JLH Headphone Amp

Have a look here:
offset1.jpg


If the meter shows 140 mV, then the current through the capacitors is 14 nano Ampere, that's 0.000000014 Ampere, it is simply the leakage current you are measuring.
 
I suppose that this pcb have some problem... :confused: I'm thinking buy the new version (blue PCB).

What do you think?

Regards

I believe, apart from the color of course, they are the same, so there is no point doing that.

There is a build guide with pictures made by Miles Campbell in this thread, did you have a look at it and measured various voltages on the PCB as advised.

It would be also helpful if you post pictures of your build (both sides of the PCB).

Hope you will sort it
Marko
 
No, there is no AC voltage on C23/24. Standart elektrolytics are all right, but they shall be connected with + to GND.
Hm, really, sorry! I misunderstood the schematic... :) But I used 2 series caps here and the sound is clear, detailed.
According to simulation there is really about -1V. I will not take apart it now for a measurement...

By the way, at startup I measure about 100 mV Offset, and after 5 min. the Offset is down to 5 mV and stays in that area.
The offset is almost the same at my both JLH amps. I built these according to Miles Campbell's build guide, except I used multiturn cermets and trimmed the offset.
 
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Tomorrow I will take some pictures of this PCB

By the pictures, I suppose that the components are the "best" quality on the blue PCB ¿?:confused:

Regards

No, I don't believe that better quality parts come with newer blue PCB kit,
e-bay sellers use what is available to them and cheapest at a given time.

Replacing input caps with something better like WIMA as oz7aff suggested is worth doing, C23/24 could probably benefit from better parts as well.

Regards
Marko