spritzer Posted June 17, 2009 Report Posted June 17, 2009 If a set would ever go wrong I'd gladly take a look at it before going to that chop shop, called Yama's. I'm even looking for broken sets to try out my theory as to why they break down...
blubliss Posted June 17, 2009 Report Posted June 17, 2009 Thanks Birgir. I just got an email back from Yama's because I was inquiring about a replacement headband. They said they could get a Lambda Pro one for $95. Does that seem reasonable? Also, I am very interested in what you find out about the ES-1. My suspicion about the glare in my system is that Mikhail has done something wonky, like providing too much voltage to the output tubes. Maybe you can tell me what I could change (resistors??) to do a simple modification? I know Kevin has said it needs major changes but I would like to change something simple first. I seem to remember Mikhail saying he would change some resistors to solve my issues??
spritzer Posted June 17, 2009 Report Posted June 17, 2009 Thanks Birgir. I just got an email back from Yama's because I was inquiring about a replacement headband. They said they could get a Lambda Pro one for $95. Does that seem reasonable? 95$ for just the headband!!!??!!?? I paid slightly more then that (could be a bit less) for a real and complete SR-Omega arc assembly (though with the black headband as the brown ones are long gone) from Craig. He had to work long and hard to get it for me but pulled it off in the end. Also, I am very interested in what you find out about the ES-1. My suspicion about the glare in my system is that Mikhail has done something wonky, like providing too much voltage to the output tubes. Maybe you can tell me what I could change (resistors??) to do a simple modification? I know Kevin has said it needs major changes but I would like to change something simple first. I seem to remember Mikhail saying he would change some resistors to solve my issues?? I know you had some issues with XF2's in the past so overdriving the tubes could certainly be an issue. The single filament supply is also a problem which should be address sooner rather then later. All you need to do so is a new 8A or more filament transformer and some way of getting that power over to the amp chassis plus rewiring the output tubes. I will do all of that and post links to parts needed and how to do all of that. I will how ever be scrapping those horrible umbilicals Mikhail used and going for a single 10pin connector instead. This will require some drilling but will make the amp a lot more safe. I'm going to use Amphenol sockets/plugs which cost some 200$ for the set but I found some Chinese plugs on ebay for 30$ shipped (which look a lot like the stuff Woo Audio uses) which I'm also going to try out. Now here's hoping I won't have any customs issues with the amp...
Elephas Posted June 18, 2009 Report Posted June 18, 2009 Another change Stax did was to fit those small rubber pads between the two external grills. Out baby elephant has one of the earliest sets and it lacks those pads. Yeah, my unit #011 doesn't have the black round rubber pads behind the grill. I hate it when people say "the Omegas" when they're referring to a single O2Mk1, a single O2Mk2, or a single SR-Omega. It should only be said when people are talking about two or more Omegas. Here's a closer look. Someone's thinking of putting Lambda headbands on an SR-Omega!!??! The horror! Blasphemy! C'mon, only real SR-Omega headbands should be installed on an SR-Omega...
hirsch Posted June 18, 2009 Report Posted June 18, 2009 Good call on the B&K, especially the 747. I'd start scouring the countryside for someone to calibrate it for you though. After looking into calibrating my own tester I started to realize that while simple enough at first glance, in order to do it and have it actually make a difference you really do need some specialized equipment. Too bad you're halfway around the globe, the guy I ended up tracking down is pretty reasonable if you can convince him to work on your gear. The 747 doesn't really need much by way of gear to calibrate beyond a multimeter, an insulated screwdriver, a capacitor, and a few resistors. A third hand is also helpful, but with care two is enough. Calibration instructions are in the manual, including the capacitor and resistor values. Just follow the steps, and don't touch the chassis when the unit is open and the unit is turned on for calibration. I also replaced all of the electrolytic caps in mine while I was in restoration mode, and it seems to do very well.
n_maher Posted June 18, 2009 Report Posted June 18, 2009 The 747 doesn't really need much by way of gear to calibrate beyond a multimeter, an insulated screwdriver, a capacitor, and a few resistors. A third hand is also helpful, but with care two is enough. Calibration instructions are in the manual, including the capacitor and resistor values. Just follow the steps, and don't touch the chassis when the unit is open and the unit is turned on for calibration. I also replaced all of the electrolytic caps in mine while I was in restoration mode, and it seems to do very well. It all depends on what you believe is required for calibration. I've become more and more convinced that most tube testers should be thoroughly gone through if you're going to bother. That means checking every resistor and capacitor (which may requiring some desoldering). This is what the guy who redid my 700 did, it's time consuming and a working knowledge of the device in addition to the tools and equipment portion. My tech's reasoning, which I agree with, is that otherwise you're simply calibrating the tester at a point in time and if you have components that are drifting the calibration that you just performed is essentially worthless. The 747 by virtue of it's SS design my be more immune to this than others but it's at least worth considering and deciding whether or not you (the buyer) feels comfortable with the end result.
spritzer Posted June 18, 2009 Report Posted June 18, 2009 Someone's thinking of putting Lambda headbands on an SR-Omega!!??! The horror! Blasphemy! C'mon, only real SR-Omega headbands should be installed on an SR-Omega... But...but...that isn't a real SR-Ω headband...
Elephas Posted June 18, 2009 Report Posted June 18, 2009 But...but...that isn't a real SR-Ω headband... Whaddaya mean it's not?! See the label sticker? Alright, if you're gonna be so anal about it... In other news, I finally got a set of allen hex wrenches that has one in 1/16" inch size. I had to buy a whole box set.
Elephas Posted June 18, 2009 Report Posted June 18, 2009 The 747 doesn't really need much by way of gear to calibrate... It all depends on... I can't decide which one of you I'd rather have as a neighbor.
luvdunhill Posted June 18, 2009 Report Posted June 18, 2009 Please dispose of those two, large round canisters properly by sending them to me. Thanks!
hirsch Posted June 18, 2009 Report Posted June 18, 2009 It all depends on what you believe is required for calibration. I've become more and more convinced that most tube testers should be thoroughly gone through if you're going to bother. That means checking every resistor and capacitor (which may requiring some desoldering). This is what the guy who redid my 700 did, it's time consuming and a working knowledge of the device in addition to the tools and equipment portion. My tech's reasoning, which I agree with, is that otherwise you're simply calibrating the tester at a point in time and if you have components that are drifting the calibration that you just performed is essentially worthless. The 747 by virtue of it's SS design my be more immune to this than others but it's at least worth considering and deciding whether or not you (the buyer) feels comfortable with the end result. I do have known tubes that I use only for checking my testers periodically. If results are stable over time, I'm happy. There's no real point in going through a resistor by resistor test in the absence of drift over time, unless you like doing that sort of thing. Even then, the fairly easy calibration procedure of the 747 means that all you've got to do is recalibrate if you do see long-term drift. Fifteen minutes to calibrate vs. resistor by resistor checking...no contest. Even then, it's probably faster to simply replace all of the resistors than to test them. It was definitely both cheaper and faster to replace all of the electrolytics in the 747 than it would have been to test them, so I didn't bother to test them. I bought new caps and put them in. Tester is stable. Done. Cost was less than $40. Took a couple of hours, but I work slowly. A simple user calibration procedure means that it's OK if the calibration is only good for a certain period of time. Test your known tubes, and if the value is off, then recalibrate. If the values drift quickly, go to the next step and replace the resistors.
spritzer Posted June 18, 2009 Report Posted June 18, 2009 In other news, I finally got a set of allen hex wrenches that has one in 1/16" inch size. I had to buy a whole box set. We need moar pics!!!!!! Full res too!!!! I would especially want some of the transformer wires since that's the first thing I have to change... Looks like it won't be easy to squeeze a new filament transformer in there plus a small 12V unit to run a ε24 and a double delay line for the filaments. \
mypasswordis Posted June 18, 2009 Report Posted June 18, 2009 Actually looks semi-decent in there, albeit somewhat cramped. Yama's quoted me $100 for an entire Lambda (SR-202) arc assembly when I asked over a year ago.
Dusty Chalk Posted June 18, 2009 Report Posted June 18, 2009 I can't decide which one of you I'd rather have as a neighbor. Response #1 -- I think you'd do well with either one, but you'd have to like cats in Hirsch's case (and before you even ask, yes, cats like elephants). Response #2 -- we live in an international market these days, so we're all virtual neighbors!
Voltron Posted June 18, 2009 Report Posted June 18, 2009 Please dispose of those two, large round canisters properly by sending them to me. Thanks! It's just wall warts under there anyway.
spritzer Posted June 18, 2009 Report Posted June 18, 2009 They are rather heavy those Plitron wallwarts, at least the Icelandic post couldn't accept the PSU and AMP in the same box.
luvdunhill Posted June 18, 2009 Report Posted June 18, 2009 It's just wall warts under there anyway. heh, nice one Those are the only parts I'd want to salvage out of Mikhail's amps. I have some of the older Vanderveen (sp?) design stuff, and they are quite excellent.
deepak Posted June 19, 2009 Report Posted June 19, 2009 Yeah, my unit #011 doesn't have the black round rubber pads behind the grill. I hate it when people say "the Omegas" when they're referring to a single O2Mk1, a single O2Mk2, or a single SR-Omega. It should only be said when people are talking about two or more Omegas. If we're being technical, there is no O2Mk1, it's just SR-007 or O2 Refer to spritzer's signature, he has it properly named in there
spritzer Posted June 19, 2009 Report Posted June 19, 2009 not funny Perhaps but Marc is right, short of the V-caps, BG's etc. crammed into those boxes there isn't much that is worth saving. The 45 step attenuators would be one thing but knowing I'd have to redo all of those solder joints just gives me a headache. If we're being technical, there is no O2Mk1, it's just SR-007 or O2 Refer to spritzer's signature, he has it properly named in there
faust3d Posted June 19, 2009 Report Posted June 19, 2009 Perhaps but Marc is right, short of the V-caps, BG's etc. crammed into those boxes there isn't much that is worth saving. The 45 step attenuators would be one thing but knowing I'd have to redo all of those solder joints just gives me a headache. But you will listen to it first, right? Before you dismantle it to a pile of spare parts?
spritzer Posted June 19, 2009 Report Posted June 19, 2009 I have to dismantle it first to see what parts need to be ordered and to know what I'm dealing with. The main focus is on the PSU (i.e. how much space I have in there) and how that digital output stage bias setup works. Odds are that it is a 20$ voltmeter with two pots but we'll see. While I have it open I'll change it over to 230v and then use it for some time, while parts arrive and I build all the upgrades. I have some cool things planned but that mostly depends on the space available in the PSU chassis. Let's just say there will be some small elements of the SRM-T2 in the operation of the amp...
faust3d Posted June 19, 2009 Report Posted June 19, 2009 I have to dismantle it first to see what parts need to be ordered and to know what I'm dealing with. The main focus is on the PSU (i.e. how much space I have in there) and how that digital output stage bias setup works. Odds are that it is a 20$ voltmeter with two pots but we'll see. While I have it open I'll change it over to 230v and then use it for some time, while parts arrive and I build all the upgrades. I have some cool things planned but that mostly depends on the space available in the PSU chassis. Let's just say there will be some small elements of the SRM-T2 in the operation of the amp... Sounds like a good plan. I really want to hear your impressions on the amp as it is now.
spritzer Posted June 19, 2009 Report Posted June 19, 2009 Impressions will come and comparisons against the A11 (mini ES-1). Considering that it would be tough to make the A11 for more then 1k$ (if you stick with sensible parts) then it should be an interesting comparison. I need to increase the voltage in the PSU though and get rid of that channel imbalance but not enough time and I will be working the whole weekend...
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