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Absolute Audio Labs ASL-1Z Preamp


MattyW

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Will after getting the deal off a century and spectacular results with an Absolute Audio Labs SIT-A15 power amp I’ve decided to take a chance on another of Watchara’s products, the ASL-1Z preamp. It’s an active class A JFET? base pre with 16db of gain and zero feedback design. It interests me as with this pre Watchara attempts to replace the harmonics which he says are lost in the analog to digital conversion of the recording process, so all those chasing the ultimate accuracy and transparency can probably stop reading here. This should however give a greater sense of realism and spatial cues in a similar way to a tube pre. I’’ expecting I’ll lose a little transparency vs my rather exceptional icOn 4PRO Slagleformer pre, though with some luck the gains in other areas will more than make up for that. Anyway I guess I’ll see.

 

This little units dimensions will be 30cm x 30cm x 10cm, it’ll have 256 steps of attenuation and an OLED display + remote control. 45 degrees inside the case and 42 degrees on the outside.

 

I think I’ll ask for the text on the display to be yellow so it matches my other components.  :)

Edited by MattyW
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1 hour ago, sdotmouse said:

how does he know which harmonics to replace? 

 

s.m


Apparently he reverse engineered a few ADC’s to figure out roughly what gets filtered out. Irrespective of what filtered out adding harmonics will not be the same as the original, though it might be closer than without. Apparently ADC’s filter out about 50DB of 2nd harmonics as noise so little wonder music only gets so close to real when played back. Probably why so many love tubes as it probably restores a good portion of that. ;)
 

Either way I’m willing to give it a try and see if it’s something I like. I’m aware this approach is something many accuracy purists will dislike, however there are others who will like such things so I’ll still share my experiences. ;)
 

Many different approaches in audio. Kind of like my preferring lower powered amps paired with the highest efficiency speakers I can get my hands on. Keenly watching the development of the Lii Song Platinum-10 drivers. The earlier prototypes were 103db efficient though no idea what the current iteration is up to.  

Watchara’s SIT-A15’s sonics are nothing short of stunning so I’m certainly going to give his pre a try. Especially given the price. He’s also developing another pre for those who just like a component that just gets out of the way though I already have that with the icOn 4PRO so of no interest to me.  :)
 

Though yeah, I’ve no issue going against mainstream commonly held beliefs in my journey. It’s all about enjoyment after all. How eachieve that is individual to each of us :D

Edited by MattyW
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On 16/09/2022 at 8:43 PM, MattyW said:

Though yeah, I’ve no issue going against mainstream commonly held beliefs in my journey. It’s all about enjoyment after all. How eachieve that is individual to each of us :D

Well said Matty! Your coin, your system, your ears.  

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1 minute ago, MrBurns84 said:

Well said Matty! Your coin, your system, your ears.  

 

Aye, it's all for enjoyment. Lately since the weather has warmed up a bit my system has been causing my mind to explode a fair bit.... The biasing point of my SIT-A15 power amp is tied to operating temperature with optimal ambient room temp betwen from 26 to 30 degrees. Given how spectacular Watchara's power amp is.... Yeah, very curious about his pre  ;)

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  • 1 month later...
  • 2 weeks later...

From Watchara’s Facebook page:

 

“ASL-1Z with SIT-A15

Preamp model ASL-1Z is a Zero Feedback circuit. It is made according to the concept. Output resistance is infinite (Infinite Z-OUT) that will not change the input impedance (Z-IN) of any power amp. Make the power work according to the factory measurement accurately.

 

The circuit consists of Complementary JFETs, Bipolar Transistor and LATERAL MOSFET. Adjusting the result of 2nd, 3rd harmonics distortion to the Sweet Spot point equivalent to a 7-digit preamp.

 

Only 3 machines were made and sold out because the equipment's features can't be found nowadays unless you open your own JFET factory or hire TOSHIBA to produce it again.

 

Power supply sector uses superior technique LT (Linear Technology) by feeder +/-V will check each other's pressure and calculate almost zero deviation. Both the disturbance signal will be destroyed together with Differential Feedback sectional control with C. urrent Diode (CRD) makes this power supply sector into Discrete Ultra Low Noise Circuit mode by default.

 

And many more. Not selling well in printing (lol)

 

No need to talk about this SIT-A15 power amplifier. The news ended since the supplier in Japan told me that I was a lot of fussy. I couldn't find the item according to my specifications. So I put on a conversion. Each one's way, it's their way.”

 

This is the video associated with the post. Sounds rather good (click here)

 

I feel rather privileged that I’m getting one of only 3 of these units which will ever be made. Looks like no more SIT-A15 will be made if I read things correctly too. Hard to tell when using page translation on Facebook.

Edited by MattyW
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  • 2 weeks later...


  • 4 weeks later...


From Watcharas Facebook page:
 

“Prepare to ship ASL-1Z and ASL SIT-A15 preamp to the 3 owners within today. Welcome and thank you for buying Thai products.

 

I design and build the best craft I have now under the concept of ZERO FEEDBACK both preamp and power amp.

 

JFET, TRANSISTOR, LATERAL/ENHANCE MOSFET, SIT. I have been studying continuously for over 20 years in the industry, deep down to the level of creation, distortion, 2nd, 3rd harmonics and elements of Facebook positives and negatives. Not just a measurement for advertising.

 

You can be assured that the product of Absolute Audio Labs. Every generation is intentionally made, not to follow the trend. There is no old word because it is "taste".“

 

947CF054-1AB5-4649-9F79-7041991FAD16.thumb.jpeg.39c37210af02f0dbd2dac624feb8b2df.jpeg

 

A3B7C664-0283-423F-BAF4-ABEE658D4B2E.thumb.jpeg.bccbf5a3e9574767ebda98fd44533b18.jpeg

 

86150B59-3317-4E3A-ACB7-3FD0E45DFEEA.thumb.jpeg.778a2cf0320956435c0a283f4eefdfb0.jpeg

 

6D3524D2-EF71-42FC-A58E-F7F9E61A83DE.thumb.jpeg.55df21b5b29695e9bafac15e59ae6fe4.jpeg

Edited by MattyW
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17 hours ago, Gav said:

I have not been here for a while, just happy with my present system, I love to see what you are up to Mat 😃

 

I didn't really need the pre..... That's more a curiosity. It was almost too cheap not to try and if it works out to be an improvement I'll end up ahead financially after selling the icOn 4PRO anyway.  ;)

 

The Lii Song Platinum-10 speaker drivers are a different story though. Very expensive drivers, and will require big custom cabinets to get the best from them though they should be next level and once more top me out in terms of what I can afford (which I've already done in the rest of the sound chain) so I'm pretty much at the end of the journey. The detail the PT-10 get is said to be up there with pricey beryllium tweeters so it should be rather special.

Edited by MattyW
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I only noticed your journey from about 14 months ago but was very interested in your findings and I learned some stuff that I have never even thought of before, as you can see I am more of a casual audiophile. I will be interested to see what your thoughts are on the new Pre Amp I think as it is designed to pair with the Amp you have one would think it would be better but you may prefer the sound from the Pre Amp you have now, not that I have any intention of upgrading from my Music First Passive Pre any time soon.

 

So have you actually ordered the  Lii Song Platinum-10 speaker drivers? any info on these yet?

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1 hour ago, Gav said:

I only noticed your journey from about 14 months ago but was very interested in your findings and I learned some stuff that I have never even thought of before, as you can see I am more of a casual audiophile. I will be interested to see what your thoughts are on the new Pre Amp I think as it is designed to pair with the Amp you have one would think it would be better but you may prefer the sound from the Pre Amp you have now, not that I have any intention of upgrading from my Music First Passive Pre any time soon.

 

So have you actually ordered the  Lii Song Platinum-10 speaker drivers? any info on these yet?


The PT-10 arrive next week. One of the first 3 pair off the production line. ;)

Edited by MattyW
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Geez I hate waiting. I know that the pre will be one of the biggest sonic changes I've had in some time. Mind you once complete the PT-10 driver based speakers will make an equally large or possibly larger difference. The wait is sheer frustration though. I'm not very patient with such things.

Edited by MattyW
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