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  1. WHONOES

    Marantz 2015 Receiver Distortion

    If you can get to the bases of H611 and H613, put you dmm on those points and measure the voltage. It should be close to four Vbe's or 2.4V. Maybe a little more or a little less but not substantially so.
  2. WHONOES

    Marantz 2015 Receiver Distortion

    That small kink is the crossover distortion I was describing. The output would sound reasonable using headphones as the load will be quite small. Having had a bit of a trawl through some Marantz info in German, I have deduced that the diodes are indeed diodes. Probably something like 1N914's in...
  3. WHONOES

    Marantz 2015 Receiver Distortion

    Good news that you have got a scope. Connect you scope to J610 and ground or J606 and ground. With a suitable 8Ω resistor fitted to the speaker connector, apply a signal to the input, 1Khz I would suggest, and adjust the output to about 1/2 scale. Hopefully the signal will not be clipping. Now...
  4. WHONOES

    Source of nylon fastening - UK based

    Try Model fixings see link below. They do a whole range of small fixings for the model fraternity. http://www.modelfixings.co.uk/nylon_screws.htm
  5. WHONOES

    Marantz 2015 Receiver Distortion

    Sounds like you (or rather your amp) are suffering from crossover distortion whereby the output transistors are not biased on. This could be caused by the thermal compensation diodes at H701 and H 702 having failed (or appear to have failed) short circuit. This would stop you being able to...
  6. WHONOES

    Under water wireless signal?

    Have to agree, ultrasonic's would be the simplest option and could be controlled from you Arduino.
  7. WHONOES

    Muff Pedal Distortion Repair

    I think the only opamps available in 67 was the μA702 (from 1962) and the much improved μA709 (from 1965) but I could be wrong.
  8. WHONOES

    Removing transformer sealant

    Or buy a replacement transformer!
  9. WHONOES

    Resistor for motor to slow speed..

    I'd go for a simple PWM circuit using a 55 and transistor.
  10. WHONOES

    Muff Pedal Distortion Repair

    There isn't an opamp in the circuit diagram!
  11. WHONOES

    What type connector is this.

    The JST bit stand for Japan Solderless Connectors which I guess as a description is not strictly true.
  12. WHONOES

    Need a little inspiration

    Could use them to run a radio or something similar. At least you would get some enjoyment of them.
  13. WHONOES

    Limiting resistor for High Power LED

    A word of caution. If you are playing with UV LED's, you need some eye protection in the form of a UV blocker. Even if you point them away from your line of sight, there will still be reflections from objects around you. UV rays can cause a lot of eye damage and you won't even realise it is...
  14. WHONOES

    How to monitor an actuator's feedback line from a microcontroller?

    So, what voltages are there on pins 8 and 10?
  15. WHONOES

    How to monitor an actuator's feedback line from a microcontroller?

    Got around to doing your sketch. See attachment. Couldn't be simpler. Circuit is same for both.
  16. WHONOES

    Infinite Switch

    Wot's an infinite switch?
  17. WHONOES

    Test peak current of a device using shunt resistor and oscilloscope

    Yup, that's another way to do it. I just assumed one wasn't available.
  18. WHONOES

    How to monitor an actuator's feedback line from a microcontroller?

    How about a resistor to pin 8 with a 3.3V zener at the ground end with the junction of the two connected to your μP. Then a 1 would represent "open" and a 0 "closed". Same on pin 10. This assumes that the supply is dc not ac.
  19. WHONOES

    Test peak current of a device using shunt resistor and oscilloscope

    Placing the resistor between the load and ground would be the sensible thing to do. Then, provided that the supply ground connection is not directly connected to mains earth, connection of the scope ground lead should present no problem.
  20. WHONOES

    The Best and Cheapest way to clean Rosin Flux for your Board.

    I have used IPA to clean boards foe the last 40 years or so. I use a cut down 1/2" paint brush to scrub the board. Then clean off with cotton based material, an old tea towel is perfect. Never had any problems.
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