joust

Member Since 02 Dec 2004
Offline Last Active Jul 21 2016 07:51 AM
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Posts I've Made

In Topic: D150A Series II Questions

19 July 2016 - 08:27 AM

Hey Capitan, (sic)

The color code for the resistor is : brown (1), red (2), red (2), gold (5%) : 1.2K, and 5% precision. If you were to get a bleeding resistor for the cap, try something like between 12K and 47K.
Yes, the trimmers are for Left and Right input and output offsets. You will find the calibration method with the user manual.

Regards,

Alain

In Topic: CDi initial setup Q

19 July 2016 - 08:15 AM

You are correct in regards to tubes : It has to do with reflections from back emf of the output transformer to the valves (tubes). There is not this distinction in the bi-polar world, since there is no output transformer.

Note : Digital amplifiers don't exist; Speakers don't process ones and zeros but a continuous signal : All amplifiers are analogue, it's the internal processing that is digital. Furthermore, because a stream of square waves is used in the amplification section doesn't mean that it is digital. I class or D class amplifiers should not be considered digital.

A.

In Topic: D150A Series II Questions

18 July 2016 - 11:03 AM

Hey Captain, I hope you are well!
1. Looks like a 1.2K, (brown, red, red) 2W resistor with another resistor (burnt to a crisp!) in parallel. All of this is in parallel with the cap. The schematics don't show these resistors. The only function I can see for these resistors is to 'bleed' the caps on power down. 1.2K is quite extreme! Replace (tentatively) with a 12K resistor.
2. Cap looks off? Can you measure its capacitance? If not, I suspect the cap to be good. It doesn't look damaged at all.
3. Nope. It looks like a cap but is probably a choke.
4. (Tentatively) Don't!
5. Lastly : What you are determining is that these 'trimmers' are very important! And no, they do not adjust as you think. They do adjust the input and output offsets :
- Locate which (2) trimmers are for output offset adjustment; Set input level controls to minimum (ccw); Measure output with voltmeter and calibrate corresponding output offset trimmer to '0'V;
- Locate which (2) trimmers are for input offset adjustment; Set input level controls to maximum (cw); Measure output with voltmeter and calibrate corresponding input offset trimmer to '0'V;

Hope this helps!

A.

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In Topic: cts4200

18 July 2016 - 09:08 AM

Did you get the LVPS to fire up?

In Topic: DSi 1000 panel lights, can they be turned off?

18 July 2016 - 09:07 AM

No. However, you could 'modify' the display to remove power to the lights. (As long as the unit is not under warranty.)

A.