Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Solid State Talk all about solid state amplification.

Confused about USB/DAC choice.
Confused about USB/DAC choice.
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Thread Tools Search this Thread
Old 4th December 2009, 07:11 PM   #1
danrgleason is offline danrgleason
diyAudio Member
Join Date: Dec 2009
Default Confused about USB/DAC choice.

New here, but have read hundreds of threads on the probelm and lots of serious reccomendations from members on the issue of how to handle USB audio.
I have a hybrid amp right now (HiFiMan EF2) which has a USB/DAC/Tube/OpAmp configuration for headphone output.
I recently acquired Denon D5000's and can detect many flaws in the USB/DAC section (sizzle, jitter, gapping) and I am geeting fed up with it.
I would like to diy a solution but want a quick fix for now, and I can build in my leisure (who says leisure anymore?).
I saw a USB-DAC on a site and was wondering if you could tell me if you thought the chips and tech used was a good start.
iBasso D4 Mamba
USB-DAC/Headphone AMP
- Dual Wolfson WM8740 DAC Chip + TI PCM2706
- USB signal input, provides I2S interface for decoding
- Works as a DAC+AMP Combo, a standalone AMP, or a standalone DAC (Line out function)
- 2-Setting Gain Switch for impedance matching
- OPAMP rollable
- AMP section can be powered by either USB or 9V battery
- 9hours play time with 9V 300mAh battery (when powered by battery)

Cost is $220 USD which is in my budget. I am going to purchase a HiFiMan EF5 which takes RCA analog in as my headphone amp.
Opamp: OPA275
Tube: RCA Clear top 12AU7
Frequency Response: 20-30K Hz
THD+N: less than 0.2%
S/N: more than 95dB
Input impedance: 50K Ohm
Output impedance: 22K Ohm headphones
Output signal strength: up to 15 Volts at 32 Ohm
Input: RCA*1
Output: 1/4 headphone jack*1
Acessory: 12AU7 tube, DY-1 power supply, compatible from 110v to 240v

Thank-you all for your time.
  Reply With Quote
Old 5th December 2009, 01:57 AM   #2
baldrick is offline baldrick  Canada
diyAudio Member
Join Date: Dec 2008
The WM8740 DACs are well regarded.
The PCM2706 is the go-to chip for usb DAC interfacing. The PCM2706 has a DAC aboard but if they are using the Wolfson chips then they are using the PCM2706 as a usb gto I2S decoder, as they mentioned.

If you follow the manufacturers' guidelines about building DAC circuits around their chips it is hard to screw up a DAC. The devil is in the analogue section of the DAC. It's what a builder does in the analogue section that defines the quality of the DAC.

That said, it may be difficult to drive a good set of headphones with either a 9V supply or USB bus power.

It might be better suited to preamp duty rather than as a headphone amp. However for the price...there are cheaper USB DAC / headphone amps out there, but you get what you pay for. The HiFi Man EF5 seems like a good choice to use as a headphone amp.
What's the output circuit on the EF5? The opamp or the 12AU7? Neither are overly good to drive low impedance cans.
  Reply With Quote
Old 5th December 2009, 01:58 AM   #3
Iain McNeill is offline Iain McNeill  United Kingdom
diyAudio Moderator Emeritus
Iain McNeill's Avatar
Join Date: Oct 2007
Location: Santa Cruz, California
My personal opinion (and I'm not a windows programmed) is that the problem with USB audio is the host computer. Windows wasn't designed as a music serving device and as such gives audio a pretty low priority. Consequently, the buffers can underflow causing drop outs. The USB is a burst mode bus and so generates lots of HF noise and then I've noticed a particularly annoying habit of sending a full scale sample here and there producing a random intermittent "snap".

I think the "network media tanks" over LAN or possibly wifi (depending on RF interference in your neighbourhood) are a better approach.
  Reply With Quote


Confused about USB/DAC choice.Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
ASRC - I'm confused on clock choice and word length thespeakerguy Digital Source 4 31st January 2006 03:33 AM
confused gtrtech Solid State 7 28th August 2005 07:22 AM
little confused?? demons_wing Chip Amps 1 21st June 2005 09:09 AM

New To Site? Need Help?

All times are GMT. The time now is 01:06 AM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.79%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio