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Pico - USB DAC/Amplifier From HeadAmp - Page 12

post #166 of 711
Quote:
Originally Posted by stevenkelby View Post
For those that don't know, SPDIF splits the data and clock signals, introducing jitter and whatnot. The music has to go through this twice, I2S to SPDIF -cable- and then SPDIF to I2S. An imod does the same thing, straight to DAC with no SPDIF. All other external DAC that I know of use SPDIF.
Quote:
Originally Posted by stevenkelby View Post
Fair enough, I'm no genius. That's just how I remember Vinnie explaining it to me. I'll go find his email.

What's the correct info?
Quote:
Originally Posted by milkpowder View Post
Constructive criticism please
sure =D

well firstly jitter is introduced into SPDIF, because of its fundamental design and the interface it uses (TOSLINK and Coaxial) jitter is actually greatly minimised by having a separate word clock and some DACs have this extra input to accept a clock from a master clock.

When an external DAC is used, if in conjunction with a CD player transport, then it may use I2S (depending on the chipset) which is then converted back to SPDIF and over the cable and into the receiver, but again, depending on the chipset at the receiving end may be converted back to I2S but afaik most don't.

As for the iMod, i think what vinnie is trying to say is that it doesn't use SPDIF at all, rather than the iMod bypassing it. He was comparing it to a 2 box solution, the same benefits could be applied to a single box CD player.

I think I've got it all right... =D

edit: also didn't mean to come across as an @$$ earlier, was in a hurry to make the post is all
post #167 of 711
Quote:
Originally Posted by justin w. View Post
kugino, i'm taking pre-orders now and I'll have an official thread on that very soon
thanks justin...i've been on the pre-order list for a couple weeks...just wondering.
post #168 of 711
I've been reading the thread over a few times but I am still confused on how pico works. I understand that pico is dac/amp, but that's about it. Somebody said dac is powered by the USB, whereas amp is powered by the battery. If I have pico connected to my home computer to work as dac, then do I still need to replace battery to have amp work? Or will there be a separate power input? If battery is the only way to supply the amp, doesn't that mean it's meant to be for portable use only? Then why is there the USB DAC? I just don't understand why there has to be 2 separate source of power.
post #169 of 711
Thread Starter 
Because the only input for the DAC is USB it will only ever be used with a computer or laptop via USB so it makes sense for it to be powered via USB. If the DAC were powered via battery the battery would have to be much larger, thus the unit itself would have to be larger. Powering the DAC via USB helps accomplish the design goal of small size.

Yes the amp is designed to be a portable amp so, to my knowledge, is always powered via the li-ion battery. I believe the AC adapter is for charging only but I've sent an email to Justin to verify that. The amp does not need the internal DAC to work, it can function as an amp on it's own fed from an external source via the line input so the battery is necessary for the amplifier.

As an example, on the go I would use the Pico as an amp only with my iPod but at work and home I can hook it up to my computer via USB to make use of the internal DAC for a higher quality source. If I had a laptop I could also use the Pico as a DAC/Amp combo on the go as opposed to using just the amp section with my iPod. It's really about versatility and portability.
post #170 of 711
I also joined the wait list. I know that the Pico is going to have an analog in to function as a standalone amp, but will it be able to bypass the amp section to function as a standalone DAC?
post #171 of 711
Nope it can't. The only output (AFAIK), is the headphone out. In any case in any DAC there is an analog output stage, which as a headphone amp isn't too shabby.
post #172 of 711
Thread Starter 
I got clarification on the battery/charging statement I made previously. I was wrong in my assumption, when the DC adapter is attached the Pico will be powered by it and not the battery. Sorry if I confused anyone.
post #173 of 711
Thread Starter 
Up until now I've only used my computer for encoding, storage and transfer not as an actual source. If I go the Pico route what, if anything, special will I need to do to my computers at home and work for the USB to function properly?

My computer at home is a run of the mill HP Pavilion with Realtek onboard audio. My current computer at work is a generic Compaq again with Realtek audio but it's expected that will be upgraded to a new 20" iMac probably running boot camp for access to both Windows XP and OSX.
post #174 of 711
Quote:
Originally Posted by elnero View Post
Up until now I've only used my computer for encoding, storage and transfer not as an actual source. If I go the Pico route what, if anything, special will I need to do to my computers at home and work for the USB to function properly?

My computer at home is a run of the mill HP Pavilion with Realtek onboard audio. My current computer at work is a generic Compaq again with Realtek audio but it's expected that will be upgraded to a new 20" iMac probably running boot camp for access to both Windows XP and OSX.
Just plug in Pico via USB and off you go! You might have to go to Sound settings and select the output, but not likely. If so, its very easy (PM me if you'll need help).
post #175 of 711
You'll need a media player that can play your file formats too of course, Foobar is the best for me.
post #176 of 711
Thread Starter 
Well that sounds easy enough. I've been using foobar almost since the day it came out so not much of a change there.

One thing though, this is probably a really stupid question but I'll ask anyway, I keep seeing this Asio4all, is that just for S/PDIF output or is that something that would be related to USB out as well?
post #177 of 711
Quote:
Originally Posted by antonyfirst View Post
n_maher: did you try to drive your K340 or ER4P with the Pico?

it will drive a k-1000!!!!!
post #178 of 711
Quote:
Originally Posted by stevieo View Post
it will drive a k-1000!!!!!
How well? Did you hear it or compare it to any other amps? I understand no one at the meet compared it to other amps as it was hooked up to Justins LT all day.
post #179 of 711
Quote:
Originally Posted by stevieo View Post
it will drive a k-1000!!!!!
ditto with the above post: how well?

btw, has anyone heard from justin when he's going to start shipping these and taking real orders? i'm on the pre-order list but that's not saying much...

i also want to know when those mosfet modules for the GS-1 are going to ship, too...so many questions, i know...
post #180 of 711
kugino,

I submitted the sponsored forum thread about the Pico pre-ordering yesterday, it will be up whenever it's approved. They should be ready to ship sometime in November.

On the modules, I'm waiting for a replacement to the 2SJ109 to be released

HeadAmp Audio Electronics - home of the Pico and Gilmore amps.  Now with Audeze, Fostex, HiFiMAN, Sennheiser, and STAX.
Find us at www.HeadAmp.com

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