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mbz

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Everything posted by mbz

  1. I've got an AU-505, refurb'd and 555 upgrades. Pair them with Altec 420A's(104-5)dB and Visaton TL-16H(106dB) tweeter, ok, it's not high end but can be had for under $1000 with crossover caps. Nice open sound, I don't mind turning off the consonance/osborn epitome gear.
  2. Buy from a reliable source though I understand shipping to NZ is an issue. Preferred sources are mouser and digikey in the US, typically free shipping to AU on orders over $60-. RS stocks the LM4562 but they want you to buy a minimum of 5, https://au.rs-online.com/web/p/op-amps/1977299 I wouldn't buy semi's from jcay, certainly not off the bay.
  3. NJM2043D for phone stage. LM4562 if you are wanting accuracy, nice tones OPA2134 if you want more body/timbre, nice tones. Choice depends on the equipment (signature) of the gear you are connecting to. Not a huge fan of jcay but then again it's about learning and having some fun. 2c...
  4. Possibly a slightly dirty switch. Work through each/all switches in turn, ie, operate back and forth a few times and note any effect on balance.
  5. Just to tidy up, relay should have both a flyback diode across the relay coil and a snubber cap across the relay contacts.
  6. Relays are typically 12 or 24Vdc, yes a flyback diode should be used. The relay contacts are switching 240Vac so arcing can occur, so the need of a snubber. I've been wrong before, will try and find time to read those links.
  7. Assume your widget includes a "spark killer" cap on the 240V line, ie, across the relay contacts.
  8. I've had a good listen to the E80's and E100's, not a fan. OP had some nice consonance gear (amp, cdp), the E100's would not be up to the job, I run the same amp and CDP with Osborn epitome's, ok, they are in a different price point... If you want to mod or upgrade the E100 crossovers as an learning exercise then go fo it but I wouldn't be throwing $2k at them, better to sell the E100's for $3-400? and buy better speakers.
  9. Certainly less harmful than over voltage however the SQ may be affected. Comes back to amp design, might not be a big issue with the regulated supply however the unregulated supply will "sag", this will affect max power output, but who listens at those levels. I assume you've checked/set the bias while feeding the amp 220Vac.
  10. I was stating that I received parts from mouser in the usual time frame. Yes there is a shortage/wait on some parts like KSC1845's.
  11. Front end (differential pair, VAS,,) of power amp likely to run of regulated supply. Output and driver transistors mostly run off unregulated supply. Agree such generic statements are a waste of time however misinformation is rife. Running 220Vac amp on nominal 240Vac comes back to amp design, tolerances... Know nothing about valve electronics. Vintage yamaha CA-800 has 6800uf/50V caps running +/-50Vdc unregulated rails. With mains drift voltage often above 50V. Pic of main caps showing hills/valleys 3-4mm high, certainly not a distorted end cover, the distortion is die
  12. Great, I've got 5 of those (apologies for the sarcasm...), model and problem would have be helpful, though I've lost interest. Down in Vic, not interested in taking on any repair work, plenty on my plate.
  13. post a pic of the power supply. Doubtful ML would manufacture a power supply, probably buy something off the shelf then rebadge. Power supply for my meridian 800 died, could either buy from meridian for $800- or buy from OEM for $80 from el14. https://au.element14.com/xp-power/ecm60ut31/power-supply-ac-dc-medical-3o/dp/1176969
  14. Regarding the HK, I assume that it's fully refurb'd. I would be keeping the amp unless you can throw some serious money at the "problem" and even then you might not "like it", eg, the yamaha 5000 series looks so nice but I found it ..... (not wanting to hijack), think I would prefer to listen to the HK. Not a huge fan of valves (got cyber 800's and aikido and consonance ref 150) I miss the slam and micro detail.
  15. Helpful to mention what gear needs work and what the problem is. Vintage gear is easier to work on, generally fully discrete and boards can take a bit of rework. Modern gear can be a PITA with proprietry IC's not to mention SMD's and multilayered boards. I assume this is for the ME(?). What's the problem...
  16. From his web site, Don't know the guy, good or bad... If he is any good, give him some space, covid can be depressing, also you had the christmas new year period included, yeah, would be nice if he responded to every email, probably hasn't had a chance to look at it. Little red flag about parts, probably an excuse, I've had no issue getting parts from mouser in the US, 3 day delivery. My wait time on "customers" is 10-12weeks, not a huge margin is amp repairs.
  17. Had a KA-7100, speaker posts drove me mad, easy job to change them out but it will loose that great original look.. The KA-8100 looks fantastic and is highly regarded in the vintage fraternity. Be mindful of ventilation, typically there would be holes/vents in the baseplate which a soft mat or pillow may block/restrict air flow.
  18. Don't know anything about the preamp, I've tinkered with the 400 power amp, got 2 in the shed waiting refurbishment. You need a good temp controlled soldering iron to work on a 400. I don't think a 400 is suitable for any tech who just replaces broken/out of spec components. The amp really needs a spkr protection kit along with the back to back diodes across C8. Main caps were often undersized, other caps probably on their last legs so it probably needs a total refurb, this is probably cost prohibitive unless you are into diy. The other alternative would be to go for the white oak (WOPL) upgra
  19. Had a quick look at his site, reads like he mods the units to become multi regional (probably chip replacement?) rathers than any AV performance improvement. Happy to be corrected by others... If your looking for a multi-regional player then maybe...
  20. Some say higher 3rd order harmonics (of the fundamental) others say higher IMD. It comes back to distortion, a bit of reading, https://www.passdiy.com/project/articles/audio-distortion-and-feedback
  21. L-2, L-3, L-30, L-200, L-410(100VAC), L-480, R-1030, SQ-505X, SQ-700X some fully refurb'd.
  22. Budget? Any particular model you like? Modern or Vintage?
  23. Regarding the possible transistor hiss, invest in a can of freeze spray, moderately expensive, light blue can from jcar. Give suspected transistor a 1 second squirt, note any improvement, allow 30 seconds for it to recover before moving onto next. Start with 2SC1000 and 2SC1345.
  24. Looks like glue on that cap on the preamp board, appears to be the sony bond glue which can go corrosive, some reading, https://www.audiosciencereview.com/forum/index.php?threads/bond-glue-issues-and-pictures.10329/ Schematic shows the amp has a protection relay however I wouldn't trust it until the protect circuit was refub'd, not worth risking spkrs. The hiss may be 2SC1000 transistors. Amp also contains 2SC1345's which are getting a bad name. List of problematic transistors from audiokarma Type Replacement(s) Fail
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