Yurid.
Hi guys. My output offset voltage is -2mV without speakers. When I connect speakers it goes up to 34mV. Is this how it should be or is there something wrong?
Did you measure the voltages +/-27-28V and the bias again with the load speakers on it? Are the same ?
Hi guys. My output offset voltage is -2mV without speakers. When I connect speakers it goes up to 34mV. Is this how it should be or is there something wrong?
Did you measure the voltages +/-27-28V and the bias again with the load speakers on it? Are the same ?
Anything under 50mV is still acceptable. 34mV is only 0.1mW dissipation in 8 ohm voice coil.
You can try adjusting the resistor on the input stage if you really want to get it lower but wouldn’t worry.
You can try adjusting the resistor on the input stage if you really want to get it lower but wouldn’t worry.
Yep, Nikos, XRK is dead right.......
Not an appreciable offset but can be changed with alteration to the LTP supply resistors.
Enjoy the music and thank you for your decision to build the AN.
Cheers,
Hugh
Not an appreciable offset but can be changed with alteration to the LTP supply resistors.
Enjoy the music and thank you for your decision to build the AN.
Cheers,
Hugh
Off topic:
While X, Vunce, and Hugh are present on this thread, I have a request to have a look at the last couple of post's in the Yarra Pre/HPA for Melbourne GB thread and try to clarify for me, " why my DC voltage after the diodes would be 35V rather than 31V." Posts #1648 and onward have information also.
Thanks for the help, seems to be a stumbling block for my brain 🤔
MM
While X, Vunce, and Hugh are present on this thread, I have a request to have a look at the last couple of post's in the Yarra Pre/HPA for Melbourne GB thread and try to clarify for me, " why my DC voltage after the diodes would be 35V rather than 31V." Posts #1648 and onward have information also.
Thanks for the help, seems to be a stumbling block for my brain 🤔
MM
That is strange,
when I measure my AN39 with an 8ohm resistor or my speakers it remains the same: about 1-2mv
When you say "without speakers" do you mean without any load or with a 8 ohm resistor ?
Same story here with 4Ω , speakers
Yes its strange .
Yrid
If the voltages-bias remains the same with No load AND load then your speakers are difficult speaker's .What kind of speakers do you have? Are they electrostatic? I assume your measurements are repeated. and correct ones.
With a 8 Ohm resistor and 8 ohm speaker a result the same.
It's your choice at 1.34 Α?
Normally, with a resistance of 0.22 it should reach 1.8 Α.
Double check your components In relation to the corresponding plan
Normally, with a resistance of 0.22 it should reach 1.8 Α.
Double check your components In relation to the corresponding plan
Thanks, I will try to install an additional resistor to get 0.22 ohm instead of 0.27 ohm. Can this cause asymmetry of the output signal?
Maybe , on both sides same source resistor of course .maybe one of the output mosfets It's starving for ampers.
Check again with sine wave.
What output mosfets Did you use?
Check again with sine wave.
What output mosfets Did you use?
Last edited:
Yes the neg halfcycle is current starving.
Simplyr reduce the output source equal resistors.
HD
Simplyr reduce the output source equal resistors.
HD