Dances with Buffaloes

Year 2010, I was chasing after Buffaloes. Hahaha. Not this kind :

But this kind :

Haha, folks within the diy audio fraternity should be well aware of the renown dac kit by now. More info can be found on the website of the designer/manufacturer of this dac kit :Twisted Pear Audio

The version that i worked on in 2010 is ESS9008, 24 BIT/192KHZ version. In July 2010, I had bought over the entire kitset from Adrian, not knowing what to expect. The kitset comprises the following :
1. Buffalo DAC board
2. IVY II board
3. The PSU boards (one for the dual +ve supply for Buffalo and one for bipolar supply for the IVY)
Adrian had decided to move on to the newer version of Buffalo using ESS9018, 32BIT/400KHZ version.... will update more of this newer version in my blog because i have managed to purchase a set and commissioned it too! Exciting huh?
Note : For ease of differentiating the two versions, i shall term the earlier ESS9008 ver. as Buffalo24 and the newer ess9018 ver. as Buffalo32

Lashed up the kitset within an hour on a MDF board for experimentation, as a functional check and an initial impression. I was slightly disappointed. Grainy and bottom heavy. Remote to what i have read so far. Nothing germane to the sonic traits described by the members of diyaudio.com. After some contemplation, i decided that i should do an output stage of my own. I believe if that if there is a strong following for this dac, it must be something worth exploring. Afterall, Noising 2010 was just around the corner ( it was to be held in Oct 2010 back then), and i would want the attending group of people to have an impression of the much raved about dac.

August 2010, completed the revamped Buffalo24. Using the Buffalo24 as a voltage source, the output stage consists of two 6AQ5 pentodes configured in triodes, with Lundahl LL1660 as output coupling. Yes ...yes, i know that the THD measurements suffers using the Buffalo24 as voltage source. But hey, it sounded way better than using it as a current output with the IVY stage by Twisted Pear! Why 6AQ5? because they are very very linear as triodes and i have them for a few dollars a piece. Connected as triodes, they have a mu of 9 and impedance of 1.9Kohm. A couple of picture of my implementation :

Tubestage power supply is based on John Broskie's PS-1 regulation. With the supply regulations for the dac, tube filament, high tension voltage and heat emission from the tubes, all in one small chassis.....which is not very efficient in heat dissipation, this dac runs hot! hot! hot! But i had left it on for 6 hours without any problem. Importantly, it sounded sweet and detailed. I fell in love with the Buffalo from that moment onwards. I then decided that i would even explore it further to see how i can get better with it, to bring it into another leap of performance...and yes, i did eventually. To be updated in the upcoming blog.