penger Posted September 13, 2008 Report Posted September 13, 2008 The 220uf 200v BG and 1000uf 15v BG both say +85 degrees C on them. For what it's worth regarding the 6528's. When I was discussing a possible sale with riceboy, I did email Mikhail to ask and he did confirm that I should be able to use them.
Jeepster Posted September 13, 2008 Report Posted September 13, 2008 Blubiss will defend Mikhail no matter what. Debating that with him is like talking to a brick wall.
blubliss Posted September 13, 2008 Report Posted September 13, 2008 Blubiss will defend Mikhail no matter what. Debating that with him is like talking to a brick wall. Not true. As soon as something is proven beyond supposition, I will be the first to verbally rip Mikhail a new one as I have done in the past for his atrocious business habits.
riceboy Posted September 13, 2008 Report Posted September 13, 2008 The 220uf 200v BG and 1000uf 15v BG both say +85 degrees C on them. For what it's worth regarding the 6528's. When I was discussing a possible sale with riceboy, I did email Mikhail to ask and he did confirm that I should be able to use them. I remembered you asking him and thanks for doing so . He did let me know the same thing as I asked him how much it would cost for a brand new SP Extreme with external power supply. Thanks for the new info you just posted.
n_maher Posted September 13, 2008 Author Report Posted September 13, 2008 The ZD runs the 6c33 with 6.6 amps of heater current per tube without any trouble. The amp does get really hot but reliability seems fine. So, IMO, a 5.0 amp 6528 shouldnt be any trouble.I'd say that those are different enough that it's not exactly a fair comparison. The Zana is larger, and at least has some ventilation at the base of those tubes. Does the Extreme have any? Also, the Extremes high voltage supply is in the outboard power supply and the heaters are on the amp section. The big amperage Plitron should be running the heaters on pengers amp.I'd respectfully ask that you go back and look at the pictures and notice that the trafo in the outboard supply is a 12.6V/4A - 6.3/8A unit. You and I both know that this is not the HV supply. Mikhail may have built other Extremes where he's moved the HV out of the main chassis (that sounds like what he told me at Canjam) but that is clearly not the case here. I'm guessing that this Extreme didn't start life as a Platinum and therefore doesn't have the Plitron trafo, but I'm guessing there. But, honestly, I really like the inexpensive 6AS7G. The 5998 is my personal favorite in this type of amp, but the right 6AS7G sounds pretty darn good for $10 tube. The 7236 can also be good and not break the bank as well.
n_maher Posted September 13, 2008 Author Report Posted September 13, 2008 The 220uf 200v BG and 1000uf 15v BG both say +85 degrees C on them.Thanks for that, even if it's really not good news. I'm hoping they are conservatively rated. For what it's worth regarding the 6528's. When I was discussing a possible sale with riceboy, I did email Mikhail to ask and he did confirm that I should be able to use them. I would say that he misspoke in this case. Even if he's still running the 6SN7 heater off of the original, chassis mounted trafo you still don't have anywhere near the current capacity that you need for the 6528s. That's ignoring the previously mentioned heat issue as well.
blubliss Posted September 13, 2008 Report Posted September 13, 2008 Ok, so nobody thinks i am a blind SP/Mikhail advocate who will say no evil, here is a doozy of a idiotic job. About a year ago I sent in my L3000 to be recabled to balanced by Mikhail. Since i got them back i have never been able to enjoy them, something seemed wrong. I tried many tubes to no avail. Well, 909 and I just had a late-night session at my place and lo and behold he noticed that something was amiss. We think he put the wrong drivers on the wrong side. Not only are the drivers facing the wrong direction, the whole housing is reversed. Looks like it will need to be recabled. That is fine since the cable he put on is the stiffest POS ever. Now I hate to add flames to the fire here but the truth needs to out. This guy can be a real moron. Makes me wonder what the inside of my amps look like?
kevin gilmore Posted September 13, 2008 Report Posted September 13, 2008 here is bluebliss in action Head-Fi: Covering Headphones, Earphones and Portable Audio - View Single Post - Where is Singlepower? Where is Mikhail? and again Head-Fi: Covering Headphones, Earphones and Portable Audio - View Single Post - Where is Singlepower? Where is Mikhail? mikhail can say whatever he wants. The filament supply for the output tubes has to be rewired as a seperate circuit and referenced to B-. Everything you are describing is due to cathode leaking because Vk is significantly greater than 100 volts. 99% of intermittent performance can be traced to this major problem. The more mikhail continues to apply spin instead of fixing the problem the longer this will continue.
kevin gilmore Posted September 13, 2008 Report Posted September 13, 2008 Hey Kevin, can you answer this question please? Your expertise is appreciated. Show me some more pictures. So far we have 2 pictures of resistors and fets running way to hot and burn damage to the circuit boards. I think hirsch's spin is now to call that an acetate failure.
kevin gilmore Posted September 13, 2008 Report Posted September 13, 2008 I have every expectation that the one person who was sending the amp to me has been contacted by mikhail and mikhail has done a major spin job on him to prevent me from ever seeing the amp. We will see what happens. Mikhail is yet to figure out who has the circuit board unit... Maybe bluebliss can supply a few pictures...
kevin gilmore Posted September 13, 2008 Report Posted September 13, 2008 The ZD runs the 6c33 with 6.6 amps of heater current per tube without any trouble. Once again earl does not know what he is talking about. source http://gilmore.chem.northwestern.edu/6c33.pdf craig has said numerous times that he only runs one of the 2 filaments to save on power and heat on the socket. So each tube is running at 3.3 amperes. craig has posted this a few times, someone else can go find the post. On to current calculations on the extreme.
kevin gilmore Posted September 13, 2008 Report Posted September 13, 2008 OK, here is another one. Lets say you stuff your extreme with a pair of 6528 output tubes. A total of 10 amperes of filament power to run them. Looking at the circuit board we see that the filament supply has a full wave rectifier diode bridge going into C57, C57 is hooked to C58 with a .15 ohm 6.5 watt resistor and C58 drives the filament dc to the two output tubes. 10 amperes of current thru a .15 ohm resistor is 15 watts. More than double the rating. Which is why the circuit board is starting to burn up around the leads of that resistor. Yep, here is that new term again... acetate failure. So if you ask if there are unsafe things inside an extreme, the answer is clearly yes.
n_maher Posted September 13, 2008 Author Report Posted September 13, 2008 Kevin, Are you sure that he's running DC filaments? I figured the rectifier and filter stages were for B+ and that he'd just be running AC filaments because of the current required even for the 6AS7. And if that is a DC filament supply on the left side of the pcb what do you think he's doing with B+? Just lots of filter stages?
Elephas Posted September 13, 2008 Report Posted September 13, 2008 I talked to Mikhail yesterday (Sept. 12) and my ES-1 has supposedly been shipped. I'm concerned by potential issues with the design, build quality and reliability of SP amps. As someone who doesn't know anything about electronics, I appreciate the efforts of anyone who's looking into the potential issues. Most amp owners, including SP owners, are nervous and a bit defensive when the design, build quality, reliability and especially the competence of the amp manufacturer is called into question. One major reason is resale value. Head-Fi and Head-Case are basically the only places where info about SP amps can be found, and also practically the only places where an SP owner can sell his amp. I doubt an SP amp will sell for a high amount on eBay. Mikhail's lies about ship dates and his shoddy business practices have been exposed and documented by some people. Some other SP customers have apparently been reluctant to speak up publicly for fear of retaliation by Mikhail and other reasons, such as the potential difficulty of selling their SP amps. By lying so shamelessly about shipping products, Mikhail has called into question his entire credibility. I ask myself, if someone can lie so easily about when an amp is ready to ship, what about his statements and claims about the quality of the amps? I don't think that Mikhail intends to change his business practices. I think he sees himself as some kind of "talented artist" who is highly in demand for his skills. The customers can all line up and wait. He'll take his time if he wants and deliver an amp when he damn well pleases, and the customers should be grateful. During all these months of waiting, Mikhail has apologized many times to me but I don't believe he actually feels any real remorse. His excuses are not believable. He claims that he did a lot of additional work on my ES-1 and Supra-XLR, more than I paid for. Basically, he's saying that while he's sorry he didn't ship my amps yet, I should shut up and be grateful. As of now, I've yet to hear an SP amp, so I'm still inclined to give Mikhail the benefit of the doubt when it comes to the overall quality of SP amps. But I'm beginning to have doubts.
Parafeed Posted September 13, 2008 Report Posted September 13, 2008 craig has said numerous times that he only runs one of the 2 filaments to save on power and heat on the socket. So each tube is running at 3.3 amperes. Beg to differ. That's not the case with the Zana I have in front of me. Both filaments are used.
kevin gilmore Posted September 13, 2008 Report Posted September 13, 2008 Kevin, Are you sure that he's running DC filaments? I figured the rectifier and filter stages were for B+ and that he'd just be running AC filaments because of the current required even for the 6AS7. And if that is a DC filament supply on the left side of the pcb what do you think he's doing with B+? Just lots of filter stages? Absolutely sure. C57 and C58 are 22000 uf caps rated at 25 volts. The diode bridge is bolted to the back of the panel. The 4 diodes in the middle are the high voltage supply, those diodes are rated at 1 amp each. As far as i can tell the B+ is diode bridge to 390uf cap, 50 ohm resistor to 390uf cap, 50 ohm resistor to 220uf cap 50 ohm resistor to 220uf cap.
kevin gilmore Posted September 13, 2008 Report Posted September 13, 2008 Beg to differ. That's not the case with the Zana I have in front of me. Both filaments are used. email craig for definite answer and then post here. Maybe things have changed since the early units. Its very hard to tell just by looking at the tube running whether both filaments are on or not. Or pop the chassis bottom and see which pins are wired. If all 4 pins, 1,2,6,7 are wired then both filaments are used. Even easier, turn it off, wait a while, pull one tube, use an ohmmeter and measure the socket between 1 and 6 and 1 and 7, a short will indicate both filaments used. http://gilmore.chem.northwestern.edu/6c33.pdf
RockCity Posted September 13, 2008 Report Posted September 13, 2008 By lying so shamelessly about shipping products, Mikhail has called into question his entire credibility. I ask myself, if someone can lie so easily about when an amp is ready to ship, what about his statements and claims about the quality of the amps? This is where I'm at. That's why I will crack it open once I get back to SoCal. You can't trust Mikhail to promise the upgrades and workmanship you paid for anymore.
n_maher Posted September 13, 2008 Author Report Posted September 13, 2008 Absolutely sure. C57 and C58 are 22000 uf caps rated at 25 volts. The diode bridge is bolted to the back of the panel. The 4 diodes in the middle are the high voltage supply, those diodes are rated at 1 amp each.Ahhh I see now, I missed the bridge on the back panel. Does the .15ohm serve to help drop some of the excess voltage he must be having to deal with after the rectifier?
kevin gilmore Posted September 13, 2008 Report Posted September 13, 2008 At 10 amps that is 1.5 volts of drop. And yes that is what it is for... A shorted filament however and flame city.
spritzer Posted September 13, 2008 Report Posted September 13, 2008 Andy, those issues that Kevin linked to have been reported by other owners as well and are caused by the filament wiring. You far from the only one with "faulty tubes" according to Mikhail. I have every expectation that the one person who was sending the amp to me has been contacted by mikhail and mikhail has done a major spin job on him to prevent me from ever seeing the amp. We will see what happens. Mikhail is yet to figure out who has the circuit board unit... Maybe bluebliss can supply a few pictures... Last I heard (last night my time) the amp will ship as expected.
Parafeed Posted September 13, 2008 Report Posted September 13, 2008 email craig for definite answer and then post here. Kevin, no disrespect intended, but I'm not guessing, I'm stating a fact! Let me say again, the Zana I have in front of me powers both 6C33 filaments. I don't need to email Craig for confirmation. (Serial Number is 38.)
kevin gilmore Posted September 13, 2008 Report Posted September 13, 2008 Yay team... My pictures of the zanadeux are the one with the tube sockets on the top of the chassis, so that you can't see anything. I have other pictures just can't find them. Craig will tell the truth. Problem is that mikhail does not know how to tell the truth anymore. The first person he needs to stop lying to is himself.
kevin gilmore Posted September 13, 2008 Report Posted September 13, 2008 Kevin, no disrespect intended, but I'm not guessing, I'm stating a fact! Let me say again, the Zana I have in front of me powers both 6C33 filaments. I don't need to email Craig for confirmation. (Serial Number is 38.) Fine. Prove me wrong. One picture is all it takes of the bottom of the tube socket. Is serial number 38 from the second batch, or 3rd batch? Or contact craig for the correct answer when he started using both filaments. I don't know the answer i just know that the original prototype and the first batch all used one filament.
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