TJIann Posted January 26, 2015 Share Posted January 26, 2015 (edited) So, I'm starting to look around at stereo tube power amps in the $1.5K or less range (see previous post). This would drive my Cornwall II (or alternatively my Heresy Is). Anyway, I've been talking with Justin at AmpsandSound and have been considering his Stereo 15. My only reservation is the EL84 tubes. Here's why. I have owned many guitar tube amps in the last few years. I've never cared for any of them where the power tubes were EL84s. The ones I love usually have EL34 power tubes, or 6L6s. That said, it may very well be a different ball game with stereo amps, I just don't know as I have never owned one. Is it just primarily a power difference, or is the tone/sound that much different for music through EL84s vs. say EL34s? I do know that I want at least 15 watts output, maybe as much as 30 or so. I'm sure I'm opening up a can of worms to discuss tube brands, matching, etc. But what the heck. Just looking for your all's take. Thanks. Tim Edited January 26, 2015 by TJIann Quote Link to comment Share on other sites More sharing options...
Dr Morbius Posted January 26, 2015 Share Posted January 26, 2015 I haven't heard my Cornscala's through EL84's. But right now I'm hearing them with an H.H. Scott 272 amp which has EL34's and it's like if heaven had an audiophile section - this is thee system to have! 1 Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted January 26, 2015 Share Posted January 26, 2015 The Stereo 15 on Cornscallas sounds really nice. Good bottom end too. 1 Quote Link to comment Share on other sites More sharing options...
TJIann Posted January 26, 2015 Author Share Posted January 26, 2015 When it comes to sound quality, the tube type is one of the least important contributors to the final sound. In order of importance, I would rate it like this: 1. Circuit topology - that means such things as class of operation, push pull versus single ended, balanced versus unbalanced phase splitters, feedback and so on. This is where the magic happens. 2. Output transformers - quality here makes a very big difference in smoothness and extended response. 3. Tubes - from input to output, these are a bit like spices in a soup. They can flavor the sound in subtle ways, but nothing like the magnitude of change in #1 4. Power Supply - this is really covered in #1, but it's fair to mention it separately too 5. Caps and other parts. Less spice than #3, but still detectable. Amp designers put their BS&T into #1 and #2. Often the rest is a crap shoot. Makes sense on the tubes now that I think about the very different situations. For guitar amps its typically about varying levels of tube saturation to get that perfect overdriven tone. For stereo its about clean headspace....avoiding distortion. Hence, tube type should not matter too much. Quote Link to comment Share on other sites More sharing options...
Jim Posted January 26, 2015 Share Posted January 26, 2015 Tim, I would also ask him if you can use a separate tube for it. I've seen a bunch of posts on that amp from him with people really liking it the way it is. Quote Link to comment Share on other sites More sharing options...
justinsweber Posted January 27, 2015 Share Posted January 27, 2015 Hey guys, thanks for the kind words. Here's some of my thoughts about el84s versus EL 34's. I don't like el34s. I do like 6ca7 which mimics as 6l6 in sonic signature. El84s represent a fantastic tube for Hifi use. Moderate power, quite, can take a beating, lasts a long time and able to be sourced as NOS without a mortgage. My Stereo 15 was built with close colab station from Shannon parks. It's largely a st35 with major enhancements made by me. These include a huge, low dcr power supply with large choke filtering. The amp is cathode biased which is a older approach to regulation and thusly a more classic tube sound. My twist is crazy large power supply and filtering providing for quite operation. The iron used is wound by transcendar on spec for me. It's under rated and performs well enough that the circuit is the limiting factor. I liken the sound to a 6l6 with bass. For those thinking about Amps and needing to be cost contious, triode electronics stereo 35 or better yet stereo 70 are well though solid performing kits. I don't do stereo el34 amp because I think so highly of the stereo 70 kit offered. It's fantastic and will provide 35watts if hard to beat sound. In my mind it's the best el34 based stereo amp. Now in mono blocks there are some other choices ;-). Quote Link to comment Share on other sites More sharing options...
mikebse2a3 Posted January 27, 2015 Share Posted January 27, 2015 If the amps are built to equal standards my preference is the EL84 over the EL34. Of all the EL34 amps that I've owned or listened to (for a reasonable length of time to develop an opinion about) that I would be very happy to live with long term is the Marantz 8B. miketn 1 Quote Link to comment Share on other sites More sharing options...
analogman Posted January 27, 2015 Share Posted January 27, 2015 (edited) When it comes to sound quality, the tube type is one of the least important contributors to the final sound. In order of importance, I would rate it like this: 1. Circuit topology - that means such things as class of operation, push pull versus single ended, balanced versus unbalanced phase splitters, feedback and so on. This is where the magic happens. 2. Output transformers - quality here makes a very big difference in smoothness and extended response. 3. Tubes - from input to output, these are a bit like spices in a soup. They can flavor the sound in subtle ways, but nothing like the magnitude of change in #1 4. Power Supply - this is really covered in #1, but it's fair to mention it separately too 5. Caps and other parts. Less spice than #3, but still detectable. Amp designers put their BS&T into #1 and #2. Often the rest is a crap shoot. I do not know what the word is you intended to use, but as for your item #1 that is NOT the definition of circuit topology. This statement is not only not true but inane: "When it comes to sound quality, the tube type is one of the least important contributors to the final sound." (I am assuming we are talking output devices here) Edited January 27, 2015 by analogman Quote Link to comment Share on other sites More sharing options...
justinsweber Posted January 27, 2015 Share Posted January 27, 2015 Ive never gotten the chance at a Marantz 8B. I would love to hear though. I build some Dynaco MKIV I loved a great deal too... Id say the MKIV was a wholy different animal compared to the ST70. Quote Link to comment Share on other sites More sharing options...
russ69 Posted January 27, 2015 Share Posted January 27, 2015 The EL-34 can produce about twice the power of an EL-84, however they both sound very nice. It's more a question of how much power you need, with most EL-34 amps making more power. 1 Quote Link to comment Share on other sites More sharing options...
Guest David H Posted January 27, 2015 Share Posted January 27, 2015 I really like the EL-84 (Poor mans 300b). Dave Quote Link to comment Share on other sites More sharing options...
juniper Posted January 27, 2015 Share Posted January 27, 2015 If the amps are built to equal standards my preference is the EL84 over the EL34. Of all the EL34 amps that I've owned or listened to (for a reasonable length of time to develop an opinion about) that I would be very happy to live with long term is the Marantz 8B. miketn I have what I have heard is the "poor mans 8b" a pilot sa260 , it has stomped every combo I have tried, around 25 well regarded amps including a pair of Atsah monoblocks. The balance is so nice and bass has a lot of clean fast slam... Quote Link to comment Share on other sites More sharing options...
tube fanatic Posted January 27, 2015 Share Posted January 27, 2015 (edited) When it comes to sound quality, the tube type is one of the least important contributors to the final sound. In order of importance, I would rate it like this: 1. Circuit topology - that means such things as class of operation, push pull versus single ended, balanced versus unbalanced phase splitters, feedback and so on. This is where the magic happens. 2. Output transformers - quality here makes a very big difference in smoothness and extended response. 3. Tubes - from input to output, these are a bit like spices in a soup. They can flavor the sound in subtle ways, but nothing like the magnitude of change in #1 4. Power Supply - this is really covered in #1, but it's fair to mention it separately too 5. Caps and other parts. Less spice than #3, but still detectable. Amp designers put their BS&T into #1 and #2. Often the rest is a crap shoot. I do not know what the word is you intended to use, but as for your item #1 that is NOT the definition of circuit topology. This statement is not only not true but inane: "When it comes to sound quality, the tube type is one of the least important contributors to the final sound." (I am assuming we are talking output devices here) I may as well throw my $.02 in here and say that I don't like the EL84 at all (but have used its analogue, the 6GK6, when pressed by someone). Regarding Mark's points: 1) Let's ignore the definition of "topology." I completely agree with the assertions here! 2) No question about this. 3) Completely agree once again. I can vary operating parameters and make many tubes sound almost identical (I say almost because, with auditory memory being so short, it's impossible to be exact). 4) Definitely a factor although in single ended amps, which vary so little in their DC current draw, a huge p/s is unnecessary and creates unwarranted expense. If the ripple is .003%, dropping it to .002% is a waste of time and money (with all due respect to Justin). 5) The least important factor to me. I have never been convinced that a $50 coupling cap sounds any different from my standard CDE DME series caps for $1. Same for "designer" resistors. The 15 cent metal films which I use are as good as anything else. That's my take, fwiw! Maynard Edited January 27, 2015 by tube fanatic Quote Link to comment Share on other sites More sharing options...
analogman Posted January 27, 2015 Share Posted January 27, 2015 (edited) Some of the more easily found vintage 6BQ5 amps out there can be sublime as well as reasonably priced AMAZINGLY good fidelity as well as excellent bass Reliable and easy to work on/restore/tweek (if tweeking's you bag) Stromberg-Carlson's ASR-333 and the PHONO stage equipped version, the ASR-433 come to mind as two extremely nice standouts in the 6BQ5 catagory And these are just integrateds with tone controls (oh no!) Make the hair stand up on the back of your neck matched with anything efficient, but still able to drive a more difficult load in the 80s like vintage JBLs to very nice room filling levels Have to spend a LOT of money to come close It's difficult to beat a nice U.S.A. made 6BQ5 amp with anything else in it's power class as far as sound quality and fun goes Plenty of tubes to choose from if that's your thing Edited January 27, 2015 by analogman Quote Link to comment Share on other sites More sharing options...
TJIann Posted January 27, 2015 Author Share Posted January 27, 2015 Anyone own a PrimaLuna Prologue 5 with the KT88s in it? Quote Link to comment Share on other sites More sharing options...
NOSValves Posted February 1, 2015 Share Posted February 1, 2015 (edited) Do you have a preamplifier? If so what is it? I'd also like to hear the music types you plan to listen too, room size and sound level you would like to achieve... Edited February 1, 2015 by NOSValves Quote Link to comment Share on other sites More sharing options...
TJIann Posted February 1, 2015 Author Share Posted February 1, 2015 I have an Outlaw Audio 975 Preamp which I really like. It covers all the media I have connected to my system. I listen to everything from classical to jazz to blues to classic rock (probably a good portion of the time) to country to heavy metal. So, all genres. I thought about a tube preamp, but I need a versatile 5.1 system as my TV and Blu Ray is hooked up as well. Quote Link to comment Share on other sites More sharing options...
NOSValves Posted February 4, 2015 Share Posted February 4, 2015 So are you planning on using the tube amp to always power your fronts? Or just when listening in 2 channel via some type of amp switch? Room size and maximum listen level is important when choosing a tube amplifier. Quote Link to comment Share on other sites More sharing options...
Bonzo Posted February 4, 2015 Share Posted February 4, 2015 (edited) I just picked up an amp built by a friend of mine. It's basically an RH single ended design using 6L6 power tubes, 12AT7 driver and 5U4 rectifier. It can use EL-34, 5881 etc. power tubes as well. It's running 300 VDC to the plate. It can also use a GZ34 and similar rectifier tubes. It runs very cool and sounds great. It drives my big Cornscala/JBL/Econowave speakers very well. I'm using a modern Vincent pre-amp that has tube output they claim is class-A. I have only used 6L6 tubes currently. I may try others as they become available. Edited February 5, 2015 by Bonzo 2 Quote Link to comment Share on other sites More sharing options...
Bonzo Posted February 4, 2015 Share Posted February 4, 2015 My apologies if it appears I hijacked the thread, not my intension at all. My friend built a similar amp based on the EL-84 and I have heard both. I preferred the 6L6 amp based on it has tighter and more controlled bass response. The El-84 does sound sweet and is a favorite of some of his audiophile friends. I think that amp has an approx. 3 watt output while the 6L6 has 8 to 10 in class A. For Jazz trios, acoustic music etc., I could be very happy with the EL-84 amp. 1 Quote Link to comment Share on other sites More sharing options...
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