How good / bad is this amp made?

[Evenharmonics]

I've been using this AudioSource amp for my surround sound for couple years and the "auto on" sensor went bad and I decided to open it up. It's a stereo amp rated at 100W.

Can you tell something about this amp from this picture? Looks to me, it has no soft-start or speaker protection circuit.

An externally hosted image should be here but it was not working when we last tested it.

Since I already replaced it with another amp, I thought about salvaging parts from this for a diy amp. What are your thoughts?
Thanks in advance.

 

[john dozier]

I would not touch it with someone else's soldering iron. Regards

 

[amptech]

Use transformer for a different project

 

[Bare]

Well It can't be all that bad sounding If you've been using it for years .
Isn't the relay box at the end of the input board some kind of protection thump/circuit?
Parts board(s) quality doesn't seem impressive in the photo.
But certainly the pieces are salvageable, ie; Case, transformer, heat sink and connectors seem suitable for reuse.
Often/usually those bits are ..The ..most expensive parts of a DIY amp.

 

[sakellogg]

take no offence,please.

but cheap boards, not much for caps on power supply.
but you have a case and heatsink maybe a transformer for a start to somthing better.
maybe a pre.

 

[sakellogg]

i type slow i guess

 

[Evenharmonics]

I wasn't expecting much of quality from $99 (new) stereo amp. 2 years of moderate use as surround sound for my home theater wasn't so bad, I guess.

Existing power supply doesn't seem much for a stereo amp, as if they skimped on it.

Thanks for the inputs.

 

[Ian Finch]

There's no reason (yet) to believe it's any worse than other amps posted here. A schematic would help to make a more informed decision as to what is worth keeping or losing. If some parts aren't the fancy types guys admire, it's no big deal to swap them for whatever types are popular.

OTOH, binning the PCBs and starting another amp from scratch is a major job with no guarantees you will get discernible improvement anyway.

 

[geraldfryjr]

Knowing the numbers on the chips would tell us a lot more of its quality and capability than judging it by the color of its PCB's and components.

jer

 

[destroyer X]

You have a nice enclosure, a reasonable power transformer

heatsink to 50 watts continuous or 100 watts of music... and all connectors needed to assemble a diy audio amplifier.

This can save a lot of money if you have such kind of intention.

Any diy audio amplifier published in this forum will be better than this one..it was made to be cheap, a lot of integrated circuits to reduce cost..small condenser into the supply, 3A diodes...anything special on it...and it looks you have integrated circuits in the output..and these folks are good for 30 watts rms and not much more than that to each channel because of dissipation issues...so...if it is really a chip amplifier (i could not see, picture has not good resolution and focus)... then it is just a pretty toy...not serious if you compare with our average diy amplifiers offered in our forum.

I do think you will have only pleasure doing it....well.... this is what i feel, but this depends on your character, your passion, your skills, your know how, your time to do it, how much money you can spend.... well..depends on a lot of things.

Watching it i feel myself interested in this enclosure, this transformer, this heatsink and i would dismantle and install all connectors back to place..will see if it has some peak meter to be used and will be starting to research what to build.

This looks cheap...looks simple...the performance may be average..we have top performers in this forum....you can have it easy..there's no junk schematics in this forum..at least i could not see junk here.

regards,

Carlos

 

[Jay]

Looks like a gainclone chip. Should sound better than it looks. And looks like there is opamp pre also. JRC4558 may be? May be not, because any chip amp rated above 50W deserve more than a 4558.

 

[Andersonix]

It's bad ju-ju to scavenge a working amp. Hod rod it with more PS caps. Then when it blows up you can scavenge from it...

 

[Stormrider]

If this is the Amp100 (looks like it) it has a pair of LM3886's. It's probably one of the better commercial chipamps.

The AmpOne had discrete amplifier circuitry and tested very well at avsforum.

Both amps are slight upgrades over a typical receiver, but that's all.

 

[Evenharmonics]

This is AMP100 (stereo) by AudioSource. Chip is TDA7293 and spec is 60W @ 8 Ohm, 75W @ 4 Ohm, 160W @ 8 Ohm bridged.

I was about to build a monoblock amp for center channel of my home theater and I decided to look inside of this amp before listing on ebay. Based on the going rate of used ones, I may get better value out of salvaging parts from this amp than selling it and buying new parts for a diy amp.

Here's another look at the module.

An externally hosted image should be here but it was not working when we last tested it.

 

[wahab]

Chip is TDA7293

Keep it alive , you ll have trouble equaling the perfs of this chip
with a discrete design set apart power output.

Moreover , it is vastly superior to NS 38XX chips thanks
to its mosfet output stage.

In this amp it is used at conservative power since it s rated
110W/4R and 140W/8R as limit values by Stmicro.

 

[nigelwright7557]

It is quite shocking when you open some of these cheapie amps to find tiny transformers and heat-sinks.

If I were you I would find a better design and build your own.

 

[freax]

replace the coupling caps in-line with the signal path and call it a day, then once it dies for good strip it for spare parts.

I don't see this amp lasting much longer anyway.

Those large filtering capacitors aren't exactly name-brand if you know what I mean.

 

[techbiker]

Looks nice!

I see some quality metal film resistors and who knows the brand of those filter capacitors? Could be decent. I would say fix it, then sell it if you are looking for something different.