I purchased the DV at the recommendation of a co-worker who had previously enlightened me to Massdrop. I am a big fan of planar technology for speakers and the opportunity to pick up a pair of HE4xx at half the price of other high-end cans was enticing. Needless to say, no iPhone/iPad is going to power them adequately, so the AQ Dragonfly Red DAC (excellent and portable!) was purhchased. This ignited the desire to build-up a dedicated headphone “rig” for critical listening. However, I didn’t want to spend anywhere near what I’d invested in my main stereo setup!
Enter the Darkvoice 336SE. I was initially impressed with the sound but sensed there was plenty of room for improvement. The initial setup consisted of the DV and an old hi-end Sony disk player for a source while determining how I was going to actually use the DV. Settling on my iPad Pro/iPhone X as sources, I purchased a Schiit Modi3 DAC. It should be noted that I did quite a bit of reading on the DV while awaiting shipment. Many cited how the DV didn’t work well with their HE4xxx and other planar (low impedance - the HE4xx are rated at 49ohms) headphones. In my experience, nothing could be farther from the truth.
After three weeks of ownership, I was considering my options to improve the sound. There seems to be several options for upgrading the DV from tube rolling to internal mods like updating the caps and going to a better volume pot. The decision was made for me when my stock power tube failed. It was off to eBay where three power tubes were purchased (RCA 6AS7G, RCA 6080, and GE 6AS7GA), and two driver/output tubes (Tung Sol 6SN7GT “mouse ears” and 6SN7GTB).
I started with the 6080 with the stock 6SN7. Much improved sound. Fuller, especially in the bottom-end. However, it wasn’t a “open” as I would have liked. It should be noted that the Dragonfly Red was my baseline and I was looking to improve on its excellent sound. Going to the RCA 6AS7G - again with the stock tube, was a game-changer. Wow! I was met with a far broader and deeper soundstage with a separation of instruments that is the hallmark of planars. Bass and lower midrange was improved slightly, but there’s a definite upper mid-range bias. Curiosity getting the better of me, I plugged in the 6SN7GTB. This shifted the bias to the bass-end and, for me, it was too muddied and was decidedly less “open” than before. This setup epitomizes what folk refer to the “tube sound”. However, 6SN7GT “mouse ears” brought it home with a rich lower-end and a sparkle on the top end though more decidedly more “digital” in overall character. BTW, I was surprised that with all the changes in the tubes, only the GTB possessed any “hum” which dissipated over a few short hours. If you get into tube rollin’ with the DV, this is where I would start. The costs and availability of these tubes are excellent and you should be able to source them both from eBay for less than $75 for NOS pieces.
What’s next? I have some other power tubes on the way: Tung Sol 5998A, GE 6AS7GA, and Tung Sol 7236 with the 5998A really piquing my interest. For now I’m going to let the RCA 6AS7G and Tung Sol 6SN7GT combo settle in more before any further evaluations.
I’ve never really been into “cans”. The Darkvoice 336SE (and the HE4xx) has changed my perception of headphone listening. For less than $600 invested (including headphones), I encourage anyone interested in trying a tube amp setup to give this a try!