Paid $102.99 from Massdrop including the upgraded tubes. I should have bought two!
I have them set to the high gain setting and have listening impressions for the following outputs with the 6CQ6 tubes:
|Headphones||Headphones Plugged Into:||Device Plugged Into:||Sound Impression|
|Q701||Macbook Headphone Jack (directly)||N/A||tinny sounding. Can't drive the low end, I'm guessing about half the decibels for sound below 200hz compared to the sound in the 500hz range. Sound in the 1000hz and up range comes through clear (almost too much of it)|
|Q701||Little Dot I+||Macbook Pro Headphone Jack||More linear sound. The bass is nice and warm and there's still detail in the mids & highs. Very large upgrade! Well worth it!|
|Q701||Dragonfly Black 1.4||Macbook Pro USB||More linear compared to directly in the headphone jack. Bass is a little reduced compared to the little dot I+ in the headphone jack. Sounds "cool" but linear. Resonance is very clear compared to the little dot I+. Extremely spatial sound. Makes "concert hall" recordings sound awesome (ie: live music, classical)|
|Q701||Little Dot I+||Dragonfly Black 1.4 (Into macbook pro USB)||Not much of a difference from the Little Dot I+ plugged directly into the headphone jack. Makes it clear that the MAC DAC is not that bad the computer is more limited as a headphone amp. Lose a bit of resonance detail but save $100-150 by cutting out the additional device.|
The instructions detail how to change the jumpers & dip switches but don't give instructions on how to open it up. Only need to remove lower screws on front & back plates, no other screws. Tubes are cool enough to touch but unit itself is almost too hot to touch after an hour of use. Hissing & crackling goes away after an hour of use.