DRBILL

I just finished installing Bob Crites A/AA crossovers and refitted drivers. The result is stunning. You never notice your windows getting dirty on a day-by-day basis, but when you wash them you see how much you were missing. <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /> While I was at it I did routine maintenance. I cant remember the last time I did it. I tested the tubes, reset the bias, snugged up a few loose RCA plugs, cleaned and lubed the pre-amp controls, dusted everything including the CD player lens. A lot of audio gear wont complain about a lack of maintenance until it fails. Dusting and improved ventilation should be at the top of the list, with bias correction a close second. DRBILL

About every year and a half as best I can figure it. There is absolutely nothing that can be added to this subject! Or maybe it is like a bedtime story of which the children never tire. I'm guilty, too. I recently asked a serial number question! DRBILL

I had one grunch but the eggplant over there.

Get the blue ones. RadioStore has them. BILL

try WWW.VACUUMTUBES.COM Don't forget, any that you buy from over the pond will be for 120vac. Best, DRBILL

Mais oui! I could toss a couple of dozen down right now! Sadly, because of a medication that I have to take for RA, my immune system is compromised. I may never taste another oyster. My favorites are from the North West. Small, but full of flavor. With my own eyes, I watched my son, when he was fifteen, put away five dozen in one sitting. It almost broke the bank. I could go on with this story, but perhaps your imagination can finish it. DRBILL

DJK, I'm back and sad to see the storm still raging! Sad. But, yes, you are perfectly right. I have the AAs on order and they should be here soon. This is probably overkill, but I am having the diaphragms in the tweets and mids replaced, too. Clean slate, as it were. The AK2 is a poor substitute for anything. I'm ashamed for Paul's sake. Thanks for your input. DRBILL

I am so terribly sorry that I was the cause of this enmity. It is almost enough to make me want to "sign off" on the forum. As a matter of fact, I'm going to take a week off without reading or posting anything. Brother Colter opted out. A week might reveal other areas that need my time. Who knows. DRBILL

It is a VERY bad idea to operate a tube amp with no load. I hate to be the one to take exception with our venerable brother on this issue, but someone might be inclined to take his advice and destroy something valuable or irreplacable. I have read the warnings too many times in too many manuals to be less than sure about this issue. Vacuum tube amplifiers, unterminated with a proper load, can go into self-oscillation which can cause self destruction. You can lose the output tubes, the output transformer and/or the power transformer. The expensive items usually open in time to protect the fuse (as PWK liked to note). In many amplifiers, you will see a resistor from the 16 ohm output to ground. This is an attempt to prevent oscillation. I keep a couple of 8 ohm wire wound resistors with alligator clips on my bench just to be safe. That's the only intent of this posting --"just to be safe". DRBILL

That's tough. Here goes. I read somewhere that certain brands of carpet have conductive fibres to prevent static discharges. This was useful in rooms housing sensitive electronic equipment. Perhaps your test lead contacted one of these and established a path from your chasis to ground. Was this AC or DC? If it was DC I'll have to make up a different answer. [] DRBILL

That is interesting. But, of course, the voice coils and the secondary winding of the output transformer are copper and I can't think of any way around that. And the "grainy" or "raspy" sound disappeared with the Heresy substitution. Please keep us up to speed with your research. DRBILL

Yes. It had something to do with the nut that held the on-off switch. [] DRBILL

Well. I think it was Mark Twain who said "Beethoven's music is a lot better than it sounds."! [] DRBILL

Michael Marx at vacuumtubes.com makes a market in tube testers. He could probably direct you to the people who do his work. He will also have your manual which probably has calibration instructions I got my tester (B&K-700) from him. It came with calibration instructions that took about an hour and only required a volt/ohm meter and a few common resistors. I was amazed the first time I had mine apart. There is very little to them! DRBILL

My drivers are away for a retrofit by <?xml:namespace prefix = st1 ns = "urn:schemas-microsoft-com:office:smarttags" />Bob Crites and Im awaiting new AAs to replace the strange AK-2s. So what do I do for my daily music fix? It suddenly came to me. Pop the Heresys on top of the K-Horns and hook them up to the wires that come from the bass bin to the AK-2s. This results in a four way system with the woofer and its crossover intact and the Heresys getting the information that previously went to the mids and tweets. And it isnt half bad! It has a punchy sound that you feel in your sternum. It would really please those who prefer a cone mid. Of course, it isnt the seamless sound of an intact K-Horn, but it will sure do until I get my gear back. <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /> The most important thing is that it cured the anomaly that prompted me to get new diaphragms and crossovers. I know that Im on the right track. It might be overkill, but there is nothing quite like a clean slate. My beef was a brittle, raspy sound, almost unnoticeable unless you were listening for it while massed violins or womens voices in chorus were present. DRBILL

ME TOO! DRBILL

Sorry, but I have been having trouble sending a post. DRBILL

I'll take them! Do you take PayPal? DRBILL

There is obviously something to retrofiting crossovers or Bob Crites wouldn't have any business. My speakers have AK-2 "balancing networks". Sometimes I imagine I hear a slight raspyness in very complex waveforms like massed strings or a chorus of womens' voices. It makes me wonder if I need a new crossover or perhaps there is a crack in a diaphram. I know for sure that my left tweeter has more output than the right one. (Yes, I swapped left for right amplifiers and the same tweeter was too loud.) I know quite a bit about amplifiers and precious little about speakers. I will appreciate any guidance. DRBILL

Thanks, Lads, I once had a chart. I'm pretty sure the boys borrowed it. Mayhaps the wife trashed it while dusting. It couldn't have been me, methodical as I am! Best, DRBILL

I would appreciate help decoding 8617980 8617982 KLIPSCHORNS Thanks, DRBILL

When I was in college (late 50's) I visited the registrar's home to hear his "stereo" (Mac's and Patricians). He had a device that he called a "decompressor" that went between the preamp and the amp. It had two controls. There was one that established the loudness that the unit used as a threshold and one that established the slope of additional loudness. It was mighty exciting on things like cymbal crashes. The flaw was that it brought up the background at the same time. You could get a little sea-sick listening to it for very long. I'm sure there is sombody out there that remembers these things. It might work better for home theatre than it did for symphonic music. DRBILL

And in addition to all the rest, your prose is stunning. Thank you. DRBILL

Keep good books. "You can't make what you can't measure because you don't know when you've got it made" (a quote from PWK, I assume original). DRBILL

I'm putting my money on static discharge. What is the Relative Humidity in your recording area? I have experienced the same thing with acetate, but seldom with mylar. There was some kind of anti-static spray but I don't remember what it was. You could use it on tapes or LPs. That was a long time ago. Maybe some of the brothers will remember. DRBILL