[adhoc]

i dont get what's the fuss about the battery..

it's not as if it's a wimpy small form factor ipod-battery- it's a (realtively) manly 9v energiser..

 

[joni]

Slightly off topic but I am delighted to confirm that the V7 SuperMicro (with similar seperated output stage) has finally lost the painful brightness after about 150 hours and now sounds very balanced and...........NICE

 

[tonyjang]

i dislike the whole idea of going through 25$ worth of batteries before the amp sounds good. i don't know, maybe it's just me? i'm still a fan of xin's amps though. keep up the good work.

 

[bobjew]

hey joni, I was going to ask about you, glad it worked out. My SD is still a bit crispy. Amazing how much things change in a few days!

tonyjang: rechargeable batteries!

 

[joni]

........to tell the truth I was very sceptical about the reality of burn in before this...We are not talking subtle here

 

[penbat]

Sounds like Xin has just done some better prototypes so any results with the current prototypes are not conclusive.

http://www.xintechs.com/talk/topic.asp?TOPIC_ID=40

Xin says "Spent more time to tweak the amp circuit this weekend and made more prototypes."

Tis a pity that this burn in thing makes conclusive testing take so long.

Sounds a lot like an SD is worth buying anyway due to the excellent price and portability.

 

[penbat]

I suggest that any test comments on the new prototypes be done in a new thread !

 

[bobjew]

penbat: Any testing with any protoype will not be conclusive! Conclusions will only be valid with a final production model. Common sense, no?

 

[penbat]

Quote:

Originally posted by bobjew penbat: Any testing with any protoype will not be conclusive! Conclusions will only be valid with a final production model. Common sense, no?

Yeah but i was under the impression that only the casing was liable to change.

 

[bobjew]

Yes penbat, and your impression was very correct...until yesterday. The nature of prototyping I guess. Its never good to make conclusions too quickly.

The SD.
At about 190 hours the SD is still chugging along and it sounds on the verge of total burn-in. Just a tinge of over-sibilance left and that could just be me and an admitted over-sensitivity to the stuff, but it just doesn't sound natural to me yet. Maybe another day or two?

 

[penbat]

More words of wisdom from Xin:

"What is the effect of "tweaking the amp circuit" ? Better sound quality ?

Yes, perfected sound and battery life. For the two prototypes I sent out so far (one to Bob Jew and one to cmascatello), I did not have time to tweak them. Bob grabed his amp right from my bench; Cmascatello told me he was going to a trip. Lately I found their amps had short battery life and some sounding issues. I'm sending them new amps that have perfect sounding and guaranteed 15 hours of play.

Now these little amps use ICs from all the major IC makers: Analog Devices, National, Linear, TI and Maxim, to get the best of them all. The result of such a combination is: very low battery drain (only 9.9mA) and rounded sounding (no aggressive charactor from any single IC maker). Hard to believe how many ICs I've searched and tested so far! Although the idle current is so low, the output current is 110mA (linear).

I'm still benchmarking, listening and improving while I'm waiting for them to set up the production line. The most impressive thing is the image - the sound has very good depth and detail, including bass resolution. Sound stage is entirely off head and forwarded. Now I can say the Dual is very well tweaked and I'll officially send out more prototypes for beta testing. "

Looks like this thread is just about dead and a new thread will start up for the new prototypes.

 

[bobjew]

I did not have time to tweak them. Bob grabed his amp right from my bench;

Huh? That's slander, I hope you didn't purposely misquote Xin, penbat, and I hope you can prove that Xin said that to you. I don't know what problem you might have, but please don't make it mine. That is far from any truth that actually happened and I can prove it.

 

[cmascatello]

So it sounds like I am going to be getting a new SuperDual to test with. My burn-in has progressed quite a bit on the "old" prototype. I am 60 hours in and the sound is noticeable softer (in a good way). The Dual got a nice bit of use on my cross-country flight this AM and I was enjoying the differences from the out-of-box sound (I left it for 2 full days of burn-in w/o listening). The one observation I had on the plane and subsequent listening today was that the battery died after about 10 hours -- it is nice that Xin has already notcied and apparently fixed this.

I guess Bob and I will start again from scratch with the new prototypes. We can start a new thred when one of us gets the new one(s). Too bad, though, cuz this thread had a boatload of hits...

 

[bobjew]

I did find that post by Xin on his website:

1-My friend George was there. He will verify no amps were grabbed.

Just talking to fellow member lindrone and he thought it was one of those cultural problems and that statement should not be taken literally. I have an email to Xin about this. If he were pissed off, why would Xin then proceed to say he would send us both new prototypes? If I do get that new proto I will continue to report on its sound and progress as I have done up to now.

2-An email the day after. Does this sound like someone who was pissed off because one their prototypes were grabbed?

>Hi Bob,
>It was a great fun to me too and thank you for the dinner.
>Thank you for the posts. Couple things:
>1) I, myself, would love to make the battery removable/replaceable. As this
>the first commercial/professional amp, my company does not want people to
>open the case and make the circuits exposed - for customer service concern.
>Once this first product goes well, we'll certainly make a new case so you


[Message truncated. Tap Edit->Mark for Download to get remaining portion.]

 

[penbat]

Obviously i only know what was posted by Xin on his site but I am sure he was only talking metaphorically, that is Xin could only give you what happened to be available on that day.