[osu1277]

Hey All
I am trying to build an amplifier to be placed between my cars auxiliary input and my ipod, since currently the volume must be turned up 100% of what it is for the stereo CD player in order to hear the Ipod.

I need general help. Does anyone have any experience with this sort of thing? ie using the car's battery as a voltage source, perhaps I can accomplish my goals using a simple C-MOY amp? What kind of output would I need to drive speakers in the car, or is this irrelevant?

I feel like if I build a simple CMOY amp with a gain of 2 everything should work out fine, am I right?

 

[nikongod]

NOOOOOOOOOO

cmoy uses a virtual ground. you will probably create a wicked ground loop, and possible explosion.

there are commercially built devices to do what you speak of (search line drivers for car audio on the Google) you will find both schematics and ones that are already built. the overall idea is similar to a cmoy, but the ground system, and perhaps capacitor arrangements (input and sometimes outputs) are also different.

 

[osu1277]

can you elaborate? I dont understand why the virtual ground would not work for a car stereo. Keep in mind I am not wiring this directly to my car speakers; it goes into the AUX of my stereo, where I am sure the signal is further amplified. As far as I can tell, if you imagine the ipod as a black box with voltage output X, adding the amplifier with G=2 should make voltage output 2X, and the output in the stereos twice as loud....right?

 

[nikongod]

if you plug the cmoy into the cars power, the cmoy's ground reference will be at what the car stereo sees as +6V. naturally, the signal from the cmoy to the stereo will have this voltage offset too...

there are at least a few schematics on the web detailing how to make what you want.

 

[Uncle Erik]

When I use the iPod as a source, I usually have to turn it up all the way. The internal amp isn't too powerful. However, I've never had any problems with it other than battery drain. If that's the issue, a simple charger would fix it.

If you want something like a preamp, you can pick up a cheap battery-operated CMOY on eBay cheap. Instead of electrical jeopardy (Nikongod is correct), it should give you what you're looking for. As a side benefit, you'd also be able to take it with you to enhance your listening on foot.

 

[BennyBoy]

SoundStream makes a MTube8 line drive that sounds cool(uses 6dj8 tubes).
This would work great for your Ipod.

http://www.soundstream.com/processors-mtube8.htm

 

[nikongod]

that soundstream thingy could be the sexxiest bit of car audio gear i have seen since their old cheater amps.

 

[BennyBoy]

It really is a great sounding unit! I got one for my pickUp thinking it was a 6 way crossover, Its not! is only good if your using the x-overs in the amps.
I've got a really nice Pioneer HU that does a beautiful job of crossing all channels in the digital domain with time/phase adjust. The MTube8 would kill all of that! So I sold it on Ebay. Would be perfect for a mid-line HU that needed a sub out and a second input for an Ipod. The sound was very tubey(great for a car).

 

[osu1277]

well ideally Id like to make the design as simple as possible, with my priorities being no maintenance (ie no battery changes, etc) and decent sound. Is there any reason I wouldnt be able to design a very basic amplifier myself? I searched for some of the above mentioned circuits but could not find any, and Im beginning to wonder why you would need anything more than 2 op-amps, one for each channel, and a common ground / voltage source, of course with all the resistors for the right amount of feedback and capacitors to weed out any stray AC signals..?