AMB Gamma2 DAC sound impressions? - Page 7

For my case, I have to use the σ25 because my USB port is a bit underpowered at about 4.5V but if I remember right, Ti measured lower noise floor with an external regulated PS.

Yes, the measured noise floor is slightly lower and cleaner (free of hash) when using σ25, σ11 or other good linear regulated PSU.

Hi everyone, I'm currently searching a good DAC that could match my equipment. I've built so far a pair of back loaded horn based on Fostex mid range FE206E, and hopefully by the end of march, I should be able to output some decent sound from my KT88 PP (30W GEC design).

After some hours of browsing I began to make a list of components that seem to have good feedback from the community (mainly the wolfson dac) and began also to write down what functionality I'd like.

Reading this forum I found the gamma 2 thread. This DAC seems to fit my need perfectly !

On the other hand the V-DAC have lots of good article as well.

So basically, Is there anyone that have been able to compare both and that would be kind enough to share his / her thought ?

Thanks a lot !

Fred

Considering the class of sound the Gamma2 outputs and despite me having no experience with the V-DAC, I can safely say that it will be better.

Well, despite me having no experience with V-DAC and Gamma, I'm sure they sound both pretty well

There is just too much good comments for both

Anyway I will probably go the hard way by building a gamma

Thanks !

Anyone thinks the Gamma-2 is way too bright? Every headphone I connect to it seems to have a good amount of bass loss

 

Or is it the way sound supposed to sound?

What are you comparing it to? It has more bass than some of my sources and less than others...it's all relative. I think it's very balanced/natural and I wouldn't change it if I could.

 

1) Are there any other sound issues you're experiencing, there could be a problem.

2) Are you sure it's not your amp or transport or cables? (transports make a pretty big difference...I've tried 6 different ones with the y2).

 

I think #1 is unlikely. #2 needs to be addressed most likely.

If you use γ2's output to drive headphones directly, then the γ2 must be built with 470uF output capacitors.  If it has the default 22uF caps then you will experience severe bass rolloff, especially with low-Z headphones.

Thank both Shahrose and AMB. Severe bass roll off is exactly what I wanna to describe. And that compares to my headphones connect to iPhone, laptops etc... since I don't have any other DAC.

 

And yes, I'm talking about headphones connect directly to y2 output. However my Stax system connect via RCA L/R sounds ridiculously good with the y2

 

Edited by SillyHoney - 7/6/10 at 10:44pm

There's your problem. I've done that for a couple weeks just to try it out with the HD800/HD650 and I get the same results. Bass rolloff and loss of punch/dynamics, though it still sounds surprisingly good.

You can always experiment switching the output caps to tailor the sound to your needs.

The impedance of your hd650/hd800 has a nominal impedance of ~300ohms whereas sillyhoney's dynamic headphones(listed in sig) are about ~10-20x lower (meaning the rolloff frequency is about 4 octaves higher).

 

I think the bass rolloff sillyhoney is experiencing is a lot different from what you heard.

Corner Frequencies of the bass roll-off (assuming default 22uF caps) for :

 

ATH-AD700 @ 32ohms: 226.07hz

ATH-CK7 @ 16ohms: 452.14hz

HD800/HD650 @ 300ohms: 24.11hz

 

Sillyhoney didn't just experience bass roll-off with the CK7's, they were experiencing mid-range roll-off  

Edited by Nebby - 7/15/10 at 9:35am

 

Haha midrange rolloff.

It's strange though, I definitely have less bass from 100hz down from the y2 output than I do from my amp.
 

Take a look at Headroom's HD800 Impedance graph:

 

The HD800's go past 600ohms at about 120hz. Now I'm just making a guess here as I don't have enough knowledge to definitely say it's the cause, but driving a 600ohm load from a DAC line out might be causing what you're hearing. Does your Gamma2 use the OPA2365AID or the AD8656ARZ?

Edited by Nebby - 7/15/10 at 9:51am