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Almost forgot. Here's a photo of the speakers. Actually they aren't really lying on their sides. Seems that the photo uploader has a mind of its own. It's right side up prior to uploading. Maybe the site remodeling can fix that.

My quest to sample as many speakers as possible has finally lead me to a pair of Martin Logan's. I've always been fascinated by electrostatic speakers and it was time. A pair of reQuest speakers popped up on craigslist a while back. Retail was around $4500 in the late '90s. The owner said the panels were shot, and he was letting them go fairly cheap. In talking with him and with Martin Logan I came to question his diagnosis of bad panels. He assured me the crossovers were OK. In fact, he had removed them and sent them back to ML. They had tested them and given them a clean bill of health. He had the documentation and the response curves from ML to prove it. Only problem was that if the panels were bad, it would take $2K to get new ones. I went over to take a look. They were immaculate. He was sure the panels were bad so the price was really, really low. I bought them. I got them home, set them up and they didn't sound too bad. The panels sounded fine to my ears, but the bass was dramatically missing. I got to thinking. He had the crossovers out, so maybe he screwed up the wiring on the woofers. I opened each one up and checked the phasing on the woofer wiring. Sure enough, one was hooked up backwards. Eureka!! I put them back together and they sound great. Great imaging. Great balance and now Great bass. Sometimes you get lucky... Here are some photos for the curious. First one is the crossover and high voltage power supply. Second one is the schematic.

Sorry. Limits are fixed. You gotta delete both sent and received messages to free up space.

Just a note, but a properly done BillD mod slightly alters the gain on BOTH outputs. A C1 cranked full throttle (BillD or not) will likely drive any amp into distortion.

Likely failed electrolytic caps. Send it to Bill at http://www.flannerysvintageaudio.com/ You can just send him the amp. I just finished recaping a True sub. Not an experience I want to repeat. Bill does good work. Tell him thecarversite sent you.

It LIVES!!! Currently spread across the bench and probed in almost every possible way, the Sunfire Sub is alive and thumping. I've learned a LOT and I'm still confused about the grounding inside this little monster. But, it works. Here's a scope trace that shows the output waveform and the tracking downconverter controlled rail voltages. Not sure why it isn't tacking better, but that's a mystery to solve tomorrow. Maybe at higher levels it behaves more nicely. Once I'm sure it is working WELL, I'll write up all the parts that had failed and mistakes I made along the way. 50Hz sine wave.

From my research, zero ohm resistors are essentially used as jumpers. They have the added benefit of behaving like high amp safety fuses as well. Consider this. There is really no such thing as a zero ohm resistor. Resistance is more like a few milli-ohms. So -- for a 1/4 watt zero ohm resistor that is really a 2 milli-ohm resistor the following holds. How many amps will this little beast handle before it vaporizes? P = V * I V = I * R Substituting for V we get P = I * R * I Solving for I I = sqrt(P/R) Using P=1/4 watt and R=.002 Ohms I = sqrt (.25/.002) I = 11.18 amps So -- our itty bitty 1/4 watt zero ohm resistor is really an 11 amp fuse. Why not use a fuse? These are used for safety. I.e. Keep the house from burning, not protect the subwoofer. Further, a zero ohm 1/4 watt resistor can be inserted on the board with the same machine that puts all the other resistors. The same can't be said for an 11 amp fuse. In the case of my poor abused subwoofer, BOTH the positive and negative sides of the output transistors were shorted. Direct short between high and low rail (depending on what the FETs were doing). Those little guys saved the board from having traces blown off. Note that one of the FETs in the high rail is also shorted. God knows what happened to this subwoofer, but it must have been exciting. There is likely more damage. I'll post later after I replace the dead semi conductors, zero ohm resistors and do a complete recap. Several caps are completely shorted. L2 - the inductor at the top was completely blown off its mounting points.

I believe Retriever has nailed this. Its a zero ohm resistor. You can tell because of the black stripe seen in one of the photos. Black is zero in the resistor color code. Based on the size I would have to guess it's 1/8 watt. 1/4 components are easily available at Digikey. One step at a time, and I'll have that sub thumping away again.

Wow. Thanks for the offer but this is really just a wild crusade to save a very dead sub that is suffering from a variety of problems. I appreciate your offer.

I've acquired a Sunfire sub that should be scrapped, but I'm too stubborn to toss it out. It suffered some sort of disastrous event that left transistors dead, caps swollen, an inductor that had one end lifted from the board and two so called jumpers that had been vaporized. Of course there may be more damage I've not yet found. But, I need help in identifying two components labeled JP1 and JP2. I suspect they are fusible resistors of some sort, but values and wattage are a mystery. I need enough info to order a pair. The schematic available on the site here - called the "tracking downconverter schematic" is about 90% accurate for the sub. Unfortunately, there are not part numbers for JP1 or JP2. I offer up the following photos. 1- Schematic showing how they are used in the circuit 2- JP1 and JP2 in their original, unmolested state - photo courtesy of PMAT 3- Photo my board with JP1 vaporized and JP2 seemingly hanging in there 4- Photo my JP2 removed from my board next to a 1/4 resistor. It measures open on a ohm meter. PMAT measured .1 Ohms in circuit on his board. Any suggestions would be appreciated.

Thought I would add that after rebuilding the speakers, I've had no trouble. They have been powered by TFM-45's, M-500 mk II, M-1.0t Mk II opt 2, TFM-75 and a couple of Mitsubishi amps. All good.

Both Papajoe (actually his friend) and I have experienced driver failures in Thiel 3.6s recently. I thought I would capture the details and a pretty good diagnosis of the problems in a new thread. SPOILER -- It's NOT Carver amps causing the problem. Its NOT the age of the amplifier. It's the crossover. Papjoe's failures occurred with a TFM-42 amp (TFM-45 with no meters). Mine occurred after a succession of amps, but the M-1.0t mk II opt 2 was the one holding the bag when the failures occurred. Bear in mind that the Thiels are very inefficient speakers. They are rated at 86db. REALLY inefficient in the grand scheme of things. That means that at even moderate volume levels, you are pushing some serious power into them Crank them up high, and it can get crazy. All that power goes somewhere. Some into the drivers, some into the crossovers. The Thiels have three completely independent crossovers mounted on two boards. All three are loaded with capacitors, inductors and resistors. Some of the resistors will get HOT under heavy load. Unfortunately, the early Thiel 3.6s mounted capacitors right next to and on top of the potentially HOT resistors. The resistors are actually touching the caps. That means that when the resistors get hot, the capacitors will melt. When they melt, they short - perhaps intermittently. When they short, the drivers are exposed directly to the amp. Way more low frequency energy than they were designed to adsorb. This results in physical damage as well as heat damage to the drivers. This is especially the case with the mids and tweeters in the Thiels. See photo below for my collection of melted caps. Since the Thiels are so inefficient, you tend to run them at fairly high power levels. That means that even moderately high listening levels will generate lots of heat in the crossovers. Lots of heat means melted caps which means failed drivers. This doesn't happen over night. It's cumulative. Over the space of 25 years it adds up. Pretty soon a cap shorts and a driver fails. It doesn't take much to kill a driver after a cap shorts. After the failure, somebody gets fired up and fixes/replaces the driver without checking the crossovers. BANG. It happens again. Everybody points fingers at everybody else. It's the amp! It's Bob Carvers fault! The amp needs a recap! It's clipping too much! The dealer lied! Thiel did a crappy rebuild job! NOT!!!! How can you tell if your crossovers suffer from this problem? Visual inspection is good, but you may not want to tear your expensive speakers apart to reveal the crossover boards. An easy check is to disconnect the amp from the speakers, and remove the driver. Remove as in completely disconnect the wires. Measure the resistance between the positive connection of the speaker and the positive connection to the amplifier. The tweeter should be about 20 ohms. Significantly lower or higher means trouble in the crossovers. The midrange should be about 17.5 ohms. Woofers should be pretty low at 1.5 ohms or less. Thiel eventually figured this out and started building their crossovers with some space between the heat prone resistors and the capacitors. But there are sill a lot of 3.6s out there with the problem. Here is a Before photo of the tweeter crossover in one of my Thiels. Here is one after the rebuild. Note the spacing. Here is my collection of fried capacitors (and resistors) from all six crossovers.

Followup. I finished up the Thiel 3.6s a while back. Rob at Thiel rebuilt the drivers and sent me enough parts to rebuild the crossovers. He also sent some official Thiel wire the replace the funky stranded stuff. New ID plates and binding posts were also on the menu. They sound fantastic. But.... a couple weeks ago one of the rebuilt mid range drivers failed. IT WASN'T ME!! I have been babying these guys because of the stupid amount of money and work I put into them. I contacted Rob and sent it back to the Thiel mother ship. The driver had a weak joint where a wire had broken. Rob fixed it for free and had it back to me within a week. Here's a photo of all the failed cross over components. Some of the ceramic resistors were open. In addition to the failed and fried components, I replaced all the electrolytic caps. Following Rob's advise I also arranged the components on the cross over to avoid caps leaning on hot resistors.

Thanks to all who provide the education.

OK. I would like to post to the "What are you listening to?" thread. But I'm having a hard time figuring out an easy way to post the album art. Anybody have an easy way to do this??? Thanks

I recently managed to destroy three (out of six) drivers in my Thiel 3.6 speakers. Lets just say that a system installed in a back room, powered by a mk II and controlled by a Logitech RF remote is an accident waiting to happen when listening from the other end of the house. Turns out I destroyed both mid ranges and one tweeter. I pulled one of the mid range drivers and nearly passed out. The solder joints looked like they were done by a three year old. Looking closely, you could see where the speaker was previously wired with solid core wire - now clipped off. In its place was some funky stranded wire poorly soldered to the speaker lugs. WTF??? I opened up the other mid range and found the same thing. I opened up all the drivers. Somebody had completely rewired both speakers with that funky stranded wire. Funky because there was some kind of plastic core that the strands wrapped around. That made stripping and soldering a challenge to the three year old that did the work. Same bad joints on the crossovers. One connection on the binding posts broke upon disassembly. Good grief. I checked the Thiel web page. Got some kind of strange temporary page saying they were making changes. Uh Oh. Called the phone number. No announcement that you have reached Thiel. Just some nice piano music and a beep to leave a message. Oh No!! I left a message. Within a couple of hours I got a phone call. Ultimately I talked with a gentleman named Rob in Kentucky. Rob listened to my story. Expressed shock at the rewiring and patiently walked me through all the things I should check Resistance values at various points on the crossover. How to get the crossovers out of the cabinet. How to get the wiring out of the cabinet. What the wiring should look like. Even told me what damage to look for in the cross overs - and they WERE damaged. All this off the top of his head. Bottom line is that Rob is rebuilding the drivers (replacements not available). He is also providing new wiring, binding posts and ID plates. He helped me compile a parts list to repair the crossovers and provided instructions on how to mount some of the parts to avoid future damage. He is even sending some silver solder to use in reassembly and some drawings to make sure I don't screw up the wiring. All the parts are drawn from left over Thiel stock. WOW. Turns out Rob was the Director of Manufacturing at Thiel. I was telling him how nice the cabinets looked inside. He then explained to me EXACTLY how they manufactured them - right down to some of the angles they used on the CNC machine to make sure the glue flowed correctly. He figures he probably made my speakers! There is a box of drivers and parts on its way to me from Kentucky right now. It will keep me out of trouble for several days. It wasn't cheap. It's not a cheap world. In fact it cost quite a bit more that the speakers will be worth - especially considering what I paid for them. But they were without question the best speakers I've had. Hats off to Rob and Thiel Audio. Thiel is going through some tough transitions. It's not easy making a buck in high end any more. Best of luck to Thiel and a big Thank You to Rob. A few photos below.

Amazon same day got them delivered. I'll start some listening shortly. Throwing caution and rational thought to the wind, I got three titles. Supertramp - Crime of the Century, Let Zep - Celebration Day, and Yes - Close to the Edge. No overlap with any of the SACD discs I have.

I would be using the balanced (XLR) analog outputs of the BDP-95 direct into the VK-40 preamp. So, no HDMI would be involved. No video either That's how I listen to SACD recordings. Hopefully the BDP-95 can handle the resolution since I just ordered up a couple of discs. I'll know this evening. Not the first time Amazon same day delivery has fed my habit.