Since there's almost no information on the Japanese amp maker Utsusemi-Works and their Sound Tiger portable amps within the English speaking, I've decided to create a thread here with some brief impressions, since it'll likely be of interests to fans of amps such as Mass Kobo, Brise Audio, and Bakoon Products (Satri Circuit Labs), etc.
Utsusemi-Works is a small operation run by Tetsuya Oishi in Tokyo who handmakes all products. Information on their product line-up can be found in both Japanese and English. I had the pleasure of ordering their top-tier model, the Concerto, directly from Oishi-san recently, so can offer some impressions of the buying experience and the amp itself. Delivery takes some time because it is hand built in small quantities.
The Concerto is a solid-state balanced amplifier driven by 4 replaceable/rechargeable batteries. There is no gain/volume, so adjustments are made on the source. For this reason, there is a fantastic synergy with Lotoo DAPs, not only tonally but also because Lotoo have variable line-out, which works perfectly with all the amps from Utsusemi-Works.
When ordering, you can request certain customisations. I opted for a stainless steel plate and the brown vintage looking case above - I think I was the first to have received this case. The build is excellent and exudes both a sense of precision and a sense of passion. The Concerto amp is balanced in and out, but can also be used from a single-ended source with the correct cable. Shown below here with an IC from Brise, 3.5mm-4.4mm.
Oishi-san is very careful about every aspect of the design, including the usage of interconnects and the batteries. He recommends the white Fujitsu seen above. I also ordered an interconnect from a company called Haru Audio from Japan who is working closely with Utsusemi-Works. I have not extensively compared with other interconnects, but I'm very gratified with the Afterglow Resolution IC included in the order.
Let me offer some brief impressions on the sound. I can only speak for the Concerto here. As I understand it from @KKNAYANA, their amps vary in tuning quite widely and also according to region. The Concerto, however, is very clean sounding, with a hint of slight richness in the lower mids and a smooth but precise top region. The overall presentation is taut, dynamic, balanced, highly musical, and immensely engaging. Technical performance is also excellent, with especially vivid sense of imaging and layering. Background is 100% pitch black quiet. No noise whatsoever.
With the Lotoo Paw Gold Touch Ti, the Concerto retains the tonality of the Ti's tuning but expands the soundstage, generates more definition, and improves coherence. On peakier headphones, such as the WP900, the Concerto also renders the overall presentation somewhat less strident without taking away any of the dynamics.
On its own, the Concerto is an outstanding amp, especially at the price point. However, I want to say that the Concerto works *amazingly* well in connection to other portable amps. Yes, this now involves multiple amps, but the results are so incredible that it's worth it.
The added dimension includes a truly staggering sense of width and depth, an incredibly "lifelike" sense of dynamics, and a excellent sense of layering and imaging. The overall role the Concerto plays here, however, is to give a desktop sense of authority to the presentation. Sounds hyperbolic but I encourage anyone who has the opportunity to try pairing the Concerto with either a Mass Kobo or Bakoon amp. I also understand this pairing works well with Brise's Tsuranagi amp.
In sum - fantastic amp. The whole experience of ordering from Utsusemi Works was a total pleasure and I offer a hearty recommendation!
Utsusemi-Works is a small operation run by Tetsuya Oishi in Tokyo who handmakes all products. Information on their product line-up can be found in both Japanese and English. I had the pleasure of ordering their top-tier model, the Concerto, directly from Oishi-san recently, so can offer some impressions of the buying experience and the amp itself. Delivery takes some time because it is hand built in small quantities.
The Concerto is a solid-state balanced amplifier driven by 4 replaceable/rechargeable batteries. There is no gain/volume, so adjustments are made on the source. For this reason, there is a fantastic synergy with Lotoo DAPs, not only tonally but also because Lotoo have variable line-out, which works perfectly with all the amps from Utsusemi-Works.
When ordering, you can request certain customisations. I opted for a stainless steel plate and the brown vintage looking case above - I think I was the first to have received this case. The build is excellent and exudes both a sense of precision and a sense of passion. The Concerto amp is balanced in and out, but can also be used from a single-ended source with the correct cable. Shown below here with an IC from Brise, 3.5mm-4.4mm.
Oishi-san is very careful about every aspect of the design, including the usage of interconnects and the batteries. He recommends the white Fujitsu seen above. I also ordered an interconnect from a company called Haru Audio from Japan who is working closely with Utsusemi-Works. I have not extensively compared with other interconnects, but I'm very gratified with the Afterglow Resolution IC included in the order.
Let me offer some brief impressions on the sound. I can only speak for the Concerto here. As I understand it from @KKNAYANA, their amps vary in tuning quite widely and also according to region. The Concerto, however, is very clean sounding, with a hint of slight richness in the lower mids and a smooth but precise top region. The overall presentation is taut, dynamic, balanced, highly musical, and immensely engaging. Technical performance is also excellent, with especially vivid sense of imaging and layering. Background is 100% pitch black quiet. No noise whatsoever.
With the Lotoo Paw Gold Touch Ti, the Concerto retains the tonality of the Ti's tuning but expands the soundstage, generates more definition, and improves coherence. On peakier headphones, such as the WP900, the Concerto also renders the overall presentation somewhat less strident without taking away any of the dynamics.
On its own, the Concerto is an outstanding amp, especially at the price point. However, I want to say that the Concerto works *amazingly* well in connection to other portable amps. Yes, this now involves multiple amps, but the results are so incredible that it's worth it.
The added dimension includes a truly staggering sense of width and depth, an incredibly "lifelike" sense of dynamics, and a excellent sense of layering and imaging. The overall role the Concerto plays here, however, is to give a desktop sense of authority to the presentation. Sounds hyperbolic but I encourage anyone who has the opportunity to try pairing the Concerto with either a Mass Kobo or Bakoon amp. I also understand this pairing works well with Brise's Tsuranagi amp.
In sum - fantastic amp. The whole experience of ordering from Utsusemi Works was a total pleasure and I offer a hearty recommendation!
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