Longdog Audio P6100M Biamp 2x2 (4 units)
13 lost · Anchored, Artisan, Characterful, PRaT, Reference, Romantic
Against the Anchored brief, the Longdog Audio P6100M Biamp 2x2 (4 units) keeps the slot decisively.
Audio Note OTO SE Phono Signature (35th Anniversary)
Integrated amplifier
Relative price
above typical
Among the 59 integrated amplifiers in the catalogue, this one is above typical.
A band places a component against its peers and carries no price. It is deliberately the only price indicator on this page: a second one, measured against a different set, would narrow the two together far enough to give the figure away.
What it is
Audio Note (UK) OTO SE Phono Signature — 35th Anniversary refresh (2026) of one of the longest-running valve integrated amps in production (since 1991). Pure Class A parallel-SE pentode topology, 12W from 4× EL84. Built-in MM phono stage with 40dB gain (3mV input sensitivity). Hand-built Hove, East Sussex.
"Level 2" in Audio Note hierarchy: Pure Class A SE Pentode + Materials/component quality criteria met. Step up from Cobra (Level 1, push-pull) to single-ended topology = AN UK's preferred sonic signature. Signature variant adds: Audio Note (UK) Copper foil capacitors in critical areas + Tantalum resistors in critical areas + custom IHiB output transformers. (Standard variant uses aluminium foil capacitors.)
35th Anniversary refresh upgrades: (1) new output transformer designed specifically for OTO SE wound in-house; (2) redesigned main PSU now including in-house choke + optimised time constants; (3) refinements to power amp board; (4) phono stage sensitivity increased + line stage after phono eliminated for phase integrity + reduced noise; (5) revised wiring loom + internal shielding; (6) new in-house designed mains transformer.
Variants: OTO Line SE (line only), OTO Line SE Signature, OTO Line SE Silver Signature, OTO Phono SE, OTO Phono SE Signature, OTO Phono SE Silver Signature. Silver Signature uses silver wire + premium internals.
CRITICAL ELECTRICAL FIT: 12W output mandates ≥92-94dB sensitivity speakers. Excellent partner for Living Voice (94dB), Audio Note AN-E (96dB), AN-J (94dB), Klipsch Heritage, Devore. 47kΩ MM phono load standard. 4Ω + 8Ω speaker taps (multi-impedance output transformer).
Tube-rolling: 4× EL84 + 2× ECC83 + 1× ECC82 (and Phono adds 1× ECC83 + 1× 6DJ8 for phono section). Easily obtainable common valves; NOS upgrades available (Mullard EL84 reference).
TNT Audio review: praises "tone and grace... but with more punch, grip, control and juice" after 35th refresh. Stereophile recommended historically; Class B reference in Audio Note hierarchy.
Competition record
Assessed against 15 rivals across the sixty systems: it takes the slot in none of its 48 head-to-heads.
Where it gives ground
The dimension the engine names as the weakest link, counted across every head-to-head it lost.
- timing and drive ×4
Who it comes up against
Sugden ANV 50
4 lost · BBC Sound, Twin Arms
Against the Twin Arms brief, the Sugden ANV 50 keeps the slot decisively.
On its own merits the Audio Note OTO SE Phono Signature (35th Anniversary) is the weaker integrated amplifier for that brief.
an absolute wonder at creating tension and dramaHi-Fi+, Dickinson, 2020
Leema Hydra II
4 lost · Cavity-Native, Characterful, Romantic
Against the Cavity-Native brief, the Leema Hydra II keeps the slot decisively.
Audiolab 9000P
4 lost · Characterful, PRaT, Romantic, Silent Path
No completion of this shape fits that slot's budget.
NVA S300 Stereo (Artisan)
4 lost · Artisan, Cavity-Native, Intimate, Reference
Against the Intimate brief, the NVA S300 Stereo (Artisan) keeps the slot decisively.
Icon Audio Stereo 30 SE (KT150)
3 lost · Vocals-First
Against the Vocals-First brief, the Icon Audio Stereo 30 SE (KT150) keeps the slot by a whisker.
On its own merits the Audio Note OTO SE Phono Signature (35th Anniversary) is the weaker integrated amplifier for that brief.
Audio Note P1 SE
3 lost · Intimate, Silent Path
Against the Silent Path brief, the Audio Note P1 SE keeps the slot decisively.
EAR Yoshino V12
3 lost · BBC Sound, Vocals-First
Against the BBC Sound brief, the EAR Yoshino V12 keeps the slot decisively.
With the Falcon LS3/5a Gold Badge, the pairing gives up most on timing and drive.
On its own merits the Audio Note OTO SE Phono Signature (35th Anniversary) is the weaker integrated amplifier for that brief.
Exposure XM9 Biamp 2x2 (4 units)
3 lost · Artisan, PRaT, Reference
Against the Artisan brief, the Exposure XM9 Biamp 2x2 (4 units) keeps the slot decisively.
EAR Yoshino 890
2 lost · Intimate
Against the Intimate brief, the EAR Yoshino 890 keeps the slot decisively.
Chord ULTIMA 6
1 lost · Cavity-Native
Against the Cavity-Native brief, the Chord ULTIMA 6 keeps the slot decisively.
Longdog Audio P6100M (pair)
1 lost · Anchored
Against the Anchored brief, the Longdog Audio P6100M (pair) keeps the slot decisively.
Exposure 3510
1 lost · Twin Arms
Against the Twin Arms brief, the Exposure 3510 keeps the slot decisively.
On its own merits the Audio Note OTO SE Phono Signature (35th Anniversary) is the weaker integrated amplifier for that brief.
It sits well above the share of the budget this brief aims at the integrated amplifier position.
Sugden A21 Signature
1 lost · BBC Sound
Against the BBC Sound brief, the Sugden A21 Signature keeps the slot decisively.
With the Harbeth P3ESR XD2, the pairing gives up most on timing and drive.
On its own merits the Audio Note OTO SE Phono Signature (35th Anniversary) is the weaker integrated amplifier for that brief.
Quad Artera Stereo
1 lost · Silent Path
Against the Silent Path brief, the Quad Artera Stereo keeps the slot decisively.
What the reviewers said
OTO SE 35th Anniversary with phono Audio Note OTO SE Phono Signature 35th Anniversary· Harmonic texture
preternaturally quiet Positive Feedback 2020 (std Phono SE Sig)· Low-level noise floor
natural, articulate... pitch definition Positive Feedback 2020 (variant)· Bass control
rich, naturally warm Positive Feedback 2020 (variant)· Tonal body
very resolving... musical Positive Feedback 2020 (variant)· Micro-dynamic resolution
How it scores
Voice
- Tonal body 74 from listening evidence
- Harmonic texture 72 from listening evidence
Bass
- Bass control 74 from listening evidence
- Physical impact 56 from specification
- Bass extension 56 from specification
LowerVolume
- Low-level noise floor 78 from listening evidence
- Micro-dynamic resolution 74 from listening evidence
- Tonal consistency 76 from specification
Specifications
| power 8ohm w | 12.0 |
|---|---|
| power 4ohm w | 12.0 |
| power class | A |
| damping factor | 6.0 |
| line inputs | 4 |
| line input sensitivity mv | 300.0 |
| line input impedance kohm | 100.0 |
| has phono | True |
| phono mm | True |
| phono mc | False |
| phono mm gain db | 40 |
| phono mm load | 47kΩ + 100pF |
| pre out | False |
| pre power separable | none |
| internal bass management | none |
| headphone out | False |
| frequency response hz | 20/20000 |
| dimensions mm | 440/140/410 |
| weight kg | 17.0 |
| power consumption w | 100 |
| integrated dac | False |
| digital inputs | 0 |
| notes |