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Monkeyboi

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Monkeyboi last won the day on May 17 2014

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  1. Found it. Should have searched properly. DOH
  2. I agree. I've purchased and used Elna SILMIC II caps from reputable suppliers like Element14, RS and Mouser over the years and I have never seen purple coloured ones, just the brown ones like @Monkey_Relish said. If there has been a recent production change by Elna I'd really appreciate knowing about it before I order some replacements to keep the on hand stock levels topped up. All Elna SILMIC II caps have a distinctive vent stamp marking on the top of the can. See the attached picture. The caps marked C4, C104, C9 and C109 are genuine Elna SILMIC II caps. The others on the board aren't Elna SILMIC II and bear a completely different vent stamp. If the purple caps don't have the distinctive vent stamp then I'd suggest they're fakes. Other than obvious physical appearance differences one can also detect fake electrolytic capacitors by - Measuring the capacitance, ESR and leakage with suitable test equipment. These are non-destructive tests and you can easily compare the measured results with the manufacturer's data sheet. Testing the rated voltage and ripple current. These can end up as destructive tests as the fakes generally don't pass. Opening a sample up and comparing with the genuine product. Unfortunately a destructive test but if you were buying commercial quantities and using them in a product for sale, doing this can potentially save a maker thousands of dollars in recall or warranty repair costs. (and yes it does happen *) * I recently heard a tale of woe involving fake NE555 timer ICs. These are the regular 8 pin DIL packaged devices. Cheap as chips (no pun intended). A guy in the US ordered thousands of them from a supplier in a well known Asian country which starts with the letter C (and it's not Cambodia), and implemented these in a design which went to production. Unfortunately none of the boards worked. On fault diagnosis they tracked the problem to faulty 555 timer ICs. An autopsy of the 555 timer ICs revealed they were 8 pin DIL packages with no die inside them. Yep someone was happy to take an order for thousands of these, have the packages printed with what looked like genuine 555 markings and sent them to the buyer. Now 555 timer ICs are really cheap especially in large quantities. Why someone would source them from C#i^@ is beyond me. It might have been a supply delay issue?? Anyway even the cheapest Elna SILMIC II cap retails for far more than a 555 timer IC so the incentive to make fakes is considerably higher. The bottom line here is caveat emptor. Cheers, Alan R.
  3. Good to hear that Jon. She'll look like new with some new timber sides. Cheers, Alan R.
  4. Hi Jon, I have repaired and serviced many of these vintage Sony amps and pre-amps from their ES range of gear over the years. Good news is that unless the amp has been abused, had the ventilation slots obstructed, used in a very dusty or corrosive environment they very rarely go wrong. These ES series amps were designed and built back in the day when Sony engineers produced quality components and designed firstly for performance and cost was a secondary consideration. No doubt probably you've already lifted the lid off of it and will appreciate that the build quality and attention to detail is superb ๐Ÿ‘ (unless someone has already been there and butchered the Bejesus out of it ). In answer to your questions (paraphrased) - A complete or partial recap? Absolutely not if it's working well and performing to specification. I see too many amps where good intentioned but misinformed DIYers (and some techs) have literally ruined, damaged or otherwise simply altered the "tone" of a previously perfectly good amplifier because they substituted alternative capacitors for ones that Sony engineers didn't intend to be used in the their design. This amp uses very few electrolytic capacitors in the signal path. Is a service / evaluation of performance to ensure the amp is still performing to specification worthwhile? Yes, a measurement of power output, frequency response, channel balance, distortion and signal to noise ratio by an experienced and competent tech who has the appropriate test equipment and more importantly the expertise of how to perform the tests correctly and how to interpret the results will quickly reveal any problems without even taking the cover off the amp or heating up the soldering iron. A thorough visual inspection is also recommended. When is it appropriate to replace electrolytic capacitors in an amp like this? Only if they are faulty, show signs of end of life (bulging, venting or leaking) or when tested, measure out specification for capacitance, ESR or leakage current. IME, if it ain't broke or showing signs of imminent failure don't "fix" it. Film and ceramic capacitors rarely fail and IME it would be unusual to find a faulty one in an amp of this class and price point. What would an inspection / performance test cost? IMHO and IME, if it is done properly with documented test report, budget about 2 - 3 hours labour cost. The hourly rate will vary from service centre to service centre. You'd need to shop around and get quotes and please ask for a written report as part of the service. As mentioned above, this report should include the test results and an estimate for any work that needs to be done (if necessary) to bring it back to original factory specifications. What would be the cost of a modern equivalent? How long is a piece of string? Sorry but I couldn't resist answering it this way. Too many variables to take into account. Finally, this fine piece of classic vintage Sony gear deserves to see many more years of completely reliable service and excellent performance. Most modern 21st century gear just isn't built like this anymore. As for where to take it to be evaluated or possible repair? No specific recommendations but ask yourself these questions. If it was a classic vintage car or a piece of fine antique furniture would you trust it to just any old hack? Please as much as you might be tempted to spray cleaner into the potentiometers or the pre-set trim-pots please, please, pretty please refrain from doing this unless you have the the correct spray. There's only a very few substances that should ever be used in carbon film potentiometers and trim-pots and sadly a lot of so called service techs don't actually use the right stuff. Ignorance, lack of experience or care factor = zero? - take your pick. I'm always wary of second hand gear offered for sale where the seller claims the amp was "recently serviced and completely re-capped". IMHO and IME the first questions that should be asked is "serviced by whom and why a complete re-capping?" I've had the unfortunate experience of having to fix some of the butchering done by other novices and techs that have absolutely NFI what they were doing. Ranging from now being presented with a non-functioning amp, through to intermittent faults to complaints of "it doesn't sound right". At the higher end of gear manufacturers choose their components fairly carefully. so if they have chosen to use a particular electrolytic capacitor in the signal path over a film capacitor it probably not based purely on price alone. I sometimes see amps on my workbench with the complaint from the customer like " I had this amp re-capped and now it doesn't sound right". In the past year I recently repaired a high end power amp from a well known Japanese manufacturer with the above complaint. Someone had replaced ALL the Black Gate electrolytic capacitors with other makes and types. Even some of the coupling capacitors with film types. Some of those audiophool forums have a lot to answer for. Poor advice of the blind leading the blind. For the benefit of everyone following this thread. In short, don't blanket re-cap vintage amplifiers with caps not intended to be used in the original design and expect it to sound like it did when it left the factory. Cheers, Alan R.
  5. Trust me Bob. I used to be able to do SMD work under +3 or+5 diopter illuminated magnifying lamp, but alas my tired ol' eyes have had to move it up a notch since then. Up until a bit over a year ago I was able to cope with just the illuminated magnifier for most work. IIRC the last non-microscope job was done for the late Ozcal (Gordon Macfarlane) on his workbench soldering some boards with SOIC ICs and 0402 components for one of his DIY projects just using one of my temperature controlled irons and a very fine tip. But I'll have admit the microscope on my workbench makes the work so much easier, less frustrating and a lot less time consuming. IME, if you do enough of this type of work it's well worth investing in the equipment. Unfortunately it ain't cheap and my microscope setup on an articulated arm is far from portable. Cheers, Alan R.
  6. IMHO this isn't the right unit for your intended purpose of an active crossover for a two way speaker if I'm interpreting your question correctly. It's a stereo module with a subwoofer output that's shared between the 2 channels. It's also expensive IMHO at USD169 (discounted according to Arylic's website) for what you get. Distortion is quoted as 0.9% at a mere 1W output. It's probably only going to get worse as the power output increases, which brings me to the next issue and that is of the claimed rating of 40W / channel. Hmmmmm...... but at what distortion level? Many of these Class D amps don't deliver hi-fi performance so those accustomed to listening to better gear will most likely be disappointed. Not suggesting there's anything fundamentally wrong with Class D amps as there are some very good ones out there, just not in this price point or this particular module. Finally, you can use the finest components in a product but if the circuit design and implementation are mediocre that's about all one can expect as an outcome. I note with interest the reviewer didn't measure the output power, distortion figures, signal noise ratio of even demonstrate the unit in action. Just a lot of comment and pricing of the add-on units you could buy for it. Also what's the cost of the PC based DSP software package? I did visit their website but couldn't find this software anywhere on it. Cheers, Alan R.
  7. I use this stereoscopic microscope with a high res camera on my workbench at home to do SMD work. It isn't anything fancy or expensive like a Mantis or Tagarno but I'm very comfortable with 0402 sized components and have handled smaller. In conjunction with a suitable reflow station, a selection of tips for point and drag soldering and of course the various tweezers etc it gets the job done neatly, cleanly and with high reliability. SMD work / rework is a skill. It takes time, patience and the right equipment / tools to get a good result. I often tell students and novice DIYers to practice on some bit of kit that's going to get chucked out so it doesn't matter if they stuff up developing their skills and techniques. Cheers, Alan R.
  8. I concur with your observations. Most service techs these days don't normally repair to component level. If anything, I equate many techs these days to the days of valve B&W TV when the "TV tech" would turn up at your home to fix the tele armed with a small toolbox, some basic hand tools and a selection of replacement valves (tubes). He would turn on the set and fiddle with some of the controls. If that didn't resolve the issue then off would come the back panel and he'd start swapping the valves and possibly fiddling the normally non user accessible adjustments. As a kid at the time I used to watch these guys do their magic but I never recalled any of them using a multimeter or a soldering iron. If the problem couldn't be fixed in the home (usually by swapping out the valves), the TV would end up in the back of his van and be taken to the workshop where the real techs would repair it. As I completed my qualifications in electronics the older more experienced techs would refer to these guys who came to your home to fix your tele as "valve jockeys". Today these valve jockeys still exist within the industry but instead of just swapping out the valves they swap out entire PCB assemblies and 99% of the time not on the initial visit. So now the industry has "evolved" from valve jockeys to card / module jockeys. ๐Ÿคฃ Nothing's ever held in stock and more than often the customer has to reschedule a return visit to have the replacement card / module installed. When I worked for the Big T we were trained to diagnose to component level but as you have pointed out these days it's a board swapping exercise only. Stuff that goes faulty simply gets swapped out and replaced. If the original card is still under warranty it's returned to the manufacturer and the repaired card is placed back in the pool of spares. Gone are the days where out of warranty cards were repaired and tested by Base Repair. Likewise the same for test equipment which used to be recalibrated within the company in Brisbane. Everything is now outsourced. So it brings me back to the repair of AV and hi-fi gear. Lots of really good vintage gear doesn't use plug in PCB assemblies and if it did the pool of available of available spares has long evaporated, which basically means that if the tech can't diagnose and replace to component level the device is now landfill. We live in a disposable world where even the simplest failed component can't be replaced because those skills just don't get taught these days and as has been so eloquently pointed out by @Addicted to music "this is what the clients demand, this is how competitive the market isโ€ฆ itโ€™s the market that dictates the way you work!" . And you're completely correct on the generally poor level of handiwork especially on the part of some novices that potentially wreck a completely functional product with some audiophool modification by literally butchering the PCB. Repair in this industry could easily deserve a thread all its own let alone some of the pitfalls of DIY modifications done by persons with NFI as to what they doing. Perhaps I might be coming across as a bit harsh and critical, but I hate seeing a classic bit of hi-fi kit end up as verge collection simply for the love of replacing a 50c capacitor or two that some "service tech" somewhere deemed unrepairable. Cheers, Alan R.
  9. Here's an interesting comment / observation from a friend of mine referring to his recent listening to the 192/24 FLAC digital download of Neil Diamond's Hot August Night album. "Unlike the CD/LP they managed to get rid of all the tape hiss that this album was plagued with. It is such a good recording I found myself criticising the mics and grumbling at some slight sibilance." which suggests to me that we can develop greater and greater expectations with the improved quality of both equipment and mastering techniques. I'm looking forward to hearing this FLAC release as I agree with his observations that both the double LP and the double CD versions of this concert do leave a fair bit to be desired in terms of SQ. Cheers, Alan R.
  10. Sadly your experience at TAFE is typical of many students. I believe several things are at play that are contributing to this - The industries are demanding less and less time spent in the formal learning environment, relying on shortened traineeships based on workplace learning which in itself isn't a totally bad thing (the workplace learning that is) unless the practical application and learning in the workplace is either glossed over, not done at all (box ticking without any demonstrated competencies), delivered by incompetent individuals or they just don't care. Incompetence on the part of those delivering the training as your quoted experience whilst receiving ESD training illustrates. But sadly it goes a lot deeper than that. An approach that teaching the basics is a waste of time. The rationale being the newbie techs will only be swapping out boards / modules and taking the path of flowchart diagnosis. If it ain't on the flowchart it's toast and unfixable. An inability to use even basic test equipment (e.g. a DMM) and interpret the reading(s). Not having even a basic grasp of the fundamental principles (Ohm's Law, Kirchhoff's Laws, d.c. and a.c. theory, etc). When I was lecturing on the TAFE circuit it was quickly brought to my attention by the heads of the various faculties that the system is solely based and funded by the numbers of students that graduate with a competency certificate / diploma / associated diploma or advanced diploma. If a student fails to achieve competency the funding subsidy for that student isn't received by the TAFE / RTO. To which many RTOs / TAFEs will reassess a student with the same assessment as many times as it is necessary to attain the required pass mark. As we all know with objective assessments (pick A, B, C or D) it's only a matter of time or multiple attempts before the student guesses the right combination to get to the required number of correct answers. I recall delivering a series of training sessions for a company's workforce in their workplace on the subject of testing and the use of test equipment. The target audience were all trainees who recently had completed their Certificate 2 in Telecommunications with a private RTO. Out of the 16 students only 2 knew what Ohm's Law was. Needless to say I was gobsmacked. Of the two who did know they had received previous training prior to commencing their traineeship. So I had to ask the question of the other 14 students knowing full well the curriculum of their Cert 2 studies as to why they were unfamiliar with this basic concept. The answer given was "... the trainer at the RTO where we were doing our Cert. 2 with said that we didn't need to know Ohm's Law, basic a.c. / d.c theory or any of that other nonsense as we would never use it in real life...." WTF? Apparently having a basic understanding of electronics is now considered to be not essential to working within the industry. Cheers, Alan R.
  11. If you're into DIY perhaps consider the Analog Devices AD8403 chip? 4 potentiometers in the same chip. Can be remotely controlled with external circuitry. Cheers, Alan R. AD8400_8402_8403-1502326.pdf
  12. I have all of these above and more and yes I do know what these things are and more importantly know how and why to use them. It's a pity some others in the industry simply ignore ESD issues. As I commented, it's like hitting one's head repetitively on a brock wall trying to convince others that they can potentially create more faults than they started out with by not observing ESD precautions even at the board swapping level. Sadly most new techs can't diagnose to component level, but that doesn't surprise me when at a basic fault analysis workshop 90% of the audience who supposedly hold a Diploma in Electronic Engineering qualifications have not even a basic grasp of how to apply Ohm's Law or Kirchhoff's Laws when analysing a circuit. โ˜น๏ธ Where and who are issuing these competency certificates? Not worth the paper they are printed on IMHO. Cheers, Alan R.
  13. Bugger. Unfortunately it can happen so easily. I occasionally do a bit of contract work for a company who provide synthetic based image / workwear to their field technical workforce. Trying to explain that a rayon or polyester based polo shirt isn't the best choice for workwear when handling static sensitive PCBs is like trying to shovel an extremely runny s&#^ up a steep incline with a pop stick. The mentality of just replacing or swapping out the same or multiple PCB(s) many times until they finally get it working is sadly well ingrained into the work culture. This attitude doesn't sit comfortably with me as put myself in the position of the customer who ultimately pays for the work. But in such large corporations despite the mountains of documentation that exists on ESD handling precautions very few of the field service staff care to follow the guidelines. I'm guessing the "rationale" behind their thinking is either based on ignorance or "I'm not paying for it, so...." Decades ago I recall they used to run ESD safe handling training, provided wrist and ankle straps on every equipment rack, antistatic kits to all the technical workforce, ESD safe bags for storing and transporting PCBs and just about every site had prominent stickers in plain sight with the slogan "One zap and it's scrap". Now finding any of the aforementioned is more the exception than the rule. I think the lack of understanding of the impact of damage caused by ESD is largely unappreciated because it's unseen. Out of sight = out of mind for most people. Cheers, Alan R.
  14. One of the things most people overlook with the earlier Quad ESLs is their rather strange impedance curve. Whilst most well designed amplifiers can drive these with no problem, some amplifiers aren't happy. Here's a few links you might find interesting reading. Interaction of QUAD 57 and 303 (audiomisc.co.uk) Solid State Amps for Quad ESL 57? | Audiogon Discussion Forum There is plenty of discussion about these all over the internet. If you haven't already discovered it you will have noticed you can't drive your 57s to a very loud level unlike your Gales and perhaps the 57s aren't ideal for all types of music especially at elevated levels. Whatever you do don't overdrive your Quad ESLs to the point of arc over in the panels. Also the protection circuitry in the 57s is designed to crowbar (put a very low impedance load) across your amplifier's output. Hence possibly another reason not to overdrive them. I have a pair of Quad ESL2905s which I run off a ME-850HC without issues as the ME is quite happy running 0.5 ohm loads. When I use my Sony TA-N9000ES power amp pushing the Quads to higher SPLs sometimes trips momentarily trips the protection in the Sony. Cheers, Alan R.
  15. Nice to see she's finally finished. Happy listening. Cheers, Alan R.
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