NOSValves Posted August 31, 2002 Share Posted August 31, 2002 As long as were on the transformer subject. I do have one Tidbit about Scott transformers. HH Scott wound all there transformer in house themselves. I have no Idea where EICO bought or built or what with there transformers. But in a age where there prices were across the board the cheapest on the market if the HF-81 indeed has magical transformer I'm pretty sure it was a freak of economic Nature. EICo engineers most of been locked in a closet to be able to out design all the others companies that were 3 to 4 times the cost in the day !! Craig Quote Link to comment Share on other sites More sharing options...
Tom Mobley Posted August 31, 2002 Share Posted August 31, 2002 mdeneen, I'm thinking you are one of the guys who might be able to decode and update the schematic. I don't believe in magic myself, so I'm thinking this deal could be done. But I don't understand how you reject the "magic" version of construction in the top half of your post and then turn around and think the switch stuff could be part of the sound quality? Do you mean the tone control circuits could be part of the sound quality? That could well be, but I don't see how stuff that's switched out could affect the sound. It seems to me that what's really needed is the phono and a couple AUX inputs and an 8-ohm output. Skip tuners, tapes, tape loops, all that jazz. What do you see as minimum necessay functionality? Tom Quote Link to comment Share on other sites More sharing options...
Clipped and Shorn Posted August 31, 2002 Share Posted August 31, 2002 Tom, When mdeneen had my Eico HF-81 on his bench, he observed the idiosyncracies of the circuit and the characteristics of the transformers. He also attempted to coach Craig through a debugging of the one he had at the time. He is familar with the schematic and the layout, but is not particularly impressed with or inspired by its design. We were hoping to get mine in proper working order so we could both hear the "mysterious" correlation between the unit's idiosyncracies as seen on the bench and the particular sonic characteristics which give rise to its apparent sonic popularity on these boards among other places. Because there seemed to be nothing special at all about its inherent specs on the bench we were curious to understand and explain why the sonics often ended up being attractive for its owners . He concluded that it must be a result of its totality, something which kh has said as well when referring to the integrated synergistics { lots of 12AX7s leading to pp EL84s, how bad could that be?} of the "beast". Since there was nothing in the essential circuit or parts to predict this attractiveness at least when he looked at it on the bench, he was concluding, although ironically and perhaps prematurely, that it may lie in its particular quirkiness. Thus cleaning it up could result in a loss rather than a gain. We are busy, or I should say, mdeneen is at the moment, with the final tweaking of the "mystery" amp being built on my old Dynaco-ST-70 chassis and transformers. He is using a process of empirical engineering which is like a painter going from a sketch to the final painting. There is a lot of shuffling of resistor values and minor conceptual adjustments to get the new design up to top speed. There are some exceedingly promising characteristics on the scope, and then next the final stage of field testing for the sonics. I am still hoping to play with my HF-81 at some point, or perhaps offering it up for sale to you guys here first. Later. -C&S ------------------ Cornwalls currently upgrading to all tube components This message has been edited by Clipped and Shorn on 08-31-2002 at 01:53 PM Quote Link to comment Share on other sites More sharing options...
jazman Posted August 31, 2002 Share Posted August 31, 2002 With all due respect to mdeneen's technical knowledge, c&s's logic, and Craigs disbelief anyone can out engineer Scott, others, One element that is not considered enough here is the concept and value of "Craftsmanship" involved in the transformer manufacture. Craftsmanship involves practices and knowledge passed generally through experience and word of mouth from one craftsperson to another, usually not written down, and may not completely correlate to what is measured on the bench. That said, there are many knowns, the Williamson circuit design, the parts used, both are great starting points. Much of the sonics resulted from use of the best tubes available for that period of time. Now we have two elements of the amplifier that are dependent on craftmanship that is pretty much lost. Like Mobile, I certainly think it's a worthwhile project. I also believe it will take more than simply assembling parts to achieve the same sonic "magic", plus a lot of additional money and time for product development. At best it will be a modern attempt to produce something close to the original. The bottom line is, "Talk is cheap". Everyone seems to think it's easy. Those who are truly serious should start to consider how much of their funds they are willing to commit, and when to have their first meeting to incorporate. I hope this was not too much reality to speak. Klipsch out. This message has been edited by jazman on 08-31-2002 at 04:59 PM Quote Link to comment Share on other sites More sharing options...
Clipped and Shorn Posted August 31, 2002 Share Posted August 31, 2002 There is a vagueness in this discussion which has not been directly answered. Is anyone implying or stating here that the transformers for each of the Eico HF-81 were hand-made by craftsmen at the Eico plant? Perhaps hand winding machines at transformer companies were used to make prototypes of transformers that were ordered to specific specs, but when it came time for mass production I seriously doubt there were craftsmen winding these things, come on. Generally we are talking about hundreds of thousands maybe even millions of transformers during that era. There were at least a million Dynaco ST-70s. A lot less for the Eico's, but still. I know you guys want to make this little amp into the holy grail, but really. -C&S ------------------ Cornwalls currently upgrading to all tube components Quote Link to comment Share on other sites More sharing options...
Tom Mobley Posted August 31, 2002 Share Posted August 31, 2002 Well, it is a little tough to buy one and tear it apart for pieces, but I do know where there is one that is reputed to work good but is really nasty looking. $180. Can anybody here analyze the transformers if I get them? Tom Quote Link to comment Share on other sites More sharing options...
NOSValves Posted August 31, 2002 Share Posted August 31, 2002 C&S , Oh yes absolutely EICO had a full crew spending all there time hand winding and taking extra care to make there transformers the very best !! They hired the absolute cream of the crop audio engineers. Searched out the best combination of the cheapest parts known to man and Bamb made the greatest Amp ever !!!!! All for $69 a piece they bested the like of Fisher , Scott , Heathkit , Bogen the works and beat there prices by 60%. What a pipe dream !!! Craig I'm sorry but I'm running on very little sleep and just had to cut through the Bullsh!t This message has been edited by NOS440 on 08-31-2002 at 06:36 PM Quote Link to comment Share on other sites More sharing options...
lynnm Posted August 31, 2002 Share Posted August 31, 2002 Sheeeeeesh! Here we have an example of why DIY and assorted audio freaks will always be fun to watch. Even when the combatants agree they will find reasons to Diss each other! Go in pieces Amigos! ------------------ It is meet to recall that the Great Green Heron rarely flies upside down in the moonlight - (Foo Ling ca.1900) Quote Link to comment Share on other sites More sharing options...
NOSValves Posted August 31, 2002 Share Posted August 31, 2002 That's to funny !! Quote Link to comment Share on other sites More sharing options...
Tom Mobley Posted August 31, 2002 Share Posted August 31, 2002 running on very little sleep, now there's something I can identify with. but, I've only got 3 more hours and I'm off for four days. provided the network doesn't explode like it did this time last week.... I found a schematic for an HF-12, reputed to be half of an 81. http://engr.uark.edu/~lar/hf12sch.gif Tom Quote Link to comment Share on other sites More sharing options...
Clipped and Shorn Posted August 31, 2002 Share Posted August 31, 2002 I don't think anyone is dissing any one here. This seems to be a fairly rational discussion about the feasability of remanufacturing a vintage piece and the speculation on the value of such a project. This, all brought on by the time-machine fantasy of an unbuilt original kit appearing on eBay and the the contemplation of what determines the value of such a rarity. Many here enjoy this vintage piece which were acquired as bargains, others are not completely convinced of its exceptional nature based on its face value specifications. This all seems to be well within the realm of individual preferences and the normal range of human variations. The underlying subtext of physics versus mysticism is also standard human behavior these days with some swearing by the revelations and benefits of astrology, herbal concoctions and homeopathic remedies and others holding firm to science and reliable evidence. The common ground can only be established here by a philosopher's rigour regarding our use of language. The stickiness comes about by vague and subjective language being mistaken for more precise terms. Communication needs real clarity. When we enter the realm of our personal experiences with listening to our rigs, this gets very subjective and the language actually fails us, so it is actually impossible to compare one person's sonic experience with another's merely through the use of words. Hey, if you like what you are hearing, that is cool, likewise if you love what you are hearing, likewise if you think that what you are hearing is the bomb, is the balm, or is the bam. I just ask that you take me at my word when I say what I am hearing is IT for me. -C&S ------------------ Cornwalls currently upgrading to all tube components Quote Link to comment Share on other sites More sharing options...
sprocket Posted August 31, 2002 Share Posted August 31, 2002 So what if this is a dumb question.. I'll ask anyway. What is the big deal with an not yet built Eico? Is not a factory wired Eico just as good a find. Besides the better condition cosmetically speaking it will end up just an other face in the crowd after it is assembled, right?? What part of the equation am I missing? Quote Link to comment Share on other sites More sharing options...
Tom Mobley Posted August 31, 2002 Share Posted August 31, 2002 anybody know the characteristics of the magic trannies? Tom PS You've all heard of the Tube Asylum? This is the Tube Minefield. Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted August 31, 2002 Share Posted August 31, 2002 C&S, your grasp of science and its subsequent reinterpretation via text is about as mystical as it gets. kh ps-The EICO actually has some excellent measurements for those that believe this is a valid forcast of sonics and "what sounds good." I actually have the full measurements and graphs on my machine at home. I have not resorted to their use as I personally believe that measrurements are ultimately very crude devices for forecasting the sound of an amp or any component. It can be helpful in design but in sonics, it has proven time and time again, to be rather crude, ironically enough. We have not even devised the tests that best forecast this. On another note, major F1 and Motorcycle teams have massive amounts of instruments to test each car on every lap, with computer readouts on most aspects. Yet time and time again, the teams have said that the ultimate communication of the car or bike is from the driver relaying the feel and handliing of the car. Some Formula 1 drivers in the past are notorious here. I used to use measurements in the 70s to help in purchases until I realized how futile this was. Please dont equate listening to equipment with astrology...it actually shows your lack of understanding here. No hard feelings here... but reading these musings from someone that has neither particularly good ears or an understanding of engineering in relation to the subject at hand is not easy. kh Quote Link to comment Share on other sites More sharing options...
Deang Posted August 31, 2002 Share Posted August 31, 2002 I have a friend who says, "A little bit of dirt in the music is a good thing." He believes extremely clean and sterile sound is not "musical." I don't really agree with him, especially since I prefer my sound a bit on the incisive side anyways. Maybe the "dirt" in the Eico circuit complements the ridiculously clean, antisceptic sound of the big horns you guys like. Quote Link to comment Share on other sites More sharing options...
NOSValves Posted August 31, 2002 Share Posted August 31, 2002 Mobile, I take it now you went out and researched and found the perfect set of ears now too !!! I swear some people just take this stuff way to serious ! Its all about the music and enjoying your hobby ! Craig Quote Link to comment Share on other sites More sharing options...
NOSValves Posted August 31, 2002 Share Posted August 31, 2002 Just noticed something about this Unbuilt kit. Its not truely unbuilt its Half built. I'm sure that it didn't come with the transformers mounted on the chassis or the tube sockets mounted also the selector switch had already been soldered on. This actually isn't the premo collectors peice after all. Craig Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted August 31, 2002 Share Posted August 31, 2002 Perfect ears? No. A LOT of listening experience with a variety of tube amps of all differenct topologies, from SET, push-pull, triode wired/ultralinear, Williamson, OTL, cheap, expensive, vintage, modern etc? YES. Ditto with some top name solid state. A life-long background in music and audio? Yes. But Perfect ears? No. All of this is opinion based on experience, education, and some speculation. But alas, it is opinion. kh Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted August 31, 2002 Share Posted August 31, 2002 Well, we were all getting along so smashingly and now this. Ironically enough, ole Mdeneen and I, though having many differences in opinion on things audio, appear to have come to understanding concerning our differing ideas. I cant quite say the same for his two students, though we have our moments. C&S and I had a great exchange and total agreement on Mr. Kinkade's complete lack of depth and substance. Audio doesnt come as easy. Ahhhh...it's all just a bunch of metal and glass mixed in with some plastic and paper hoping to convey something of the music we adore. Me? I just poured a glass of Pete's Wicked Ale (yeah, it was on sale).... Things could be worse... I plan to finish it off listening to some Max Roach and Sonny Rollins. kh This message has been edited by mobile homeless on 08-31-2002 at 09:11 PM Quote Link to comment Share on other sites More sharing options...
jazman Posted August 31, 2002 Share Posted August 31, 2002 It seems that few are willing to accept or consider craftmanship as part of the formula. Test instruments are great to an extent, but they never can determine what a combination of parts and elements will sound like. You have an idea, but you don't know, and the instruments will not tell you. HiFi+ magazine reviews products without mentioning or displaying one graph in it's publication. This may be considered mysticisim by some. Has anyone heard of Yoshiaki Sugano, creator of Koetsu MC cartridges? Don Garbers products are a more recent entry. If you have not, do some homework. Science and craftmanship are not seprate, they really should work together. I don't know where, other than C&S's rhetorical references, anyone elevated the HF-81 to mystical status. It is however more than evident, by the judgement of more than a few ears, and not just the ones in this forum, that something good is happening with this piece of equipment and it's interface with music. So mdeneen, if it's nothing but test instruments and parts, you should be on your way to many, many dollars since C&S has an HF-81 to be torn apart and rebuilt, we await the results. NOS404, if it was the cheap parts, maybe Scott is the one who is ripping you off with the parts markup. (There's supposed to be some humor in the above so no flames please.) BTW, EICO as a company was known to produce many very good electronic instruments at a good price point, so they had more than a little know how, and their audio line may have been an additional avenue to leverage their knowledge. It's not beyond my mind to consider EICO as a company was combining many elements in their products, some scientific know how, some craftsmanship. The HF-81 is not the only audio product they produced that is still highly regarded by todays standards. So, if anyone is willing to pursue this as a serious undertaking, let's discuss ways to get started. Klipsch out. Quote Link to comment Share on other sites More sharing options...
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