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RE: Tube swapping in Alpha DAC

Per the comments in a previous post: Swapped out the two Sovtek 12AX7WXT in my DAC with GE 5751. � vast improvements in top-end air: cymbals shimmered � good improvements in space: the sense of the recording venue improved � transient attack: let's just say that I was repeatedly startled by the content from very familiar recordings � tranparancy and detail: improved to such a degree that micro-dynamic shadings among guitars, piano, and vocals enabled a whole new level of immersion into the music; the decaying tones among some percussion were simpy mesmerizing � smooth: bye-bye tizzy asnd brittle top-end � width of soundstage diminished a very small amount; apparent depth increased by a significant, but not large, degree What a deal. The GEs cost less than the Sovteks ($8 vs. $12) and improve the quality of the music emerging from my system. The change was more obvious and significant than many wire swaps I have made.
dischead
horizond151
2 posts
 
I tried GE 5751s in my Alpha and hated them. The clarity and speed of the Chinese 12AX7s were gone, replaced with a more golden sound, but also much less resolution.
hellohifi
120 posts
 
Mullard 12AX7 are incredible, if you can get them. You have to be careful about who you buy them from. Just because the frosting on the tube asys they are Mullards, doesn't mean that they are. Goodluck. thanks, Brian@HelloHiFi.com ph805.527.9739 fax805.527.9808 www.hellohifi.com eCatalog available. New equipment demo’s by appointment. All quotes are good for 30 days. Customers in every state, & 26 countries (angol/ingles/englisch/beszelunk magyarul!/ hablamos en espanol/wir sprechen deutsch).
horizond151
2 posts
 
I don't know about Mullards, but JJ Tesla 12AX7s have made a nice improvement in the sound - not quite as fast as the stock Chinese, but richer and deeper. At $10 per tube from Ned at triodeel.com, its well worth the $20 investment.
cspra
6 posts
 
If your Alpha is the 18 BIT model try the GE 5751 Black Plate or the Raytheon 5751 Black Plate. I have found those two sound different from one another, but will give a nice clear sound. With a 96/24 Alpha the Chinese 12AX7 is not bad. Some like the Mullard 12AX7 but I think they sound bland in the Alpha. The Brimar NOS 12AX7 is the tube to listen to, but prepare to shell out the cash.
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