tube fanatic Posted March 7, 2017 Author Share Posted March 7, 2017 Like myself, Dennis had to employ what I fondly call the "Kobayashi Maru of audio design" philosophy to allow use of all those tubes (for those unfamiliar with that, see this link: http://www.startrek.com/database_article/kobayashi-maru ). I suspect I know how he did it but would love to see the amp's schematic to confirm. In any event, I'd venture that you hear definite differences between those tubes. Heck, you can even switch tubes to tailor the sound to the particular type of music that you listen to! Maynard Quote Link to comment Share on other sites More sharing options...
dirtmudd Posted March 7, 2017 Share Posted March 7, 2017 2 minutes ago, tube fanatic said: Like myself, Dennis had to employ what I fondly call the "Kobayashi Maru of audio design" philosophy to allow use of all those tubes (for those unfamiliar with that, see this link: http://www.startrek.com/database_article/kobayashi-maru). I suspect I know how he did it but would love to see the amp's schematic to confirm. In any event, I'd venture that you hear definite differences between those tubes. Heck, you can even switch tubes to tailor the sound to the particular type of music that you listen to! Maynard site can not be found Quote Link to comment Share on other sites More sharing options...
tube fanatic Posted March 7, 2017 Author Share Posted March 7, 2017 10 minutes ago, dirtmudd said: site can not be found It comes up fine here. Try this instead: http://memory-alpha.wikia.com/wiki/Kobayashi_Maru_scenario Maynard Quote Link to comment Share on other sites More sharing options...
Schu Posted March 7, 2017 Share Posted March 7, 2017 what... people don't know what the "no win" scenario is? Quote Link to comment Share on other sites More sharing options...
derrickdj1 Posted March 7, 2017 Share Posted March 7, 2017 On 3/6/2017 at 7:27 AM, tube fanatic said: To know what is really happening when switching to different tubes it's necessary to graph (or use a simulator) the operating parameters based on plate/screen voltage and current, bias, primary impedance of the opt, and the latter's ability to handle higher amounts of current than the stock tube. I tend to scratch my head a bit when some designers claim that their amps can work with tubes which have very different operating parameters. Switching to some tubes has to take the distortion level to very high values. It's also worth checking the current draw of the filament. For example, if an amp is designed for the 6V6's 450 ma current draw, you need to know if the power xfmr can handle the 1.25A draw of, say, a 6Y6 and so on. It's always wise to check with the manufacturer or designer before swapping in "similar" tubes. Maynard I love this and it is so right on. I had one of our long term forum members turn me on to using some type of equalizer and it can be cheaper than rolling tubes. I can't figure out why people want to do it with only tubes when an equalizer can help get you to that special place, duh. Quote Link to comment Share on other sites More sharing options...
mike stehr Posted March 7, 2017 Share Posted March 7, 2017 1 hour ago, derrickdj1 said: I can't figure out why people want to do it with only tubes when an equalizer can help get you to that special place, duh. So you are using the equalizer to achieve higher levels of distortion? Quote Link to comment Share on other sites More sharing options...
derrickdj1 Posted March 7, 2017 Share Posted March 7, 2017 11 minutes ago, mike stehr said: So you are using the equalizer to achieve higher levels of distortion? Nope, just to help tailor the sound to my likes! You don't have to always boost with an EQ'lizer. To each his own but, shopping thru a multitude of tubes to get the sound right, is not for me. The changes between different tubes with tube rolling are small and can be addressed with some EQ IMHO. I'm still learning an open to ideals. Quote Link to comment Share on other sites More sharing options...
NOSValves Posted March 9, 2017 Share Posted March 9, 2017 On 3/3/2017 at 8:40 AM, wdecho said: Technically yes but my amplifier can use them for an EL34 as most SE EL34 amplifiers. This is with single ended EL34 amplifiers. The cathode resistance is somewhat higher for an EL34 tube which will equate to less power than with an SE amplifier designed for a 6L6 amplifier but with our speakers there will still be plenty enough power. Expect maybe a watt less power. I probably should add that my SE EL34 amplifier is the Tubelab SSE one. This among others is what I found. Do some research yourself to see if your EL34 amplifier may be able to use them. The 6P3S is a beam tetrode unlike the EL34 but it should not matter in the amplifier. http://audiokarma.org/forums/index.php?threads/heres-a-terrific-el34-substitute-at-1-5-the-price.246656/ That Russian tube is tough as nails...I used them on and off 5 to 10 years ago. They use to cost about $3 each.......Like all things once the word gets out demand rises along with the price. Quote Link to comment Share on other sites More sharing options...
seti Posted March 10, 2017 Share Posted March 10, 2017 14 hours ago, NOSValves said: That Russian tube is tough as nails...I used them on and off 5 to 10 years ago. They use to cost about $3 each.......Like all things once the word gets out demand rises along with the price. True! That is why I am stocking up on those russian caps and tubes. Good stuff. Quote Link to comment Share on other sites More sharing options...
Stump Posted April 15, 2017 Share Posted April 15, 2017 On March 1, 2017 at 8:24 AM, hogwylde09 said: Nothing like a good Telefunken or even a NOS or ANOS RCA. I've tried them all from my Marshalls to my McIntosh. Output tubes a little different. Hard to justify spending a grand on a matched quad of 6550-Kt88 Sent from my SM-N900V using Tapatalk I agree completely. V1 in the early, single channel Marshalls, JCM800 and earlier, models 1987, 1959, 2204, 2203 and JTM45, shapes the biggest part of the tone, output tubes the least, unless you're able to play them at high volume. My favorite tubes in my 50 watt Marshall 1987 model, is a Tungsram ECC83/12ax7 in V1, a Mullard CV4004 in V2 and a Brimar CV4004 in V3. The whole matched triodes thing, that some tube dealers recommend for the phase inverter(V3), is a bunch of baloney in my opinion. Most current production power tubes, of the EL34 family, sound and work just fine at considerably less cost. I have a pretty good collection of Old Stock tubes and have compared them directly against their modern counterparts with the only tube not comparing favorably being the KT77. There's just something about the original GEC Gold Lion that none of the modern versions have yet captured. My Dynaco PAS3 preamp uses the original Old Stock tubes, with Telefunken 12ax7's, which sound better than any modern tubes I've tried in it yet. In my ST70, I'm using Old Stock 7199's, the original Mullard GZ34, but current production JJ 6CA7 power tubes that sound nearly as good, but different than the Mullard XF2's that were in it. Some of my guitar amps use current production tubes in all positions and sound just fine, though I prefer to have a good Old Stock tube in the first position. The older, simpler design guitar amps seem to benefit the most from Old Stock tubes, the newer, more complex amps the least. This is just my experience, but in any case, tube rolling can be fun and yield some excellent tone, regardless of new or old manufactured tubes. Quote Link to comment Share on other sites More sharing options...
derrickdj1 Posted April 15, 2017 Share Posted April 15, 2017 I've wanted to try a pair of Telefunken 12 AX 7 but, they can be pricey. There are several variants ranging from $45 to 450. The $450 price is a lot for one preamp tube. Quote Link to comment Share on other sites More sharing options...
Stump Posted April 15, 2017 Share Posted April 15, 2017 There's no tube worth $450, regardless of the hype surrounding it. The majority of mine are pulls from old equipment. I've purchased a few, but never more than $35. 1 Quote Link to comment Share on other sites More sharing options...
jimjimbo Posted April 15, 2017 Share Posted April 15, 2017 There's no tube worth $450, regardless of the hype surrounding it. The majority of mine are pulls from old equipment. I've purchased a few, but never more than $35. +1 to that 1 Quote Link to comment Share on other sites More sharing options...
derrickdj1 Posted April 16, 2017 Share Posted April 16, 2017 Just think for a $2,400 I could load the amp with all Black sable tubes. I didn't spend that much on the amp. That is the good thing about our forum, people know how to get good sound without being a fool, lol. Quote Link to comment Share on other sites More sharing options...
OldSkool77 Posted April 16, 2017 Share Posted April 16, 2017 I think you guys should just be buying the new Russian tubes and leave the old NOS tubes to me...err, others. Basically, NOS tubes are just dusty and yucky. Best to avoid them completely. Quote Link to comment Share on other sites More sharing options...
mike stehr Posted April 16, 2017 Share Posted April 16, 2017 5 hours ago, derrickdj1 said: The $450 price is a lot for one preamp tube. The differences in sonics are too subtle to justify that kind of cost...considering the circuit/topology the particular 12AX7 is in, the types of parts used...etc... 1 Quote Link to comment Share on other sites More sharing options...
seti Posted April 16, 2017 Share Posted April 16, 2017 It depends on the production. I love the look and sound of my globe NX245 but the EML Mesh 45 build quality is unmatched. They are expensive but construction is amazing. I use a mix of old and new. You can even look at all the different old tubes and there is plenty of construction variation quality. The same can be said of new production variation from china to russia. Quote Link to comment Share on other sites More sharing options...
Schu Posted April 17, 2017 Share Posted April 17, 2017 man... there are some horrible sounding tubes out there, and not all of them are cheap. Quote Link to comment Share on other sites More sharing options...
tube fanatic Posted April 17, 2017 Author Share Posted April 17, 2017 11 hours ago, Schu said: man... there are some horrible sounding tubes out there, and not all of them are cheap. If you encounter a tube which sounds positively awful in comparison with others of identical type there's something wrong with it. Normal production tolerances from one brand to the next are usually so minimal as to cause no appreciable change in its operating parameters. And, as has been discussed before, if a tube of "similar" type to another sounds awful, then the logical conclusion is that it isn't right for the particular circuit in question (such as amp manufacturers which claim that output tubes can be a 6K6, 6V6, 6L6, and so on). Maynard Quote Link to comment Share on other sites More sharing options...
Schu Posted April 17, 2017 Share Posted April 17, 2017 Makes sense... although I have found a wide variance in like tubes. As you state, it could be production tolerance being less than ideal during a period where hand made and machine made items varied wildly... even the military stuff sounds different from each other. Is being able to hear variation partly a function of such a revealing speaker? Partly because I am a hyper critical listener? I refuse to mention the word placebo because I work at listening intently and do so multiple times to confirm my thoughts. Quote Link to comment Share on other sites More sharing options...
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