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|14th February 2002, 09:29 AM||#11|
Join Date: Feb 2002
so, you tricked me into signing up at this place by calling
Thanks for the compliments about my system...
I really don't understand, why the use of TV dampers hasn't
spread more widely in the DIY crowd. They are plentiful, dirt cheap
and in my opinion they outperform the ususal top $ suspects.
You mentioned that 2 tube amp of mine. Actually the tube has
a gm of 65.000 and a mu of 300. It's a pulse regulator for
color TV applications. The number is 6HS5, 6HV5, 6JD5.
That two stage amp is dismantled, because I needed the
OPTs. I'll try this tube again. A friend of mine is fascinated by
it and I will build a phonostage for him using this tube.
Actually the main reason why I was tempted to reply to this
post was not because you mentioned my name. But because of
some remarks you made to Don's post. Please don't get it wrong.
This might sound a bit provocative, but it's not meant in a mean
way. I just want to express my opinion.
What's wrong with Don trying to cross a technical hurdle ? I've
seen it too often when someone enthusiasticly talks about a
certain technical issue, someone else comes along and thinks
he has to remind him that it's only the music that counts.
I guess all of us are music lovers and music is important to us.
But why can't someone also just build something just for the
purpose of building it ?
I hereby publicly admit that I sometimes build something just
to try a technical concept. I can understand Don. For example
I built an all DHT phonostage, just to take that hurdle. When it
was done and worked it was like climbing a mountain and
reaching the summit. I had a wider view.
In the end a lot of those attempts to take technical hurdles
actually brought me closer to the music.
For me the creative process of envisioning a new amp, finding
the parts and building it, is just as much pleasure as listening
to music. Yes music is important to me, but it's not the only
thing that counts.
Ciao ... Thomas
|14th February 2002, 03:06 PM||#12|
Join Date: Jan 2002
Location: Munich, Bavaria
welcome on this fine place! glad you are here!
... not my intention, after our last talk, but very happy about the accidental result
Wish this would work on Manfred, too, the guy is immune to flattering and one probably had to menace him with a blunted and already bloody knife (or worse things) to get him posting
honours to those who deserve it
a few years back, i received a lesson about sonic influence of rectifiers in form of rectifier trading in a SET circuit. Different rectifiers led to different sound. $$$ DH rectifiers, Telefubnken, Valvo, Mullard, etc..
Probably each of us has mental blocks and so have i. I simply was not willing to pay for those suckers, easily calling an RE604's price. Moreover as I heard fantastic sounding tube amps with SS recitfiers in their PS. I was giving not the fact room in my mind that tube rectifiers work better in tube amps because of that. But then i heard your amps with heaps of dirt-cheap vacuum diodes in the PS and changed my mind. Manfred's PP #46 amp also uses them and it sounded better than V.Kühns fancy AudioNote-grade KR300B SET amp at the Fertin speaker demo.
this i want to listen to!
µ=300, i stand corrected, probably my mind simpy refused to accept this value
I see your point, Thomas, and it really was not my intention to downtalk enthuisiasm. I guess i hinted it in former posts of this thread and tried to be very careful to express it. And, i picked up the ball later and tried to throw in my 2 cents by suggesting good sounding tubes. To make it up
Don probably is way deeper into advanced PP circuitry than me.
Anyway, the source of my complaints is circuit complexity (you also could call this sub-circuit interaction) and the designer's ability to mentally penetrate it. 2 years ago, i tried to help a guy with refurbishing his McIntosh and getting a better sound from it. He got lost in understanding the circuitry and i have to admit, so di i. I am quite good in reading and understainding PP circuitry meanwhile, but this was too complex for me. Ok, i thought, then let's ask the real gurus, and so i did. One, who can tell from the schematic how an amp will sound, refused to deal with such a complex circuit and the other one (Peter H., he has no real access to circuit-sonics relation anyway) phoned me back 4 hours later to tell me he is not shure whether the circuit will run stable but he admitted "not having looked into the last dark corners of the structure".
Peter is no fool, he managed to design a commercially marketable SET 845 amp with nothing but 6SN7 driving the output tube to a bandwidth of 40kHz. to come back to the topic, as he is not into audio-wise listening, he too took a techical challenge. At this moment he was not believing into adding additional expensive signal transformers and fancy tubes ("they just add distortion") and as a customer ordered this design to have a new product, cost was an issue. No listening was done during the development of this amp, atleast not by Peter. Miraculously, the amp turned out to be sonic gold.
But, to come back to topic, he would have taken the challenge anyway just to prove an 845 can be driven by small signal tubes like the 6SN7 and without help of "a power amp as driver stage".
Thomas, looking from this point, you are right. Gettinig a wider view. So, Don, do you hear me, you do not let me discourage you to build your amp!
I have to be spoken guilty myself concerning my complaints: I have a preamp design in work using DC coupling over three stages, all current suckers, and PS voltages are towering. But: I finally got rid even of the power supply caps, no caps anymore except for the speaker XO. The design looks very simple to me, others (including Manfred ) complain about it's complexity. And remind me i have not built much in the last few years and nothing like that. And will step into many traps. And so on.
Thomas, one thing, all your circuit improvement you showed me were aiming at getting a simpler circuitry and avoiding components deterioating the sound in your opinion, at incredible cost if necessary.
As it is with my preamp design , in your DHT phono preamp a lot of traps are to be avoided and sometimes with huge effort, but the circuitry itself is simple, complies with the KISS rule. The traps can be tracked, found and neutralized, clear cause-effect structures. This maybe is a different sort of challenge compared to tame a McIntosh-like circuitry which is a complex web of nodes and which node is a cause and which an effect is not an easy task ton make apparent.
Agreed. So it is with me. Envisioning a new amp, yes, that word fits
But i have to say that music and it's spirit plays a major role for me and i probably never would build a device just to find out how good it works, i have too many fronts to fight at and i try to do it right the 1st time and then to focus on another front. As far as audio gear is concerned.
|14th February 2002, 03:08 PM||#13|
Join Date: Feb 2002
I think it is important to see oneself as an experimenter, with those open horizons you mentioned, vinylsavor, as a goal worthy of their own intrinsic interest. OF COURSE it is wrong to lose sight of musical enjoyment (that is the yardstick for our experiments, #1, and #2, it is an important element of the positive-reward cycle that keeps our enthusiasm up for these efforts.)
I have been forced reluctantly to admit to myself that part of the reason I engage in DIY audio is a delight in pursuing technical challenges for their own sake. It is not the only one, but it is part of the whole appeal for me.
I guess I am confessing to having some of the spirit of the inventor or engineer as well as the music lover. There is some pride and satisfaction to doing something new or something old in a new way, apart from whether it works especially well.
Of course, if you are lucky, following your curiosity and intuition leads you towards better sound too, but it isn't always the case.
I like the example set by Mick Moloney of Supratec, who has built dozens of phono stages and has been very free with his reports about what he liked and what he didn't. By doing this, he has given us all a big bunch of information to work with and also inspired further experimentation.
Vinylsavor, it's good to hear you on this subject, you know a lot about it!
|15th February 2002, 07:20 PM||#14|
Account disabled at member's request
Join Date: Dec 2001
Location: Hickory, NC
Thanks for all the replies!
Hello Bernhard, Thomas, J. Epstein
No need to apologize for opinions held! I have just been off the air the last couple of days. I understand the "keep it simple --" philosophy, I should have clarified my project as more oriented to searching out new design territory rather than a straight-forward building an amplifier project. The need to "get it right" the first or second try is not a concern. I expect to try out a number of variations, fully expecting some to not work so well. Thats what learning is all about! The chassis I have prepared has a surplus of holes punched in it for extra tube sockets so that it is more of a test bed design. I originally conjured up the "Elliptron" idea specifically so as to get outside of the usuall limits of tube amplifier designs, of course that includes the freedom to stumble and fall a few times, but I think there is considerable potential for some good designs here too. The distributed loading idea has been well proven in the past by such designs as Leak, Bogen, McIntosh, Electro-Voice, Audio Research, Fisher, Hiraga, Michaelson Austin, Luxman .... I just wanted to point out, in my original post, that these type of designs are not so inaccessible as most assume, since a common ultra-linear transformer can be used, although with the small headache of a dual floating power supply requirement. I believe this type of tube design has not been explored much by DIYers because of the large stumbling block of a custom transformer and the lack of familiarity. Without some confidence in a successful outcome, no one wants to do a risky, expensive, custom transformer design. Maybe the Elliptron will serve to break down some of these barriers if some good DIY designs result. The design is well suited to the use of inexpensive TV horizontal output tubes as well. I strongly urge anyone interested, to give this approach a try too. I am not trying to keep it to myself. Maybe a new tube cult-tribe-mafia will develop even!
|16th February 2002, 08:02 PM||#15|
Join Date: Jan 2002
Location: Munich, Bavaria
Waiting on your schematic, floating separate PSs not a stumble rock IMO, might get tempted to give up my 1st try -> success obsession and try it out myself.
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