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niss_man

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Everything posted by niss_man

  1. What do you mean considering. The police here in Qld have had the stingers as highway pursuits for a while now. I saw one yesterday when driving to the Leyburn historic sprints , he had pulled over a car in the oposite direction.
  2. I'd use the free program rew to do a sweep. It will tell you more than just singular frequency steps. You may find one of the tweeters has a dip in the frequency range where you tested but the rest is similar to the other speaker. If this was the case then the tweeter will only be matched at the frequency point where you measured and the rest may be out.
  3. Yes. It will be good to see the manufacturers spec from your own sweeps. It may or may not look like a good graph when done but it is what it is. Measure your speakers in the same spot under same conditions and see how they compare to each other. Then tweak with the pots as you suggest to get the best sound to your ears. I'd also measure a few off axis ones 15, 30, 45, 60 to check the off axis power response as well.
  4. I'd look at vw golf as well. Have owned mine since new. Now at 220 thousand km.
  5. What's the sound quality of the dac hat like?
  6. If you need parts, maybe Falconacoustics.co.uk can help.
  7. Love the engineering and build quality there. The elnas are great quality and resistors for that matter. All quality stuff in those beasts. You can see these were built for quality/sound and not just for marketing/profit like most stuff these days .
  8. I take it you didn't do any speaker measurements and are tuning by ear. That's all good, but you can't beat accurate measurements and a good crossover program. Final tweaks done by ear though.
  9. So long as the techs use the same value of caps and keep with the quality brands, it will be good. They can order everything that is needed. Btw have you tried looking on the Mark Levinson website for ML recommended technicians, maybe there is some info there.
  10. I don't wish to be rude, but why? That would be like taking your car to a mechanic who diagnoses a faulty cam chain tensioner, you then says thanks very much and take it home to try fix yourself. That's a bit disrespectful to the techs. The technicians will still charge you for their time to have a look at the amp and even then a quick look over maybe will still not find the root cause of your problem. I see only 2 methods, either get the schematics and try to fix it yourself ( you will need a fair amount of skill to fault find this amplifier if it is anything other than a simple fix) or get the professionals to do this. There is nothing worse than being a tech trying to fix something when you know some other person has been in there and made a shamozle of it and now expects the professional to fix their stuff up.
  11. Matty are those kit speakers or something you built from scratch? Have you got any measurements of them?
  12. The Zeus has actually got 8 of these 22000uf 100v caps in it. Total of 176000uf in the power supply. And another 2000uf each on the amplifier boards.
  13. @Sub Sonic Regarding one channel with less volume than the other. I reccomend checking the balance pot position to get even signal level between channels. Sometimes it only has to move only slightly for the channels to have good balance as I did find with my AU555.
  14. There is a good thread on how to make these measurements using REW software on diyaud https://www.diyaudio.com/forums/software-tools/338511-howto-distortion-measurements-rew.html You dont need a $30000 spectrum analyser using this method and it is easy to do. Even I had a go at it after reading that thread. As far as measuring musicality is concerned, I believe it would be very difficult to do but it should be able to be done. There would be so many more things involved than just a few distortion, harmonic and frequency sweeps though. For the hobbiest this would be nigh on impossible. For a large amp/speaker manufacturer this would be a fun thing to try and find out. Another thing, from an engineering point of view I believe we can measure all that we need (there is no magical juju). It is the interpretation of that info that will be the difficult bit. Simon Zeus
  15. What stunning photos@rickus
  16. Your local astronomy club should be able to help.
  17. I have recived interest from a local buyer who will pick it up this week. If the sale falls through I will get in contact with the next bidder.
  18. Item: Behringer DEQ2496 and FBQ2496 Location: Brisbane Price: $150 Plus postage Item Condition: Excellent Reason for selling: Bought a couple of years ago with intent to use but never have. Too many projects on the go. Payment Method: Pickup - Cash, Paypal, COD Only Extra Info: Photos:
  19. Another LDR attenuator. This one uses arduino to create an attenuator that does not need matched LRD's and can be calibrated for perfect channel image and variable input impedance up to 50K ohms to match whatever amp your connecting it to.
  20. As a final post. There is one other mod that can be done to the power amp stage circuit of this amp called a "Baxandal diode mod". I have performed this mod to @lebone 's amplifier so I will be taking this over to his place and making a direct comparison between the 2 before deciding to do this last mod on this amp. The mod is supposed to drastically improve distortion levels. From what audio memory I have, I thought it made the bass slightly tighter and clarity across the audio band seemed to improve. A side by side comparison should be good because audio memory quickly fades especial in between performing hours of modification.
  21. Some final power measurement through the oscilloscope using 7.3ohm resistors as load. Power out both chanels driven just before clipping. 18.8v peak. 18.8 x 0.71 = 13.35V Rms Power = 13.3 x ( 13.35 / 7.3) = 24.2 W both channels driven Clipping on both channels Power output one channel driven = 29.6 W
  22. Some final pics before it gets put back into use as the lounge room amplifier. Wood split gone. After fixing the splits, I gave the wood cover a light sand and sprayed on a few coats of clear laquer satin finish. The scratch is still visible in the right light/angle but is better than before. That cover is sexy A clean up and de-oxit of terminals and connections. The Black base plate had a sand, service stickers removed and re-painted satin black. As good as I can get it. Its funny those marks on the tone control metal cover look like an actual hand print. Maybe from the manufacturing process? who knows.. Power amp board. The pots were originally all quite stiff in their action. Like someone may have put lots of wd40 that had gone tacky with time. So all the pots and switches were removed and cleanned properly to give a nice smooth action. Cheers Simon
  23. Amplifier board parts. Its had a nice clean inside as well. Note the early models have these UFO ceramic transistors. I left them alone as they are excellent Mil spec ones and I like them and they test fine and they look really cool. Pots are changed to multi turn types. After amp was adjusted and bias set now..... Final LC measurement is 1.43 - 1.22 = 0.21 % THD back to correct specs RC 1.45 - 1.22 = 0.23% THD also excellent.
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