[francisdemarte]

Quote:

Lol, sounds like a tool...or maybe a shill? You can't deny criticism with something so subjective as one's like/dislike of hi-fi gear! There is NO right or wrong here! I'm not going to get offended if someone lists everything I have in my sig as throwaway crap that their dog shouldn't even have to listen to. That's fine, I enjoy it and will continue to do so regardless!

Wow, I just read a few post and I agree, total fanboys running rampant in that thread. I had high hopes for the Shiit as a maker of competitively priced, American made original designs. Maybe in Version 2 of the Asgard they will spring for real heat sinks instead of using the case as a giant hand burning heat sink. 
 
Beware those 'audiophile' types that tell you cables made of un-obtainium make a huge difference and that having op amps in your amp is akin to killing babies and kicking puppies. 
 
 
 
 
 
 
 

 

[Pariah1]

 
Quote:

Wow, I just read a few post and I agree, total fanboys running rampant in that thread. I had high hopes for the Shiit as a maker of competitively priced, American made original designs. Maybe in Version 2 of the Asgard they will spring for real heat sinks instead of using the case as a giant hand burning heat sink. 
 
Beware those 'audiophile' types that tell you cables made of un-obtainium make a huge difference and that having op amps in your amp is akin to killing babies and kicking puppies. 
 
 
 

Lol, exactly right. And me too, I wouldn't at all mind buying an US based product for once!
 
And sorry to be so harsh, but when that kind of nonsense abounds it's just plain silly and not to be tolerated by more rational minds.
 
I'll say it right now too: The M-Stage is not "THE BEST" amp EVER, at it's price range or any range. None are. This is simply too subjective. Not to mention that no one has tried every headphone amp since they began to come out to be qualified to say which is "the best" in any price range. Impossible. All we can hope to really claim is that we like an amp and feel it is good/great for it's price. Anything more is pure hyperbolic excess.

 

[kwkarth]

For the record, I do not recall anyone ever saying the Asgard was the best amp ever in that thread.  So we all need to have more respect for one another.
 
For the record we do not encourage or condone any criticism of subjective opinions on Head-Fi.  Everyone's opinion, if respectfully and intelligently offered is welcomed.

 

[purrin]

 
Now we return to our regularly scheduled programming...
 
Here's what I did to the OPA2107 for those interested. The notch and pin 1 at at the bottom. I put some goop over the solder joints just in case they accidentally break off. The last thing I want is -15V accidentally touching an input pin.
 
For the record OPA2107 (w/ mods) >> OPA2107 > OPA2134 (stock). YMMV.
 
I keep thinking this setup would mate well with Denons. Unfortunately, I sold my markl modded D5000s a while ago. 
 

 

[purrin]

Not "Pure Class A?"  LOL, something I just realized and maybe coolfungadget can address.
 
The Ebay ad says "Pure Class A". I don't think this is true. For one, it appears to employ an opamp without a class A biasing circuit. I looked on the board for something and even measured for maybe some resistance between the output and -15V rail (didn't do it for +15V, but that wouldn't make sense for an OPA2134). Also, according to the Lovely Cube schematics (which has a very similar board layout with some minor changes), I don't see a CCS circuit or any bias circuit to on the output buffer (I'm not sure about this though) Finally, this thing seems to run warm, but not HOT like a "Pure" (or heavily biased into) class A amp should.

 

[Kuze]

So is this good or bad.

 

[purrin]

Quote:

So is this good or bad.

Good in that it's still a good amp that doesn't get so hot that you can fry eggs on it.
 
Bad (from a reputational or legal point of view) for possible false advertising. Again I'd like to make clear that I only suspect this amp isn't "Pure Class A". An answer from the manufacturer or seller would clarify this.

 

[francisdemarte]

CoolFunGadget is just copying what Lehmann says about the Black Cube Linear. From http://www.lehmannaudio.com/index.php?id=25
 

"The selectable gain (0dB, 10dB, 20dB) of the Black Cube Linear effectively optimizes the output level of the zero global feedback Class A output stage. Practically all high quality dynamic headphones available will show their best possible performance, no matter if you have an easy to drive low impedance pair of headphones or an ineffective pair of 600 Ohms studio cans."

 

So Lehmann would be the better people to ask what they mean by this.

 

Purrin: Might want to snip down those leads. I've been told long leads add to resistance and a errant touch could short out the chip.

 

[purrin]

Quote:

CoolFunGadget is just copying what Lehmann says about the Black Cube Linear. From http://www.lehmannaudio.com/index.php?id=25
 

"The selectable gain (0dB, 10dB, 20dB) of the Black Cube Linear effectively optimizes the output level of the zero global feedback Class A output stage...

 

So Lehmann would be the better people to ask what they mean by this.

 

Purrin: Might want to snip down those leads. I've been told long leads add to resistance and a errant touch could short out the chip.

 
Heehee - the one the in picture was my initial soldering experiment with the OPA2134 - just to make sure I could do it right. I significantly shortened the leads on the OPA2107 that I actually installed (it was more painful to do this with the shorter leads.)
 
What I would really like to do buy a few high quality DIP riser adapters with a little bit of space underneath to wire up resistors of different values - that way I can plug and play with different values and slap a heatsink on the opamps. Maybe I can even send a few to Cravenz or whomever else wants them.
 
The zero global feedback is very likely correct. Playing around with the DMM didn't indicate any global feedback loop. Taking a second and closer look (based on Lovely Cube schematics) at the output stage, it does appear to be Class A biased with the emitter resistors on the input transistors. So I stand corrected on this. However, a "Class A output stage" is not the same thing as "Pure Class A" amp as advertised, unless you did what I did on the opamps... and even then I would hesitate to call it Pure Class A.
 
Now I have this crazy idea to buy another one and run balanced. LOL, probably not.

 

[SP Wild]

Not pure class A.  I feel kinda ripped off.

 

[BlutoSlice]

WooHoo my M-stage Matrix is here, in only a 4 working day delivery time! 

 

[DarkScythe]

purrin, which version of the M-stage do you have?
 
I don't really know anything about what you guys are talking about, but I just got my MkII amp yesterday and have been listening to it. Prior to that, I had borrowed an "original" M-stage from my friend to try out. You said the "pure class A" should run hotter, I think. On a whim, I just went to feel my amp and it is definitely warmer then what I remember my friend's amp feeling like. His was quite warm, but mine is almost too hot to touch for more than a couple seconds.
 

 

[kwkarth]

The amp could be all class A.  The amount of heat dissipated depends entirely upon how far into class A the output stage is biased.  An amp can claim to be class A and only dissipate, say 20mW of heat.  It will run relatively cool.  It also will operate as a class A amp up to 20mW output.  Beyond that level it will operate as a class A/B amp.  Sonically, it won't be as good, but legally, is can be said to be class A.  I had a small Kenwood amp that was that way.  It was a 20WPC output and was claimed by Kenwoood to be class A.  In the fine print of the manual, it explained that it was class A for only a small portion of the output capacity.

 

[purrin]

DarkScythe: I have the MKII version. As I stated above, I now believe the output stage is Class A. My amp is warm to the touch, even for extended periods. (Ambient temperature is about 72-78F)
 
However, the input/gain stage is a simple opamp OPA2132, which is definitely not class A (unless you bias that chip into class A, which does not appear to have been done - and what my resistor mods do). It may be fair to say that the output stage of the M-Stage is class A, but to say that the amp is "Pure Class A" in its Ebay ads is misleading considering that not all stages are class A. Note that even the designer of the BCL (upon which this amp is based) is carefully selective in making those class A claims.
 
But to put things in perspective, I don't feel ripped off at all. This was one of the best deals I've ever gotten and many thanks to the OP.

 

[SP Wild]

You didn't pay $1100 for the matrix like I did. 
 
So therefore the input stage is not even class A.  First I was led to believe that the Lehmann was fully discreet - which I presumed meant no op-amps - which turns out not to be the case, and now there are dubious class A claims - not happy.  Lehmann, like Musical Fidelity is on my blacklist.
 
I have no negative comments regarding sound quality though.
 
Quote:

DarkScythe: I have the MKII version. As I stated above, I now believe the output stage is Class A. My amp is warm to the touch, even for extended periods. (Ambient temperature is about 72-78F)
 
However, the input/gain stage is a simple opamp OPA2132, which is definitely not class A (unless you bias that chip into class A, which does not appear to have been done - and what my resistor mods do). It may be fair to say that the output stage of the M-Stage is class A, but to say that the amp is "Pure Class A" in its Ebay ads is misleading considering that not all stages are class A. Note that even the designer of the BCL (upon which this amp is based) is carefully selective in making those class A claims.
 
But to put things in perspective, I don't feel ripped off at all. This was one of the best deals I've ever gotten and many thanks to the OP.