[franmon83]

Quote:

FYI, especially with the HDAMs, the sound only settles down after 350 hours (100 hours at the factory during testing + 250 or about two weeks of being left on continuously). We had weird issues when we first were playing with HDAMs in various DACs, such as the treble disappearing for 50 hours. Overall though, I found that with use some harshness in the sound tends to disappear.

Hi Currawong,
 
I had to look into the site's glossary to learn what a HDAM was, but now I know 

 (I learn stuff every time I visit this forum). Now, am I right in concluding that in the Compass 2, the HDAM is what is referred to as the Earth/Sun/Moon OPA on Audio-gd, and that as such, it should not be used when the signal passes through the DAC (only the via the line in)? Is there other(s) HDAM(s) already wired in the DAC signal path that I should know about? Finally, if there is indeed no HDAM in the DAC->amp signal path, does your comment regarding settling down of the sound still apply?
 
Thanks to you and to all the others for answering my questions! I try as best as I can to figure most answers myself, but some information is harder to find out than others.
 
Cheers 

 

[franmon83]

Quote:

Congratz on your purchase franmon83...

 
These all-in-one devices are a lot of fun and various configurations can be had.
 
I still own the FUN(A) (successor to the original Compass) and have tried it out with various sources, outputs, inputs etc....Lots of FUN..lol....Currently I am running optical from FUN ---> Pure i-20 dock (iPod Classic) ---> a tube buffer --> powered speakers.
 
Good times..
 
Cheers!!!

Thanks HeatFan12,
 
Your helpful information and threads on the 11.32 and 15.1 gave me a lot of insight regarding Audio-gd and amps/DACs in general. I guess I will have to upgrade my recordings quality though in order to get the best out of this beauty! I keep discovering nice (and sometimes less nice) details in my collection which I never knew were there in the first place!

 

[franmon83]

Must say right now that Pink Floyd's "Have a Cigar" synths never sounded so good in my ears... Starting to like it 

 

[Hooster]

This is the problem with hi fi. It is high fidelity to the source. Some sources might actually sound better with low fi gear. Nice to see you are discovering this.
 
Regarding popping from your usb, It sounds like your computer has issues with keeping the data streaming.

 

[franmon83]

It is now 5 days that I have the Compass 2 and I must say it really starts to shine! I do not feel the bass lacking at all anymore (@Kaptiva you can relax, I'm sure you'll enjoy your purchase as much as I do now) and the details are so sharp, the voices so clear, its stunning. I am nearly always using the optical input now, so I cannot give an update as to the quality of the USB input. My initial observations relative to the sound being unbalanced with a strong bias towards the upper mids are not accurate anymore. Everything is at its place, instrument separation is really good, bass is deep, rich, yet bouncy. I threw lots of different music styles at the unit, and it now plays them equally well. I will continue listening to different stuff for some time, so I can be sure about what the definitive sound qualities of the Compass 2, but if it only manages to stay as good as it is now, I'll already be more than happy about my purchase 

.
 
I'm really curious though as to what explains this long burn-in time with solid state amps and DACs. I can understand that headphones, with all their mechanical parts, need some burn-in time, but I since everything in a solid state amp/DACs is static, I wonder what explains witnessing such a difference in sound after tens of hours of burn-in. If any of you guys know it or have a link to some documentation about it, I'd be grateful to learn about it. 
 
Have a good one

 

[Hooster]

Quote

 
I'm really curious though as to what explains this long burn-in time with solid state amps and DACs. I can understand that headphones, with all their mechanical parts, need some burn-in time, but I since everything in a solid state amp/DACs is static, I wonder what explains witnessing such a difference in sound after tens of hours of burn-in. If any of you guys know it or have a link to some documentation about it, I'd be grateful to learn about it. 
 
Have a good one

 
Your brain is not static. it is an amazing machine that is constantly learning and adapting on a conscious and unconscious level. Your brain is getting used to assimilate the sound of the component. Put simply, you are getting used to it and learning to appreciate it. Call it burn in if you like.

 

[Currawong]

Quote:

 
I'm really curious though as to what explains this long burn-in time with solid state amps and DACs. I can understand that headphones, with all their mechanical parts, need some burn-in time, but I since everything in a solid state amp/DACs is static, I wonder what explains witnessing such a difference in sound after tens of hours of burn-in. If any of you guys know it or have a link to some documentation about it, I'd be grateful to learn about it. 

 
Heat I reckon. I ran the OPAs in a DAC/amp without any music playing as a test and they get quite warm. Exactly the same things happened to the sound over 250 hours as occurred with another set that had been running with music playing.

 

[Mad Lust Envy]

Questions...

I'd possibly get the Compass 2, as I was in love with my NFB-5 but let it go mainly because I wanted an amp with a line in.

1st:



This wasn't explained on the AGD website, but that is how I'd get the digital filter I used with my NFB5. Linear phase brickwall (up to 96khz).

However, in the NFB5, it was a simple touch of a button. Here... I don't understand that image at all. Can someone clearly explain where I'd do this, and if possible take a picture of it?

edit: I see it now. The website has the WRONG pictures when you click.

http://www.audio-gd.com/Pro/Headphoneamp/Compass%202/Compass2moduleWM.JPG

THAT'S where you change the filters...

Wait, the ES9018 doesn't have adjustable digital filters, right?


2nd

I'd obviously be using the line in, and would like to know if the line in is always going to have the op-amp in the signal path, and not ACSS, and if so, is it worth getting Earth over the stock op-amp? I had Moon on the NFB-5, and I couldn't tell between it and the stock op-amp... and barely thought ACSS was better than both op-amps by maybe 1%.

Right now, it's between the Compass-2, or the SA-31 and ODAC. I prefer the simplicity of the Compass 2 (as well as having a volume knob, and not buttons for volume control), and I'd be using either of these for the DT990/600.


3rd:

3600mW / 25 ohm (150mW class A)
2000mW / 50 ohm (300mW class A)
1100mW / 100 ohm (600mW class A)
400mW / 300 ohm (Full class A)
200mW / 600 ohm (Full class A)

I see that 25/50/100ohm show class A specs. How is it switched from class A to non-Class A? I don't quite get that, and I'd prefer to have the higher power specs.

 

[franmon83]

Quote:

Quote

 
I'm really curious though as to what explains this long burn-in time with solid state amps and DACs. I can understand that headphones, with all their mechanical parts, need some burn-in time, but I since everything in a solid state amp/DACs is static, I wonder what explains witnessing such a difference in sound after tens of hours of burn-in. If any of you guys know it or have a link to some documentation about it, I'd be grateful to learn about it. 
 
Have a good one

 
Your brain is not static. it is an amazing machine that is constantly learning and adapting on a conscious and unconscious level. Your brain is getting used to assimilate the sound of the component. Put simply, you are getting used to it and learning to appreciate it. Call it burn in if you like.

You're probably right up to a certain point, because I know the brain definitely has the power to modify your perceptions, hell it can even cure diseases! But, I doubt it is the only factor. To be certain (more certain), one should buy two units of the same model, burn one in for 250 hours and not touch the other one, then perform A/B testing on them with the same source material. Now, don't ask me to do that, unless you pay for the amps 

.

 

[franmon83]

Wait, the ES9018 doesn't have adjustable digital filters, right?

Indeed, I was myself unsure when I got the unit, since the website is less than obvious about it, but the filter adjustments are only available with the Dual WM8741 upgrade. 

 
I'll let someone else answer your other questions though, as for #2, I only tried the stock OPA and the Moon one. I hear a little (not night and day for sure) difference between the two, but I cannot comment for the other two available ones. I have no clue what is your question for #3...

 

[WizardKnight]

In the future am wanting to buy a home DAC AMP. The Compass 2 has both USB and Optical inputs I am needing. Franmon83 have you tried the USB input anymore to see if you are still hearing popping sounds? I hope can see a lot more impressions here about the Compass 2. Please keep them coming in.

 

[pb21cyclist]

Hmm I like the sound of this. Can anyone explain, or point me in the direction, of what all the upgrades that seem to be available do?! Also would these be suitable for HE400s, I suspect they would but just want to make sure not being too au fait with amps.

 

[Mad Lust Envy]

Having owned the NFB5, which is a amp/dac with similar characteristics (and the Compass 2 improves further upon it), the HE400 would probably love the Compass 2.

 

[Kaptiva]

Quote:

3rd:
3600mW / 25 ohm (150mW class A)
2000mW / 50 ohm (300mW class A)
1100mW / 100 ohm (600mW class A)
400mW / 300 ohm (Full class A)
200mW / 600 ohm (Full class A)
I see that 25/50/100ohm show class A specs. How is it switched from class A to non-Class A? I don't quite get that, and I'd prefer to have the higher power specs.

I am guessing it will automatically switch between Class depending on power requirement of your load (headphone) just like some Class A/AB amplifier does. Looking at the output power of Class A, that will also means it will be running Class A for most headphones in the market...IMHO 
 
I'd got my Compass2 yesterday. So far liking the detailed sound it produce very much. I'll let it burn in more to see if other sound characteristic changes. I am feeding it from MacBook Air USB output and heard some random "ticking" sound. Is that what franmon83 described as popping sound as well?? From Audio-gd web, it says that TXCO requires burn in time... hopefully after long period of burning in this will diminished. Will report back on this if it improves.

 

[WizardKnight]

I have been looking at pics of the Compass 2 and the USB input looks much taller than the USB ports on my laptop. Do you need some special type of USB cable for this DAC AMP? Also am curious if anyone has chosen any of the upgrades for the Compass 2 such as the DIR9001 SPDIF interface or the OCC wires upgrade? Does anyone think this would improve the sound quality?