While powering a headunit one day my Pyramid PS26KX power supply randomly failed. I’ve owned this unit for over ten years and it’s been good to me. Only had to replace the bridge rectifier once previously and it has worked flawlessly until just the other day. I have determined that the 2N3772 TO-3 transistors mounted to the heatsink on the back of the unit have failed as well as a rectifier inside the unit.
Is there an updated/upgraded readily available replacement for the 2N3772?
I can find them but they are either random Amazon/potential fake parts or very expensive per part (almost 7 bucks a piece). I’d love to continue using it. Is anyone aware of a viable substitute?
Thanks for looking!
Is there an updated/upgraded readily available replacement for the 2N3772?
I can find them but they are either random Amazon/potential fake parts or very expensive per part (almost 7 bucks a piece). I’d love to continue using it. Is anyone aware of a viable substitute?
Thanks for looking!
I'd use the originals. It can't have that many in it.
I've used some TIP35C in some instances (IIRC). Again. I'd use the originals.
Does this supply have the large 5w shunt resistors in series with their emitters?
I've used some TIP35C in some instances (IIRC). Again. I'd use the originals.
Does this supply have the large 5w shunt resistors in series with their emitters?
I believe there are four total 2N3772’s. I don’t remember seeing the shunt resistors but I do not have the unit in front of me right this moment either. Looking at a schematic I found online they are calling out the 2N3055 in place of the 2N3772’s. It looks as if those are an inferior part though. I guess I will bite the bullet and order the real deal. If it last another ten years it would be money well spent. Thanks for your help as always Perry.
I had the same issue with mine .
I tried using the same part number but from a local election shop so who knows how long they were sitting on the shelf or if they were genuinely parts . The power supply would last a week and blow them again .
I ordered replacements from mouser Electronics and haven’t had an issue since
I tried using the same part number but from a local election shop so who knows how long they were sitting on the shelf or if they were genuinely parts . The power supply would last a week and blow them again .
I ordered replacements from mouser Electronics and haven’t had an issue since
Probably an example of not fixing the fault that blew it in the first place.
Amps rarely blow for no reason.
Could have been a short or part short on output and this has blown an output transistor or two.
Maybe that has taken a driver with it ?
I would give the amp a thorough going over before powering it up again.
Check output transistors for shorts. Or sometimes caps can blow shorting out.
Check speaker system for shorts too or repairing the amp will just see it blow again sooner or later.
I have fried speakers before and sometimes they become part shorted.
First off it’s not an amp it’s a power supply .
And 2nd once I ordered the parts from an authorized dealer I’ve never had an issue since .
But thanks for your input
And 2nd once I ordered the parts from an authorized dealer I’ve never had an issue since .
But thanks for your input