mobile homeless Posted August 23, 2002 Share Posted August 23, 2002 quote: Originally posted by Clipped and Shorn: bw, mdeneen has the long range cure for this up his sleeve, the concept of utilizing circuit engineering to bypass or render the particularities of NOS tubes irrelevant to the design goals, which means that for the price of some inexpensive resistors, one might be able to get optimum results with new tubes available at a fraction of the expense of NOS mania. This is mysterious to me. How is mdeneen doing to use circuit engineering to bypass the positives and negatives of tube selection? Are you saying that through his circuit, he would render a $5 Golden Dragon 12AX7 to be just as viable as a Long Plate Mullard? Or render the generic Chinese EL-34 to be on the par with a Mullard EL-34? Please clarify here. Let's put it this way, if Mdeneen is able to eek out a circuit that renders generic new tubes with just as good a sonics as highly touted NOS options, then he should quit whatever he is doing and become a full-time amp designer. So far, I have never heard any amp, not matter what design, not be improved by better tubes. Some bring about more positive results than others but there is usually an across the board reaction to certain tubes here. ie Mullard EL-34 will make thy Sovtek EL-34 sound rather pedestrian. Admittedly, operating points can be changed to for certain tubes but how he is going to accomplish what you claim above will be quite interesting. If he succeeds in making a remodeled ST-70 into an amp that uses generic tubes and achieves sound that renders tube selection superfluous, then he should post this across the net or be geared up to make a hefty profit. I have a fine candidate for a makeover with my ASUSA EL-34 amp which has some hefty iron w'choke that VTV called far better than anything the ST-70 had to offer. Although it's a fine amp whether in triode or Ultralinear, it does not scale all heights (btw, it does employ fixed bias). kh Phono Linn Sondek LP-12 Valhalla / Linn Basic Plus / Sumiko Blue Point CD Player Rega Planet Preamp Cary Audio SLP-70 w/Phono Modified Amplifier Welborne Labs 2A3 Moondog Monoblocks Cable DIYCable Superlative / Twisted Cross Connect Speaker 1977 Klipsch Cornwall I w/Alnico & Type B Crossover Links system one online / alternate components / Asylum Listing f>s> This message has been edited by mobile homeless on 08-23-2002 at 02:29 PM Quote Link to comment Share on other sites More sharing options...
Clipped and Shorn Posted August 23, 2002 Share Posted August 23, 2002 mobile, I confused the issure somewhat in my ranting. The Dyna Mystery amp we are building was not the project designed to override the limitations of generic new tubes. I will be using high quality NOS in my amp. NOS Mullard EL 34 double getters, Mullard GZ34, and Telefunken and/or Mullard 12AX7s and or 12AU7s. The mention of this other revolutionary concept had to do with some ideas he was playing with regarding Pre-amp phono sections. I probably spoke out of place and only meant to tantalize as I myself was tantalized by the very notion. We shall see what we shall see and hear what we shall hear, but if anyone has the creativity and background to do it, mdeneen is the man. -C&S ------------------ Cornwalls currently upgrading to all tube components Quote Link to comment Share on other sites More sharing options...
fini Posted August 24, 2002 Share Posted August 24, 2002 How's the "Dustpan Amp" coming along? fini Quote Link to comment Share on other sites More sharing options...
NOSValves Posted August 24, 2002 Share Posted August 24, 2002 MDeneen, This is indeed a interesting Idea. If we could indeed limit the effects of NOS tubes are on gear it sure would make using tubes much more affordable. The prices have surely just begun to rise as the demand has risen so drastically in the last few years. I myself find on my Scott amps that output tubes seem not to have such a big effect on the sound compared to the low driver signal tubes like 12AX7. I really think at this stage in the signal path the most influence on what you end up hearing is created either good or bad. Craig Quote Link to comment Share on other sites More sharing options...
jazman Posted August 24, 2002 Share Posted August 24, 2002 mdeneen, First I will make my technical disclaimer. "I can not challenge your idea based on superior technical knowledge and experience." That said and out of the way, my humble research seems to point to much of sonic character and signature of NOS tubes is supposedly based on the metallurgy and science of the gas employed in the tubes which each manufacturer guarded like the nations gold supply. If that is so, will changing the operating conditions ever be able to alter effects the physical properties of the tube's internals have on the sonic quality? It's the sonic character that makes NOS tubes so desirable. It's just a "grasshopper" question. Klipsch out. Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted August 24, 2002 Share Posted August 24, 2002 I feel the same way, while getting the circuit nearer the ideal operating point of a certain type of tube, this does not really have much to do with the actual tube's construction and the variables within. In other words, if two 12AX7s have the same operation perameters and both run ideally at load and voltage A, then the difference between the tubes construction and makeup will still be a deciding factor as to how the amp will sound. Going toward a more ideal operating point is better for the amp in general, but the specifics of the tube will still way in ultimately in how the amp will sound. And making an amp expressively for a certain tube, like a generic Chinese 12AX7, though perhaps closer to the ideal of the tube will not, in my view, pass the same circuit ideally set up for a tube of better quality. Besides, tubes of the same type vary so much in their ideal operating points that this theory seems to not totally achieve what it sets out to do. It's an interesting idea but I just am not sure if it will do all that is intended. kh Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted August 24, 2002 Share Posted August 24, 2002 I believe NOS said the opposite (output tube have more affect), which was surprising to me as well. I find the small signal tube and the output tubes to both affect the sound with the nod depending on the amp. Not so sure about it all relying on statistical variation or even what this is saying exactly. And mdeneen is right in that the many variables of the makes tubes is almost too tough to comprehend, then again, I find this complexity to exist in much of audio as in life in general. Finding out the proper measurements or testing to uncover this is a constant struggle. kh Quote Link to comment Share on other sites More sharing options...
Clipped and Shorn Posted August 24, 2002 Share Posted August 24, 2002 I think I understand this on the grasshopper level. The output tubes are generally run toward the hottest (higher voltages) and are being used already closer to their optimum linearity, whereas the input tubes are generally run "cooler" (lower voltages compared to what they are actually capable of handling) and are therefore more susceptible to these variations found closer to the extremities of the curve. The NOS tube in the first input stage outperforms the generic tube, among other things, because its specs are more reliable and its numbers can be counted on wheareas the generic tube might be more of a crapshoot spec-wise and may end up way out on the curve somewhere. So the point is to find a way of using the less spec reliable generic tube in a less critical part of the curve, eg. run them much hotter than usual or whatever circuit mod is necessary to get them on their best behavior. I favor the explanations that deal with the numbers which the electrons can be measured against rather than the mystery of the metallurgy and the secret gas, which 5 years down the line will be so NOS expensive that you might have to tap into your already diminished retirement fund to afford replacement. If there is hope for the cheap generic currently manufactured tube answer, I am all for it. Thus there is an apples and oranges comparison here. The variation between different brands of output tubes is based on a different analysis than the variations for the input tubes, and in the context of this particular discussion it is the input tubes, especially the first one, which is more critical, not to say that output tubes are not critical also, but for reasons different than the ones under discussion here. Finding a way of minimizing the problems with non-NOS output tubes is a different discussion. How am I doing? -C&S ------------------ Cornwalls currently upgrading to all tube components This message has been edited by Clipped and Shorn on 08-24-2002 at 03:14 PM Quote Link to comment Share on other sites More sharing options...
NOSValves Posted August 24, 2002 Share Posted August 24, 2002 Mobile and all, I guess I wasn't clear enough. In my amps with Bias voltage and balance adjust where I can tweak the output tube to where there operating perfectly it doesn't seem to matter at all whether I use Bugle Boys, Telefunken or Cheap Russian Military tubes the sound seems to be Identical. Now this may not hold true with amps that don't have these adjustments built in. When switching between one brand tube to the other in output tubes you may be changing more than you think one set may match each other and work better together than the ones you where using. So with my amps it seems that the Low Signal tube (12AX7's) seem to make a huge difference compared to any of the other tube rolling I have done. So yes I believe that in a properly setup and operating curcuits the Low signal tubes are where the most gain or loss in sound quality can be had. Craig This message has been edited by NOS440 on 08-24-2002 at 03:30 PM Quote Link to comment Share on other sites More sharing options...
Clipped and Shorn Posted August 24, 2002 Share Posted August 24, 2002 Transistor rolling..... what a hilarious concept. That's funny, but telling as well. This thread is pretty interesting, even though it started out about vinyl, but then again there is the NOS vinyl versus CD parallel or the mono vinyl versus the stereo vinyl and why.....Mullard is to Blue Note as Telefunken is to Archive etc. -C&S ------------------ Cornwalls currently upgrading to all tube components This message has been edited by Clipped and Shorn on 08-24-2002 at 04:59 PM Quote Link to comment Share on other sites More sharing options...
mike stehr Posted August 25, 2002 Share Posted August 25, 2002 It occurs to me that one of the most common SS topologies - for most good quality amps - is to use say, 48 output transistors in the output circuit. Pardon me, But what SS topologies have this many output Transistors? That seems like a lot, 24 per side? That would be a large amp. Does the larger Class A SS stuff have this many output transitors? Quote Link to comment Share on other sites More sharing options...
maxg Posted August 26, 2002 Author Share Posted August 26, 2002 Hijackers!! Saboteurs!!! I started this thread about vinyl and now it has been taken over by all you tube heads making posts I cant understand... On the other hand...are you guys saying that the power tubes make less impact on the quality of the music than the input tubes??? If so I had better start playing with those - changing from 6550's to KT88's made a huge difference to my sound! Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted August 26, 2002 Share Posted August 26, 2002 Max, the input tubes, in my opinion, offer just as much potential (if not more depending on gear) for sonic improvement in an amplifier. I have found this so whether dealing with a single-ended triode, modern pp Ultalinear and/or triode, or vintage unit. Obviously, some amps will be affected more than others and some tubes will bring out more change then others, but the positive results can be extremely worth it, as your amp will move up another level. I didnt get the best from my Welborne Labs amps until moving to different input/driver tubes. Then again, sometimes it's a matter of taste and changing these tubes can add a different flavor to the sound. But to answer your question, I consider the input tubes VERY important in achieving the best sonics. This is also a place where I find great NOS selections to offer a real improvement over just about anything new, this across the board. What are your input/driver tubes in your 6550/KT-88 monos? kh This message has been edited by mobile homeless on 08-26-2002 at 05:34 AM Quote Link to comment Share on other sites More sharing options...
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