Monoblocks
above typical
Among the 25 monoblockss 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.
EAR 509 — 100W mono valve power amplifier; founding EAR product (1976) still in continuous production for 30+ years. Designed by Tim de Paravicini originally for professional studio use; signature "balanced bridge mode" output transformer topology with no feedback on secondary. Self-biasing with dial-set bias adjustment and LED indicators (intuitive user-replaceable valve maintenance). Hand-built Cambridgeshire UK.
Two output tube generations exist: mk1 used 13E1 industrial pentodes (specialty tube; harder to source NOS); mk2 onwards use KT88. Mk2 recommended for new buyers due to current valve availability. 25th Anniversary Jubilee Edition has higher-grade chassis finish.
EAR official: "high-performance monoblock amplifier designed for professional use, delivering 100W per channel into 4, 8, or 16 ohms. With a transformer secondary that uses no feedback, these amplifiers are stable under any load."
Each pair is valve-matched at the factory: "We analyse a wide selection of valves to find the most suitable match before pairing each EAR 509 for stereo." Pair shipping with serialised matched valves.
CRITICAL ELECTRICAL FIT: 25kΩ input + 100W/8Ω + DF 20. Speaker matching less critical than 890 due to higher DF (20 vs 15) and stable no-feedback transformer secondary. Multi-tap output (4/8/16Ω) — match to nominal speaker impedance.
Stereophile Class A historic. Robust studio-use lineage gives MTBF figures unusual in valve gear (TdP-trained service available 30+ years post-purchase).
Assessed against 14 rivals across the sixty systems: it takes the slot in none of its 44 head-to-heads.
The dimension the engine names as the weakest link, counted across every head-to-head it lost.
13 lost · Anchored, Artisan, Characterful, PRaT, Reference, Romantic
Against the Anchored brief, the Longdog Audio P6100M Biamp 2x2 (4 units) keeps the slot decisively.
With the Emmae Reginae (custom), the pairing gives up most on bass control.
On its own merits the EAR Yoshino 509 (pair) is the weaker pair of monoblocks for that brief.
rhythmically tautPROXY: EAR 890 (Stereophile, valve power)
4 lost · BBC Sound, Twin Arms
Against the Twin Arms brief, the Sugden ANV 50 keeps the slot decisively.
4 lost · Characterful, PRaT, Romantic, Silent Path
Against the Characterful brief, the Audiolab 9000P keeps the slot decisively.
With the Audiolab 9000Q, the pairing gives up most on vocal presence.
With the Neat Petite Classic, the pairing gives up most on bass control.
On its own merits the EAR Yoshino 509 (pair) is the weaker pair of monoblocks for that brief.
deep, tight, controlled bass without overbearingHiFiMART user review + Audio Tailor review
3 lost · Vocals-First
No completion of this shape fits that slot's budget.
3 lost · Intimate, Silent Path
Against the Silent Path brief, the Audio Note P1 SE keeps the slot by a whisker.
With the Emmae Reginae (custom), the pairing gives up most on low-level clarity.
With the Music First Audio Baby Reference V2, the pairing gains most on quietness at rest.
On its own merits the EAR Yoshino 509 (pair) is the weaker pair of monoblocks for that brief.
EAR 509 monoblock pair, classic Tim de ParaviciniEAR Yoshino 509 monoblock + Stereophile heritage
3 lost · BBC Sound, Vocals-First
No completion of this shape fits that slot's budget.
3 lost · Artisan, Intimate, Reference
Against the Intimate brief, the NVA S300 Stereo (Artisan) keeps the slot decisively.
With the NVA P50SA MKII, the pairing gives up most on vocal presence.
On its own merits the EAR Yoshino 509 (pair) is the stronger pair of monoblocks — but it loses here on fit: the pairing with the NVA P50SA MKII gives up vocal presence under the Intimate weighting.
3 lost · Artisan, PRaT, Reference
Against the Artisan brief, the Exposure XM9 Biamp 2x2 (4 units) keeps the slot decisively.
With the Emmae Reginae (custom), the pairing gives up most on timing and drive.
With the Exposure 3510 Preamplifier, the pairing gives up most on vocal presence.
On its own merits the EAR Yoshino 509 (pair) is the weaker pair of monoblocks for that brief.
rhythmically tautPROXY: EAR 890 (Stereophile, valve power)
2 lost · Intimate
Against the Intimate brief, the EAR Yoshino 890 keeps the slot decisively.
With the EAR Yoshino 868L (Line), the pairing gives up most on low-level clarity.
With the Emmae Reginae (custom), the pairing gives up most on low-level clarity.
On its own merits the EAR Yoshino 509 (pair) is the weaker pair of monoblocks for that brief.
2 lost · Characterful, Romantic
Against the Characterful brief, the Leema Hydra II keeps the slot decisively.
With the Emmae Reginae (custom), the pairing gives up most on bass control.
With the Leema Neutron, the pairing gives up most on vocal presence.
On its own merits the EAR Yoshino 509 (pair) is the weaker pair of monoblocks for that brief.
Hydra II reference Leema stereo power ampLeema Hydra II positioning
1 lost · Anchored
Against the Anchored brief, the Longdog Audio P6100M (pair) keeps the slot decisively.
With the Neat Petite Classic, the pairing gives up most on bass control.
With the NVA P50SA MKII, the pairing gives up most on depth of bass.
On its own merits the EAR Yoshino 509 (pair) is the weaker pair of monoblocks for that brief.
1 lost · Twin Arms
No completion of this shape fits that slot's budget.
1 lost · BBC Sound
No completion of this shape fits that slot's budget.
1 lost · Silent Path
Against the Silent Path brief, the Quad Artera Stereo keeps the slot by a whisker.
On its own merits the EAR Yoshino 509 (pair) is the weaker pair of monoblocks for that brief.
EAR 509 monoblock pair, classic Tim de Paravicini EAR Yoshino 509 monoblock + Stereophile heritage· Harmonic texture
ripe and sumptuous... carnal delight SoundStage! Ultra (Thorpe) 2024 (opinion column)· Tonal body
rhythmically taut PROXY: EAR 890 (Stereophile, valve power)· Dynamic coherence
clean transient decay PROXY: EAR 890· Transient attack
| is monoblock | True |
|---|---|
| is balanced internal | True |
| is dual mono | False |
| power class | AB |
| power 8ohm w | 100.0 |
| power 4ohm w | 100.0 |
| damping factor | 20.0 |
| accepts rca | True |
| accepts xlr | True |
| accepts din | False |
| input impedance rca kohm | 25.0 |
| input impedance xlr kohm | 25.0 |
| input sensitivity rca mv | 800.0 |
| input sensitivity xlr mv | 800.0 |
| speaker terminal type | binding post |
| speaker terminal count | 1 |
| gain db | 30.0 |
| snr db | 94.0 |
| thd pct | 0.25 |
| frequency response hz | 3/30000 |
| dimensions mm | 300/165/230 |
| weight kg | 17.0 |
| power consumption w | 180 |
| sold as pair | True |
| notes |