Review of 1950s GE JG5670 triple mica Tubes for iFi Pro iDSD DAC
This is a review of the 1950s GE JG5670 triple mica tubes that replaced the stock GE 5570 tubes for the iFi Pro iDSD DAC. The installation was pretty straightforward, except that the back panel is permanently attached via wires. It needs to be gently maneuvered through the main cover in order to access the tubes. FYI, I primarily use my iFi Pro in my main stereo system in my living room. I rarely listen to music through my Audeze EL-8 closed back headphones through this system. So my observations are exclusively based on using the iFi Pro in that configuration.
If you don’t want to read a long, more detailed review, here is a summary of what I heard. The more detailed review is below. The first things you notice after swapping the tubes are increased dynamics at both ends of the spectrum, more clarity and transparency, and more detail. These are not subtle changes. Beyond that, I heard more body on acoustic instruments and more specificity for each instrument occupying its own space in the larger soundstage. The soundstage didn’t appear to benefit from greater depth or width with these tubes. Bass seemed to be a bit tighter and more pronounced. And finally, these tubes are more musical. Everything sounds “right” with these tubes, like you want to tap your feet and move your body and smile when playing great music through them. Not bad for simple tube rolling.
For the more detailed review, I’ll share some of my sources from which these observations were derived. If you listen to “Moon Dance” on Kenny Barron and Mino Cinelu’s “Swamp Sally” album, the percussion thwacks jump right out at you. At every level, from soft to medium to loud dynamics, these tubes handle them well, and stop on a dime when the music calls for it. Very impressive!
I love Anouar Brahem’s music. It’s middle eastern jazz recorded beautifully on ECM records. When listening to “Lover of Beirut” on his “Astounding Eyes of Rita” album, the oud and the bass clarinet sound like they are in your living room, intimately playing for you. The transparency is unreal. When the darbouka joins them toward the end of the song, you can feel its presence in your room. Sublime music.
I listen to a lot of electronic music. I know “Toku “ by Monolake on their album “Ghosts” inside and out. Or so I thought. Listening to it with the NOS tubes, I heard details that I’d never heard before. There are different sounds coming from everywhere in the soundstage, and every one of them had more nuance and detail than ever before. Quite revelatory!
Listening to “Tundra” on Amber Rubarth’s “Sessions From The 17th Ward”, all three instruments (violin, cello, and percussion) sounded richer and fuller than before. The sound was anemic with the stock tubes. But with the new tubes, it was if somebody fattened the instruments, but in a totally good way.
As far as bass goes, it was tighter and more pronounced than before. Listen to “Sarasate” on “Uncommon Ritual”. The bass just jumps out at you and growls. Whether it was acoustic bass or electronic bass, it was tighter and more integral to the mix of the song. Listen to “Narabeh “ on Compa’s “narabeh” for some deep electronic bass. Play it loud, but not too loud because you’ll blow your speakers. Very impressive.
I especially love these tubes because they make everything sound more musical. Listen to Tony Rice’s guitar playing and David Grisman’s mandolin playing on “I Am a Pilgrim” on their “Tone Poems” album. They are both virtuosos on their instruments, and with these tubes, you’re on the edge of your seat waiting for the next volley of notes to envelop you. Both instruments just sound “right”. Or listen to some difficult music like Ricardo Villabos’s electronic music “re-imagination” of some avant garde classical music on “Reblop” from “Re: ECM”. These tubes make the music more accessible and approachable, which allowed me to enjoy it much more.
As you can see, I love these tubes. I still have a potentially even more likable set of tubes to try in the 1955 set ofWE396a’s. They are harder to find, much more expensive, and will potentially enhance the sound even more. Can’t wait to try them down the line. If people respond favorably to this review, I’ll do the same for that set of tubes. Happy tube rolling everyone!