Happy Friday Perry. Checked the circuit. When I turn the amp on, I'm getting -13 volts to L210 and 211 feeding the SD to the driver board. It's almost instant. Doesn't appear to be any delay. Is this functioning properly?
Are you applying remote AFTER you already have B+ and ground connected?
Does C82 charge relatively slowly (not instantaneously) after the remote is applied?
Does C82 charge relatively slowly (not instantaneously) after the remote is applied?
Yes. Applying remote after B+ and ground connect.
C82 charges instantaneously. Charges to the -Rail voltage.
C82 charges instantaneously. Charges to the -Rail voltage.
I have - Rail on both sides of the cap instantaneously. Do I need to ground my meter some where differently than speaker negative?
You have to measure the voltage directly across the cap.
What is the DC voltage across the cap with no remote voltage applied?
What happens if you parallel another 100uf cap across it?
What is the DC voltage across the cap with no remote voltage applied?
What happens if you parallel another 100uf cap across it?
With no remote voltage applied the cap reads .62 volts. With power applied it read 0 volts. Added a second cap. Applied power. Voltage across cap falls to 0v.
Q51 no remote voltage referenced to secondary ground.
E - +14.4
B - +13.8
C - +14.4
With remote
E- +14.4
B - +14
C - -18.3(-Rail)
E - +14.4
B - +13.8
C - +14.4
With remote
E- +14.4
B - +14
C - -18.3(-Rail)
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Desolder R56. Does the cap charge to about 5v?
With R56 back in the circuit, if you parallel a 1000uF cap with C82, do you get a noticeable delay before the collector of Q52 drops to the negative rail?
This circuit may not be the problem but I'd like to make sure it's working correctly.
With R56 back in the circuit, if you parallel a 1000uF cap with C82, do you get a noticeable delay before the collector of Q52 drops to the negative rail?
This circuit may not be the problem but I'd like to make sure it's working correctly.
With no turn on the voltage across the cap is +2.6 Volts
With turn on the voltage slowly drops to +.4
With 100uF cap, Takes about 2 seconds to drop to -rail.
With turn on the voltage slowly drops to +.4
With 100uF cap, Takes about 2 seconds to drop to -rail.
There is a definite noticeable delay in oscillation. It doesn't start oscillating till after the speaker relay engages.
If I let the rail bleed all the way down, it doesn't delay the oscillation. If I power it right back up it does delay oscillation.
Does the bulb light before oscillation begins?
Do you see approximately 0v of drive for both the positive and negative drive (at the FETs) before the oscillation begins? Black meter probe on the source pad and red meter probe on the gate pad.
Do you see approximately 0v of drive for both the positive and negative drive (at the FETs) before the oscillation begins? Black meter probe on the source pad and red meter probe on the gate pad.
Sorry for the delay in response. I put two outputs in the amp to test and answer your question. The amp runs. I've powered on and off several times to make sure. I removed the 1000uF cap that we added. Powered the amp up and the bulb glows bright. Put it back on and the amp powers up as it should. Could this be a design issue with this amp?