Hello Terry
greetings really fast work in picture you use 560 ohms in parallel with the 2
in4148 in series any reason schematic shows 1K on my protype build over
current protection would kick in at 70% volume on 2 pair ax14 version adding
.22 5 watt in parallel with the existing .1 solved the problems
warm regards
Andrew
greetings really fast work in picture you use 560 ohms in parallel with the 2
in4148 in series any reason schematic shows 1K on my protype build over
current protection would kick in at 70% volume on 2 pair ax14 version adding
.22 5 watt in parallel with the existing .1 solved the problems
warm regards
Andrew
Need some advice for the FX100 amp as per post #540. C9 and C10 are 10pF as per sch. But I have either 4.7p or 22p in stock. I have right now soldered 22p 50V in those places. I also have 24p 100V. Which one should I use?
reg
prasi
reg
prasi
Hi Sonal,
Do you have a schematic that matches your layout? Mine is not working and I'm having trouble finding the error without the schematic.
Thanks, Terry
Layout is ok but Polarity of 10uF/ 100V capacitor near 1k2 5W resistor is reversed. I missed it on revision of layout. I have attached corrected photo.
Attachments
And we have very good news! the amp plays really nice. I have installed all 3 pairs and playing music thro test speakers.
I figured the problem with hum was due to me twisting both left and right channel grounds together on the i/p.
Also, it seems the amp gets better and better with bias with 3 pairs. earlier it was around 70-72 mA per pair with 32 V supply- not so good. Now its 90mA per pair with 45V supply, really nice. I would like to increase it further to try but current heatsink is limiting factor.
Thank you Mr. Mile!.
@ Andrew
Ah! why didnt I think of that!. Guess when I am building something, I miss even trivial calculations. Thanks for the tip, but its working fine with 24p in those places.😀
reg
Prasi
sorry for poor quality pic, its mid night here and too lazy to get the camera out.
I figured the problem with hum was due to me twisting both left and right channel grounds together on the i/p.
Also, it seems the amp gets better and better with bias with 3 pairs. earlier it was around 70-72 mA per pair with 32 V supply- not so good. Now its 90mA per pair with 45V supply, really nice. I would like to increase it further to try but current heatsink is limiting factor.
Thank you Mr. Mile!.
@ Andrew
Ah! why didnt I think of that!. Guess when I am building something, I miss even trivial calculations. Thanks for the tip, but its working fine with 24p in those places.😀
reg
Prasi
sorry for poor quality pic, its mid night here and too lazy to get the camera out.
Attachments
Schematic for FX100PSU, from what I understand 10uF/100V capacitor in reverse polarity is causing short-circuit of BC546 base to ground.
Attachments
Hi Sonal,
Yes, with the cap reversed the relay now engages, however I have 29VDC across the relay, should be ~24VDC.
I have the schematic you just posted but it does not match your layout.
Yes, with the cap reversed the relay now engages, however I have 29VDC across the relay, should be ~24VDC.
I have the schematic you just posted but it does not match your layout.