Zesto Audio Andros Allasso Step Up Transformer



For the Ultimate Audio Connoisseur

“The most flexible Transformer ever.”

Bob Levi

President LAOC Audio Society 2017

Out of stock

What to Know About the Allasso Step Up Transformer
“You are now free to roam the cartridge planet”!

 3 Reasons You May Want a Step Up Transformer

  • You own a very low or very high output MC cartridge.
  • Your cartridge Loading/Gain is difficult to match on your current system.
  • You own more MC cartridges than MM and don’t want to buy another phonostage.

 Why You Need a Phonostage with a Step Up Transformer

A step up transformer does not have the RIAA curve equalizer. It doesn’t have power either. It goes between your turntable and your phono preamp.

Why a Phonostage is So Important

When a vinyl record is made the volume of the bass is reduced and the treble is increased. Otherwise, the bass would cut a groove too big for a stylus to read or for the music to fit the record. The phonostage reverses the process by taking the delicate signal from your cartridge and adjusting it so that the bass and treble are restored to their original volume. This common standard is known as the RIAA curve.

 Works on Any Phonostage

The Allasso is extremely versatile. It will work with any standard phonostage with a 47K MM input.

What Does a Step Up Transformer do?

It amplifies the delicate signal from your MC cartridge. An MM cartridge has a higher output than MC, so a MC needs to have a different step up ratios/gain to reach the same output.

 You Have Lots of Choices

You now have 40 options in Stereo and 40 options in Mono. It has enough adjustments to tailor it specifically to your cartridge or your next one. It’s just you and your ears, no math skills required.

 What is Allasso?

Allasso in Greek means to change or transform one thing to another.

Key Features

  • Allasso in Greek means to change or transform one thing to another.
  • It’s very versatile! Will accommodate the widest range of cartridges with 40 adjustments in Mono and 40 adjustments in Stereo.
  • It’s flexible to allow you to control the 4 step up ratios/gain settings, each having 10 load positions.
  • Designed with the highest quality MC transformers. They are quiet, with extra shielding and large enough with the multiple windings to handle even your high output cartridges.
  • It’s easy to use as all the adjustments are on the front, nothing is hidden inside.
  • All adjustments can be done on the “fly” without clicks or pops.
  • No math skills are required; it’s just you and your ears.
  • Enough adjustments to tailor it specifically to your cartridge or your next one.
  • Works with any standard MM input on any phonostage.
  • Designed to reduce “Hum” with 2 ground lift switches and 2 ground binding posts.
  • The Mono switch is specifically designed to reduce “Hum” in your Mono cartridge.
  • A unique feature of the Mono switch is it takes a single input and sends to both outputs.
  • It’s quiet, with extensive grounding in the circuit design and enclosure.
  • RCA connectors are high quality, Gold plated, recessed with an isolated ground.
  • Recessed RCA connectors are durable and will hold up to the typical Audiophile who loves to change their configuration.
  • Elegantly designed 18 gauge steel enclosure to help isolate the electronic “chatter” from nearby equipment.
  • Easy to read large type on back panel.
  • Each unit is hand built “Made in the USA”.


  • Frequency response -3dB at 0.4Hz to 100 KHz
  • Phase deviation 1° typical at 20Hz
  • Transformer noise 2 dB @ 20 Ω, 1.8 dB @ 12 Ω
  • Hum rejection                 125 dB @ 60 Hz
  • Voltage gain                 12dB, 16dB, 18dB and 22dB
  • Step up ratios                  1:4,    1:6,    1:8 and 1:12
  • MC load 40 positions in Mono, 40 positions in Stereo
  • Recommended output load 47KΩ @ 200pF (MM input)
  • Inputs Balanced and Single Ended MC
  • Outputs Single Ended
  • Grounds Independent input ground-lift switches
  • Grounds Two ground binding posts
  • Mono Takes one input and sends it to both outputs
  • Dimensions 4”H X 6”W X 8”L (101.6mm X 152.4mm X 203.2mm)
  • Weight 5lb (2.27Kg)
  • Shipping weight 8lb (3.63Kg)
  • Box dimensions 7”H X 9”W X 13”L (177.9mm X 228.6g X 330.2g)

Gain, Ratio and MC Loading Chart

Gain 12db 16db 18db 22db
Ratio 1:4 1:6 1:8 1:12
Position Ω Ω Ω Ω
1 175 77 45 20
2 260 115 65 30
3 360 160 90 40
4 500 220 130 60
5 670 300 175 80
6 870 390 230 100
7 1100 490 300 130
8 1485 660 400 180
9 1900 840 530 240
10 2375 1055 690 300


Michael Fremer | Stereophile | April 2019

…”Zesto’s George Counnas designed the Allasso (Greek for change or transform) to be both incredibly flexible and easy to use…

Best of all, rather than overload your primary and secondary coils, Counnas says that “it’s about the best sound, not the math.” He suggests beginning with the middle load position (5). I’d still use math to set the gain, based on the cartridge’s output, but you’re free to experiment while listening. Turning the Andros Allasso’s knobs produced no thumps or bumps through my speakers….”

Read the Full Article Here

Zesto Andros Allasso Step Up Transformer – Quite Possibly The Last SUT You’ll Ever Need!

Michael Corsentino | Positive Feedback | March 2019

“From my cold, dead hands!” - Charlton Heston, describing the only way anyone would be able  to take away his guns. I’ll state right up front that after a month in my reference system that’s exactly how I feel about the Zesto Andros Allasso step up transformer. In fact I was completely smitten with this little sonic marvel in a matter of hours, we bonded that quickly…”

Read the Full Article Here