Thank you, very kind.
The graph i would say is what i hear now, hinge frequency too high.
I'll study the schematic more closely, after i "sort out the vital issues" as you said.
In adjusting Bias and then DC Offset i got all of a sudden very wrong values for dc on left channel. And no sound, only crackles on peaks.
Only test i did up to now got me a strange ohm readings on the left trimpot compared to the right one.
To be continued...
The graph i would say is what i hear now, hinge frequency too high.
I'll study the schematic more closely, after i "sort out the vital issues" as you said.
In adjusting Bias and then DC Offset i got all of a sudden very wrong values for dc on left channel. And no sound, only crackles on peaks.
Only test i did up to now got me a strange ohm readings on the left trimpot compared to the right one.
To be continued...
Increasing capacitor 2513 will give you this:
(green is original 47nF, red is 63nF, blue is 100nF)
I would recommend unsoldering the trimpot and either cleaning it thoroughly or replacing it with a new one.
I have fried a channel of an old amplifier with trying to adjust the bias and have sworn to myself after that never to touch an old trimpot without cleaning it first.
Ah, yesss. The blue line looks perfect for my dear Elipson 1303. I will definitely do that.
Thanx for doing those simulations for me, it would have taken me much longer, starting with waking up the Windows side of my Linux PC ;-)
Don't brag, in my younger days I had about three flavours of linux alongside with Windows in my home pc - if set up right then the only hurdle will be installing missing updates.
Surely you know but I just mention that adding capacity is easiest done by soldering additional capacitor across the "nominal" capacitor pads.
Lesson learned here also. I hope i did not fry anything though.
Will get to the trim pot today. I spent the day yesterday replacing a bulging cap in the so-slow-powering-up wife's Acer LCD monitor. The hardest part was dismantling and reassembling ;-( At least that job went well!
I'm thinking about fudging something with fixed resistors (copying the working channel?) if i can't revive the trimpot. No spares around... Another artistic job coming up ;-)
Unless: are there trimpots in switching computer power supplies? i got a few of these lying about...
Thank you for your valuable help!
Don't brag, in my younger days I had about three flavours of linux alongside with Windows in my home pc - if set up right then the only hurdle will be installing missing updates.
Surely you know but I just mention that adding capacity is easiest done by soldering additional capacitor across the "nominal" capacitor pads.
Ah, noted. But if there's no room, i just replace the cap, correct?
But i might be able to win the bragging game: i am also in the process of reviving my Amiga4000 (1992) with PCI slots and modern cards (Graphics, LCD Monitor, Net, USB etc). Installation is done, i was at programming graphics resolutions when all hell broke loose. That AmigaOs is lovable....and eternal ;-)
Of course i kept the 2000 and 3000. Trimpots in there? ;-).
Why not clean the existing ones - this one
worked ok after cleaning. The important thing is to measure them after cleaning - when rotating slowly the wiper the resistance must not "jump".
I did, take it out and clean it. That was not the trouble.
Found something else while the board was out and solder side in view.
Would you be so kind as to read https://www.diyaudio.com/forums/sol...djust-idle-current-dc-offset.html#post6357474 ??
You've been of great help already, Thanks!
Found something else while the board was out and solder side in view.
Would you be so kind as to read https://www.diyaudio.com/forums/sol...djust-idle-current-dc-offset.html#post6357474 ??
You've been of great help already, Thanks!
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