Modifying An Amp?

[mrafrica]

its just something i do. i like to learn as much as i can about stuff so taking it apart is my thing to do. ive repaired many ipods and things along that nature so i would like to work on amps next and modding them. and i am buying the right equipment that i need. but if you have something cheap and that can be improved why not experiment with it?it can be a waste of money if your doing stupid stuff that has no point to it what so ever. some people dont get the point of certain things that others do. and oh well. they dont need to.

[Boon]

whats the function of the toroidal transformer? and could any changes be made to that?

The toroids step up the voltage from 12v to whatever voltage your amp uses for the output.

You could re-wind them or replace them with different windings (need a bigger toroid really) to get more voltage on the output rails but you would get less current so it would compromise the amps performance at low ohm loads but make more power at high loads. However the output section is often designed so that the components maximum limits with regards to voltage are often within a couple of volts of the toroids output - cheaper this way - so you might find you have to replace a lot of the output components as well... at which point the time/effort/money makes it better to just buy a new amp.

I agree with the idea of messing around with old amps that you don't really care about any more - especially if they're cheapies that don't have much sell value. It's how I learned most of what I know now. Another way is to post up on forums asking for blown amplifiers - offer to pay shipping and you'll be surprised how many people are happy to get rid of blown amps they can't be bothered getting repaired.

The 2 most important things - firstly, get an o-scope, even if it's just an old/cheap one. Otherwise you're mostly just stabbing around blind. O-scopes are incredibly useful for audio in general and compulsory when you're playing around with amplifiers.

The second thing is safety. Read up about what the components do and what the voltage is likely to be around them. A Sundown SAZ-3000D has about 130v on the rails and I'll tell you from experience it gives a hell of a kick when you so much as brush a pinky finger on that part of the circuit board.

Bigger amps have enough voltage to blow the tip off your o-scope's probe and I don't like to think about what will happen if I ever touch one by accident. They also have a nasty tendency to explode quite spectacularly when parts have gone bad so cover the amp up or wear safety glasses when you turn on an amp in unknown condition

[mrafrica]

thanks for all that info. that was helpful. i was looking at o scopes and they are expensive. ill try to find an old one somewhere. yeah ik about the electricution hazards. ive got my fair share of shocks from things. i will read up on stuff like you sugested. they really can blow up and whatnot? thats abit of a hair raiser. lol. one time i did connect some amp i found in a stream up to a 120 outlet. that was wayyy before i knew anything about electronics. i of course let it dry out. it only smoked and blew the circuit breaker. ive wondered about your car boon. what kinda equipment do you have in it? and holy shit 8000 watts in that small of a car??

[Boon]

That car is stripped out now for my next install... it was to be 2 DD9515's and 2 American Bass VFL400.1's but equipment issues meant it never got run to its potential (mainly 1 of the subs and 1 of the amps being broken)

Was good fun while it lasted. Next year I'll build something proper in an even smaller car

[Toxiccasper]

You meant multimeter not o-scope

[ChevyBoy]

You meant multimeter not o-scope

no, he definitely meant o-scope

[mrafrica]

oh i c. niceee. i cant wait to see that build. big stereos in small cars now thats tricky and awsome. whatever vehicle i get all i know is its gonna bang hard with my new amp im getting =] the lovely gf is buying me a sundown saz-3000d. i told her ill need some bat's and shes like oh god that shit is exspensive.

[bobonit]

no, he definitely meant o-scope

Yea, it would be kinda hard to view a waveform on a DMM

[Ben Building]

Back in the day, I remember guys adding huge capacitors to their amps' capacitor banks. Whether this actually translated into more power or a higher damping factor is anybody's guess.

[Boon]

Back in the day, I remember guys adding huge capacitors to their amps' capacitor banks. Whether this actually translated into more power or a higher damping factor is anybody's guess.

It depends which bank they added them to... if you put them in the filter bank on the low side of the power supply then you would have just the same effect as a 'regular' cap put across the power inputs.

If they added a HEAP of them to the high-side of the transformers then they could possibly burp them (or get momentary power) without the power supply having to pull large current and thus drop voltage and become inefficient. This is basically the idea behind the T15K.