[metril]

Hey guys. I'm new to these forums in the sense that I've just registered after being an onlooker for the past 2 years. I recently got myself an HTC Fuze and I want to make an amp for the thing. I don't think it can drive my head phones. Any way, the Fuze uses a 11 pin mini usb. I have the adapter for the thing that allows me to connect your 3.5mm phones.

I also have a Turtle Beach SRM (usb external sound card) that is out of warranty and would like to see some use. The SRM has line in and out connections. My question is how can I power the thing without connecting it to a computer?

The thing gets its power from the mini usb connection ( I think its 5 pin). I want to use the SRM as an amp. Any ideas?

 

[metril]

Anyone have any idea how I can use the Turtle Beach SRM as an amp without connecting it to a computer USB port?

On another note, what can I do with two TL071CP JFET Op Amps and twp LM741N Op Amps?

Thanks again guys.

By the way, I'm an Aerospace Major in progress so I might not understand too many technical electrical terms, but I am willing to learn.

 

[OtterMarc]

Metril,

You don't give us many details. Your Fuze phone should sound at least "all right" as is. Having an external amp for a phone source is likely less effective than getting better headphones, but I've no direct experience with the Fuze, so it's just an opinionated guess.

The 11 pin connector is not USB - it merely can connect through to an USB source.

What headphones have you got and what is their impedance, if known? Normal cheap ones that came with the phone, or better? Most cheap ear bud phones are 16 Ohms.

Your Turtle Beach SRM is meant to be powered by USB, meant to also decode a digital signal sent to it through USB and provide a decent audio output, and vice versa. Getting both power and signal into in a different way is kinda like finding a way to get a tractor engine to push a newspaper wagon. It's a very impractical non-solution. Read up on Alien DAC powering options (here in head-fi) for an idea on its complexity - you'll likely change your mind.

If you muck with something that works fine - Murphy says you'll eventually break it!

Re headphones - I like to show people the difference in sound from the dollar store stuff, then 10 dollar ones, 20, 40 and up, letting people see for themselves if they hear a difference in quality. If you start with good sound, better headphones will help - to a point. Cell phones aren't renouned for their 'good sound', so the need for expensive headphones isn't there. Still, many improvements exist over dollar stuff.

As to your op amps - best thing is to maybe experiment with them. Both are single amps, so you've enough for stereo, twice. Neither are considered great for sound, but that's a good thing to test for yourself. You might not hear that with crappy one dollar headphones, but you might with 30+ ones.

Use the circuits given in their spec sheets, in books from your library or google. Then... hide your wallet as the quest for improvements kicks in!!

Bonne chance

 

[metril]

Thanks for the advice and help. The SRM has digital in/out and analog in/out. I wanted to power the SRM and have it take an analog in, amplify the signal and have it output to the analog out. When connected to the computer, I can do this, but I rather not have to use the computer to control the SRM.