[Kel Ghu]

Hi,

I need a USB-powered amp for my laptop. Of course, I want the best I can find and it must be small. Something like the headamp pico would be good. Though, I don't want to always use its DAC, but also use its line-in and still have the amp powered by the USB port. Too much hassle taking the AC adaptor around... There's plenty of portable amp with DAC out there, but I only know one that can be powered by USB without using its DAC, it's the Headroom BitHead. Do all the others do so?

thank you for your help

regards,

--Kel


List of USB-powered amp
- Headroom BitHead
- Meier Audio Porta Corda MkIII-USB
- Meier Audio Move
- Headphonia Headstage Lyrix Pro USB total and Pro USB Total
- Voyager Portable Headphone Amplifier by Graham Slee

 

[jamato8]

From what I understand the reason others don't is because if you are running your laptop off of a battery then it is going to have all the more drain when also charging the battery or running the amp section of amp/dac.

 

[oicdn]

The Move was used like this, but it's DAC section suffered.

Another reason you won't find an amp that's also powered off the usb is I think you only get 5.5v out of the USB port. Most amps require ATLEAST 6-7v to run without clipping, hence the reason most portables use 9v batteries.

 

[GreatDane]

The Meier Porta Corda MkIII-USB will allow analog input to be amped while being powered by USB. I believe the 5 volt is ramped to 10 volts.

I had never tried this until about 10 minutes ago. For a quick test I connected my 5.5G iPod (HP out) into the Corda, iPod at full volume. Driving 325i required at least 70 % of full volume on the amp to be satisfying. No ill effects at even full volume(high gain).

 

[Capunk]

Headamp Pico?

 

[jamato8]

The Pico and Predator use the internal battery for the amp.

 

[oicdn]

^ Yup, they only use usb power to power the DAC section. That's why the Move suffered as a DAC, cause it used USB power to power ALL of it....

Basically, you just have to plan well, that if you are traveling or whatever, make sure the battery is charged. The way around that? Stick it on the charger every night regardless, like you do with your cell phone.

 

[Kel Ghu]

Yeah, but I want to make as simple, light and small as possible for travelling.

I'll make a list in the first post. It seems that all those that can be powered by USB have a voltage inverter (it is the case for the Headphonia).

Can you guys, who have a portable amp with USB, try using their analog line-in while powered with USB?

Thanks!

 

[oicdn]

I can't believe I forgot about it. The Voyager can be powered by USB or battery, and sounds FANTASTIC. The Voyager DOES NOT have a charging circuit, so if you plug it in, or use it via USB, you don't have to worry about exploding batteries. But you also won't have a DAC.

 

[Zorander]

Quote:

Originally Posted by oicdn /img/forum/go_quote.gif ^ Yup, they only use usb power to power the DAC section. That's why the Move suffered as a DAC, cause it used USB power to power ALL of it....

The Move will default to the highest voltage supply it gets, i.e. if the Move has a 9V battery inside it or 9-12VDC power from an external PSU, it will use those power sources instead of the 5V USB power. The USB port will only act as a digital transport in this case.

The reportedly average quality of the DAC (I'm fine with it) is simply the characteristic of the DAC chip itself, not due to the nature of how it is powered as you described.

Cheers!

 

[Zorander]

Quote:

Originally Posted by Kel Ghu /img/forum/go_quote.gif Can you guys, who have a portable amp with USB, try using their analog line-in while powered with USB?

The Move's digital input (DAC) is disabled if an analog (line-out) cable is plugged in. The line-out cable must be un-plugged in order to use the Move's DAC again.

 

[oicdn]

Quote:

Originally Posted by Zorander /img/forum/go_quote.gif The Move will default to the highest voltage supply it gets, i.e. if the Move has a 9V battery inside it or 9-12VDC power from an external PSU, it will use those power sources instead of the 5V USB power. The USB port will only act as a digital transport in this case. The reportedly average quality of the DAC (I'm fine with it) is simply the characteristic of the DAC chip itself, not due to the nature of how it is powered as you described. Cheers!

No, it's not inherent of the DAC chip in the move, well, not entirely anyways. It's mostly power related.

SEVERAL "higher end" DACs use the same chip that's in the move (as well as even CHEAPER dac chips)....a recent example is the PREDATOR uses the same chip as the Move and nobody is complaining about it's DAC capabilities.

It's not only circuit implementation, but power limitations/implementations which give it it's "average" sound.

 

[Kel Ghu]

Anyone with an iBasso D1? I really want an iBasso... I think...

 

[fkclo]

With a special cable the iQube can be charged from a USB outlet.

And it sounds good too.

F. Lo

 

[trb36]

I use and love my D1 with my laptop, but I'm not sure it's what you are looking for. It's not USB powered - the USB input is only for its DAC. It's powered by an internal lithium battery, and charged with a wall-wart, which you said you didn't want.

The only USB powered amps that I am aware of are the headroom total airhead/bithead (although the headroom website says the bithead sounds better off batteries than USB) and the graham slee voyager. I came close to buying a voyager, but it was too much and I wanted a DAC.

So basically, if you don't mind dealing with the power adaptor, go D1, otherwise, voyager, or if you have a tight budget airhead.