Yes input is connected to the ground and used following layout.
http://www.diyaudio.com/forums/atta...imate-fidelity-amplifier-apex-ax14-layout.jpg
Chances of any fake transistors ?
http://www.diyaudio.com/forums/atta...imate-fidelity-amplifier-apex-ax14-layout.jpg
Chances of any fake transistors ?
Are both boards doing the same thing? Double check that you have exactly the correct transistor in each spot. Orientation looks OK but I can't see from the pics if the MJE350 is correct. Looks like it is a different brand than the MJE340.
Thanks for great feedback Guys..
Problem was fake 2SA1943 & 2SC5200 transistors, De-soldered a pair from old working amp and tested.
Now this amp is working fine good sound on +-30volts.
Building 8 channels, tested other channels too, some are giving +voltage , some -voltage at speaker out and two are giving no voltage at speaker out, but heating like hell, so have to replace all 8 pairs of power transistors.
MJE350 is of different type package than MJE340. Rest all of the component are fine.
Two days wasted in checking all the tracks, soldering and other transistors.
Problem was fake 2SA1943 & 2SC5200 transistors, De-soldered a pair from old working amp and tested.
Now this amp is working fine good sound on +-30volts.
Building 8 channels, tested other channels too, some are giving +voltage , some -voltage at speaker out and two are giving no voltage at speaker out, but heating like hell, so have to replace all 8 pairs of power transistors.
MJE350 is of different type package than MJE340. Rest all of the component are fine.
Two days wasted in checking all the tracks, soldering and other transistors.
Hi Max,
I'm thinking yes but there is a little noise. It is hard to tell the reason. I didn't spend a lot of time rerouting wires and such to see if it would go away. With so many parts there are lots of opportunities for noise to get in. With the P30 attached there are 140 transistors lit up. 😱
It's a good sounding amp.
Blessings, Terry
It is 4:51AM. Yes, I should be asleep. I woke up thinking about the amp that went up in flames yesterday. 😱
It was the first time that had happened to me. I've had resistors smoke before but never flames. Sure made a nasty looking spot on the board. The designer has already worked out the solution.
Ain't diy fun? 😀
Blessings, Terry
It was the first time that had happened to me. I've had resistors smoke before but never flames. Sure made a nasty looking spot on the board. The designer has already worked out the solution.
Ain't diy fun? 😀
Blessings, Terry
Nice etch job. I see your drill is deforming the foil a little. I had that trouble until I did some reading and learned the importance of high speed drilling. I since bought a Dremal drill press and some carbide bits and actually enjoy that part of the process. I haven't broken a bit since.
Blessings, Terry
Blessings, Terry
