O2 AMP + ODAC - Page 56

I also have that scratching issue and only in right channel. Started after some 2 months maybe? Bought from Head'n'HiFi. But since it happens only when turning the knob, it keeps me calm. :)

 

It could very well be!  Sounds like a lot of folks are having that same issue. If anyone wants to test that theory, the Bourns Pro Audio PTD902-2015F-A103 works as a substitute for the Alps 097 pot in the O2 amp.  It is also a 10K audio taper, 9mm body, 15mm shaft, all same as the Alps and fits right into the O2 PCB holes.  I've built O2s with both the Bourns and Alps pots.  Mouser #652-PTD902-2015FA103, onlinecomponents.com #PTD902-2015F-A103.

 

The pot comes right out with a vacuum desoldering gun like the Hakko 808, but it would probably be next to impossible to get out with solder wick or a hand solder sucker bulb without destroying the PCB.

Edited by agdr - 2/8/13 at 6:13pm

I was thinking of getting this amp, but I was wondering if there will be any more noticeable changes with my ATH-M50s than say my motherboards integrated sound? I will purchasing the V moda M100s soon as well and I just wanted my audio to be more refined and having a better sound stage, etc. 

 

Yes... SIGNIFICANTLY higher level of clarity, better soundstage, more detail... Noticable even with low-end headphones.

There's a discussion about this elsewhere. Standard, cheap, audio chipsets are so well implemented these days that there is a good possibility that you are already getting hifi out of it and the ODAC won't make any difference. It depends on the manufacturer. My 5 year old laptop has an output impedance of .5 and for the life of me I can't tell the difference between it and the O2/ODAC. A friends computer is the same. Both are Dells.

Perversely, Macs usually have high output impedance which means that while the chipset may be hifi, it will interact with low impedance headphones in negative ways. Older Ipods also have this issue, and the Iphone 5 (but the 3gs and 4 are fine).

I also suspect that where manufacturers have gone for high end chipsets (like Wolfson) then they become hostage to implementation issues and so you get worse audio. A good example of that would be the dire Samsung Galaxy II and III (and maybe I). It's purely about marketing because standard, off-the-shelf chipsets are likely already hifi.

The standard Realtek soundcards I have had in pretty much every computer I have owned are always noticeably noisy. 

 

I never use them for music, rather the ODAC or Music Streamer II which both sound great. 

Edited by Satellite_6 - 2/9/13 at 6:33am

I have a realtek and it's pretty near dead silent on my highly sensitive etymotics. The only way I can tell that there is noise is by plugging and unplugging, and the slightest, tiniest bit of shh disappears.

For an off-the-shelf chipset, already implemented, noise is probably the only thing that could be a problem if the manufacturer doesn't pay attention, but apart from that it should be hifi (perfect square waves, no audible distortion, flat frequency response etc).

 

That is awsome! Is that DIY or special order from JDS?

It's problematic to make claims about Realtek like this. Realtek is a company who makes a variety of chipsets. One cannot generalize to all Realtek chipsets, especially given that implementation is a factor. It's not much better than trying to claim that all Geforce cards can play Crysis at 1080p on high frame rates.

 

Have a look at my profile, I have a bit more images there... For example:

 

 

It's from Mayflower Electronics (but they cooperate with JDS)... It has 1/4 headphone out, RCA out (but you can choose RCA in instead I think), 1/8 in and SIP adapters (in order to be able to use different gain resistors, you have to do a request for this). This particular one also has different volume knob, rubber feet and few internal tweaks (like better capacitors etc.). You can order O2 desktop amp alone, or have ODAC installed inside (as I have).

Edited by RustA - 2/9/13 at 7:35am

An off-the-shelf implementation is already implemented. So I think you can generalise.

Sure, if there is no such thing as an off-the-shelf implementation, then you can't. In the meantime I have tested both realteks and sigmatels and I cannot tell any difference between them and my ODAC except for a tiny bit of noise.

That is pretty darn cool. I kind of wanted a version like that but I have the standard JDS lab version. From the website it looks like you cannot buy it with an ODAC tho. . . 

 

You can from Mayflower, scroll to the bottom... http://www.mayflowerelectronics.com/products.html

 

Not sure about JDS Labs, maybe you could ask them if they can do it for you... However, as I said, Mayflower cooperates with them, they are even supplied with ODAC boards from them as far as I know. The good thing on Mayflower is that you can get a lot of upgrades if you ask for them. That's what I like.

Nope. Tried some bass heavy music with Foobar. No issue.

 

I also do not hear it... It's not that all the O2 amps are faulty or anything like that. As I suggested, check the pot... Or leave it as it is since there are no practical impacts.