Moonriver 505 Hybrid phono stage

                                                                             De-emphasis EQ

The de-emphasis circuit is passive, the best possible approach for extreme flat frequency response without interference with the other stages. The EQ circuits involve 2 equalisation curves, a RIAA and a DECCA or COLUMBIA curve for 78rpm records. Both EQ circuits are formed using a minimalistic approach with very few, extremely low tolerance, audiophile quality components.

The 505 Hybrid phono stage

The Moonriver Audio 505 phono stage meets all the needs of any demanding audiophile  who loves vinyl records, both now and in the future. Designed with audiophiles, record collectors and vinyl freaks in mind, it boasts 4 inputs for all your turntables, tone-arms and cartridges. It also supports every possible adjustment on the fly with dedicated knobs and switches to ideally match your MC or MM cartridge.

The unique, adjustment feature of the Moonriver 505 hybrid phono stage allows “on the fly” listening tests with various adjustments without the need to switch off, remove the cover, switch on again and wait to warm it up.

The hybrid design combines  the use of ICs and discrete solid-state circuits  to form  an ideal, high performance and ultra low noise circuit. While the IC op amps offer very low noise levels, a discrete circuit offers lifelike drive and dynamics which is impossible to get from IC op-amps.

As for the sonic signature of all Moonriver Audio products, we strive to balance the fine line between musicality & resolution. The soul of the music is in the midrange, this is where most of the emotion, the passion, the joie de vivre is contained.

On a technical level, it’s within the frequency band of 200 – 4,000Hz. Without a solid foundation underneath the midrange, the music sounds thin & brittle and often un-involving. If the brain perceives that the sound is artificial, then it’s difficult to be swept away by the message contained within the music.

Similarly, accurate timbre reproduction is essential. A New York Steinway does have noticeable sonic differences from a Hamburg Steinway, while a Guarneri violin sounds distinct from a Stradivarius. To capture all those nuances, the loudspeakers & electronics need to act in unison, neither obscuring, nor exaggerating detail.

The sound and the level of performance of the Moonriver 505 phono stage is hard to describe and it must be heard to be believed.

Layout highlights

The layout of the PCB is designed with 3 principles in mind: Isolation in-between noise sources and sensitive audio signal as the transformer and gain stages, a minimalistic approach with less components as possible in the signal and the shortest signal path possible. Moonriver 505 is using double shielding, one for the transformer and one for the active gain circuits. This approach eliminates the need for an external transformer and the disadvantages of it.

Made In Sweden

Our products are designed and made in Sweden. We hand-assemble each unit, a painstaking but precise procedure. Through a global inventory that is constantly updated, it is our sophisticated research, efficient development and extensive listening tests -the fun part- that lead us to select the right component for a no-compromise audiophile sound.

We also care for sustainability as well as for reliability. Moonriver products are covered by a 3-year warranty and are designed to last for decades without any need of maintenance.


  • Inputs: 4
  • Minimum gain: 34dB
  • Maximum gain: 72 dB
  • Capacitance values: 100, 220, 330, 470, 680pF
  • MC load impedance: 10, 47, 100, 470, 1KΩ and custom
  • MM load impedance: 22K, 47K, 75KΩ
  • De-emphasis curve: RIAA and Decca or Columbia
  • Stereo / Mono function
  • XLR and RCA inputs and outputs
  • Separate shielding for the transformer and gain stages
  • Auto mute function
  • Dimensions (mm): 430 (W) x 390 (D) x 135 (H)
  • Weight: 12 kg