Audio T Verdict
The Audio Note IO I is a specialist low-output moving-coil cartridge whose 0.04mV output and 1O internal impedance demand careful electrical and mechanical matching.
Its construction combines a tapered titanium cantilever, AN Type 1 diamond, AlNiCo magnet and continuous 99.99 per cent pure silver coil wire extending to the output terminals.
It is not suitable for a conventional moving-magnet input or most general-purpose moving-coil stages without additional gain. Correct tonearm setup and a properly matched step-up transformer are fundamental parts of the complete installation.
Audio Note IO I Low-Output Moving-Coil Cartridge
The Audio Note IO I is a very low-output moving-coil cartridge designed for use with a suitably matched step-up transformer and moving-magnet phono stage.
Its output is specified at just 0.04mV at 5cm/sec, with an internal impedance of 1O and a recommended matching impedance of approximately 3O to 4O.
The cartridge weighs 11g and has an optimum tracking force of 2.5g.
This Is an Exceptionally Low-Output Cartridge
The IO I produces substantially less voltage than a typical moving-coil cartridge. It should not be assumed to work correctly with a conventional active MC input.
Gain, noise performance and electrical loading must all be considered. Audio Note primarily intends the cartridge to work through a correctly matched low-impedance step-up transformer feeding a moving-magnet phono stage.
Moving-Coil Generator
In a moving-coil cartridge, the stylus and cantilever move small electrical coils within a fixed magnetic field.
The movement generated as the stylus traces the record groove is converted into a low-voltage electrical signal, which is then amplified by the phono system.
The low mass of the moving coil can provide an accurate mechanical response, but the resulting electrical output is far smaller than that of a conventional moving-magnet cartridge.
Correct Phono Signal Path
Audio Note specifies a 3O to 4O matching impedance for the IO I.
A suitable low-impedance step-up transformer raises the cartridge's voltage without using powered amplification. Its output then connects to a conventional moving-magnet phono-stage input.
Recommended Signal Path
- Audio Note IO I cartridge
- Tonearm cable
- 3O to 4O step-up transformer input
- Step-up transformer output
- Moving-magnet phono-stage input
- Amplifier line-level input
Avoid Connecting To
- A normal amplifier line input
- A moving-magnet input without a transformer
- An unsuitable general-purpose MC input
- A step-up transformer with incorrect loading
- An active MC input after a step-up transformer
- A phono stage without sufficient gain
0.04mV Output Voltage
The IO I produces 0.04mV at the manufacturer's specified groove velocity of 5cm/sec.
This extremely small signal requires substantial low-noise gain before it reaches a normal amplifier line input.
A phono system designed around a more conventional moving-coil output may produce insufficient volume or excessive background noise when used with the IO I.
Electrical compatibility should be assessed before the cartridge is fitted rather than after installation.
1O Internal Impedance
The cartridge has a published internal impedance of 1O.
Audio Note recommends a matching impedance of approximately three to four times the cartridge's internal impedance, resulting in the specified 3O to 4O range.
This electrical relationship is a key part of choosing the correct step-up transformer version.
Matching with an Audio Note Step-Up Transformer
Low-impedance Audio Note step-up transformers are designed specifically for cartridges such as the IO I.
The
Audio Note AN-S5/L
has a fixed 3O input and provides one natural matching option.
The transformer output must connect to a suitable moving-magnet phono stage, normally with a 47kO input. It should not connect to an active moving-coil input.
The Step-Up Transformer Does Not Replace a Phono Stage
A passive step-up transformer raises the cartridge voltage but does not provide complete phono gain or RIAA equalisation.
Its output must feed a suitable moving-magnet phono input before the signal reaches a normal amplifier line input.
Can It Use an Active Moving-Coil Stage?
A specialist active phono stage may be usable if it is expressly designed for a 0.04mV source, a 1O cartridge and the required electrical loading.
Many conventional MC stages do not provide enough quiet gain for such a low output and may not offer the required 3O to 4O load.
Compatibility should be confirmed with the phono-stage manufacturer and Audio T rather than inferred from the presence of an MC setting.
99.99 Per Cent Pure Silver Coil Wire
Audio Note winds the IO I coils with custom 99.99 per cent pure silver wire.
The coil wire continues directly to the cartridge output terminals, reducing the number of separate internal connections in the signal path.
This is particularly relevant because the cartridge generates such a small electrical signal.
AlNiCo Magnetic Circuit
The IO I uses an AlNiCo permanent magnet and a soft-iron pole piece in its generator assembly.
Audio Note also uses AlNiCo for the IO II, while other IO models employ different magnetic arrangements and materials.
The IO I does not require the separate field-coil power supply used by the flagship IO Limited.
Tapered Titanium Cantilever
The cantilever is manufactured from a tapered titanium tube.
Audio Note uses a comparatively long, rigid cantilever intended to transfer the stylus movement to the coil assembly while limiting unwanted flexing.
The titanium cantilever is a permanent part of the moving-coil assembly and must be protected from sideways pressure or accidental impact.
AN Type 1 Diamond Stylus
Audio Note's current specification identifies an AN Type 1 diamond stylus for the IO I.
The solid diamond is shaped as a natural octagon and is mechanically pinched into the titanium cantilever before being secured with adhesive.
The stylus, cantilever and moving coils form an integrated precision assembly rather than a removable user-replaceable stylus module.
Current Stylus Specification
The current manufacturer specification lists an AN Type 1 diamond for the IO I.
The stylus is not interchangeable in the manner of an Audio Note IQ moving-magnet stylus. Inspection, repair or refurbishment should be arranged through Audio T or an authorised Audio Note service route.
Butyl Rubber Cantilever Damping
A precision butyl-rubber damper controls movement of the cantilever and coil assembly.
Audio Note adjusts the suspension tension during cartridge manufacture and testing.
The damper setting is not an owner adjustment and should not be disturbed during installation or cleaning.
Rigid Aluminium Body Construction
The IO I uses aircraft-grade aluminium side cheeks and a large mounting surface intended to provide rigid mechanical contact with the tonearm head shell.
The body can accommodate up to six fixing bolts where the tonearm head shell and mounting arrangement permit.
The number, length and position of fixings should be determined by the tonearm and cartridge instructions. Fasteners should never contact or obstruct the internal cartridge mechanism.
11g Cartridge Weight
The IO I weighs 11g before mounting hardware is added.
The tonearm must provide sufficient counterweight capacity to balance the combined cartridge and fixing-bolt weight while still applying the required tracking force.
Some arms may require a different counterweight, supplementary weight or cartridge mounting arrangement.
Low Compliance and Tonearm Matching
Audio Note specifies typical horizontal and vertical compliance of 5 to 10µm/mN.
Cartridge compliance, cartridge weight and tonearm effective mass together determine the low-frequency arm and cartridge resonance.
The IO I's relatively low compliance and 11g weight mean that compatibility should be calculated or confirmed for the intended tonearm rather than assumed from physical fit alone.
The
Audio Note Arm Three/II
can be considered as part of an Audio Note vinyl system, subject to complete turntable and setup compatibility.
2.5g Optimum Tracking Force
Audio Note specifies an operating range of 2g to 3g, with 2.5g identified as the optimum tracking force.
Tracking force should be measured at record height using an accurate stylus-force gauge after the tonearm has been balanced.
Too little force can cause mistracking and groove damage, while excessive force places unnecessary load on the cartridge suspension and record.
Use 2.5g as the Setup Target
The published 2g to 3g range is not an invitation to select an arbitrary value. Audio Note identifies 2.5g as the optimum starting point.
Final setup should be verified after alignment, arm height and anti-skating have been adjusted.
Cartridge Alignment
Correct overhang and offset angle minimise tracking error as the stylus travels across the record.
Alignment should be performed with a protractor appropriate for the tonearm's mounting distance and chosen alignment geometry.
The cartridge body and stylus assembly should be handled carefully throughout the procedure. Pressure must never be applied to the cantilever.
Arm Height, Azimuth and Anti-Skating
Tonearm height establishes the initial relationship between the cartridge body, cantilever and record surface.
Azimuth should place the stylus correctly in the groove when viewed from the front, while anti-skating should be adjusted in accordance with the tonearm manufacturer's guidance.
These settings interact with tracking force and alignment, so the complete installation should be checked after any adjustment.
Professional Installation Recommended
The IO I combines high value, very low electrical output and a delicate non-replaceable stylus assembly.
Professional installation is strongly recommended to confirm tonearm compatibility, cartridge alignment, fixing security, tracking force, arm height and phono-stage matching.
Audio T can also check for hum, grounding problems, channel identification and correct step-up transformer connection.
Stylus and Record Care
Dust should be removed with a suitable stylus brush, moving from the rear of the cartridge towards the stylus tip.
Do not brush from front to back or apply sideways force to the cantilever. Cleaning fluids should only be used when specifically approved for the cartridge and its adhesive system.
Clean records reduce accumulated stylus debris and unnecessary wear. The cartridge should be protected from impact whenever the turntable is not in use.
Red or Blue Side Cheeks
The Audio Note IO I is available with red or blue aircraft-grade aluminium side cheeks.
The Audio T product options currently identify these as blue and red versions.
The generator, silver coil wiring, titanium cantilever and AN Type 1 diamond remain the same, so the colour choice is primarily visual.
Key Features
- Very low-output moving-coil cartridge
- 0.04mV output at 5cm/sec
- 1O internal impedance
- Recommended matching impedance of 3O to 4O
- 99.99 per cent pure silver coil wire
- Coil wire extends directly to the output terminals
- AlNiCo permanent magnet
- Soft-iron pole piece
- Tapered titanium cantilever
- AN Type 1 solid diamond stylus
- Precision butyl-rubber damper
- Aircraft-grade aluminium side cheeks
- Large cartridge mounting surface
- Provision for up to six mounting bolts
- 11g cartridge weight
- 2g to 3g tracking-force range
- 2.5g optimum tracking force
- Red or blue finish options
Frequently Asked Questions
Can the IO I connect to a moving-magnet phono input?
Not directly. Its 0.04mV output is too low. A correctly matched step-up transformer is required before the moving-magnet phono input.
Can it connect directly to an active moving-coil input?
Only if the phono stage is specifically designed for a 0.04mV cartridge with 1O internal impedance and the required loading. Many conventional MC inputs are unsuitable.
Which step-up transformer impedance is required?
Audio Note specifies a matching impedance of approximately 3O to 4O. Its low-impedance transformer versions are intended for this requirement.
Does a step-up transformer replace the phono stage?
No. The transformer output must still connect to a moving-magnet phono stage providing gain and RIAA equalisation.
What stylus does the IO I use?
The current manufacturer specification identifies an Audio Note Type 1 solid diamond.
Is the stylus user replaceable?
No. The stylus, cantilever and moving coils form an integrated assembly. Inspection or refurbishment should be arranged through an authorised service route.
What is the recommended tracking force?
Audio Note specifies a range of 2g to 3g and identifies 2.5g as the optimum setting.
Will it fit any tonearm?
Not necessarily. The arm must accommodate its 11g weight, mounting arrangement, low compliance and required tracking force.
What does the compliance specification mean?
Compliance describes the flexibility of the cartridge suspension. Together with cartridge weight and tonearm effective mass, it affects the arm and cartridge resonance.
Should the cartridge be professionally installed?
Yes. Professional installation is strongly recommended because alignment, tracking force, tonearm matching and phono-system loading are all critical.
How should the stylus be cleaned?
Use a suitable stylus brush from the rear towards the stylus tip. Never brush backwards or apply sideways pressure to the cantilever.
What is the difference between the red and blue versions?
The colour applies to the aircraft-grade aluminium side cheeks. The internal generator, cantilever, stylus and electrical specification remain the same.
Why Buy From Audio T?
- Experienced Audio Note vinyl-system specialists
- Tonearm effective-mass and cartridge compatibility checks
- Step-up transformer impedance matching
- Moving-magnet phono-stage compatibility advice
- Professional cartridge mounting and alignment
- Tracking force, arm height and anti-skating adjustment
- Grounding and hum-reduction assistance
- Ongoing cartridge inspection and servicing support
Contact your nearest Audio T store
to discuss tonearm compatibility, step-up transformer matching, installation and demonstration options.