Hi I have a technical question.
I recently got two mono amps (ADE HSA 300) and one of them doesn't output music. Instead it outputs a constant DC voltage. One of the MOSFETS gets extremely hot within 1-minute after turning on the unit. It is only plugged into power and there are no external signals connected (neither RCA or XLR) and it still outputs the constant voltage.
I took a look inside to see if there are any burnt marks or burnt smell but there isn't.
What could it possibly be?
They are both the same type of amp. They are old (around 30ish years) and the working one sounds absolutely amazing.
Thx in advance. If you need further details, let me know 🙂
I recently got two mono amps (ADE HSA 300) and one of them doesn't output music. Instead it outputs a constant DC voltage. One of the MOSFETS gets extremely hot within 1-minute after turning on the unit. It is only plugged into power and there are no external signals connected (neither RCA or XLR) and it still outputs the constant voltage.
I took a look inside to see if there are any burnt marks or burnt smell but there isn't.
What could it possibly be?
They are both the same type of amp. They are old (around 30ish years) and the working one sounds absolutely amazing.
Thx in advance. If you need further details, let me know 🙂
You need to find the schematic for it and either post it here or a link.
From your description it sounds like a blown output transistor.
Keep it away from your speakers if you want to keep them.
From your description it sounds like a blown output transistor.
Keep it away from your speakers if you want to keep them.
Many amplifiers output a DC voltage, the problem is when this is more than a few tens of millivolts - what voltage are you seeing? The size of it will help explain the issue.
I suspect the amplifier to have shorted transistors. You need to review the schematic diagram, and check all the transistors, diodes, resistors and capacitors which are associated with that channel. Since amplifiers are DC coupled, one bad transistor often means a lot of others are also bad, so be thorough testing all the parts.
If no circuit drawing emerges then I can reverse engineer the circuit if unlky hntr (unlucky hunter?) supply me good pictures of the pcb's and the rest of the amp (pm). A nice puzzle and probably useless because of a defunct fuse.
Sadly our natural senses are deaf/blind to Electrical parameters (resistance - capacitance - voltage - signal level - inductance - etc.) so specialized instruments were developed to detect and, most important, measure them.
Sight/sound/smell can not detect 99.99% of problems, except GROSS ones such as sparking/smoking/catching fire/cracking/exploding.
Combine that to not knowing how the circuit works and both lead straight to a tech who is both trained and equipped to solve your problem.