Does your signal source have grounded shields?
Does the mono/stereo switch make a difference?
Have you confirmed that the voltage in the audio circuit are close to what the diagram shows?
Have you tried tracing the audio through the circuit?
http://www.bcae1.com/temp/harmon kardon - tc300_[ET].pdf
Does the mono/stereo switch make a difference?
Have you confirmed that the voltage in the audio circuit are close to what the diagram shows?
Have you tried tracing the audio through the circuit?
http://www.bcae1.com/temp/harmon kardon - tc300_[ET].pdf
The difference between -0.81 and -1.05 probably isn't significant but I'm not familiar with this circuit. Q234 could also be making a difference. DOn't change anything yet.
Does swapping the L/R RCAs change the low channel.
What's the resistance between the RCA shield (RCAs plugged in) and the primary ground (no power applied)?
Does swapping the L/R RCAs change the low channel.
What's the resistance between the RCA shield (RCAs plugged in) and the primary ground (no power applied)?
Hi Perry when you say gain pots do you mean SW100 and VR100?
I checked SW100 and VR100 and the outer pins marked in RED on the circuit image below had continuity with the negative speaker terminals also marked in red.
I also tested VR103 and VR203 outer pins to speaker negative terminals and there was no continuity.
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I checked SW100 and VR100 and the outer pins marked in RED on the circuit image below had continuity with the negative speaker terminals also marked in red.
I also tested VR103 and VR203 outer pins to speaker negative terminals and there was no continuity.
SW100 is the mono/stereo switch. The pot closest to the corner of the board is VR101.
VR100 is the gain pot.
VR103/203 are to ensure that both inputs (center conductor and shield) have the same level of drive to the circuit.
Continuity isn't a definitive term.
What was the resistance between the red terminals of VR100 and the negative speaker terminals?
If you place your meter on the red terminal and the other outer terminal of that section of the gain pot, do you see a change in resistance as you turn the pot? 0 ohms to 100k ohms?
Are you sure that you were turning the gain pot when you said it made no difference?
VR100 is the gain pot.
VR103/203 are to ensure that both inputs (center conductor and shield) have the same level of drive to the circuit.
Continuity isn't a definitive term.
What was the resistance between the red terminals of VR100 and the negative speaker terminals?
If you place your meter on the red terminal and the other outer terminal of that section of the gain pot, do you see a change in resistance as you turn the pot? 0 ohms to 100k ohms?
Are you sure that you were turning the gain pot when you said it made no difference?
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