Anyone know what this amp is?

[MikeHunt79]

I got these amps for next to nothing, and I'm after a schematic, but I don't know who makes it or what model it is. It's a car amp and has 24v + and - rails, and that's all I've found so far...

I've already hacksawed the PCB in half on one of them and now it doesn't work, so I'd like to find some more info before I get started on the other one...

Pix:

ouside

inside

doorstop

 

[9designs2]

I've already hacksawed the PCB in half on one of them and now it doesn't work

Really !!!!!!!

WHY ?

 

[MikeHunt79]

Really !!!!!!!

WHY ?

I was hoping to use the Power supply part of it as the amp does not output anything to the speakers... The PSU part is pretty nicely made, but the amp part is pretty cheap and nasty and wouldn't really give a very good sound unless it was used for a boombox or something.

After hacksawing it, I found out the power supply was the problem all along...

Nice solid rails with no load, but as soon as I loaded it with something with a small load like a fan, the voltage just drops to zero... I think it may be something to do with the oscillator.. It would be nice to fix it as I even went to the trouble of changing the number of windings on the toroid...

Anyway, forget the jargon... Anyone recognize this beastie?

 

[MikeHunt79]

Hey, I managed to fix it in the end, well the PSU part at least. The hacksawing payed off.

Anyway, I now no longer need to know what amp this is, so feel free to delete this thread if you like mods.

 

[86JR]

usamps and orion both did them in anodized purple.

but i doubt they would be that messy, so probably pro plus or other naff.

 

[blue4ice]

I was also going to say US AMPs based on the colour but as you said it looks too cheap and messy for that. I have a TU-600 valve amp and the wiring is a lot better than the amp in the OP.

 

[TomO]

looks like the cheap rubbish they used to knock out of motor factors about 10 years ago. i had a couple of mates with them as they actually believed the ratings on them. needless to say they were ****. probably about £70-£80 when new for that one.

 

[Attu90]

looks like the cheap rubbish they used to knock out of motor factors about 10 years ago. i had a couple of mates with them as they actually believed the ratings on them. needless to say they were ****. probably about £70-£80 when new for that one.

Exactly what they are I had a couple of those about 10 years ago until I knew better and ditched them

 

[badbob]

This is a joke right, you really haven't cut the PCB in two?

 

[Deleted member 651465]

Why couldn't you just desolder the power supply, or unscrew it.

Surely a hacksaw wasn't the best idea considering you're planning on using it again

 

[MikeHunt79]

looks like the cheap rubbish they used to knock out of motor factors about 10 years ago. i had a couple of mates with them as they actually believed the ratings on them. needless to say they were ****. probably about £70-£80 when new for that one.

Yep, just by looking at the internals you can tell it's made as cheaply as possible... Nasty lo-fi op amps, capacitors made by some unheard of brand, etc...

The PSU is pretty good tho, nice thick windings on the toroid, and good thick wires from the connector to the PCB. May be good for around 1kw at a push, bit I'm only using a 400W class D module for now and it works really well.

This is a joke right, you really haven't cut the PCB in two?

No joke, I unsoldered a few components, and hacksawed away. Do it outside tho, you don't want lead in your carpet...

Why couldn't you just desolder the power supply, or unscrew it.

Surely a hacksaw wasn't the best idea considering you're planning on using it again

It's all on one PCB. PSU at one end, amp in the middle, pre-amp on the other end.

I now have a 4 x 100W class D module in there, which actually has good sound quality, and should work really well in the car once I get my crossover finished.

Piccy of it running, I've just got an mp3 player connected and it works:

EDIT: Module just about fits in the case, you can see the sawwed off part of the PCB in the top right:

 

[daz]

"Purple Mosfet" as they're known on talkaudio forums (talkaudio.co.uk/vbb) are basically the cheapest of the cheap amps. And are pretty poor.

 

[MikeHunt79]

"Purple Mosfet" as they're known on talkaudio forums (talkaudio.co.uk/vbb) are basically the cheapest of the cheap amps. And are pretty poor.

Cool, I'll keep that in mind if I ever blow the PSU FETS or rectifiers...

Even tho I never actually heard the sound from a working one, I can agree that they will sound pretty bad... I like to think I've done a little recycling here, as they were destined for the bin.