the sound is still present in the ignition.
sorry for my ignorance. my multi-meter on Buzer, two radiators buzz as if the masses was common. while the radiators are not in contact.
sorry for my ignorance. my multi-meter on Buzer, two radiators buzz as if the masses was common. while the radiators are not in contact.
6L6 taught me that ACA pcb is having GND around one screw hole - so that's where heatsink is having GND from
is squeal there when you powering on and off just one channel ?
is squeal there when you powering on and off just one channel ?
yes, each independently.
in order: switch on,
small whale song,
crackling with music at low volume,
and the volume of the music goes my volume defined by my laptop and the music becomes clear.
in order: switch on,
small whale song,
crackling with music at low volume,
and the volume of the music goes my volume defined by my laptop and the music becomes clear.
15 posts just to finally have doubt in what you wrote 
:
confirm proper Iq and test points on schematic (voltage at inner side of output cap)
:confirm proper Iq and test points on schematic (voltage at inner side of output cap)
I also get the whale song on power up and the thump on power down.
I use a single laptop supply for both channels going through a double switch.
I use a single laptop supply for both channels going through a double switch.
For ACA 1 (mod. 6 watt/4 ohm), I built the P.S. with 8 x 1N5402, toroidal transformer is 80 va, 2x11 volts Talema.
Diodes become very hot!!
Diodes become very hot!!
this is true, the sound is really excellent. I listen last night for 5 hours. this is my first diy amp, my first real amp and I do not know if it was normal. it seems not.
I'm really not an expert in electronics, and I do not understand the way to follow. if you can explain to me the controls to do. if you have the patience.
I'm really not an expert in electronics, and I do not understand the way to follow. if you can explain to me the controls to do. if you have the patience.
looking at schematic in article - measure voltage across R3 (one probe on each end of R) and measure voltage at + side of C1 , referring to GND (black probe to GND , red probe to C1)
I think it's pretty normal. I also have the whale and thump😉
The 2 laptop PSU's are Lenovo 90W 20V.
When I tried to measure the voltages when powering on, the laptop PSU has difficulties to power up, voltage jumps up and down, it takes around 5 to 6 seconds till stable output voltage. Measuring at the 230V side gives also the strangest power consumption readings till stable.
I don't care! After those few seconds they are stable and playing very fine😀
Thump is less than my AlephJ
thank you for your time
not gone yet the mod, I board the resistance in stock😉, I expected to get an idea of the origin sond. and that all goes well and I would mod before closing the chassis
not gone yet the mod, I board the resistance in stock😉, I expected to get an idea of the origin sond. and that all goes well and I would mod before closing the chassis
LM317 regulated PSU
Hi,
I have built regulated supply for my ACA. It is rectifier - 10,000uF - LM317 - 470uF.
When I replace 470uF output cap for 1000uF the sound is worse - congested, less dynamic, less bass, mids stand out. WHY is that? All electrolytic caps are ordinary one, no low ESR.
Thanks.
Hi,
I have built regulated supply for my ACA. It is rectifier - 10,000uF - LM317 - 470uF.
When I replace 470uF output cap for 1000uF the sound is worse - congested, less dynamic, less bass, mids stand out. WHY is that? All electrolytic caps are ordinary one, no low ESR.
Thanks.
Why? My ACA draws 1.1A which is fine for LM317. Anyway it doesn´t explain why 470uF output cap sounds much different than 1000uF.
LM317 output current is a bit low to for 1000uF. Look for circuits using LM317 using transistors for boosting output current.
Oscillation? 1000 uF is very big for the output of a LM317... you normally see values around 10 - 100uF