Somehow I cannot reach 55mv bias. It can reduced to 230mv in minimum pot position. I used 1k multiturn trimpot.
Voltage across 100ohm resistors are 1.3vdc.
Other components are based on Greg's parts list.
Where should I look&check?
Voltage across 100ohm resistors are 1.3vdc.
Other components are based on Greg's parts list.
Where should I look&check?
I mean, r21-r22. Parallel resistors with fuses.
Greg's build guide suggests removing fuses and check voltage between fuse clips for successful build.
'Connect your multimeter probes to the empty fuse clips F1 to read the voltage across the 100 ohm resistor R21.'
'Turn the power on while looking at your multimeter.
If the reading is more than 6V turn off immediately.
If the reading is in the 0.9V to 3V range then OK.'
Greg's build guide suggests removing fuses and check voltage between fuse clips for successful build.
'Connect your multimeter probes to the empty fuse clips F1 to read the voltage across the 100 ohm resistor R21.'
'Turn the power on while looking at your multimeter.
If the reading is more than 6V turn off immediately.
If the reading is in the 0.9V to 3V range then OK.'
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I found my problem. I 'somehow' soldered 0.47ohm resistors between base-emitter pins of each output transistors..
What damage may cause this? Which parts should I change or replace?
Final note;
Don't drink while soldering!!
What damage may cause this? Which parts should I change or replace?
Final note;
Don't drink while soldering!!
Most likely - no problem. Output transistors are closet this way. As soon as you correct the problem, the amp is going to run fine.
If there are no other mistakes 😉
Cheets,
Valery
Member
Joined 2009
Paid Member
this amp is so good you might spend years trying more complex 'modern' designs for just a bit more performance before you go back and realize how good the AKSA 55 was
Made a layout for this little amp a while ago.
Still couldn´t fire it up due to other projects.
First layout after ages it seems so a few questionable choices like a mix of THT- and some SMD-parts.
First order at JLCPCB and I naively ordered a lot of 10 and will only need 4 max.
If anybody´s interested, I can let go of 6 PCBs for the cost of shipping.
Still couldn´t fire it up due to other projects.
First layout after ages it seems so a few questionable choices like a mix of THT- and some SMD-parts.
First order at JLCPCB and I naively ordered a lot of 10 and will only need 4 max.
If anybody´s interested, I can let go of 6 PCBs for the cost of shipping.
Attachments
Hello, I am looking for two PCBs from the Baby Aksa.
If anyone has that, I'd be interested in it.
Thank you
Liva
If anyone has that, I'd be interested in it.
Thank you
Liva
Sorry, only seen your message just now.
If you can live with the few oddities my layout has, you sure can have two or more PCBs for shipping costs.
(I´m in germany)
Anybody tried to reduce the gain on the Baksa?
I´m sure I´ve read that you can reduce the gain on an Aksa at least some.
Otherwise I´ll go with a voltage divider at the input.
Thanks for the interest but Hugh ( Aksa ) found me
two PCBs from the Aksa55 and the 100.
Thank you
You´re welcome and wow, that´s a good solution getting the original PCBs from the designer himself!
Get back when you have it working. I hope to fire mine up soon as well.
Hi...
MrHifiTunes had friendly ask me to make a layout for this amp and i did. The next question was if i can share the gerber files. Of course i can share....
As schematic i used the Bimo schematic.
Perhaps someone has an idea to make something better....ideas welcome.
If no other ideas, i think it is finished. I can't give any guarantee. I have to test the pcb by my self but i have too many other projects...
Have a look to the pcb, schematic and so on...
Version 2 because it is existing a similar pcb with other TO220 drivers as in the Bimo schematic.
Greetings
Peter
MrHifiTunes had friendly ask me to make a layout for this amp and i did. The next question was if i can share the gerber files. Of course i can share....
As schematic i used the Bimo schematic.
Perhaps someone has an idea to make something better....ideas welcome.
If no other ideas, i think it is finished. I can't give any guarantee. I have to test the pcb by my self but i have too many other projects...
Have a look to the pcb, schematic and so on...
Version 2 because it is existing a similar pcb with other TO220 drivers as in the Bimo schematic.
Greetings
Peter
Attachments
Member
Joined 2009
Paid Member
I would've recommended providing footprints for LTP emitter degeneration resistors (Hugh was not adverse to them if low valued). and C3 looks a little under-valued at 15pF. Great amp!
