Tom Mobley

Well, it's no big deal to try it both ways. The actual doing of this is really sort of trivial, the soldering needed is not even hard to get at or anything. I'm refinishing my LS's right now, all the drivers are out of the boxes. I have the Eico hooked up to a set of 4-ohm Nakamichi car speakers just laying there out in the open, the sonics are, uh, er, "somewhat degraded" right now. I'm hoping to have the speakers back together by Tuesday evening, I'm going to go ahead and cannibalize the cherry drivers out of my 77 Heresy's to put them back together. I amy need to recruit a set of good ears here in Phx to do before and after testing, mine are not that great or educated. Any volunteers? Audiophile ears in Phoenix? Here's a proposed procedure: 1) listen to stock unit a while 2) bypass balance pot, trivial soldering, listen 3) if OK, bypass tone controls only, keeping 12AU7 in circuit, listen 4) bypass half the 12AU7 and the tone controls, listen 5) look at routing the (line in) wiring around the selector switch, have to check what (if any) equalization might be being applied to the line inputs on there. Comments, criticism, suggestions? I need to get a test tones CD and one of those Rat Shack SPL meters. Any suggestions on the test tone CD? Good disc, good vendor? Tom

Yeah, they built a huge new HD less than one mile from me. I'm going to have to create a new budget category for it. Funny how I didn't need to make all these trips to HD when it was 7 miles away in heavy traffic. I'll get the book, I'm good with books. Thanks for the recommendation, it's hard to know which of this stuff is worthwhile with a pointer from somebody. Tom

I saw that bleaching stuff at HD, looked like a two part deal that you mix up. Not real sure I want to get into that, could be a bear to get the stuff off and out of the grain, certainly don't want the stuff bubbling the new finish or attacking the glue that holds the plywood together. Tom

Kelly, did you see my post above about removing the tone controls with and without dropping half the 12AU7? How does this compare with the step by step method you mentioned or you Canadian friends method? Tom

Done. Notice my cell phone number in there also. Tom Got any bright ides on the PS buzzing? It vibrates the amp. Nothing I've done has changed it at all. It is putting out the correct voltages, Craig walked me through through checking the voltages in the amp after I bought a decent meter. with LS's hooked up there is a low level hum that's not responsive to the controls at all, nothing changes it including changing out all the tubes. Edit: typos

HDBR, They are oak 3/4" plywood. They were built by a cabinet maker in the Chicago area in the 80's. He did about 10 sets for people up there. The finish on them was badly yellowed and hard as a rock. I ended up renting a belt sander to get the stuff off the top and sides. I used this stuff called Kleen Strip Remover in the mouths, it's watery stuff that smells a LOT like acetone. That old finish was hard, it took three applications of the stuff to get it off, then orbital and hand sanding to finish up. Even that conditioner stuff turned it dark. I'm thinking about that pickeling stuff now. Not what I really wanted when I started. I may just go to the Tung oil, it doesn't require sanding between coats, sanding these things is a non-trivial deal. I use high pressure air and a vacuum to get the dust off, not good enough? I can see the sanding dust coming out of the grain with air. I can't think of any other way that doesn't involve a garden hose. Tom

Little tough to tell right now. My LS are torn down to refinish the boxes, my Eico is currently hooked up to a set of Nakamichi car stereo speakers. I think their sensitivity is, uh, somewhat less than the LS's. being kind about it. However, the PS itself is still buzzing away like it always has. I've replaced the PS caps and the can cap, no fix, no difference. It sounds just like the transformer in the 4 foot flourescent light over the workbench behind me. In fact, I turned off the light to see if it was really the light or some kind of weird interaction. Pat, did you see my offer to help you with the email address of the thief you recently encountered? HDBR, please have a look at the topic I addressed to you over in the updating older speakers section, if you get a chance. Tom

Hey guys, If you've ever tried to collect on an insured UPS or PO package you'll be well prepared to deal with collecting on the surge protectors equipment warranty. I've never heard of anybody actually getting anything out of this yet. It's widely regarded in the computer business to be a marketing scam. Tom

Clipped, unless your amp has pre-amp inputs labeled as such (few do) you're going to be using the method given by HDBR above. There's just not much way to get around it Tape in and Aux in are about it. Tape in is probably cleaner. Tom

HDBRbuilder, I'm having serious trouble getting the finish on these LS cabs to come out like I want it. See these pics: LS cab pics The stripped and sanded oak plywood is very light colored, everything I put on it darkens it substantially as you can see. I've tried Tung oil, regular satin urethane and water base clear satin varathane which was supposed to be crystal clear. Everything I put on it instanly gives it this darker, reddish appearance. The water base is lightest, followed by Tung oil over wood conditioner, then plain Tung oil and regular urethane. All the products are Minwax, BTW. Actually, the part where the sample finish is was not stripped, just sanded with an orbital sander, first with 120 then with 320. The wood feels real smooth and looks great, but was really hoping to preserve the blonde-ness of it, not get the darker, reddish effect. Got any bright ideas? Tom

Mike, That thing looks pretty good to me. Those pics were taken in a very harsh light, maybe direct sunlight, makes things look worse that they really are. I don't care much about a few scratches on the faceplate, but what I could see of the works looked pretty cherry to me. It'l be interesting to see what shows up, unless it's totally roasted I should be able to get out of it OK later. I though the BIN price was very attractive. Tom

Kelly, Why don't you start another thread labeled Super HF-81 or similar, make the first two posts be the ones from this thread along with your post from the "Clean HF-81 on Ebay" thread, I'll put in my replies from here and over there, we'll consolidate the deal into one thread. I'm willing to use my HF-81 as a breadboard sort of thing for the changes, but we may need to recruit some real ears from Phoenix for testing since mine aren't really much good. I've got a set of Heresy's and LaScala's to listen to. The actual work involved in bypassing the tone controls is trivial, move a couple wires. So, basically, I'm suggesting we make this into an online project, use my existing HF-81 as a breadboard. Once the design is validated on my Eico, build a open tube prototype on a metal chassis, then a finished product with your cool wood, polished copper/brass, all that. Tom Or I'll do it (start the thread), if you want to proceed that way. Or, we could take it off-line, but I'd rather do it in the forums, excellent chances of picking up good ideas from the others. There's some very knowledgeable people on here.

this is a flash animation with sound: dancin' turkey Tom

Ed, >>When I received the preamp the input selector switch was broken. I contacted Kirk at Cary for a RMA to have the switch replaced and I also paid to have the AE-1 completely checked out to be sure it was in proper operating condition. When I got the AE-1 back from Cary it didn't work...it sounded great on one channel and nearly no volume in the other.<< Yikes, this is really not good. Are there other reports of this kind of service from them? I thought they were supposed to be pretty good? They must not have even powered it up. Tom

Mike, They are all three 500V, the 20 is a little physically smaller but not much. I just bought this Scott 222C on ebay, I've decided I want to keep them until it shows up, probably ask $10 plus $3.80 for a stamp. I just know that if I let them go before it shows up it'll need one. Kelly, Spent some time with my upsidedown HF-81 and the schematic, here's what I see: Looking at channel 1 (left side looking at the amp rightside up and from the front) the signal leaves the vol pot via a green wire and goes straight to the pin 7 of the 12AU7, then exits from pin 6 via one of the .1uf caps, to a solder lug and on to the tone controls through a brown wire. Signal returns from the tone controls on a gray wire which goes directly to pin 2 of the 12AU7, exits from pin 1, goes through the other .1uf cap to a solder lug and directly to pin 7 of the 12AX7. These solder lugs mentioned have two purposes, one to provide mechanical suppport to the cap and to provide a handy place to hook up that goofy tape out circuit. Two methods of bypassing the tone controls present themselves: first and simplest, run the signal wire from the vol pot directly to pin 2 of the 12AU7, disconnecting the wire that now runs to pin 7 and disconnecting the gray signal return from pin 2. This amounts to a brute force type bypass of half the 12AU7 and the tone controls. Presently unknown is how leaving half the 12AU7 dead would affect the live half, I have someone looking into that. The other unknown is the effect of dropping half the amplification. I don't know if that first stage of amplification is more or less "soaked up" by the stuff in the tone controls or not. Which consideration surfaces the other fairly obvious method: keep the first stage of the 12AU7 and it's output cap, but instead of running the circuit from the cap to the tone controls as detailed above instead run the output signal from the cap directly to the input pin 2 of the 12AU7, again disconnecting the gray signal return wire from the tone controls. This approach retains the amplification function and capacitance of the first half of the 12AU7 while dropping out the tone controls. I really have not enough experience with this stuff to have a feel for which method would work best, but it does occur to me that if the gain is thrown off too far by either method it might be resolved by swapping out the 250K vol pot for a 100K or 500K, depending on which way the old ball bounces. The other channel is the same electrically but a little different mechanically because of the unwanted and unneeded "Speaker Selector Switch" which, if thrown, completely disconnects the output of the channel 2 line stage from it's output stage and instead splits the channel 1 line stage output between both channels of the output stage. Channel 2's line stage output is just left dangling in mid-air while channel 1's line stage output is suddenly split between two power amps with no compensation for the different resistance and impedence it now sees. Eico's willingness to implement this sort of brutal approach is leading me to figure that the first method given above might be OK. Just so we're on the same page I'm using the term "line stage" to refer to the functionality of the two sections of the 12AU7 and "output stage" to mean the 12AX7 and the two 6BQ5's, which may not be technically correct. If running only half of the 12AU7 turns out to be the way to go, the bottom of this amp would be cleaned up and simplified considerably by leaving out the caps and tone controls, the goofy "Speaker Selector Switch" and the even goofier "Tape Out" wiring. Clear as mud? Good. Tom (proofreading this at 3:30 AM, errors and omissions may occur, but I can't see them now)

Hmmm, one of the posts seems to be a little on the large size. Guys on dialup will think it froze up on them. Tom

Craig, I looked at that earlier. Looks pretty good to me. I don't like his limited payment options though. He did at least know what the blue thing is under there.... Tom Incidentally, I now have a set of 3 Sprague Atoms 40, 40, 20 I was thinking to use to replace the can cap. I put put a can cap in it, I'll make somebody a smokin deal on these. Tom

Kelly, Your super HF-81 is exactly what I've been thinking about doing. I've been analyzing the schematic to see how to leave out all that stuff without changing the basic characteristics of the amp, I'm stuck on the part where the tone controls and half the 12AU7's get dropped. I would appreciate any guidance I could get from you or your Canadian friend on this. The schematic is difficult for me to decipher because of the involvement of the RIAA stuff in the selector switch and the tone controls being being sort of in between the the two sections of the 12AU7. I do however have a close friend with a PhD in EE who spent time on this stuff back in the sixties. He has offered to help with detail of the circuit mods. Apparently there may be issues with dropping out half of the 12AU7, he thinks this will change the way the remaining half operates. Might need to look for a tube that is similar to half a 12AU7, which in turn will inevitibly raise other issues needing to be addressed. He's digging through his old tube books for one. It may be worthwhile to check into creating a sort of dummy circuit for the unneeded half of the 12AU7, just to keep it live. Are you thinking about retaining any of the physical appearance of the Eico? I've gone around and around with this aspect as I was thinking about marketing a kit for this. Tom

Pat, If you're using Outlook or one of it's variants, display the email from the guy and go to the menus, View/Options, it will show you the internet header in the box in the lower part of the window. Usually the internet header is longer than what will fit in the box so there's a scroll bar on the right. Make sure you are at the top of the header, click the first character and hold the button down, drag the cursor to the bottom. What you end up doing is sort of bouncing the cursor off the bottom of the box a few times to get it to scroll down to the bottom of the header. If you do the click and hold thing right you will see the lines of text highlight as the cursor goes down to the bottom of the header. Then let go of the mouse button and hit Control-C, that will copy the header text into the clipoard memory. Open an email to me tmoble@earthlink.net Once the blinking cursor is in the body of the new email to me hit Control-V, the message header text will be pasted into the new email. Title the message something like "email header text from Klipsch Forum" and I'll get it, help you decode the header info for the guy's ISP and whatnot. If you have trouble with this, call me on my cell at 602-550-2009, I'll walk you thru it. Tom (Are you using a Mac? If you are you will still be able to do this, but I don't know the specific menu choices or keystrokes.)

I ordered the diaphragms for my K-35B's from them, EV was on backorder. Anyway, ordered on their site late Sunday nite, got the pieces Fri afternoon. Took me a few minutes to figure out how to reassemble them. I had to drill the solder out of the center of the rivets that hold the terminals on, feed the tinsel wires through the holes, assemble, solder wires from the outside. There's a mark on the diaphragm that corresponds to a notch in the magnet for keeping polarity straight. Really wasn't that bad once I figured out the hole in the rivet deal. The original wires that ran from the coil to the terminals is the same size as the coil wire itself, probably is the tag ends of the wire left long. It must be 32 gauge or something like that. I could hardly see it, it was so fine. Kinda makes a guy wonder why he needs to run a 14ga wire from the crossover to it. That wire is thinner, much thinner than one strand of the 14ga stuff running to it. Tom

jeez. and that Mac pre-amp, must have been a killer setup. Wish I had some money laying around.

dean, the only meaningful upgrade I've seen for Heresy's involves the mid-range being a little hot. It's the same driver as a KHorn (so is the tweeter) so with the smaller woofer some have complained the midrange was overwhelming the bottom. The Heresy has the t23 transformer, I believe someone on here has detailed a change involving moving the squawker tap on the transformer to cut the squawker output a few db, even things up a little. I recall it's from tap 3 to tap 2. I did this to mine, but I typically listen to these at very low volume, I think this mod helps more at higher volumes. HDBR is right, AFAIK, about the adding supposedly better woofers. It is an air suspension box, cone excursion is going to be limited. On my 77 models the woofer cone doesn't move (excurse?) much even at high volumes. If I were going to do anything to mine it would probably involve better sealing of the boxes. Gaskets or RTV mounting the horns and woofer, weatherstrip or something on the backs. Not very glamorous, for sure. Tom

Well, I'm far from an expert, but it looks to me like those nets contain extra parts to protect the drivers, especially the tweeters from abuse in a pro audio environment. There's a lot of stuff there. Didn't you mention having built a set Al K's for somebody? You didn't let them get out without at least trying them on your LS's, did you? Are your drivers V's or M's? Do you want to try out my Al K's for a week or two? I have no tweeters and my amp is all apart for the cap replacements/upgrades. Cover shipping and they're yours for a couple weeks or a month. Or, I might even do the shipping if you give me some credit on a future Scott overhaul or something. Who knows, I might even end up needing rescued on my Eico. Let me know what you want. Tom tmoble@earthlink.net Edit: I've also got a pair of stock AA, I think they're early models.

It's there. It's bigger than the Isophon plans show. I'm thinking there's going to be a clearance issue when it goes back together, there might need to be an "adjustment". Tom

Dean, Chris, "Dean, you're on to something ... I'm thinking about the "next phase" after 50 ... three years to go. Let's see ... company would be virtual with imbedded IP (smart people on this forum, me excluded) ... What's the money angle we could exploit?" Only about half year left for me, why do you think I'm digging around looking at reproducing or re-issuing the Eico, stuff like that? I have no real retirement to speak of, what I did have mostly evaporated over the last year or two. I need some little business that I could run from home or a small shop. I was over at AES in Tempe the other day, was astounded at the size of their place. The market for this stuff must be much larger than I was thinking to support a specialty shop like that, and it's only one. I'm good at most of business but that "money angle" part, too bad. Tom