Guys, I need your kind help: I'm trying to assemble my first ampli using the 3e AUDIO 260-2-29A modified to accept SE input signal. I'm an absolute beginner in this matter and I tried to get as much infos as I could out of other knowledge. I tested the board with a cheap LDAC using my phone as a source and it sounded great. Then, since I took the chance to grab a 100k logarithmic pot by EIZZ at a very good price, I connected it between the LDAC and the ampli input. Well with great surprise and disappointment was terribly bad with the sound level constantly low all along the swipe and getting to max at the last two steps of the pot! The pot pins are marked as "IN-OUT-GND". I connected the LDAC output to "IN" and the ampli input to "OUT".
I replaced the EIZZ with a cheap linear pot getting a decently gradual regulation of the volume.
See in attachments a chart comparing the EIZZ and the linear pot resistance curve: they appeared quite nice, don't they?
Can't believe I'll have to get rid of the EIZZ for a cheap linear pot!
I have no clue on how to work this around!
What am I doing wrong?
I replaced the EIZZ with a cheap linear pot getting a decently gradual regulation of the volume.
See in attachments a chart comparing the EIZZ and the linear pot resistance curve: they appeared quite nice, don't they?
Can't believe I'll have to get rid of the EIZZ for a cheap linear pot!
I have no clue on how to work this around!
What am I doing wrong?
Attachments
your linear one curve looks more like a volume curve....
if you can get one of log on cheaper one to compare ,that will be good to see the exact problem
3eaudio
I am sorry but didn't get you ...the cheap pot is of linear type ...how may I get a log curve out of it?
I am sorry but didn't get you ...the cheap pot is of linear type ...how may I get a log curve out of it?
Is there stil a coupling cap in the amplifier? Did you measure at all? Just suppose there is DC at the amplifiers inputs and verify if there is not. Without speakers, use 10 Ohm resistors as load.
Many if not most volume controls are sensitive or allergic to DC.
Last edited:
@jean-paul
See, I'm just a dummy in electronics ...I hardly get what you're saying ...can you please be more clear? Keep in mind I have nothing but a multimeter for measurements.
Besides, the mod applied is as directed by the ampli board manufacturer.
See, I'm just a dummy in electronics ...I hardly get what you're saying ...can you please be more clear? Keep in mind I have nothing but a multimeter for measurements.
Besides, the mod applied is as directed by the ampli board manufacturer.
Attachments
Tried this 100k log pot. It works fine. Definitely don't think the configuration of the ampli board could be as you supposed. I've seen others use the same EIZZ pot and ampli board ...
Attachments
I tried a linear one and it worked fine. Couldn't hear any difference compared to the 100k linear one.
Adding a 12kΩ resistor across the eizz pot IN and OUT terminals may give you more usable volume control range.
@chrisng,
Awesome news!
I applied one resistor per channel as you suggested and now the Eizz pot is regulating the volume just fine!
Perhaps there us a slight loss of volume, but I have no equipment to mesure the performance other than my poor ears.
My greatest thanks Chrisng for your kind help!
Awesome news!
I applied one resistor per channel as you suggested and now the Eizz pot is regulating the volume just fine!
Perhaps there us a slight loss of volume, but I have no equipment to mesure the performance other than my poor ears.
My greatest thanks Chrisng for your kind help!