Pro-Plus 4CH Amp

artnmotion

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Trying to fix one of these. My mate dropped a screwdriver into it while trying to fix it while it was on. This blew a few transistors. The transistors are BUK455 60B's. Replaced these with BUK455 200A's as RS doesnt stock the 60B's any more and i cant get hold of any from Farnell or CPC. The amp worked for a while but then stopped working. On closer inspection a 80 Ohm resistor had fried attached to the gate of one of the intact 60B's. Going to try and replace the 60B with a 200A but they have different current and voltage ratings so im not sure its going to work. Can anyone help plz


Art
 
lol ... Ive got another one but this one is 4channel that can be bridged to 2 channel. Kicks out quite a bit of power. Quality isnt amazing but it makes some noise ;).
 
Here are the Philips datasheets. The voltage ratings in this case would not be of concern, the current however is, the 60s are much higher rated.

I don't know why the resistor on the Gate has frazzled, there should be virtualy no current as they are FETs lol. Possibly due to the devices breaking down internally.

I bet they were a bit warm :).
 
Depending on how they are configured, I don't know :Dunce: , the Drain-Source on-state resistance is lower on the 60B too.
 
Thanks spectre, there are two of them in a push pull configuration i think. One is a 60B one a 200A. Im thinking it might be a good idea to match these. When it first when bang 2 of the 60s were replaced leaving 2 left. They might be damaged.

I put it back in the car and it worked for a bit, the protection light was on and the power light. Then smoke started coming out of the amp lol so rushed to turn the head unit off to turn the amp off lol .. it reeked
 
I think matching would be a good idea :).

I have bought components from a local company to me for years called Aitken Electronics, they are a good supplier for audio power transistors etc. I was amazed to find they had a website a couple of minutes ago as they are a small back street shop that until recent before they went more into DJ equipment used to have stuff like dusty valves and obscure components with no markings in sun-bleached boxes from yester-year under the glass counters LMAO.

Get in touch with them HERE to contact them, maybe they have some '60Bs.

I do think the current rating of the 200Bs is a problem though at 13A compared with 38A for the 60B.
 
Dont wanna chuck it out. If its nackerd ill probably keep it for parts. Cant see it doing anything to the headunit but it could start a fire if im not carefull lol
 
Have you tried maplin or Radioshack?
They stock a lot of the older style components.

you will be better matching all 4 fets together, that way you will get less distortion and imbalance.
 
I can't imagine Maplin stocking them or does that just occur with things I need lol.

I thought Radio Shack had closed ?
 
Had to give up fixing the amp .. had a petrol leak .. hoses had perished. Reverted to my mountain bike lol
 
got some 200's put them in but it then fried another resistor, gonna have to replace another fet .. grr
 
just wondering how an electronics engineer didnt know that in most amps the output trannys had to be matched even more-so in bridgeable high power amps... but i do have one question as youve uprated the trannys is the amp putting out more watts .. also if it has uprated the power can it sustain the higher outputs without it burning out the board
 
well thats gonna cause early failure if its used at its original rated output
 
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