Trying To Learn the RMS Rating of This Amp

[Umbra]

I've got what I believe to be an SPX Audio amp, model PK06210/212. I picked it up for $10, but there was no stickers or logo on it. I opened it up and punched in whatever numbers I could find and came across this amp which looks just like it. I can find practically zero info about it online. I'm sure it's not great, but it works well enough.

Here's a picture (not mine)

I'd like to set the gain on it appropriately. I don't have an oscilloscope, but I do have a DMM. The guides I found require the RMS to be used in the formula. "400W" seemed to come up most frequently, but I'm not sure if that's peak or RMS.

I was hoping someone might remember this amp, or maybe tell me how I might continue without the RMS number.

On a semi-related note. Just playing around i noticed if I hooked up my DMM between the amp and sub I can see the volage rising and dropping with the gain and the various parts of the song, but not the amperage. I don't know much about electricity, but I was hoping if I gleaned the amperage I could figure out the wattage it was putting out at the time.

Thanks in advance for any help you might be able to offer.

Click to read more...

 

[jrdnhsnbrg 10+ year member]

You can't use a song to set the gain unless that song has a straight 50Hz tone. Use a tone generator app or test tone CD to set your gains.

Read this, too: http://www.caraudio.com/forums/general-discussion/534027-%5Bhow-%5D-setting-gains-dmm.html

 

[Jeffdachef 5,000+ posts]

I dont really hear good things about spx audio based on online reviews. My guess is that you'd be lucky to see more than 100 actual rms from it, but thats clearly and assumption from online reviews and you know how accurate they are @_@.

 

[n2audio 5,000+ posts]

I see a yellow fuse (20A)

That lines it up with something in the 150-175w rms range.

I wouldn't use a DMM to set the gain on an amp you don't have a semi-accurate power rating for (using the fuse size is a rough approximation).

Just do it by ear.

 

[Dub7sonoma Premium Member]

Also you cant measure amperage with a dmm without running the amps output through the meter. Most dmm (cheaper ones) only have a 10 amp fusing on their circuits so if you are producing more than 10 amps, you will pop the fuse in the meter. Amp clamps are more common and easier to use when measuring amperage. You don't have to remove or install anything to take measurements

 

[hispls 5,000+ posts]

Anybody in this thread care to take a stab at defining an "RMS"? The level of ignorance on this board is shocking.

 

[neo_styles 10+ year member]

Anybody in this thread care to take a stab at defining an "RMS"? The level of ignorance on this board is shocking.

Shh they don't own Zed, so they don't know lol.

Care less about what the amp is rated for and use your ears as your guide. If we all cared about "RMS" handling, the entire cheater amp industry would have gone up in smoke a long time ago.