Mini guitar amp idea...

[ca cat]

Recently I noticed some realy cheap car audio amplifiers on Ebay, like this one:

http://cgi.ebay.com/Mini-Hi-Fi-Audio-Stereo-Amplifier-Car-Motorcycle-Boat-/110621827623?pt=Car_Amplifiers&hash=item19c1932227#ht_4095wt_905

Could it be used as a guitar amp - with an input buffer or some preamp and some suitable power supply? Using one chanel only on 1x12 8ohm speaker cab? And maybe in stereo configuration with 2x12 cabinet?

[Mark Hammer]

180W+180W for $12.50, AND it's "hi-fi" 

On a more serious note, though, a great many of the power-amp chips used in solid-state "practice" amps - the kind that usually go for under $150, and might have a 10-12" speaker - are the very chips intended for the car and marine audio market.  Chips that run just fine off a single-ended 12VDC supply.

So yeah, if there was a suitable power supply and preamp stage, it might sound just fine.  I have a 40+40 car power amp I picked up for $10 that I wanted to eventually turn into a bass amp.

[defaced]

Input Power: 12V 6A DC

Can't get more power out than what you put in.  So you're looking at, assuming 100% efficiency (which is very unlikely), 72 watts.  Will is work as an amp, sure, that's the same idea as the TinyGiant amp from MusicPCB, but as you noted, a preamp to shape the guitar sound may be desirable depending on what your goal is. 

[Renegadrian]

I had a Lepai (which died shortly after) that was great! its chip was a little fragile (ta 2020) on input voltage; as I powered it with a car battery. Nominally a car battery should put out 12V but it can give peaks up to 15 or 16V, enough to kill that fragile chip. It seems that newer models use different and tougher chips. I read a lot on that amp and that chip, and a lot of other people had the same problem. You can get a new Lepai or similar amp for cheap! I'd use a preamp to hook a guitar, yeah.
MP3s didn't sound that bad, obviously its quality is not top grade but it works great for the money, and it can be easily modded (like swapping the 4558 inside for a NE opamp, or even burr brown, and change some caps.)

[jcgss77]

It is actually a 30 watt amp, according to the RMS value.  It seems to me that whenever someone tries to tout an amp to have a peak power which is 11x the rms, they are trying to make it sound better than it is.  (Pyle is infamous for this-and they do make a 30 watt guitar amp which they market as a 400 watt.  Honorable.)  Anyone with any electronics knowledge will know you can't possibly get 360 watts (180 + 180) from 12V and 6A.  It would probably make a decent guitar amp, but you will need to do one of 2 things: 1-find a transformer which exceeds 12V 6A, rectify, and filter, OR B-find a good laptop power supply with those ratings.  Good luck with the power supply.

With that price, it just might be worth buying the unit to build your own amp, like the Tiny Giant?

[CynicalMan]

Check out the power amps here:
www.taydaelectronics.com/servlet/the-(-IC-)-Integrated-Circuits-cln-Audio%2C-Amplifier--dsh--Instrumentation%2C-Op-dsh-Amp/Categories

Like mark said, pretty much all of the solid state practice amps out there have a car amp chip in them.

[ca cat]

I already have Little gem MK II, great for practice silent amp. I know that you have to ask the Chineese Mathematics and Physics Society to know by what standarts you get 180W out of that tiny chip / amp I saw the RMS value and that's the power I need.

I have all tube 50-watter, and it is obviously too loud to play in my apartment. So i am looking for something solid state with max 15W power to play with. I was foling around with TDA2030 chip, but had no succes (GGG practice amp layout).

I could propably use thist little amp for some other projects, so I will propably buy it. Put a good buffer in front of it, and it can be a nice little amp.

[Mark Hammer]

I love those ten dollar 3" powered computer speakers in plastic boxes running off 6vdc that state "360W PMP" on the box.

Uh-huh.

[Steben]

I have all tube 50-watter, and it is obviously too loud to play in my apartment. So i am looking for something solid state with max 15W power to play with. I was foling around with TDA2030 chip, but had no succes (GGG practice amp layout).

2 things:

- Do you want to use saturation of a power amp? If not, 50W amp with low volume is fine.

- With saturation in mind, 15 Watt still is way to loud if you want to go down from 50W AND standard semiconductor chip in overdrive soudns bad.
general thumb rule: 10x less power = 2x as soft in perception.

[Quackzed]

i have a 1x12 cab i'd recovered a while back, this might be a fun project for me.
a little solid state amp run off a 12v dc 'wall wart' seems pretty convenient. most amps don't run off of batteries...
i can imagine a 6pdt rotary switch, to choose which 'preamp' to use...
say, fender,vox , marshall, boogie, tweed, orange...
o.k. i've gone too far...