drdna wrote:

Okay, what is that, and where can I hear it?

http://www.goodsoundclub.com/GetPost.aspx?PostID=8522

and I have been expecting it  with a LOT of anxiety. Dima have sent the Avicenna out today, ironically this week the new PurePowe regenerator shell be shipped as well.  Between them I hope it will be a very radical attack on the electricity problems. Talking about the subject of the thread: if I able to resolve the electricity problems then I consider bringing the DHT one more time and repeating the experiment with properly sound power lines. BTW, some aspects of random none-harmonic noise injection will very much side functionalities of Avicenna, perhaps 2% of what the unit will do.  I am sure if Avicenna does sonically what is expected from it then I will be talking about it.

drdna wrote:

I guess you mean the "Arabian" power regenerator you have been working on with Dima? Well, I will wait to hear the results enthusiastically. If it works, I want one too! The idea of analog dithering opens up a whole new world of possibilities regarding circuit design. It is too bad I am totally ignorant on the subject. I have no idea where to start. Adrian

Romy the Cat wrote:

The second solution, that I order of magnetite more enthusiastic about, I will keep for a time being secretive but if it work then it will be the most ridicules and the most affective idea that I have seen in tube amplifications.

serenechaos wrote:

Sometimes it's good to be sucked at first?

serenechaos wrote:

How does it suck? It does not generate second and fourth harmonics? It did change something else in a negative way? There was an unexpected negative effect on Sound, which you don't think can be "fixed?" Sometimes it's good to be sucked at first?

Nope, it did not generate any necessary harmonics at least at the magnitude to be useful.  Very sad, as the idea was superbly elegant. The only one “non-orthodox” try I will make it will be with elections randomization in IDHT (will be posting) and it is not work then I at this point have conceptualized what I will try. I will be the version 3 of the circuit below:

… I have magnetic but I need juts to pick with tube to use.

All, those DHT people admit that DHT are not neutral and in a way colored. Well, I care less about THEIR definition of neutrality but I would like to verify the subject of intrinsic DHT coloration. Is it possible that DHT coloration are the property of specific implementation (did not mention 3-4 stages with crappy vintage parts?) I mean if to use fast amorphous 1:4 input, good DHT, no-nonsense PS, amorphous output, and to put it in DSET over 3000Hz then would it be as “clean”, as “fast” as DHT theoretically might be? I do not know but I think it will be as optimum configuration for a possible use of DHT in non-melodramatic application. It is ingesting to learn how different a DHT will be from my 6E6P. Did you see anywhere a single stage DHT? I think that last time Telefunken did it in their V301 amp. It was PP, my will be SET, well I have higher sensitivity and need just 1.5W…

nl wrote:

Gordon Rankin of Wavelength Audio did a series of one-stage DHTs with a step-up transformer input about ten years ago. I think they were called the Mercury series. By all accounts, they sounded good, but of course had limited gain, not much power and had to be driven by a powerful preamp, which involves at least one and probably two stages if you use tubes.

I did not know it. I wonder how your DHT people consider the sound of one-stage Wavelength compare to the multi-stage. Did the Rankin’s one-stages amps had the DHT coloration that you admit exist in other DHT amps. Anyhow, I feel that those Wavelength Mercury series might not be even illustrative if DHT might do really “clean” sound as I am sure Gordon targeted mass-market with this full-range addenda. In DSET configuration it shall be a different amp. The inductance of input transformer shell not be nearly 100H and the output transformer might have a LOW of less turn. That all shell greatly improve HF end. Also, 10 year back Gordon most likely did not use amorphous core that I found a very good thing to do for HF DSET.

nl wrote:

I think using a DHT amp only over 3000hz would be somewhat self-defeating. I would try to use it at least over 600hz,

Why?

nl wrote:

… and use a 45 tube, not a 300B. The 45 is a wonderful tube for running compression drivers. If you use a 45, however, you probably won't have enough gain even with a 1:4 stepup.

I most certainly not going to go with 300B if I decided to go there. Most like it will be 2A3 or anything else with sub 1000R on plate that would allow me to use my currant OPT transformer. If I find the DHT idea worth for me to stick with then I might order a dedicate OPT and then I will be open for high-gain high impedance DHT. At this point I do not know how it all meaningful. Perhaps I need to take 6V.3 6A3 and juts plug in on 6C33C filenames with a regulating resistor and to see where it would go. I mean there are many ways to implement the thing but do not looking DIY project but for a sensible sonic result.

nl wrote:

Personally, I would forget about the input transformer, and just use a 6SN7 driver. RC coupling is fine. Many people like carbon comp resistors for the plate load, and paper/oil capacitors for the coupling cap here. PIOs take some time to break in. You might later try substituting an inductor for the load resistor. Of course you want to use a good 6SN7, not a new-production Russian or Chinese model.

I do have a very good driver (my 6E5P if I wish to go two stages). I did when in past from 2 stage Milq to one stage Milq I did like the new level of “laconic clarity”. I would like do not lose it.  Also, it is HF only DSET that need juts 1W? What do I ever need two stages? Well, I might need but juts do not know about it, will see. At list the idea of transformer and DHT is worth to try before to go for 2 stages a, coupling, DC stability, sound of the driver and all the rest. I also not really not willing to modify the 6-ch Milq as whatever it does now is fine. So, to do some work on it I really need to have evidence that DH will be advantageous for my MF driver.

nl wrote:

A nice 6SN7-45 amp, RC coupled with carbon comp/PIO, and a decent powersupply that doesn't sound drecky (which probably means NO cheap high-value industrial grade electrolytics, or at the very least a film cap that is isolated from the electrolytics with a resistor or choke), and whatever tricky bias schemes turn you on, would be a good intro into the sound of DHTs.

I do not know. I hardly ever see heard not drecky low power DH amps. All of them sounded very dead to me those idiotic full-range amps and the idiotic music that they looks like constantly play.  I have seen a few DH with stupidly made high-sensitively systems with horns- but it you read my site then you know my attitude toward sound of stupidly made horns. So,  I do not know which ingredient was wrong in the DHT that have seen before – I think most like it was the awareness of the amp builders but it another subject.

nl wrote:

Pay attention to the quality of the filament supply. The Tent Labs boards seem to get some acclaim, but I shy away from IC regulators in this position. You can try an IC current source filtered with a cap and choke such as Hammond 159ZC, which is 60mH and 2A, 0.7R.

Interning as you are today a second person who insists in DC filament supply. It is pretty me everyone strongly  in past suggested me to use AC on filaments. Can you elaborate on it?

nl wrote:

Then, I would use it on your S2 driver in the 600-12000 range, and turn off your other S2. I would also turn off the "injection channel." That would give you a better idea of how it sounds.

Come on, of course when try to evaluate how my MF sound in with different amps then I turn off my "Injection Channel”, how with it? To use the S2 driver in the 600-12000 range is another subject, I would like do not go there at this thread. BTW, the 6E5P with the "Injection Channel” might be very much make the DHT triode journey not necessary. I do not have a position about it at this point. Well, you are local from east cost, right? So, feel free to bring your single DSET and to see how injected Macondo work against DHTed Macondo. I wish I spent more time (or had more time) to evaluate THIS aspect when I had my 300B. I am planning to do this try again.

nl wrote:

Lastly, put in a line-level filter at the input instead of using a speaker-level crossover. The same circuit as is used with your 6E5Ps would be fine.

I a not intending to use speaker-level crossover. I am not going to put a resistor in primary of input transformer, using the transformer shunting inductance as a second order high-pass. Probably I would need to add some coils in parallel with primary….

nl wrote:

Given that you are using a solid-state preamp with presumably lots of driving power, you might consider a 1:4 stepup and use of either an EML 20B tube or the AVVT AV8 tube. That might get you enough gain. I think Rankin used the 20B in his Mercury amps. The 20B would take a rather special output transformer, as it has an Rp of 3200. I think Rankin used a parafeed output here. A typical 5K:8 OPT could also work, on the 16 ohm drivers, as the reduced inductance is not so much a problem since it would be used above 600hz. The AV8 is somewhat more forgiving, with an Rp of 1500. The new TJ PX25 has a gain of 8 and an Rp of 1500, another possible choice here.

Thanks, I will look at those tubes and will consider them. I am not convinced but I might use this input transformer:

http://www.lundahl.se/pdfs/datash/1544a.pdf

… that can go up to to 1:6…

nl wrote:

The 45 is a wonderful tube for running compression drivers. Many people like carbon comp resistors for the plate load, and paper/oil capacitors for the coupling cap here. PIOs take some time to break in. Of course you want to use a good 6SN7, not a new-production Russian or Chinese model. ...a decent powersupply that doesn't sound drecky (which probably means NO cheap high-value industrial grade electrolytics... Pay attention to the quality of the filament supply...the 26 takes a VERY high quality filament supply. I use batteries with a cap and choke with my 01As.

nl wrote:

simply because the point is to try something new.

Romy the Cat wrote:

I see more interest not in the wondering of why we make choices but rather in the questing what choices might be made in order to accomplish this or that effect.

Romy the Cat wrote:

I kind of know where to do but I very frequency might not know how to go.

Yes,  the laconic clarity is too rare and too worthy to let go.  My limited experience suggests that the 45 may have this very special ability, taken alone.  Conversely, the "good" 6SN7 is wonderful with respect to tonality and tonal integrity, both.  The good 6SN7 also has acceptable clarity, but I have not heard it developed specificially for this.  Neither have I worked with the 437A, although in years gone by I heard lots of whining about the troubles with finding good ones.  I know nothing about the new production WE tubes except that their saga reads like a soap opera.

I am a little suspicious of the Allen Bradley Club mentality, including vintage (carbon comp) resistors, transformers, caps, etc.  When I have bothered to listen, I have often chosen "selected", "non-inductive" wire wound R for plates and "selected" tantalum R for cathodes and other RCs, etc.  My objective in the trials has been to retain the capability to sound hard and correctly dirty, when that's what is wanted.  Care with stacking, grounding,and other issues goes a long way toward calming things down to allow for a proper "hardness potential" without consistent hardness.  This may also be a factor in the "randomness" capability, which is really only freedom of movement, and not "randomness", per se.

I have read a few DIY posts where guys claim to have solved AC filament noise on 45s by putting a small coil right on the tube pin, or what have you.  I cannot comment on this.  The AC 45s I heard, buzzed and, looking back, I think only certain qualities of those old amps are worth recreating; and not many, at that.  But, I am no longer interested in the vintage sound, at all, that's for sure.

Best regards,
Paul S

nl,

nl wrote:

I offered to be of assistance, as I have a little experience in these matters, but assistance is not appreciated so I will be leaving the Kingdom of Romy for more productive environments.

where did this come from are you crazy your master have eventually took over you?

nl wrote:

This is Romy's site, so I suppose in the Kingdom of Romy only single-stage high-gm amps sound good, and the 6E5P is the "perfect" high-gm tube, and that is that.

Ironically you are so much off. I have no vision on the subject; in fact the whole notion of DHT vs. single-stage high-gm amps is created by you. My quest was my about my specific single-stage Milq vs. DHT, there is different if you can see it.

nl wrote:

At the end of the day, he tried it and came to a personal conclusion. I also tried it and came to a personal conclusion. Romy is still just farting into the air.

At this point the person who is farting into the air is you. You did not say that you trued you’re a single-stage approach, at list you did not pass any sharable comments about your observations of the result in order the people who you would like to learn were able to make own assumption about the sincerity of your findings. You pretty much bark conclusion but they worth as much as anyone’s else barking - I do not think that you care about my conclusion if I do not provide you with soothing that resonates with what YOU know is truth is. However, you were the people who during initial introduction of you position brought the evidence: “However, even Lamm is now using the GM70 for his $140,000 statement amplifier.” nl, I am sorry those arguments is not soothe that sane people bring up. Not to mention that I might hit under the belt and reply that “many people around (and it is fact) the world who can afort the most sophisticated, kinkiest and advanced DHT through their DHT away after they were exposed to Lamm ML2.0.” Oh, did I mention that it was IDHT?

nl wrote:

Your 6E5P tube is not so special. People have been making WE437 spud amps since the 1960s. There is a class of amps that use a high-gm tube driver and a DHT output. Gordon Rankin has done this for about twenty years, and still does. However, I would suggest moving away from the high-gm driver, simply because the point is to try something new.

The 6E5P/6E6P and WE437/6C45P have absolutely nothing in common besided the people who did not deal with them decided to label them as "high-mu tubes". Hey, the WE437 and 811 tubes are probably the same as well, the both have grass… The really is that thee is a lot of special about the 6E5P/6E6P. it is completely up to you to discover it. in contrary to you I do not feel insulted if you do not support my poinjt of view…

nl wrote:

I will reproduce Jim de Kort's findings with the 437 spud, which roughly mirrors my own results. He used an amorphous Tribute transformer.

Thanks, for posting it. It was interning but absolute not educational in my view. I do not know who Jim de Kort is but leading a dairy of a person with a shovel who decided to turn over all sand in Sahara juts because he has no map where the treasures are. This is a typical DIY syndrome – I do not like those. The Jim de Kort say nothing about sound, nothing about own objective, nothing about what he is would like to accomplish, nothing about why he want to accomplish it. He has the damn solder gun and ability to solder – it never was enough to make sound.

nl wrote:

Even a single tube performing all the tasks can't come close to my three tubes per channel DHT amp system. There is no getting around the immense difference in sound. Yes, the 437A and 6S45P sound incredible and perform a unique task, but compared to a DHT it really can't hold water. I was doubtful about the comparisson before, but now I am fully convinced. Even three stages of (good) DHT's can't be beaten by a circuit using only one IHT.

And It is possible that you are correct – I just do not know and it looks you are not able to provide more justification of your view beside your desire for your readers to kiss you in your ass just because you express own views. That is fine; after all it is poorly voluntary sharing. You might be correct – but I would like to get my own answers, similar that if this subject were your curiosity then you would not be satisfied with my answers. I also do not belie that you experiments were “kosher” (let start from the fact that you used apparently used 6C45P, which is very crapy tube, partially as an out tube – many Russians build headphones with it). My quest is very limited and and I do not care what can't and can hold water compare to what.  I have Milq sound that I am comfortable. The recent 300B amp that I tried did have some minor tonal advantage that kind of evaporated when Macondo was injected. The DHT amp did have the “pace randomness” advantage, something that you with all your apparent DHT experience did not know, or might be do not know or perhaps will not even know. I did appreciate this DHT’s randomness a lot and I would like my amp to be able to do the trick. Do not worry it will. If my 6E5P/6E6P driver will not be able to handle it then I will try the DHT – I have no agenda in it. it is possible that the randomness  did come from the DHT, even though I have no evidence about it as no other DHT user repost it. I just need to learn how to make DHT if I got for it to sound as accurate, as “clean” as dynamic as my 6E5P/6E6P…

Paul S wrote:

I am a little suspicious of the Allen Bradley Club mentality, including vintage (carbon comp) resistors, transformers, caps, etc.  When I have bothered to listen, I have often chosen "selected", "non-inductive" wire wound R for plates and "selected" tantalum R for cathodes and other RCs, etc.  My objective in the trials has been to retain the capability to sound hard and correctly dirty, when that's what is wanted.  Care with stacking, grounding,and other issues goes a long way toward calming things down to allow for a proper "hardness potential" without consistent hardness.  This may also be a factor in the "randomness" capability, which is really only freedom of movement, and not "randomness", per se.