It's actually 25 Watt RMS.
It says so on the box .

The 700 is the model number and the name is WMAX , so it looks like 700W to the inexperienced user , yet on the Ebay item description it say's 700 Watts. What a bunch of Turds.
PSnetwork , i'd report the user for false item description if I was you . I'd do it myself , but I NEVER ever buy things from ebay that are worth more than 2-3 bucks.

But still it is 25 watts and if you are planning to power small speakers then it might be good for you .

 

What?

How many hours do you want to run the amp at full power?

Your amp is drawing 0.5A, not 5A.

At 0.5A, a 5Ah battery will last for 10 hours.

a 12v lead acid battery should not be discharged below 11v or it can be damaged. This means that quoted Amp/hours divided by current draw cannot give a true time.

 

a 12v lead acid battery should not be discharged below 11v or it can be damaged. This means that quoted Amp/hours divided by current draw cannot give a true time.

Yes , but you would have to see in the datasheet to what voltage a 5Ah battery
goes down to after giving it's full 5 Ah . Usually if they say 5Ah then that should mean that it provides that capacity without going into a danger zone

 

Not wanting to nit pick but I think the rating is usually for the 1/20th discharge rate. Admittedly that audio amp might have an average draw of less than .5 amp so 10 hours could be about right..
With a battery tucked away out of sight it might be a good idea to have a battery monitor / or low voltage cut off set to 12.1v. 12.1v is a usual voltage for considering an LA battery to be flat.

 

It's actually 25 Watt RMS.
It says so on the box .

The 700 is the model number and the name is WMAX , so it looks like 700W to the inexperienced user , yet on the Ebay item description it say's 700 Watts. What a bunch of Turds.
PSnetwork , i'd report the user for false item description if I was you . I'd do it myself , but I NEVER ever buy things from ebay that are worth more than 2-3 bucks.

But still it is 25 watts and if you are planning to power small speakers then it might be good for you .

look man, i'd rather go with 12v 2A amplifier because im not using a high power rating, just only 10W, 5w for each speaker.

i'll really be glad if someone here will answer this question for me:

for example if im buying 12V and 2A amplifier, and im using the all 2A with 12v and 2Ah SLA battery, so it will last for one hour if im using the all current in the amplifier?
im thinking like that because the capacity says: 2Ah, 2 Amper Hour

 

What's wrong with that first "500W" amp?
It draws only 0.5A and will be good enough for 3W per channel output.

 

What's wrong with that first "500W" amp?
It draws only 0.5A and will be good enough for 3W per channel output.

thats isnt enough, i need power of 10W total.

 

Do you know the difference in listening power between 6W and 10W output?

 

Do you know the difference in listening power between 6W and 10W output?

actually no.

 

You would be better off with something like this:

http://www.ebay.com/itm/DC-7-5-15V-..._Audio_Amplifiers_Preamps&hash=item56593c8d88

This is a class D amp that claims to be 90% efficient, which is quite possible. A typical class AB amp is going to be about 50% efficient, so you would get nearly twice the battery life using a class D.

Plus, it is half the price.

Bob

 

look man, i'd rather go with 12v 2A amplifier because im not using a high power rating, just only 10W, 5w for each speaker.

i'll really be glad if someone here will answer this question for me:

for example if im buying 12V and 2A amplifier, and im using the all 2A with 12v and 2Ah SLA battery, so it will last for one hour if im using the all current in the amplifier?
im thinking like that because the capacity says: 2Ah, 2 Amper Hour

Yes it will last abit less than 1 hour if you are using 2 amps continuously . Probably 40 mins , maybe less.
If you are planning on using 2amps continuously then you should probably get a 4Ah battery at least.

Also you should look into that D-class amp that someone posted above . It waay more efficient and it's small

 

You would be better off with something like this:

http://www.ebay.com/itm/DC-7-5-15V-..._Audio_Amplifiers_Preamps&hash=item56593c8d88

This is a class D amp that claims to be 90% efficient, which is quite possible. A typical class AB amp is going to be about 50% efficient, so you would get nearly twice the battery life using a class D.

Plus, it is half the price.

Bob

Ive seen this amp on the forum a month ago . Looks very tasty. I wouldn't have any immediate use for it but I have a sudden urge to buy it

 

You would be better off with something like this:

http://www.ebay.com/itm/DC-7-5-15V-..._Audio_Amplifiers_Preamps&hash=item56593c8d88

This is a class D amp that claims to be 90% efficient, which is quite possible. A typical class AB amp is going to be about 50% efficient, so you would get nearly twice the battery life using a class D.

Plus, it is half the price.

Bob

Ive seen this amp on the forum a month ago . Looks very tasty. I wouldn't have any immediate use for it but I have a sudden urge to buy it

really thanks for the advice guys, its looks very nice and its cheap but 2 problems:

1. where i can find 2 wires to connect them from the amp back to my battery?

2. why its doesnt have volume control ?

 

That sure looks like a volume control to me.

Bob

 

really thanks for the advice guys, its looks very nice and its cheap but 2 problems:

1. where i can find 2 wires to connect them from the amp back to my battery?

2. why its doesnt have volume control ?

IMHO, you would be better off buying a boom box ready made. Some of them have amazing sound.

I think you are under the delusion that amps draw a lot more average current than they actually do. Power ratings are largely fictional anyway, but the average power you need even for loud playback is less than one Watt. Killing yourself to get "increased efficiency" isn't really necessary. Battery life will be the result of average current draw. For example: suppose you have a 12V supply made up of eight D cell alkaline batteries which are ballpark 15 A-hr rating. Assuming one Watt average at 50% efficiency (2W total draw), that means a current draw of about 0.2A from the batteries and a total battery life of about 75 hours.

 

really thanks for the advice guys, its looks very nice and its cheap but 2 problems:

1. where i can find 2 wires to connect them from the amp back to my battery?

2. why its doesnt have volume control ?

That big knob on the board is the volume control .
You can get any wires, strip them and pop them in the back and fasten them with a screw from what I see (those small blue boxes on the board with six screws I assume. Two will be for the power supply , two for the left channel and two for the right I think) . You could solder alligator clips to the other side of the wires or you can just solder them directly onto the battery .The board itself has a power switch but if you are making an encased boombox you probablty won't have easy access to it so you might want to solder a switch between one of your battery contacts and the wire that goes to the board and lead the switch out to the exterior for easy on/off.

 

hi guys, am new here,

i have these onkyo tx-dx676 av receiver. and it has no display, all the buttons here works well, i've already check the display circuit but nothings suspicious, i notice that during night (lights off) vfd filament can be seen glowing,i mean that i thing the cathode of the vfd is working. how bout the anode? how to check if the anode and the grid is working? or maybe the vfd driver M66004FP?

thanks guy,
pls share your ideas

 

hi guys, am new here,

i have these onkyo tx-dx676 av receiver. and it has no display, all the buttons here works well, i've already check the display circuit but nothings suspicious, i notice that during night (lights off) vfd filament can be seen glowing,i mean that i thing the cathode of the vfd is working. how bout the anode? how to check if the anode and the grid is working? or maybe the vfd driver M66004FP?

thanks guy,
pls share your ideas

That's a thread hijack and is generally considered bad manners. You ask something completely unrelated to the thread and it confuses everything. maybe you could start your own thread about fixing your dead receiver.