Tom Mobley

Craig, here's a pair, look pretty good. http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=1378937948&ssPageName=ADME:B:SS:US:1

mdeneen, Yeah, I'm sort of up on that stuff, I didn't really understand it's really varnish. When I built my ALK crossovers I had a nasty time to get that stuff off the ends of the Litz wire inductors. I burned it with the soldering iron, used a little toothbrush shaped stainless steel brush and finally took them out to the garage and used the oxyacteylene cutting torch and wire wheel, fixed. Thanks for your postings, your experience is invaluable. Tom

C&S, thanks for taking time to look and post. All data points are gratefully accepted. Kelly, somehow I missed your post at 7:26/7:31. I'm not copping out on my guy yet, suffice it to say he's not a name recognized in audio. But, he also alluded to quality differences in what he termed "electrical steel", the lamination material. He also mentioned a couple different grades of wire and differences in that varnish-like insulation. <-- tip-off to the depth of my ignorance there, I don't know what that's correctly called. I'm wondering if the fact that these transformers have the ability to support all these different load impedences (esp. the four ohm) is an indication of their native quality. Tom This message has been edited by Tom Mobley on 09-05-2002 at 12:44 AM

Ray, If everybody operated on the kind of level-headed, common-sense basis you're expressing here, your approach would work perfect. Are you an engineer? But that's not the way people work. People get caught up in their own excitement, get emotionally committed to the item after they've bid on it a couple times, etc. Sellers hope to encourage this by whatever means available, experienced buyers lay back waiting for the moment of truth, greenhorns get caught up in an emotionally driven bidding frenzy. Experienced buyers try avoid encouraging the newbies to run up the price unnecessarily. Check the guy that bought the 14's, he bid once at the very beginning, then again at the very end. His bid hit within seconds of the end, and it ended on an even dollar, probably his max was higher. And, the truth is I'm not any better than others on this. I had changed my max bid to 312.87 from 257.76, but pulled the trigger probably a fraction of a second too late. Might not have won it anyway, no telling what his max was. This does demo conclusively that I had no real idea how much I was willing to pay for those known defective things. Crazy. Tom I'm gonna go buy the rusty HF-81 before I ruin my wallet.

Paul, Thanks for giving it a try. You never know what might develop from something unlikely. Tom

I was watching it too. I was refreshing the screen and had a mid $250 bid ready in another window. What was funny was checking the hit counter on each refresh. A LOT of people were watching that thing. The hit counter increased over a 100 in couple minutes. mdeneen, good info there. interleaved windings maybe aren't as rare as the guy was hinting. He might be prepping me for a price point. I won't forget that. I've seen elsewhere that a pair of these is considered a pretty nice amp. A pretty simple 6BQ5 circuit, looks like. Tom

Do you know him well enough to ask him if he knows anybody? Tom

the ones with the lips look nicer. Yes, jazman, any available info is more than I have now. Please do, at your convenience. Kelly, do you have contacts with historical info? Is there anybody around now that worked at Eico then? I'm a recognized expert on the GM Quadrajet carburetor, digging around on the net I was able to sort of accidentally dig up a guy who was one of the engineers on the dev team for the carb in the early Sixties. Guy is an absolute treasure trove of info, and he knew another guy who was a chassis engineer at GM during those years. This guy turned out to be a sort of bottomless well of car knowledge. Wouldn't it be cool to find somebody who worked at Eico? Anybody got any bright ideas? Tom

kelly, much thanks for the time and trouble to post that. That's helpful. I know somebody in the business, he thinks they can reverse engineer the things from a working sample without unwinding them. However, if presented with a non-working sample they may have to disassemble it. Apparently they can determine turns ratio, number of turns, other basic stuff easily, but there's a possibility that the things have interleaved primary and secondary windings, a high quality deal that provides better efficiency and whatnot that's apparently fairly unusual. Still no volunteers for a bum unit, huh? Asking around a little I find no-one with experience of bad Eico trannies, but several have mentioned issues with their Dynaco units. Hmpf. Apparently they're a premium item. Tom

Yeah, that's the ticket: settle the packing order stuff and let's get back to the Eico trannies. Anybody got any? I hate to unwind a good one but I'm not having much luck finding a bad one. Somebody has to have one. Please purdy please? Can somebody with an HF-81 get the numbers off the trannies? I need help here, I've got a line on a corroded HF-81 but the guy is hard to get hold of and the thing still works so he's not giving it away. Are there numbers stamped into the covers? printed on the laminations? Tom

Anybody got a bum or suspect Eico transformer? Or even a reasonably priced good one? rusty wouldn't matter. Tom

danocaster, I sent you a paypal. Tom

Well, back among the living.... I'm not as dumb as I look, I just mixed up the 12 and 14. I was thinking about how to hook up a stereo source to two mono integrateds. I'm thinking about bidding on these too. I see those Eico pre-amps going for reasonable pretty often, this could make a decent deal. The 81's are too expensive when they are on ebay, and I don't have time to comb pawn shops and thrift stores for the stuff. jazman, "So, the HF-81 is not a religion or mystical object to me. I am willing to ask questions and pursue answers, and if it's just all parts, let's charge by the screwdriver twist to price the damn thing and make some bucks. We'll just attach mystical attributes to it based on the number of screwdriver twists in the marketing plan. Has anybody got anything against pursuit of more information and the possibility of making a little money?" Exactly. I'm real good at figuring out how to build stuff and then productionize that process. Probably has to do with my years working as a human robot in the plywood mills. Kelly, mdeneen et al might well be right about the amp being more than the sum of it's parts and stuff like that is always cool. That in no way excludes something else from being more than the sum of it's parts too. OTOH, it might also be a very well matched combination of tubes and trannies that could be duplicated if somebody took the time to analyze the stuff and dig up the needed parts. They were selling this deal for $70, the stuff in it couldn't have gold plated for that money. And, back to my earlier question, who can analyze a transformer? Tom

ripped and torn, I was eyeballing those a little while ago. Too bad there's not more info available. What I'm wondering is exactly how a guy would hook these up as stereo. They're integrated amps, not power amps. Like from a CD player, just hook the left output to one and the right to the other? I can't think of any good reason why it wouldn't work. Yeah, and ebay was swamped with Eico stuff a while back, but a lot of it was test gear. Tom

anybody know the characteristics of the magic trannies? Tom PS You've all heard of the Tube Asylum? This is the Tube Minefield.

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

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

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

Go to the JBL vintage site, it'll be listed there with detail. http://www.jblpro.com/pages/obsolete.htm Tom

Craig, I missed that Scott 299, was out of the house and got back about 10 mins after the close. It went for 202.50 to a last minute bidder. The previous high bid was 200 even, 202.50 is the next increment so I figured the winner had a higher max bid in, no way of knowing how much higher. I'll keep looking around. Tom

Yes, I bought a set of new K-33's recently and they were $100 apiece including shipping. Hard to beat a deal like that. Although they are not the speaker that a JBL 2226 or D-130/140 is, I think they're pretty well optimized for their intended use, sound good. Tom

I'm with C&S, why couldn't the schematic be simplified down to the essentials, equivilent quality transformers found and new units built? Really only need a couple inputs, dump the tape head input and other unneeded stuff. Are 16 and 4 ohm speaker taps really needed? Seems like the skills are here on the board to analyze the circuits for what's really needed and breadboard a unit or two for testing. I'd be willing to do the grunt work of building up the test units if somebody wants to try, the circuit analysis is the hard part and needs somebody who understands tube amps and what all can be left out. Anybody interested? Tom

You mean you guys didn't know that large speakers are actually penis extenders? Amazing. And, to what exactly do you attribute the popularity of those amps with the really big exposed tubes? <sheesh> us car guys figured all this out long ago, months, even. Tom g,d & r

Jeez, you guys are a rough crowd. Both of those things look pretty good to me, and I see the part about not having a single part replaced as a positive, not a negative. At least it isn't butchered up by some goofball. The other guy adds 12+12 and gets 30, who cares? I'm not hiring him to teach math. Craig, what do think it would cost to re-cap that Scott? That thing looks pretty nice. Do you know of anybody in the Phoenix area that could do it without butchering it up? Tom

John, those are monoblocks, right? Are they well thought of? I looked at the their site, didn't recognize the tubes. I'm interested in them, but I would need a pre-amp, how would one of the Eico's work? Any ideas? Tom