2/6/2026. The following is a press release from Audio Note UK.
The legendary Oto SE receives its first major technical revision in decades, featuring bespoke in-house components and a redesigned power supply.
WEST SUSSEX, UK – Audio Note (UK) is pleased to announce the release of the Oto SE 35, a significant update to one of the most enduring integrated amplifiers in high-end audio. The release marks 35 years of continuous production for the Oto, which has been a cornerstone of the Audio Note (UK) range since its debut in 1991.
Originally conceived by Audio Note (UK) founder Peter Qvortrup and designed by Andy Grove, the Oto was the first amplifier to be fully developed and manufactured by Audio Note (UK). While the Audio Note name was already well known, thanks to the legendary Ongaku integrated amplifier, the Oto proved that the company’s philosophy of musicality and vacuum tube refinement could be successfully applied at more accessible price levels.
Peter Qvortrup explains, “When I set Andy the challenge to design a single-ended [SE] pentode version of the Oto in the early 90s, single-ended amps were a big outlier. The Oto and now the Oto SE 35 stand as a testament to our philosophy on timeless quality audio design. We still maintain and service our customers’ Oto’s, making sure they’re good for years to come. This is what true longevity looks like, and that will never change.”
“Over the last three decades, the design of the Oto has undergone various evolutions,” says Chief Designer Andy Grove. “I decided it was time to give the Oto SE a complete makeover. The result is an amplifier with a more realistic ‘bass kick’, the kind of physical presence you feel when you are in the room with a kick drum or a bass guitar. It remains an all-round musical, fun-to-live-with amplifier, but it can now summon a serious amount of attitude when the recording demands it.”
The Oto SE 35 integrated amplifier (and the P1SE 35, the stereo power amplifier version of the OtoSE) are available to order now through all authorised Audio Note (UK) specialists
Sometimes you hear of design teams conducting weeks of intensive calculation and simulation, meditation, or seeking spiritual guidance from another plane, and I do indeed often engage in that and more myself. However, that was not the case with the P1SE/Oto SE power amp – it fell into place almost immediately, and required just calculation and reference to valve datasheets to set operating points and to check speaker damping, etc.
Anyone who is engaged in creative work like design, architecture, composition and songwriting will know when what you have in front of you fits together harmoniously. It looks right, feels right, and you know it IS right. Sometimes it takes a lot of work, but sometimes it feels as if it’s been gifted, with a moment’s inspiration and a scribble of the pencil. I still remember, in 1991, sitting at the kitchen table at my parents’ place in Suffolk, where I had my workshop.
Of course, there is more to the Oto SE than just the power amp board, and the prototype was built with the help of Claus Molgaard, another engineer who was working with Audio Note at the time. We didn’t have a great deal of time, but we got the thing working relatively quickly and demoed it in the listening room shortly after. It was, of course, a bit of a nail-biter moment for me, but the demo went very favourably.
Over the years, the design has undergone some evolutions and regressions, and due to a special order unit request for a customer, I decided to give the classic Oto SE a makeover – and in some areas a redesign to bring it up to date, a little like what we have done with our Meishu amp recently.
Just like the Meishu, the refreshed Oto SE has a new output transformer design, although not quite as chunky as that one. It’s specifically designed for the Oto SE and wound in-house. The main PSU has been redesigned, now including a choke (also in-house designed and made), with optimised time constants, and there have been a few tweaks to the power amp board. Together, these mods give the Oto SE a realistic bass kick, and not that dimensionless, flat, overdamped “transistor” bass, I mean something that sounds and feels like a kick drum, bass guitar, etc.
The phono stage has also been made over, increasing its sensitivity, and, together with the new power board, it means we can get rid of the line stage that was necessary in the old Phono version. This retains phase integrity and reduces noise.
We also revised the wiring loom and internal shielding, which, together with the new PSU, has yielded significant improvements. Plus, the new in-house designed and made mains transformer helps just about everywhere.
I am very happy with the end result. Maybe it’s not quite a Meishu Tonmeister, but, for an EL84 amp, I think it’s going kick most other 300B valve amps hard in the butt, and if you don’t believe me, try it – with a good speaker of course! It’s not all filigree detail and midrange, it’s an all round musical and fun-to-live-with amp, and it can summon a serious amount of attitude when needed.
I remember being 35 years old was pretty good, and the Oto SE seems to be enjoying it as well!
Key Areas of Improvement: New output transformer designed for the Oto SE, and wound in-house.
The main PSU has been redesigned,
Now includes a Choke (also in-house designed and made), with optimised time constants,
Tweaks to the power amp board.
Specifications:
Power: 8.2W into 8ohms @ 5% THD at 1kHz
Line Sensitivity: 205mV for 8W into 8 ohms at 1kHz
Phono Sensitivity: 2mV for 8W into 8 ohms at 1kHz
Phono hum+noise: -100dB Awt ref 8V
Valves:OTO SE 35:
4x EL84
2x ECC83
OTO SE 35 Signatures and OTO SE 35 Silver Signature:
2/6/2026. The following is a press release from Audio Note UK.
The legendary Oto SE receives its first major technical revision in decades, featuring bespoke in-house components and a redesigned power supply.
WEST SUSSEX, UK – Audio Note (UK) is pleased to announce the release of the Oto SE 35, a significant update to one of the most enduring integrated amplifiers in high-end audio. The release marks 35 years of continuous production for the Oto, which has been a cornerstone of the Audio Note (UK) range since its debut in 1991.
Originally conceived by Audio Note (UK) founder Peter Qvortrup and designed by Andy Grove, the Oto was the first amplifier to be fully developed and manufactured by Audio Note (UK). While the Audio Note name was already well known, thanks to the legendary Ongaku integrated amplifier, the Oto proved that the company’s philosophy of musicality and vacuum tube refinement could be successfully applied at more accessible price levels.
Peter Qvortrup explains, “When I set Andy the challenge to design a single-ended [SE] pentode version of the Oto in the early 90s, single-ended amps were a big outlier. The Oto and now the Oto SE 35 stand as a testament to our philosophy on timeless quality audio design. We still maintain and service our customers’ Oto’s, making sure they’re good for years to come. This is what true longevity looks like, and that will never change.”
“Over the last three decades, the design of the Oto has undergone various evolutions,” says Chief Designer Andy Grove. “I decided it was time to give the Oto SE a complete makeover. The result is an amplifier with a more realistic ‘bass kick’, the kind of physical presence you feel when you are in the room with a kick drum or a bass guitar. It remains an all-round musical, fun-to-live-with amplifier, but it can now summon a serious amount of attitude when the recording demands it.”
The Oto SE 35 integrated amplifier (and the P1SE 35, the stereo power amplifier version of the OtoSE) are available to order now through all authorised Audio Note (UK) specialists
audionote.co.uk/dealers.
Deeper Dive with Andy Grove
Sometimes you hear of design teams conducting weeks of intensive calculation and simulation, meditation, or seeking spiritual guidance from another plane, and I do indeed often engage in that and more myself. However, that was not the case with the P1SE/Oto SE power amp – it fell into place almost immediately, and required just calculation and reference to valve datasheets to set operating points and to check speaker damping, etc.
Anyone who is engaged in creative work like design, architecture, composition and songwriting will know when what you have in front of you fits together harmoniously. It looks right, feels right, and you know it IS right. Sometimes it takes a lot of work, but sometimes it feels as if it’s been gifted, with a moment’s inspiration and a scribble of the pencil. I still remember, in 1991, sitting at the kitchen table at my parents’ place in Suffolk, where I had my workshop.
Of course, there is more to the Oto SE than just the power amp board, and the prototype was built with the help of Claus Molgaard, another engineer who was working with Audio Note at the time. We didn’t have a great deal of time, but we got the thing working relatively quickly and demoed it in the listening room shortly after. It was, of course, a bit of a nail-biter moment for me, but the demo went very favourably.
Over the years, the design has undergone some evolutions and regressions, and due to a special order unit request for a customer, I decided to give the classic Oto SE a makeover – and in some areas a redesign to bring it up to date, a little like what we have done with our Meishu amp recently.
Just like the Meishu, the refreshed Oto SE has a new output transformer design, although not quite as chunky as that one. It’s specifically designed for the Oto SE and wound in-house. The main PSU has been redesigned, now including a choke (also in-house designed and made), with optimised time constants, and there have been a few tweaks to the power amp board. Together, these mods give the Oto SE a realistic bass kick, and not that dimensionless, flat, overdamped “transistor” bass, I mean something that sounds and feels like a kick drum, bass guitar, etc.
The phono stage has also been made over, increasing its sensitivity, and, together with the new power board, it means we can get rid of the line stage that was necessary in the old Phono version. This retains phase integrity and reduces noise.
We also revised the wiring loom and internal shielding, which, together with the new PSU, has yielded significant improvements. Plus, the new in-house designed and made mains transformer helps just about everywhere.
I am very happy with the end result. Maybe it’s not quite a Meishu Tonmeister, but, for an EL84 amp, I think it’s going kick most other 300B valve amps hard in the butt, and if you don’t believe me, try it – with a good speaker of course! It’s not all filigree detail and midrange, it’s an all round musical and fun-to-live-with amp, and it can summon a serious amount of attitude when needed.
I remember being 35 years old was pretty good, and the Oto SE seems to be enjoying it as well!
Key Areas of Improvement:
New output transformer designed for the Oto SE, and wound in-house.
The main PSU has been redesigned,
Now includes a Choke (also in-house designed and made), with optimised time constants,
Tweaks to the power amp board.
Specifications:
Power: 8.2W into 8ohms @ 5% THD at 1kHz
Line Sensitivity: 205mV for 8W into 8 ohms at 1kHz
Phono Sensitivity: 2mV for 8W into 8 ohms at 1kHz
Phono hum+noise: -100dB Awt ref 8V
Valves:OTO SE 35:
4x EL84
2x ECC83
OTO SE 35 Signatures and OTO SE 35 Silver Signature:
4x EL84
2x E83CC
Phono Version also include:
ECC83/7025
6DJ8
OTO SE35 internal
OTO SE35 Signature internal
OTO SE35 Silver Signature internal
Andy Grove, Audio Note UK designer
Peter Qvortrup, Audio Note UK Founder