USB DAC

[jelosno]

I am thinking of using my HeadFive amp with some to be ordered Etymotic Research ER-4S ear canal thingies at work.

In order not to carry around any CDs I would like to put some of my favourite stuff on the laptop's harddrive in lossless format.

What good but not overly expensive USB DAC is there?

Anything being used already?

Stefan, annoyed by the passing minibusses with their monster boomboxes that trip the car alarms while passing by and therefore unable to concetrate and blablablablurb.....

[jelosno]

Mike,

how much is your ER4P to ER4S adapter?

do you also do a ER4 to Airline jack adapter?

Stefan

[xerxes]

What's "not overly expensive"?

What sort of price range are you considering?

[rickcr42]

Not overly expensive :

Full Kit or Half Kit with the USB DAC Chip already installed-PCM2704 chip

www.hagtech.com/hagusb.html

already built,good reviews-PCM2702 chip

www.firestone-audio.com/cgi-bin/product.asp?pdtseqnm=2

the Hagerman is a better design,the Fubar is ready to go plug n' play

[jelosno]

What sort of price range are you considering?

well, I was thinking in the USD 100 to 150 price range.

I don't want to spend to much on this since I do have the Headfive amp collecting dust next to a older Sony CD Walkman that served me well in the Australian Outback years back

The idea with the losless files on the laptop was just because of a greater variety of music I could carry around.

Since I would have to convert my CDs to FLAC (?) anyway I can also take them to work or make a copy of them for use in the portable CDP.

The hagermann seems to be right in kit form.

Discountheadphones has updated their shipping policy so there shipping costs to South Africa just went from USD 25 to zero. might order this week the Ety.

Thx for the input

Stefan

[xerxes]

Be aware that the HagUSB is only a USB to SPDIF converter. I'm not familiar with the Headfive amp, does it have a SPDIF input?

[jelosno]

does it have a SPDIF input?

Nope.
But the Hag thing has a headphone out. Might be able to rout that into the Headfive amp.
Today my laptop began to act funny. Not sure whether I should bet on that old computer...

Stefan

[rickcr42]

Be aware that the HagUSB is only a USB to SPDIF converter

Coax and line out (called headphone out but but still a line out ). What else is needed ?

The volume in your headphones is controled via the computer volume when using the Hag unit.

as with all systems that use a computer as source ! You have to have a "media player" no matter what your externals and if or not you use that volume control or the headphone amp volume control is stricly a choice/convenience thing.

The Hagerman is good enough to be an option for the AudioNote DAC so unless you are doing a custom DAC using USB-to-I2S for the interface a pretty good and cheap solution

[rickcr42]

www.audionotekits.com/

[xerxes]

But the Hag thing has a headphone out.

I didn't spot that to be honest and as the volume has to be adjusted via the PC, it is in effect just a line out.

Ideally, you want to disable the PC's volume control, there's an alternative driver available as well which defeats Windows K-mixer, which is supposed to improve the sound. You can find out more about setting up the PC for best playback at these sites:

www.wavelengthaudio.com/Cosecant.html
www.aqvox.de/products.html

As I understand it, in theory, it's better if you don't convert the USB input to SPDIF prior to the DAC, but instead convert the USB signal to I2S format, which has no timing information and therefor no jitter, and feed the I2S signal to the DAC along with an accurate clock signal.

This USB DAC module uses USB->I2S, it can be used as a receiver module for a TDA1543 NOS DAC, but also as a stand alone USB DAC with a line out:

www.dddac.de/ma_dac32.htm

At €49.00 ~ $62.00, it's also a bit cheaper than the others.

[rickcr42]

Ideally, you want to disable the PC's volume control, there's an alternative driver available as well which defeats Windows K-mixer, which is supposed to improve the sound. You can find out more about setting up the PC for best playback at these sites:

ASIO4All

As I understand it, in theory, it's better if you don't convert the USB input to SPDIF prior to the DAC, but instead convert the USB signal to I2S format, which has no timing information and therefor no jitter, and feed the I2S signal to the DAC along with an accurate clock signal.

yes if you are talking about "superdac".This about cheap while porforming well

This USB DAC module uses USB->I2S, it can be used as a receiver module for a TDA1543 NOS DAC, but also as a stand alone USB DAC with a line out

hardly portable when you add up all the chips and is a bit overcomplicated for the intended application in my opinion

[jelosno]

I think I will go for that one
www.ecp.cc/HPDAC.html

The price is about right. I might build one or two more an give them away to friends.

Not sure where to get the parts to fill the boards but time will tell. ;D

IF I do place the order I will send one to you Rick. Then you can get gray hair over it and tell me what parts to hunt for

Stefan

[rickcr42]

IF I do place the order I will send one to you Rick. Then you can get gray hair over it and tell me what parts to hunt for

actually have a stray gray hair or two already (gave the wife gray hair years ago ) but better gray then bald

[xerxes]

hardly portable when you add up all the chips and is a bit overcomplicated for the intended application in my opinion

As far as I understand it, the "USB Receiver module" can be used as a stand alone DAC, using the inbuilt D to A capability of the PCM2707 chip. Having said all that, this module does not take power from the USB cable and would require a separate power supply, so it wouldn't be an all in one solution.

[rickcr42]

Because they tried,and a good effort though tough to pull off,to produce a DAC that could be used for either portable duty or home duty choices were made that to me are comprimises that serve neither if a more specialised device.

The attempts to allow battery operation with usable battery life is the very thing that is the bottleneck holding the DAC back if in a home system.There is no secret that the very first ( and best as far as SQ goes) mod of ANY digital device is to use a well filtered high current analog power supply followed next by individual digital chip power supply isolation so that they don't "talk" to each other except in the mammer intended and the first thing to be removed invariably is the DC-DC converter that here is actually added in because of the high chip count placing high demands on the batteries.

Could the device be improved by having an "external power supply" in put that totally bypasses the present powering system ?

Yes but if you have access to a better supply then why keep the OPA2132 when there are better (though suck more current) options available ?

so say you then add a "output stage bypass" that would allow you to jack in a better output section for home duty,now you are up to 2 additional "boxes" just so you can have a portable DAC that is in step with the new catch phrases "Zero Oversampling" and "Direct I2S interface" that to be honest are way overkill if the device were stricly for portable usage rather than for implemntation into a permanant home system.

May well sound fine but for me comprimised for the home yet way bloated for the road.


Just an opinion guys.mine

rickmongo

[PinkFloyd]

jelosno said:

Mike,

how much is your ER4P to ER4S adapter?

do you also do a ER4 to Airline jack adapter?

Stefan

Do I make one?? I remember making one ages ago but didn't realise it had been remembered..... it's just basically a couple of resistors in line with the L/R channels (75ohm IIRC)

[PinkFloyd]

oh, this thing.... www.rock-grotto.co.uk/etymotic.htm no, I don't make them these days.... easy to do though just get a few 75R resistors match up two as close to 73R and bob's your uncle your good to go,,,, connect in series sith the signal wires, probably best to solder the resistors onto the jack terminals and then solder on the signal wires to the other lead of the resistors.... that's you with the adaptor.

[jelosno]

YUP, I was referring to that one.

How much would all the parts cost roughly?

Ety sells a kit including a adapter like this for a premium of US$ 40 if I am not mistaken.

Stefan

[rickcr42]

looks like it should cost about $10 US to DIY,more if you use premium resistors and/or silver wire,way more with designer connectors

[rickcr42]

BTW-maybe the "Quick and dirty" knucklhead version could be made from an aftermarket mini TRS extender cable by lopping off the plug end,shortening the cable and inserting the inline resistor in the plug before soldering it back on...... ;D