LONG POST WARNING
Bought an Ampeg B100R yesterday for a very, very low price
Was listed as spares or repair, so in my mind i was going to rip out the amp and fit a speakon on the back like I did with my BA115HP (again bought as spares or repair a few years ago)
Got it home and marvelled at the condition for the cost of approx 4 beers and then decided its a bad move to just ditch the amp section
Power on - no power. Dead as a doornail
Opened up amp and the 1.5A slow blow was pooped. Checked with a multimeter. No continuity - Ooooo result, but why???
New fuse, switched on... hummed a lot and it released a little bit of the magic smoke after around 10 seconds bummer. Looked like it came from around the transistors, but cant be sure. Will investigate later. Fuse didn't pop and it still fires up even after losing the smoke.....
So..... I've now removed the amp completely and am thinking it might be fun to work through it
First things first.... Light bulb tester.... Should I consider putting one together? I am thinking of teeing a bulb holder into an IEM cable. I'm thinking i'd need a 100+ watt bulb to make it work properly. Are these rare items these days?
Grille is held in with velcro pads. Persuaded out with a flat blade screwdriver and hope. Will staple a fabric tab on the frame to enable me to pull it out easier next time (next time????)
Speaker is fine - tested with another amp and works well. Apart from the dust it looks mint. Code is 86-118-14. 4 ohm. Looks very Eminence..ish
My initial prodding with a multimeter seem to indicate the there's a few 0.33 ohm 5w resistors that aren't showing anything like their correct values.
The transistors 2 x TIP142 and 2 x TIP147 seem to show the same readings per "pair". Will remove them later and test them individually
I've purchased some new transistors, some resistors (£6 so far) and i've downloaded the circuit diagram for the amp
I have a multimeter, a yoghurt pot half full of common sense and a desire not too end my life too early.
If anyone would like to chip in, then please feel free.
If the response is send it to a professional then please save your typing. I can't warrant spending too much on it. My time is my own and learning is good. If it takes me a few months, but I learn from doing it, then i'll be a happy bunny. If it takes months and it does my head in to the point where I launch it across the garage, then the speakon socket will be installed in the cab and the amp module thrust into the bin in disgust 😁
I'll add to this thread as I discover/damage stuff