Zesto Audio EROS 500 Select, 250 Watt Class A Monoblocks
Commanding yet remarkably revealing, the Eros 500 Select marries 250-watt Class A power with a neutral, transparent window into every source. Positive Feedback found its preferred KT150 setting delivered expansive, deeply layered imaging, effortless dynamics and lifelike musical flow. Selectable bias and broad tube compatibility add welcome system-tuning flexibility to this formidable all-tube monoblock.
WATT RECOMMENDS
Save your favorites. Compare them anytime.
Create a free HiFi Hub account to save products to your Wishlist and compare your favorites side by side.
Deliciously Crispy
Sound Quality
96/100
Build Quality
91/100
Value for Money
85/100
Pros
Exceptional transparency, neutrality and natural musical realism reveal upstream components and recordings with unusual clarity.
Middle-bias KT150 operation delivers immense dynamic headroom, a black background and a wall-to-wall, deeply dimensional soundstage.
Selectable bias and compatibility with KT88, KT120, KT150 and KT170 tubes provide meaningful flexibility for speaker matching and future tube availability.
Cons
The lower KT150 bias setting was reported to sound warmer and less resolved, with vaguer bass, reduced slam and a smaller soundstage.
The higher KT150 bias setting added punch but shortened soundstage depth versus the preferred middle setting.
WATT RECOMMENDS
Save your favorites. Compare them anytime.
Create a free HiFi Hub account to save products to your Wishlist and compare your favorites side by side.
What Reviewers Are Saying
SOUND QUALITY PERFORMANCE 96/100
Reviewers describe an unusually transparent, neutral and natural presentation allied to immense Class A authority. The preferred middle-bias setting delivers a vast, deeply layered stage and exceptionally unconstrained musical flow, though the alternate bias settings introduce identifiable trade-offs.
Transparency Resolution
96/100
Robert H. Levi repeatedly describes a fully transparent window onto upstream components, with a level of neutrality and source clarity he had not previously heard. Fine textural information and instrumental realism are especially praised, although he found the lower KT150 bias setting warmer and less resolved.
Tonal Balance Musicality
95/100
The Eros 500 is characterized as neutral, realistic and natural, with music allowed to flow without apparent amplifier coloration. Levi calls its musical realism exceptional, while the selectable bias offers a warmer, softer alternative for listeners who prefer that balance.
Dynamics
97/100
The preferred setting is credited with seemingly unlimited dynamic power, no audible strain at nightclub-like levels, and presentation scale beyond any amplifier Levi had experienced, including other tube designs. Its 250W Class A rating is said to behave more like a 500W amplifier, while the high-bias position adds punch that the reviewer did not consider necessary.
Soundstage Imaging
96/100
Levi reports a wall-to-wall, floor-to-ceiling stage with depth extending beyond the rear room boundary, set against a notably black background. Images are described as rounded, organic and lifelike, with more pronounced spatial cues; the higher-bias setting trades some of that depth for a more forward perspective.
Assessments of Build Quality, Usability, and Overall Propositions.
Build Quality
91/100
Reviewers praise the fit, finish and overall design as exceptional, and report trouble-free operation throughout the audition period. The monoblocks also provide transformer-balanced and single-ended inputs, 4- and 8-ohm taps, independent grounding switches, and selectable bias settings for KT88, KT120, KT150 and KT170 tubes.
Value for Money
85/100
At $35,000, the Eros 500 Select is positioned firmly among cost-no-object, high-powered amplifiers. One reviewer says it deserves an audition for shoppers already considering that class, but the reviews do not directly compare its price or value against competing amplifiers.
Reviews & Sources
Professional reviews and sources for this product's Watt'n Potatoes analysis.
Online Reviews & Mentions
YouTube Reviews
Forum Mentions
No forum mentions found yet
Specifications
- Watts per channel
- 250W Class A 150W Class A
- Power Tubes
- KT88, KT120, KT 150, KT170 KT88
- Auto Bias
- 3 position Bias select Switch 1 Bias setting
- Tube Watts per Channel
- KT88 = 150 WPC KT88 = 150 WPC
- Tube Watts per Channel
- KT120 = 150 WPC n/a
- Tube Watts per Channel
- KT150 = 250 WPC n/a
- Tube Watts per Channel
- KT170 = 250 WPC n/a
- Signal tubes
- 12AU7/ECC82 12AU7/ECC82
- Frequency response
- 20Hz to 30Hz 20Hz -50Hz
- Total Harmonic Distrotion
- ~ 0.22% at 1W into 8 Ohms ~ 0.8% at 1W into 8 Ohms
- Gain
- 27dB 29dB
- Noise level
- > 4 mV RMS into 8 Ohms > 5 mV RMS into 8 Ohms
- Custom Toroid
- 15 lbs 10 lbs
- Power Supply
- New custom design choke based design
- Power comsuption rated output
- 756 watts 360 watts
- Weight
- 79 lbs. 59 lbs.
- Shipping weight
- 96 lbs 79 lbs
- Mains fuse
- 10 Amp Slow Blow 6.3 Amp Slow Blow
- Output Speaker fuses
- 10 Amp & 7 Amp 8 Amp and 5 Amp
- Output Taps
- 4 and 8 Ohm taps 4 and 8 Ohm taps
- Inputs
- SE & Transformer balanced SE & Transformer balanced
- Output Design
- Push-Pull, Ultra-Linear Push-Pull, Ultra-Linear
- Grounding
- Independent Grd. Swtches Independent Grd. Swtches
- Design
- No Negitive feedback No Negitive feedback
Manufacturer's Description — Zesto Audio
Eros 500 Select Key Features
- Sextet of KT150 output tubes create 250 watts of Class A musical power.
- Class A power is fast for a more lively, immediate response to your music
- The Bias Select switch is engineered with 3 perfect auto bias settings for KT88, KT120, KT150 and KT170 output tubes.
- The Bias Select switch is safe and easy to use, change on the “Fly” so you can hear the difference.
- 4 Ohm and 8 Ohm taps gives you options for your speaker preference. 4 Ohm may give you more base and the 8 Ohm tap may sound more open.
- The optimized frequency response provides the best musical range to benefit the natural harmonic structure of the instruments
- The SpeakOn cable connector provides most reliable hookup for your subwoofer.
- Transformer balanced true differential XLR input offers noise cancelling and rejection, as well as providing ground isolation from your preamp.
- Should you need to eliminate a hum? The Eros 500 has a XLR ground switch installed for your safety. This eliminates the dangerous temptation to lift the ground from the mains.
- The combo Push-Pull and Ultra Linear circuit design provides lower distortion, more power, and a better performance out of your tubes.
- No Negative Feedback in the circuit design provides better dynamic range because it doesn’t compress the music.
- Non-inverting polarity retains the same phase as the input (so your trumpets blow and don’t suck)
- Large Custom Toroid power transformer provides plenty of available power.
- Toroids have lower noise because they concentrate the magnetic field and are very efficient in the 50 to 60Hz mains range.
- Choice of high quality gold plated Single Ended RCA or Balanced XLR connectors to suit your needs or cable preferences
- Gold pin sockets are more reliable because gold doesn’t oxidize when it heat cycles.
- An extensive grounding scheme is designed into the power supply, wiring and all tube circuitry.
- Elegantly designed, heavy duty 14 & 16 gauge zinc plated, fully grounded steel enclosure isolates external noise and vibration.
- All fuses are easily accessible
- It’s ready to enjoy with 50 hours of factory burn in on all circuits and vacuum tubes.
- Each unit is hand built “Made in the USA”
Verified Dealers
Online Dealers
All Dealers
Zoom out the map to see more dealers
Authorized dealers for Zesto Audio EROS 500 Select, 250 Watt Class A Monoblocks
- A/V Solutions — in-store — Pleasanton, California, United States (website)
- Absolute Audio - Canada — in-store — Calgary, Alberta, Canada (website)
- Altitudo Audio — online and in-store — Winnipeg, Manitoba, Canada (website)
- Audio Gallery — online and in-store — Las Rozas de Madrid, Comunidad de Madrid, Spain (website)
- Audio Philosophy — in-store — Baton Rouge, Louisiana, United States (website)
- BELHIFI — online and in-store — Meise, Vlaams Gewest, Belgium (website)
- Choice Audio — online and in-store — White Bear Lake, Minnesota, United States (website)
- Deep Dive Audio — in-store — Palm Bay, Florida, United States (website)
- East End Hi-Fi — online and in-store — Brookhaven, New York, United States (website)
- Editors Choice HiFi — in-store — Paola, Kansas, United States (website)
and 10 more verified dealers