The Minute 45 lists for $2,300 with a standard input and rectifier tube included. It doesn’t come with any 45 tubes, so you need to order a pair from SAC Thailand along with your amplifier or find your own source of 45 tubes. The good news is that the selection for high quality NOS 45 tubes are much larger than say 300B tubes, so you shouldn’t have any difficulty sourcing them.
I was given two different 45 tubes to use with the Minute, a pair of Sophia Princess 45s and a pair of Super Silvertone 45s. The Sophia Princess was a very mellow sounding tube with big soundstage and excellent midrange clarity, and overall the smoother sounding tube. The NOS Super Silvertone was a very thick sounding amp, with thick punchy lows, but not as smooth or as clear as the Sophia Princess.
For the input tube I had three pairs of 6SN7s: two RCAs in Smoked and Clear Glass versions, and a Sylvania Chrome top. The only thing I can remember is that the Smoked Glass RCA sounds warmer and fuller than the Clear Glass RCA and Sylvania Chrome top. The Minute 45 definitely has a mellow signature built into the amplifier, and I felt that better results are achieved when I don’t try to fight that character but chose tubes that has the same character as the amplifier. In this case the 6SN7 RCA Smoked Glass and the Sophia Princess 45 are the tubes I use the most for the Minute.
I actually got plenty of different rectifiers to play with. The most impressive looking is the Emission Labs 274B, used for the photo session here due to its big and imposing look, actually ranks lowest in terms of sound quality. A NOS Mullard GZ37 pair was significantly better, and the GE GZ34 is the best rectifier of the bunch (you get a clearer sound top to bottom and a more spacious soundstage). The last rectifier that I had the chance to listen to is a pair of GE GZ34s, but this time in metal base version. This rectifier is even better than the glass base GZ34, offering an even more improved soundstage, but it also made the sound even mellower than when I used the other rectifiers.
The price of the Minute 45 makes it comparable to the WooAudio WA5LE (headphone amp only version), the Zana Deux, the Apex Peak + Volcano, and Cary’s popular Xciter headphone amp. Features wise, the Minute and the Xciter offers speaker outputs, though Minute’s 1.5 Watts output makes speaker selection extremely critical.
Technicalities wise, I think the Minute ranks up there with the best tube headphone amplifiers upwards of the $2,000 tag. The analog sound naturally lends for a more grainy soundscape, somewhat like the Zana Deux and Cary Xciter. These are very different than the WooAudio and Apex Peak sound, which are cleaner and more dynamic sounding. The Minute 45 is more refined and smoother than the Zana, though the Zana’s more upfront and forward sound would appeal better for the typical Rock and Blues crowd. The Minute 45 on the other hand would work very well with vocals especially female vocals.
Though I can recommend the Minute 45 wholeheartedly, I do think that it is quite a specialized amp focused for mostly mellow female vocals. I can’t imagine listening to Classical tracks which require a more dynamic presentation and stronger bass impact. Rock fans would probably be best looking at the Zana Deux or the Apex Peak as both amps have the pace and the attack to suit Rock music.
Thanks to Drew for the Minute 45 amp loaner, and Obee for the WooAudio WA5.
Tubes used for review
- Driver tube: 45 Sophia Princess and Super Silvertone
- Input tube: 6SN7 RCA Smoked Glass, RCA Clear Glass, Sylvania Chrome Top
- Rectifier tube: GE GZ34 Glass and Metal Base, Emission Labs 274B, Mullard GZ37
Gear used for review
Sennheiser HD800, HD580, Hifiman HE-6, HE-500, Audez’e LCD-2, AKG K1000, Audio Gd Ref 7.1, KingRex UD384, CEntrance DACport LX, Hifiman HM-801.