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  1. madtech

    Luxman L85V... wow!

    Time flies! Finally getting back to repairing my own gear after 10 years of working on everyone else's. I was recapping the driver boards on my L85V and the outputs had to come out. I decided to check the Hfe on the outputs and the problematic left channel 2SA679 showed "resistor shunt between...
  2. madtech

    Toshiba SR-410 turntable service/owner manual

    I posted up the service manual and schematic on VE for the SR-410. Can anyone tell me where the 9 pin socket contact is located on the TT, mentioned on page 14, step 4? I've looked around and found nothing that looks like a 9 pin socket. I've had multiple symptoms since starting work on this...
  3. madtech

    Harman Kardon HK-770 Runaway DC Offset

    Bump. No experience out there replacing these guys?
  4. madtech

    Harman Kardon HK-770 Runaway DC Offset

    Have a minty Harman Kardon HK-770 on my bench whose DC offset can't be controlled. From the initial power up it steadily climbs on both channels. The right channel appears to climb faster than the left. The bias adjustments are spot on. All power supply caps test fine and the corrosive glue was...
  5. madtech

    NAD 3020B Recap and Service Manual Issues

    Thanks for this. I'll have to order a few trimmers in my next Mouser order.
  6. madtech

    NAD 3020B Recap and Service Manual Issues

    I just finished a recap on a minty NAD 3020B. NAD definitely used some garbage capacitors back then. Teapo and YEC makeup the majority of the caps. Out of 47 only 6 measured in spec and many had ESR above 40 ohms! Several wouldn't even register on my Atlas cap tester. After the recap I was going...
  7. madtech

    JBL Speaker Refoaming

    Cogs would appreciate the comments. We definitely had fun with that project. Good luck with the re-cone!
  8. madtech

    Minty Dual CS-5000 Won't Start

    After a careful inspection the first picture shows the problem. Definitely junk engineering on the motor control board. I scraped off the ends of the copper winding and soldered in a new piece,with a bit of hot glue to hold the wire in place. Turntable is now working and the speed syncs...
  9. madtech

    Minty Dual CS-5000 Won't Start

    The belt has definitely seen better days. I was going to buy a Thakker for it but until I'm sure about the serviceability of the TT, I'm reluctant to pull the trigger on one.
  10. madtech

    Minty Dual CS-5000 Won't Start

    I replaced the electrolytics on the motor control board. I'll have to check again for tantalums.
  11. madtech

    Minty Dual CS-5000 Won't Start

    The service manual for this one, other than the schematic itself, is somewhat useless.
  12. madtech

    Minty Dual CS-5000 Won't Start

    Yes, I performed a full recap of the electrolytics when I first tried to address the problem.
  13. madtech

    Minty Dual CS-5000 Won't Start

    I have a minty Dual CS-5000 that won't start up. When I move the tone arm over, I can see the motor "bump" but it won't spin the platter. If I give the platter a bit of help, sometimes it will spin, albeit at 48 - 50 rpm. All the electrolytic caps have been replaced but still no joy. I really...
  14. madtech

    Thorens TD 125 Mk II Unheated Garage Find

    Voltages for 16 (3.2V) , 33 (5V)and 45 (6V) are now perfect and the platter speeds are all spot on, but I can't adjust the strobe to be stationary. Solution - moved the 50 Hz \ 60 Hz mirror to the 50 Hz position and the strobe now functions properly. I can't explain that one........ time to...
  15. madtech

    Thorens TD 125 Mk II Unheated Garage Find

    I replaced all the pots and the voltages are certainly much more stable now. One of the 500 ohm pots (according to the schematic) turns out to be 1 k ohm and I can't get the A2 45 rpm voltage down low enough (sitting at 8.7v). Back to Mouser!
  16. madtech

    Thorens TD 125 Mk II Unheated Garage Find

    Yes, I was thinking about just giving it a small tweak. I have other problems I have to look at too. I can get the phase 1 and 2 voltages set up properly but I can't get the strobe pots to properly stop the strobe indicators from moving. I can get the 45 rpm strobe to settle but according to my...
  17. madtech

    Thorens TD 125 Mk II Unheated Garage Find

    So before I set the final voltages and strobe on my Thorens how do I adjust the belt guides? The top deck is level and the belt doesn't scrap on the guide going into the pulley but on the way out, it's firmly scraping on the second guide. The belt is riding properly at the top of the pulley. If...
  18. madtech

    Thorens TD 125 Mk II Unheated Garage Find

    May have just found my issue. Looking through another AK Barn find thread (lol) AKer tnsilver put up a picture of the speed control contacts. If you look at my picture you can see one of the metal reeds is hard against it's supporting metal base. It's so firmly in place that I thought it was...
  19. madtech

    Thorens TD 125 Barn Find

    Wow, great thread! Thanks for the pictures Tom. I think I figured out the problem with my Thorens TD 125 Mk II. One of the of the reeds is hard against its metal base as you can see in the picture. I have no idea how it ended up that way (in storage for 20+ years) and it's so firmly placed there...
  20. madtech

    Thorens TD 125 Mk II Unheated Garage Find

    Well the honeymoon is over. The belt (new and old) are scraping on the pulley guide closest to the back of the TT. I can push the left side of the deck all the way down and it stops scraping but even with the three levelers I don't think I can get it down that far. I can set up the phase...
  21. madtech

    Thorens TD 125 Mk II Unheated Garage Find

    New caps are in and the motor now appears to be rock solid. That definitely made my day! Cleaned the pots and set the voltages for Phase 1 and Phase 2. Picking up a new belt on Saturday and then I'll set the speed pots. Still trying to decide on whether I should set the Shure V15 II-7 aside and...
  22. madtech

    Trim Ring

    To make my foam trim rings for my AR9's 8" woofers I picked up some black foam from a craft store. Then I went to a hardware store and bought a drywall circle cutter. Clamped my carpet knife to the cutter, measured my distances and cut out 2 trim rings. They looked professionally made.
  23. madtech

    Calling Cerwin-Vega AT-10 owners and refoamers...updated 11/14

    No need for any more alcohol. Just use a small sharp exacto knife to scrape off the rest of the red bit's. Don't dig too deep or you will get into the paper cone.
  24. madtech

    Thorens TD 125 Mk II Unheated Garage Find

    A few extras in the box. Waiting for the caps from Mouser.
  25. madtech

    Thorens TD 125 Mk II Unheated Garage Find

    Yes, a very good chance it was purchased in the American PX there. I found a warranty card that he filled out but never mailed. His address was an Army Post Office (APO) in New York state. I think the unit was 322 Combat Support Group. I'll dig the card out again. How it ended up in Eastern...
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