Interested in a USB Audio Amplifier?

**JuniorGeezer** · 08-30-2010, 01:41 PM

- Not sure if volume control was mentioned. I assume that it will take place in the audio data, so the more bits, the better but 24 bits is reasonable. The effective resolution is limited to about 20 bits anyway.

- 48 kHz is fine.

- DIN form factor is too small for a usable subwoofer channel, in my opinion.

Originally Posted by 2k1Toaster

[*] Signal Channel Power Output: Is 4x40W acceptable output (generic head unit power output)?

- 4x40 W is not generic head unit power. Standard head units are limited to 4x15 W depending on the power supply voltage. 4x15 W is OK, but more is better. 4x50 W or near that is fine.

Many serious users use an active front system consisting of tweeters and midwoofers and no rear speakers. For the active front system, 4x15 W head unit power goes a long way if a subwoofer is present, but only then.

- Desirable subwoofer power depends a lot on the efficiency of the subwoofer. I have a pretty efficient 13 inch ported Focal subwoofer and my Genesis Five channel amp is rated at 140 W. It's OK but a little more headroom would be nice, so I would propose 200 W at 4 Ohms. Many people have sealed enclosures so they might need more power.

- I would imagine that this costs well above 300 USD if done right. Last time I checked about five years ago, digital subwoofer amps had a bad reputation.

**Sonicxtacy02** · 08-30-2010, 01:49 PM

I'd be willing to beta test as well, and yea i think 24-bit 48k would be more than good enough. With all the beta testing and product reviews i do around here i think you can trust me

**2k1Toaster** · 08-30-2010, 01:52 PM

Originally Posted by Sonicxtacy02

I'd be willing to beta test as well, and yea i think 24-bit 48k would be more than good enough. With all the beta testing and product reviews i do around here i think you can trust me

lol, I think you are a safe bet if you are up to it

**tripzero** · 08-30-2010, 03:40 PM

I'd be willing to beta test as well. If it'll fit in the double-din bybyte case, this would be perfect for the all-in-one thingy I'm working on.

**blk02si** · 08-30-2010, 06:11 PM

I'd be willing to beta test, document and donate to this project. I've built one of these http://shop.41hz.com/shop/ the 4 channel version. I also hook up car/boat/home audio for a living, and have all the necessary hardware to test something like this. Let me know.

Also, I assume this amp will need a dedicated 12v line since theoretically a USB port can only supply about 2watts. (5v * 0.5a * 80%)

**soundman98** · 08-30-2010, 07:53 PM

Originally Posted by JuniorGeezer

Last time I checked about five years ago, digital subwoofer amps had a bad reputation.

they have made leaps and bounds since then-- most have become very reputable amps--some brands are even making class d fullrange amps-- like alpines pdx series, and jl audio's hd series amps.. but they come at a price...

i think that expected rms, or max wattage needs to be stated as well.. 200watts rms is way more then 200 watts max... also, if your not going to be using switching power rails, like many of jl's amps, it would be nice to list the wattage at a specific resistances..

most 50wmax amp chips get around 22 wrms-- of course depending on input voltage...

maybe i am thinking of this wrong, but i thought that most factory decks had around 15-20 wmax...

and i think by generic decks, he means aftermarket hu--most are around 40x4 wmax

**justchat_1** · 08-30-2010, 08:13 PM

I still would like to see the results of a poll for how many people would prefer a 4 channel version of this that fits in a double din slot compared to how many people want a 4+1 version of this thats the size of a regular amplifier.

There seems to be a good bit of confusion over the form factor despite it being said a few times that it will be a full size amplifier not something that could fit in your dash.

**2k1Toaster** · 08-30-2010, 09:09 PM

Well I might be able to make it small with pretty good power... Would an external power supply (like a laptop brick sort of) be easier in that it could be hidden pretty much anywhere and then the sound part be in something small?

I would prefer not to do that, but it might be a way to appease everyone.

**chiefwigms** · 10-28-2010, 04:20 PM

any updates

**2k1Toaster** · 10-28-2010, 08:17 PM

Just sent a few prototype boards off to be made along with the FBv6 and a few other things. These things are big, but will not be as big in the final run. There are two audio output options using two different chips so really there are double the output power stages on this board.