Audio GD SA-31 head amp/ preamp . A powerfull Head Amp with Diamond Difference design . - Page 14

Originally Posted by Clemmaster 

 

Yep.

 

The m-stage is warmer than the SA-31 on its default state (no jumpers).

Adding the 2 jumpers makes it closer to the m-stage but I wouldn't call it warmer, even.

 

The m-stage is a really good amp by itself (an cheap at that). Paired with planars, the SA-31 is the real deal!

The big soundstage is great addition to headphones that don't particularly shine in this area (planars, again).

Originally Posted by JWahl 

 

That was mostly a rough estimation of what the power would be at 8 ohms in comparison to people who use speaker amps to power the HE-6.  I understand that the SA-31 wouldn't be able to do that with speakers due the current demands of speaker level impedances.

 

 

These are probably the most obvious candidates for the SA-31 but I wouldn't say it's less optimal at higher impedances.  Only issue I would imagine is with stock gain with a low voltage source, but this can be easily modified by soldering 2 resistors if your comfortable with that.  I can't say with the D7000 as I've never heard them but I used to own the R1 LCD-2 which is very dark and I think it would probably sound decent on the SA-31 but I certainly don't think it would add any additional sparkle to them.

 

 

Ah, yes.  I noticed that a little later.  Either way, I still find it interesting that it uses a speaker style output transistor.  That MJ4281/4302 transistor is listed as a Bipolar transistor on it's datasheet.  If I had to guess, I'd say the Toshibas in the SA-31 are probably MOSFETs given they are known for a warmer sound and the Accuphase that it's supposed to be modeled after uses a MOSFET output stage.

 

 

I'd have to agree with this.  I find it warm only in the sense that it doesn't exaggerate source material that is already borderline bright.  It's certainly not colored enough to paint a magical illusion over poorly recorded material.  As Faudrei mentioned in his review, I find the "coloration" to be in the area of harmonics, not frequency response. It could be that the topology of the amp is engineered to retain certain small amounts of the "euphonic" harmonic distortion, similar to tube amps, but in smaller amounts and not affecting clarity and black background like some tubes might.  Though it is a pleasant coloration to me, and doesn't detract from the clarity or detail of the amp.  I'm very hesitant to say it sounds like tubes because it doesn't necessarily, and "tube coloration" already conjures up certain preconceptions that I don't think apply to this amp.  

 

Also, the exceptional sense of space and depth in the soundstage could be taken by some to be larger than life and be considered a coloration.  When I first got the amp, I thought it was really laid back but after further listening I realized this was simply a product of it's increased soundstage and was still fully capable of an intimate sound when the recording calls for it with plenty of impact when called upon.  One thing I want to emphasize is that this is in no way a slow or sluggish sounding amp.  I think what is so "seductive" is the non-fatiguing presentation combined with a sense of speed and clarity normally only reserved for more ruthlessly neutral amps.  Almost similar to how an LCD-2 can be both warm and fast at the same time.

Originally Posted by JWahl 

I'm also using the SA-31 with the K702 65th, as well as my AD2000X with good results.  Hoping to pick up an HD-800 in the next few weeks that I can compare as well.  It does seem to scale well with source also.  Unfortunately I haven't got to try the jumper setting since I bought mine used and it didn't ship with the jumpers.  I noticed a nice upgrade from the Schiit Modi to Resonessence Concero, even though both are simple, USB powered DACs.

Originally Posted by Mad Lust Envy 


I'm 100% positive I put a small bag with the jumper chips in there. You may have tossed it unknowingly.

It was pretty small.

Originally Posted by Mad Lust Envy 

Yeah, if you have a local Radio Shack, im sure they're incredibly cheap. I have some more that came with my Compass 2, so if you want, I can send some to you in an envelope.

Originally Posted by Utopia 

I wonder what volume settings people are using with this amp? Obviously it's very powerful, but with my K702 Anniversaries I stay around 10/79 on low gain with my Essence ST as a source. Trying with my mobile phone, an HTC One X, I went to maybe 30/79 on low gain. It just seems to have a fairly high gain (unlike what I've been reading here). I just hope mine is ok!

Originally Posted by JWahl 

Hmmm that's very strange indeed.  Especially since I have the HTC One X and know just how poorly low the output level it has.  I just sold my K702 65th Anni but when I used them with the SA-31 on a 1.2v source, My average range was 50-70 on high gain.  I think there is one of two possibilities.  If you bought the SA-31 pre-owned, the previous owner may have done the resistor mod to increase gain by soldering 2 lower resistance resistors on top of 2 particular existing ones.  

 

The other would be if your using a y-cable out of the headphone out of the Essence ST or it uses more than 2v output at RCA.  But that wouldn't explain the mobile device.  That's my normal listening level with my highly efficient AD2000X.  The stock gain level on low is literally no gain (0db) and 10db on High gain.  The resistor mod increases both the low and high gain levels.  The only other thing if you didn't buy used is maybe they accidently installed the wrong value resistors in those particular spots.