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Kieran
19
May 9, 2014
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So, anyone know anything about this? Seems like it's pretty much a really expensive Aune T1, with the tubes just acting as a filter.
May 9, 2014
dorkvader
197
May 9, 2014
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I don't know a lot about it, but you can tell a number of differences just by looking at the pictures and specs.
First of all, those 12AX7 tubes have a mu (gain) of 100. 12AX7 are commonly used in guitar amplifiers for this reason (as they need a lot of gain). They are much less commonly seen in headphone amplifiers and preamps. They're less common, but a design with 12AU7 makes a lot more sense here.
But does it? they must be greatly attenuating the signal anyway, and 12AX7's are common. Unless the photos are taken with the LEDs on and the tubes off, they are probably underdriving the tubes. I'm not seeing much glow. It makes one wonder how much impact they have on the sound. I also notice they can't really cool effectively mounted as they are. To ensure they don't overheat, there can't be much current.
The aune T1, on the other hand, uses a 6922 (6DJ8) wihch is very much what I'd expect from a preamp.
What are the essential differences? Well, I haven't seen any interior shots of this DAC, but the ones of the aune tell a lot: http://www.hifidiy.net/24-31-1.html
It looks like a decent internal build, but due to price and space requirements, there's not a lot of room there for a quality power supply. Cheaper PCB mount jacks and switches (and potentiometer) also keep casts down.
The SNR of the aune is listed as >= 120. The jolida is 126. ENgineernig the jolida's frequency response to be up to 70 KHz before it drops is more expensive, etc.
There's really a big difference between the two.
I mean, I have an audioengine D1 feeding a DIY tube amp called a torpedo. This combination costs about what the jolida does here, and I'd say mine is a significant increase in performance and quality over the aune T1.
I'm not endorsing this DAC, as I don't know much about it. Until takeapart pictures are posted I usually won't even consider buying, but there are differences and some reason to believe that it justifies the added expense.
The weight and transformer means that that's decent, at least. I bet it has a linear regulated power supply.
edit: here's an interior shot. http://www.polkaudio.com/forums/attachment.php?attachmentid=56751&d=1301958394
Looks like a lot of the size and weight comes from that nice-looking PSU in there. I'm not sure if this is the one for me, as the transformer is sort-of in the middle of things.
May 9, 2014
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