Head-Fi.org › Forums › Equipment Forums › Headphone Amps (full-size) › O2 AMP + ODAC
New Posts  All Forums:Forum Nav:

O2 AMP + ODAC - Page 105

post #1561 of 3375

If i had my way i'd also put input to the back and use RCAs.

post #1562 of 3375
Quote:
Originally Posted by eimis View Post

If i had my way i'd also put input to the back and use RCAs.


same. the power is in the back but still no RCA's. He does however have the "desktop" version of the O2 with RCA's but on that version the power is still in the front.

post #1563 of 3375
Quote:
Originally Posted by DonJunker View Post

 

Thank you for the clarification. It's true it's only a dual polarity half wave rectifier. There may be room for some improvement on the PSU part (and perhaps better decoupling on supply of the DACs, as close a possible), even though the designer states that it won't matter and may cause the sound to worsen to e.g. improve the capacitor bank size with low ESR/ESL capacitors :)I have ordered a 15V AC 1A adapter..just to be sure :) I use Denon d2000 which is low-impedance

Everything is Chinese for me except for the last sentence:

 

 

Quote:

 I have ordered a 15V AC 1A adapter..just to be sure :) I use Denon d2000 which is low-impedance

 

Well, 1A is way above  200mA which is needed for, say, my DT 880 (250 Ohm).

 

By the way, are there any low-impedance headphones which really  require 1A-current?

 

What would happen if I used the 15V AC 1A adapter with the O2 and my DT 800 (250 Ohm)?

Would it affect negatively the sound in this case because of too much current (that is 1A)?


Edited by JakeJack_2008 - 7/12/13 at 1:03pm
post #1564 of 3375
Quote:
Originally Posted by JakeJack_2008 View Post

Everything is Chinese for me except for the last sentence:

 

 

Well, 1A is way above  200mA which is needed for, say, my DT 880 (250 Ohm).

 

By the way, are there any low-impedance headphones which really  require 1A-current?

 

What would happen if I used the 15V AC 1A adapter with the O2 and my DT 800 (250 Ohm)?

Would it affect negatively the sound in this case because of too much current (that is 1A)?


Actually I didn't mean the DAC's but the output stage of the O2 (+ gain amplifier). Basically I just mean that there maybe is room for improvement with a better voltage supply for the OPAMPs. E.g. like bypassing each OPAMP's +/- supply with e.g.  10uF+0.1uF (SMD ceramic X7R) to ground, with the smallest capacitor soldered directly on the pin and the larger one as close as possible (I think The Wire amp uses something like that too).

I'm not sure it will have a significant effect on the sound, as the designer seems to have thought of alot of aspects and has spent alot of time implementing the components. But I'll try it anyway as I have the capacitors. It sure won't degrade the performance.

 

Quote from designers home page:

Question:

1. The main cans I'll be using are a pair of Beyerdynamic DT990Pro's, 250Ohms. I may also use my Koss portapro's occasionally. On the Beyer's: am I correct in assuming that the O2 would be sufficiently powerful to drive these?

2. On Power Supplies: would I be better served by the xicon 412-218054, or the WAU16-1000? In other words, would I be better off with more voltage headroom or more current headroom? I'm more concerned with getting the best match for the Beyers than the portapro's; in either case, the price difference over the WAU16-200 is inconsequential to me.

 

Answer from designer:

1 - Yes, with power to spare. Just get the gain correctly.

2 - Go with the WAU16-400 (400mA) or WAU16-1000 (1A) (or other 14 - 16 VAC wall transformer).

 


 

I just ordered the 1A since it did cost the same as the 500mA variant :)  My headphones are 25 Ohm.

 

The current value of 1A just means it will be able to supply 1A. The O2 just draws the current from the adapter that your headphone+volume requires..as long as it is below 1A it's no problem :)


Edited by DonJunker - 7/12/13 at 1:56pm
post #1565 of 3375
post #1566 of 3375
I know this is the wrong thread and this may not necessarily apply for the O2, but when shopping for a wall wart, do you guys have any preferred brands and/or vendor?

I'm asking because I purchased a new STAX rig from Japan and I live in North America where the outlet voltage is 120 V instead of 100 V in Japan. I'm looking for a >= 4 W, 12 V DC, linear (not switchmode), positive barrel wall wart and I'm having a hard time finding one.

But while we are on the topic of wall warts, and this does apply to the O2, how does a different wall wart affect the O2's performance? e.g. I think I read that a different wall wart may be preferable for driving the he-500.
Edited by miceblue - 7/12/13 at 8:21pm
post #1567 of 3375

^LOL at that avatar

post #1568 of 3375
I'd like to build one of theses and have built a cmoy and I know I can make it fine. I would like to use it portably I know its large but it would be in a bag. I have a fiio e11 and I enjoy it but would like to build my own amp in the next level up.
I've been reading and reading and reading but I just need to ask:

1) coupled with a iPod 5.5g and lod what is the bass like? I have Hd 25 1-ii and do enjoy my hip hop and bass. I've been reading about bass mods and seems ok.

2) any idea where I can read about the different op amps, I have no idea what the differences are
post #1569 of 3375
Anyone compare odac to the bifrost looking to see if its worth the money to change
post #1570 of 3375

I'm newbie to a portable DAC.

Besides O2, does JDSLabs' Standalone ODAC works with other portable amps like Fiio E12?

 

If my below setup works:

 

iPad 2 + CCK (camera Connection kit) + OADC [DAC] + Fiio E12 [AMP]

post #1571 of 3375

All DACs work with all external amps as long as one side doesn't come bundled with both (like an ODAC + O2 combo in one box) and provided you can actually connect the two together with the same interconnects or with adapters.

post #1572 of 3375
Quote:
Originally Posted by boombobby289 View Post

I'm newbie to a portable DAC.

Besides O2, does JDSLabs' Standalone ODAC works with other portable amps like Fiio E12?

 

If my below setup works:

 

iPad 2 + CCK (camera Connection kit) + OADC [DAC] + Fiio E12 [AMP]


I have ODAC and E12, they sound great together.

post #1573 of 3375
Quote:
Originally Posted by BenF View Post


I have ODAC and E12, they sound great together.

How is your setup for ODAC and E12?
Do you play them with iDevices like iPad?

post #1574 of 3375
Quote:
Originally Posted by boombobby289 View Post

Quote:
Originally Posted by BenF View Post


I have ODAC and E12, they sound great together.

How is your setup for ODAC and E12?
Do you play them with iDevices like iPad?

Only the iPad is able to use an external DAC at will with the Camera Connection Kit. Other iDevices require a special "Apple certified" DAC....and those are mighty expensive.

 

You can use an external amp with any iDevice as long as you:

  1. Have a non-jailbroken iDevice
  2. Use a "Line-Out Dock" connector such as the FiiO L9
post #1575 of 3375
Quote:
Originally Posted by miceblue View Post

Only the iPad is able to use an external DAC at will with the Camera Connection Kit. Other iDevices require a special "Apple certified" DAC....and those are mighty expensive.

 

You can use an external amp with any iDevice as long as you:

  1. Have a non-jailbroken iDevice
  2. Use a "Line-Out Dock" connector such as the FiiO L9

Is there any other cheaper way to bypass the internal DAC of iDevices yet to have portability ?
I don't mind to use power bank or battery pack.

New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Headphone Amps (full-size)
Head-Fi.org › Forums › Equipment Forums › Headphone Amps (full-size) › O2 AMP + ODAC