the 1st watt. The Kenzie is paired with Iron I think not pretty enough for show up top... but provides the same performance and fidelity that any of my amps do... If it can't to 20-20K... don't use, build or sell it. I am is the process of building a SE Kenzie... Larger crazier power supply, 10H choke, and iron that is insane to use for such little output... The idea being, why not have log-rhythmic over kill. Quote Link to comment Share on other sites More sharing options...
Deang Posted February 23, 2014 Author Share Posted February 23, 2014 If you listen loud out of course of habit, then the quantity of watts is a factor -- but you give up quite a bit in transparency and the sense of immediacy is gone. Depending on how the finances pan out over here, you might be building the second one for me. I noticed there isn't a headphone section, at least not that I can see. Not good. : ) Quote Link to comment Share on other sites More sharing options...
justinsweber Posted February 23, 2014 Share Posted February 23, 2014 I love transformer coupled outputs for headphones... Im told they behave well to difficult impedance issues. I offered before... if you'd like to give the Kenzie a listen for 2 weeks Ill send your way. Quote Link to comment Share on other sites More sharing options...
Deang Posted February 23, 2014 Author Share Posted February 23, 2014 I'm using Beyerdynamic t5p -- the impedance is tweaked for portable devices, 32 ohms, a very easy load for just about anything. Can the Kenzie be outfitted with a headphone section? I think I'm going to start putting some money away while I decide what to do. Don't send me anything else!! I have some other decisions to make too. Right now, I'm knee deep in my own issues related to design and implementation with networks -- and I have to work at getting that sorted out before I'm allowed to have fun again. Quote Link to comment Share on other sites More sharing options...
erik2A3 Posted February 23, 2014 Share Posted February 23, 2014 Add a headphone jack. Take L and R channels off the most suitable output transformer secondary winding. One needs good power supply rejection to avoid objectionalble hum -- directly AC heated triodes aren't as suitable for headphones for that reason. The Darling is a well-known circuit - neat. Quote Link to comment Share on other sites More sharing options...
justinsweber Posted February 23, 2014 Share Posted February 23, 2014 (edited) Yup... ease enough to do. I might consider. The Kenzie/Darling is a real gem. I strongly believe that I should also be able to get the same high quality iron with outputs which will be designed/optimized for phones. Edited February 23, 2014 by justinsweber Quote Link to comment Share on other sites More sharing options...
erik2A3 Posted February 26, 2014 Share Posted February 26, 2014 Moray James : agreed on the 2a3, and would submit a significant part of the "sound" of any output valve can be highly circuit dependent. I have built and experimented with a number of different designs with 300bs, 2a3s, and 45s, in terms of output stage topologies, interstage coupling, etc., and believe that a large proportion of the perceived end-result can be attributed to the design of the circuit itself rather than a general characteristic of the tube or passive parts chosen for its construction. A "better" resistor or capacitor (with the term "better" being subjective at best) will not improve an already compromised or unsatisfactory design. I honestly haven't had many problems with microphonic 6V6s, which is certainly not to say that that problem doesn't exist. I'm referring to my experience. I have to say that in playing around with that family of power tube, I've discovered close relatives I like even more -- the pair of 6K6s that I yanked out of one of my old but still very good 1930s radios being just one example. Quote Link to comment Share on other sites More sharing options...
erik2A3 Posted February 26, 2014 Share Posted February 26, 2014 Justin: You seem to have a very open mind about this! I have no idea about whether you're heating the 1626 with AC or DC, but despite the fact that it's cathode is indirectly heated, it might be worth considering using filtered DC for headphone use. Even tiny amounts of heater-cathode leakage can cause objectionable hum, and headphones may make that issue all the more of a concern. Anyway, nice work...have fun with your projects. Quote Link to comment Share on other sites More sharing options...
joessportster Posted February 26, 2014 Share Posted February 26, 2014 Justin: You seem to have a very open mind about this! I have no idea about whether you're heating the 1626 with AC or DC, but despite the fact that it's cathode is indirectly heated, it might be worth considering using filtered DC for headphone use. Even tiny amounts of heater-cathode leakage can cause objectionable hum, and headphones may make that issue all the more of a concern. Anyway, nice work...have fun with your projects. The SE 84, Justin builds is dead quiet with Headphones at full volume and no music, I have no idea about what voltages he uses to supply what. But he's doing something right Quote Link to comment Share on other sites More sharing options...
justinsweber Posted February 26, 2014 Share Posted February 26, 2014 It’s a work in progress bringing the 1626 to phones... I’ve ordered transformers with 32ohm and 600ohm tapp, should cover almost all needs. If my calc is correct... 750mv SE no feedback... should be worth a listen. As soon as I get it up in prototype... I’ll ask for an audition. Quote Link to comment Share on other sites More sharing options...
joessportster Posted February 26, 2014 Share Posted February 26, 2014 This sounds like fun !!!!!!!, I wish i could control the shake in my left hand it makes it almost impossible to solder large items. I have been wanting to try building an amp for years. From what I see this is a hobby / job that requires steady hands Ps. I would happily give it a listen if you don't get anyone closer Quote Link to comment Share on other sites More sharing options...
erik2A3 Posted February 26, 2014 Share Posted February 26, 2014 joessportser - great! El84 amps, particulalrly single-ended versions, are great with headphones, as is the one I have. My response wasn't really with concern to that tube, however. Quote Link to comment Share on other sites More sharing options...
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