Let's Get Technical > Power Amp Tech
ADA Microtube - "protect" problem
Dante:
Protect Mode = When you first turn the amp on, it's in Protect Mode. A light is on while in Protect Mode, and no sound comes out until the amp is 'ready' at which time the light is extinguished and the amp fires up.
It can be a by trying to sit there and wait...and wait...and wait.....for that damn thing to fire up. Just be patient and it eventually will.
El Chiguete:
Ohh well then the MicroTube 100 doesnt have that light. It has independent Power and StandBy switches.
Sparker:
Hi Guys, and hope you all had (or still having) :homer: a Merry Christmas.
I think when the MT200 PSU startup thing was discussed some time ago, the neon inside the box, NE1 (a NE-2H type) was thought of as a suspect. This neon acts as an under-voltage protection for the PSU chip when the amp is switched on, when the neon strikes on the PSU chip is brought out of shutdown. The neons can degrade over time and the strike voltage can change, also they can show sensitivity to light - so shinning a torch in the case may not seem so strange. Not sure where the neon is inside the box, but you could confirm the problem by looking at the shutdown pin of the PSU chip when you switch the amp on. Covers off, multi-meter needed, high voltages present so leave it to a tech if you don't fancy getting your hands dirty. Or, just swap it for a new one and see what happens.
Hope this helps
Mike
MarshallJMP:
Only the MT200 has the protect led.This is because it's the only ADA amp that has a switching power supply.Like sparker said,change the neon bulb and the problem will usually be solved.Let me know if you can't find one,i have a few lying around.
Dante:
I had no idea that bulb was in there, and I thought Kim was making up stuff (as he is known to do) when he said it would come on with a flashlight! Go figure...
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version