Marvel

Jon, I understand your concern with upping the wattage rating on the resistors. The problem is the originals are too small so they tend to break down quicker over time. Replacing them shouldn't be too hard at all. If the traces on the board are still good, you can clean them off and replace the resistors as mentioned above, leaving the leads a bit longer so they mount away from the board. If there is room and you are careful, you could mount the resistors on a heatsink, to cool them even more. Believe me, it will work wonders. Bruce

Here's the pic. I forgot to scale it down.

I also used the Curcio under chassis ps board. I did replace the power tranny with one from Ned at Triode Electronics. The attached pic shows how massive it is compared to the original. Ned's is on the left, original on the right. It still gets pretty hot, but we have TVA power here and the voltage pretty much stays at 125 VAC. Bruce

tpg, So, does your mom understand now, that there was something wrong with it? Looks nice. His designs are great. Bruce

Craig can probably (make that definitely!) give you more info on the biasing of the KT88s. The plate current rating and the bias current aren't the same. The .02 mfd cap can stay the same value. The heaters on the KT88s pull a bit more current than the EL34. If you are using the original PS tranny, you may find it warms up even more than before. I would think it would be quite a stress on the PS to use KT88s. Whose upgrade driver board did you go with? I am tempted to replace the Curcio board I put in last spring, mostly to see what difference there would be. It sounds okay. Way better than the original, but there are better designs around. Bruce

Terry, Does that mean you aren't enjoying that little rascal yet? Sounds so sweet. Bruce

Many of them are made with a silicone rubber compound, which will resist the high heat of the tubes. I had one of the 7199s in my old Dynaco that would start to whine at me every so often. I would tweak the chassis and it would stop for another hour or so. But they were going on 25+ years. Bruce

skonopa, I do the same thing all the time. btw, I love the Wright designs. Bruce

Michael, It was the certainlywood website that I got the wood examples from for the 3D drawings. Just wanted to let you lnow I hadn't forgotten ya. The program acts up every once in awhile. I want to render a higher res image than the ones I had already done. Bruce

Anyway, my parents really love seeing Frank Lloyd Wright's Joseph and the Technicolor Dreamcoat. They have that DVD with Donnie Osmond playing Joseph. ... I think you mean Andrew Lloyd Webber. Frank Lloyd Wright designed houses. [] Bruce

Michael, I believe it would be possible, once the poly is off the wood, to steam out some of the Titebond II. Then again, you might end up havign to do the whole side again. Looks nice though. Bruce

D-Man, That second pic can be found on Bert Doppenberg's website. The purple horns are his, and the bottoms are one of the earlier Pi Speakers cabinets on their sides with the excess cut away. Other than the colors I find them pretty cool. They don't look that big until you compare them to the chair in the photo. If you go to his site and click on the showroom link you can see lots more with his horns. One guy is a dentist and has a pair in his office pointing at the patient's chair. The sweet spot! http://www.diy-systems.com/ Bruce

The lasers on older generation CD players actually tracked right on the surface of CDs. They were especially susceptible to skipping when the CD had the least amount of warping (or experienced external vibration, I guess). Not true. It had to do with the beam splitter technology. I worked on CD players. They all had a mechanism that when a CD was inserted, the lens would track up and down (towards and away from the disc) until it could focus the laser properly. It constantly tracked the disc that way. Some were just better than others. I just recently threw out the repair literature I used, or I would scan it and post it.

A Zobel is a series resistor-capacitor (R-C) network that is connected in parallel with a loudspeaker driver in order to neutralize the effects of the drivers voice coil inductance L(e). I found this on the web. Is that accurate, in a nutshell, the straight poop?

Michael, I used Caligari TruSpace 4.3 to model the LS. I used a veneer sample from one of the wood suppliers to map onto the objects. In this case a fiddleback makore. I wanted to put the drivers in but have never gotten around to modeling them. I have some other shots with other woods too. Makes a great wallpaper if you use 1024x768. Set the background to black and then center this shot. This one is quilted mahogany from a different angle. Bruce

The LaScalas have a piece of wood on the bottom of the cabinet that comes off. Quite a few screws. The allows access to the "doghouse", so you can remove the woofer. Some of the older models (I can't remmeber how old), had access through the top area. IOW the access door/hatch was on the top section (underneath the mid horn). This was obviously more difficult, so the design was changed. See my drawing that is attached. Check all the wiring before assuming the driver is bad. Bruce

You're still using something with water. The tech sprays will work better and be safer for the gear.

Are you building these yourself this time or having the cabinet maker do them? I know he made a lot of money off of you on the first pair. Are you using the Eminence CB15? Bruce

Does this have speakon connectors? They are probably wired funny.

Is that a plastic gear or metal? If someone has a good one it is possible you can make a casting of it pretty easily. Craig's generosity (if he has the part) would certainly be easier. Bruce

The model 14 has a printed circuit board in it that is an overload protection circuit. Maybe the guy messed with that and screwed it up. Perhaps someone on the Lansing Heritage forum can get you a schematic of everything in it. The forums are here: http://www.audioheritage.org/html/forums/forums.htm

I have an earlier model JVC (1972), integrated, with 7 band EQ. The thing is only 30 wpc, but weighs a ton. It is very well built. Those later ones have way more fancy stuff on them that the Japanese seem to like. It has some issues, but I can't bear to part with it just yet. It was the first good piece of gear I bought. Bruce

Too funny!

I would keep the original crossovers. If you decide to sell the LaScalas, you can quote two different prices. With the originals and with the new ones. What are the Model 14s you are talking about? Bruce

CTP, This is from the upscale audio website: "Tubes age in a couple ways. One is they lose emissions over their lifetime. In other words, they run out of gas. Or better yet steamas they dont just "quit" but lose their drive capability gradually. If you figure a tube like a 12AX7 or 6922 to be good for about 10,000 hours, and you leave it on 24 hours a daywellyou do the math. There are 8,736 hours in a year. So when did the tube go bad? It depends on how picky you are. Its like a tube of toothpaste. Kinda peters out at the end but it seems you can squeeze out a little more. Some products (and audiophiles) are more picky than others. I recommend to folks that want to upgrade to premium new old stock tubes that they do it while their stock tubes are good. That way you have the cheap ones working and available should you decide to sell the pre-amp." In other words, they should last a long time. Many factors come into play. Some amp designs have the bias up on the power tubes, thereby shortening their life span. Ventilation could make a difference, but probably a smaller one. You small signal tubes will last longer than the output tubes will. Mac amps are pretty easy on the output tubes by design. But enjoy it. I never changed tubes in my Dynaco from the mid '70s to 2002. There were times I had in on for many hours a day. I should have changed them, but they were still working. Bruce