New Xin Reference Amp by Dr. Xin !!!
May 27, 2007 at 2:58 PM Post #257 of 559
Quote:

Originally Posted by dle4e_2005 /img/forum/go_quote.gif
Click the links below for pictures of different colour of Supermacro

black supermacro and sliver Supermacro
Silver face and black body Supermacro
black face and silver body Supermacro

I might be changing my order of supermicro to the silver face and black body Reference.



Xin photo is not accurate at all. If someone were to let me know if it is the same as portaphile silver, i'll be able to make up my mind. I notice there is a different type of vol knob for the final RE base on the photo on fixup forum.
 
May 27, 2007 at 3:18 PM Post #259 of 559
Quote:

Originally Posted by theory_87 /img/forum/go_quote.gif
Xin photo is not accurate at all. If someone were to let me know if it is the same as portaphile silver, i'll be able to make up my mind. I notice there is a different type of vol knob for the final RE base on the photo on fixup forum.


Here's a pic of my old setup. I'm not sure if it's the same as a Portaphile as I've never seen one in real life.

 
May 27, 2007 at 3:19 PM Post #260 of 559
Here is some early Dr. Xin insight into what gives with the Reference:

"I did think about the plug-in of the huge cap, the problem is: LE is not just an added cap, many components need to be changed correspondingly, to ensure the integraty of the power suppply, charging and battery maintenance circuit.

LE's key is the lower voltage that allows for the use of AD8656, AD8616 5.5V OPAMPs. More and more people love the sound of these chips with SuperMicro-IV and SuperMini-IV, they also love the 4 switches, metal case and fast charging of SuperMacro-IV.

After removing and replacing the diodes in SuperMacro-IV with the new ultra-low impedance FETs, the power impedance is already all way down to 0.1 ohm (from 8 ohm!). So if you use AC/DC, the impedance is already down to the bottom. A 12V regulator's impedance is only 0.024 ohm, making the total still less than 0.2 ohm.

The bottleneck is now the batteries. NiMH's internal resistance is 0.2 ohm (0.17 after fully charged and 0.18 after discharge, to be exact). 8 AAA will be 1.6 ohm, much higher than 0.1 ohm, but still very low to a 32 ohm load. Reducing to 4 AAA, it is only 0.8 ohm. As the room is there, so why not add a 15000uF, to drag the impedance further down to 0.3 ohm at 20Hz. Such kind of power impedance is insanely low, even for a home speaker amp. Is hi-end audio all about over-kill?" from:

http://www.fixup.net/talk/topic.asp?...hTerms=15000uF

Here is another recent post concerning the effect of amp impedance vs. headphone impedance and its desirability.

http://www.head-fi.org/forums/showpo...&postcount=299

I find it interesting what Dr. Xin is doing with his Reference Amp. I may have to spring for one.
 
May 27, 2007 at 3:24 PM Post #262 of 559
The good doctor has weighed in on where the Reference lies in his amp stable:

Quote:

the Reference Edition of SuperMacro-IV, or simply put as XIN Reference. On the other hand, you can think of it as a mega version of SuperMicro-IV that's loved by almost all its owners...
The style of this amp is totally different than all my other amps except the same small metal case used by SuperMacro-IV.


So... I think it's just the Reference....
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May 27, 2007 at 3:33 PM Post #264 of 559
Quote:

Originally Posted by procreate /img/forum/go_quote.gif
That first quote is about the power supply in the SMIVLE. It was goto2003 who found that out.


Of course it was, long before the Reference was considered, but the whole Supermicro line is an evolutionary process and this was simply one bit of discussion concerning the effects of adding that large cap into the circuit. Dr. Xin of course went much further and took out much of what was not absolutely necessary for the sound.

Getting the amp to be near zero impedance is extremely desirable for handling low impedance headphones. The damping factor for this amp must be extremely good. It also has a battery powered quad-mono circuit in a small package. I hesitate to suggest that it could do as well as many desktop units but technically there is no reason it would not given the power requirements of a headphone and what this amp can supply. It would also be off AC noise sources being on battery having all those inherent advantages. There are many things to commend this amp for anyone for any use.

I think the more I consider this unit the more I want one. Just add a new iMod 5 and we may have the best of both worlds in portably and sound.
 
May 27, 2007 at 4:03 PM Post #265 of 559
OK I'm sold. Now what??? Xin has yet to post a site on fixup.net where we can buy them. So I guess we wait to purchase one, huh???
 
May 27, 2007 at 4:16 PM Post #266 of 559
I think Mrarroyo and Jamato8 are in line to receive new boards. Once the design is finished, the button on Xin's order page will be put in its place. For now, it's just the price and we'll have to wait. On his forum, he said "about a week" a couple of days ago …
 
May 27, 2007 at 6:53 PM Post #268 of 559
For a metal cased amp of this sound quality I had to take a double take on the intro price. It did not dawn on me that it was not 300 or more. There is a tremendous amount of R&D to this amp. I don't say this as someone that is jumping up and down about Xin's amps but because this amp is just so good regardless of where it comes from and that it can be bought for 250 in a metal case in the portable amp arena that now exists is a great buy. I have to add that I do like the Mini quite a bit and I really like the size and feel and it has a plastic case. The one nice feature of the Reference is the very long play time on 4 batteries, which to me is a big plus in combination with the reference sound.
 
May 27, 2007 at 7:25 PM Post #270 of 559
It is .9 inches thick and about 1/8 of an inch or about 2mm smaller in width and length than a normal credit card.
 

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