Audio T Verdict
The Audio Note P1 SE 35th Anniversary is a compact Level 2 stereo power amplifier using four EL84 valves in a pure Class A parallel single-ended output stage.
Its redesigned BA C-core mains transformer, choke power supply and M6 lamination output transformers apply the engineering developed for the anniversary OTO SE to a dedicated power-amplifier chassis.
The P1 SE requires a separate preamplifier and careful loudspeaker matching, but provides a focused route into Audio Note's low-power single-ended amplifier range.
Audio Note P1 SE 35th Anniversary Stereo Power Amplifier
The Audio Note P1 SE is a pure Class A parallel single-ended stereo valve power amplifier using two EL84 output valves for each channel.
It delivers approximately 8 watts RMS per channel into suitable 4O or 8O loudspeaker loads.
The 35th Anniversary Edition shares its revised amplifier circuit, output-transformer development and choke power supply with the current OTO SE integrated-amplifier range.
This Is the Current P1 SE 35th Anniversary Edition
The current amplifier has a different specification from the discontinued P1 SE previously described on this Audio T page.
It is rated at 8 watts per channel, has a 220mV input sensitivity, weighs 15kg and has a maximum power consumption of 125W.
The discontinued model's 10-watt output, 430mV sensitivity, 17kg weight and 90W consumption should not be used for the anniversary amplifier.
A Dedicated Stereo Power Amplifier
The P1 SE contains the power-amplifier stages required to drive a pair of compatible passive loudspeakers.
It does not contain source selection, a conventional listening-level control, a phono stage, digital inputs or network streaming.
For normal operation, it should be connected to a suitable line-level preamplifier.
What the P1 SE Includes
- Stereo valve power amplification
- Pure Class A operation
- Parallel single-ended EL84 output stage
- 4O and 8O loudspeaker connections
- BA C-core mains transformer
- Redesigned choke power supply
What It Requires
- Separate preamplifier or safe variable-level source
- Compatible passive loudspeakers
- Correct 4O or 8O output connection
- Suitable interconnect and speaker cables
- Strong, ventilated equipment support
- Careful system-gain assessment
Audio Note Level 2
Audio Note classifies the current P1 SE as a Level 2 amplifier.
Its defining criteria include pure Class A single-ended pentode operation and the selection of components and materials appropriate to this position in Audio Note's amplifier range.
The Level designation refers to Audio Note's internal product hierarchy and should not be interpreted as a conventional measurement of output power.
Parallel Single-Ended EL84 Output Stage
The P1 SE uses four EL84 output valves, with two valves operating in parallel for each channel.
Both valves in each channel handle the complete waveform rather than dividing it between opposing halves of a push-pull output stage.
The P1 SE is therefore electrically different from the separately available P1 PP, which uses a push-pull circuit.
Approximately 8 Watts Per Channel
Audio Note specifies a maximum output of 8 watts RMS per channel into suitable 4O or 8O loudspeaker loads.
This can provide appropriate listening levels with an efficient and electrically compatible loudspeaker.
It is not designed to drive every loudspeaker regardless of sensitivity, impedance behaviour, room size or required playback level.
Loudspeaker Matching Is Essential
Loudspeaker sensitivity is an important starting point, but impedance, crossover behaviour, listening distance and room acoustics also affect compatibility.
An amplifier and loudspeaker demonstration is strongly recommended wherever possible.
Choosing the 4O or 8O Output
The P1 SE provides transformer-coupled outputs for suitable 4O and 8O loudspeaker loads.
Begin with the output corresponding to the loudspeaker manufacturer's nominal impedance recommendation.
Always switch the amplifier off before moving a speaker cable between the 4O and 8O connections.
Never Operate Without Loudspeakers Connected
A valve amplifier with transformer-coupled outputs should not be operated without a suitable loudspeaker load connected.
Check both speaker cables carefully before switching on and make certain that positive and negative conductors cannot touch one another.
Never connect, disconnect or change the loudspeaker wiring while the amplifier is operating.
Redesigned for the 35th Anniversary
The P1 SE shares its amplifier circuit with the OTO SE and has received the same central engineering revisions introduced for the OTO's 35th Anniversary.
These include revised output transformers, a new mains transformer, an in-house choke power supply and refinements to the amplifier circuit.
The result is a new current-production specification rather than a cosmetic anniversary update.
BA C-Core Mains Transformer
The anniversary P1 SE uses a custom Audio Note BA C-core mains transformer.
It is designed and wound in-house by Audio Note rather than selected from a generic transformer range.
The mains transformer forms part of the redesigned power supply and is matched to the amplifier's electrical requirements.
In-House Choke Power Supply
The current P1 SE power supply includes an Audio Note choke with revised operating time constants.
The choke is designed and manufactured in-house alongside the mains and output transformers.
This arrangement replaces the older power-supply description carried by the discontinued P1 SE listing.
M6 Lamination Output Transformers
The standard P1 SE uses custom Audio Note output transformers with M6 laminations.
These transformers were developed as part of the anniversary redesign and are manufactured by Audio Note.
They provide the required transformer coupling between the EL84 output stage and suitable 4O or 8O loudspeakers.
Standard and Seiryu Electrolytic Capacitors
Audio Note Standard and Seiryu electrolytic capacitors are used in critical circuit and power-supply positions.
These are custom Audio Note components rather than generic capacitors selected solely by their basic electrical values.
The current standard specification should not be confused with older P1 descriptions referring only to aluminium foil capacitors.
Audio Note Tantalum Resistors
Audio Note tantalum resistors are used in critical areas of the P1 SE circuit.
The separately available P1 SE Signature adds niobium resistors to selected positions.
Niobium resistors should therefore not be included in the standard P1 SE specification.
Six-Valve Complement
The P1 SE uses six valves in total.
- 4 x EL84: two parallel output valves per channel
- 2 x ECC83: input and driver circuit
The valve complement remains the same as the preceding P1 SE, although the surrounding power supply, transformers and circuit specification have changed.
Connecting a Preamplifier
A conventional system connects each source to a preamplifier, with the preamplifier's line output connected to the P1 SE.
The preamplifier provides source selection and controls the signal level sent to the power amplifier.
The
Audio Note M3 Phono Balanced CD Input
and
Audio Note M6 Phono
provide examples of Audio Note valve preamplifiers, although their gain and connection arrangements must be checked for the complete system.
Input Sensitivity and System Gain
The P1 SE requires 220mV at its line-level input to reach full rated output.
This relatively sensitive input means that the gain of the source and preamplifier must be considered carefully.
Excessive system gain can restrict useful volume adjustment to the lowest part of the preamplifier's control range.
Connecting a Variable-Output Source
A source with a properly engineered variable analogue output may be capable of driving the P1 SE without a conventional preamplifier.
The output must be genuinely variable and should provide safe muting and level control. A fixed-output CD player, DAC or streamer must not be connected directly without another means of controlling volume.
Always begin with the source muted or at its minimum output level.
Never Connect an Uncontrolled Fixed Output
Connecting a fixed-level source directly to a power amplifier can send an unexpectedly high signal to the loudspeakers as soon as playback begins.
Use a suitable preamplifier unless the source has a verified variable line output and dependable level control.
No Built-In Phono Stage
The P1 SE does not contain a moving-magnet or moving-coil phono stage.
A turntable must connect through a suitable external phono stage and preamplifier, or through a preamplifier with the required phono input.
Cartridge type, output and loading must be matched to the phono stage rather than to the P1 SE.
No DAC or Network Streaming
The P1 SE does not include digital inputs, a DAC, network streaming, USB audio or Bluetooth.
Digital source selection and conversion must take place before the signal reaches the preamplifier or variable line-level source.
The
Audio Note DAC 2.1x Signature
provides one possible digital-to-analogue source within a separate-component Audio Note system.
P1 SE Compared with the OTO SE
The P1 SE and OTO SE share the same central parallel single-ended EL84 power-amplifier circuit.
The OTO is an integrated amplifier with source selection and level control, while the P1 SE is a dedicated power amplifier intended to follow a separate preamplifier.
Customers requiring a single amplifier chassis with direct source control should consider an OTO configuration rather than the P1 SE.
P1 SE Compared with P1 SE Signature
The current P1 SE is available in standard and Signature versions.
Both share the same circuit topology, power output, valve complement, sensitivity, dimensions and principal power-supply design.
The Signature adds Audio Note niobium resistors in selected areas and replaces the standard M6 lamination output transformers with I HiB-core output transformers.
Standard P1 SE
- Standard and Seiryu electrolytic capacitors
- Tantalum resistors in critical areas
- BA C-core mains transformer
- In-house choke power supply
- M6 lamination output transformers
P1 SE Signature Adds
- Niobium resistors in selected areas
- I HiB-core output transformers
- Higher component specification
- Same 8-watt rated output
- Same six-valve complement
Matching Audio Note Loudspeakers
Audio Note's efficient loudspeaker designs provide natural candidates for demonstration with the P1 SE.
The
Audio Note AN-K/LX
has a published minimum amplifier-power requirement of 7 watts per channel.
The
Audio Note AN-J SPE Hemp
provides another possible system partner where its sensitivity and room interaction suit the installation.
Published minimum amplifier power is only a starting point. The complete combination should be assessed at the intended listening distance and playback level.
Room Size and Listening Level
The usable output of an 8-watt amplifier depends on loudspeaker sensitivity, listening distance and the acoustic characteristics of the room.
A combination that provides sufficient headroom in a smaller room may reach its limits sooner in a large open-plan space.
Customers who listen at high levels or use recordings with wide dynamic peaks should discuss the required headroom during the demonstration.
Installation and Ventilation
Position the P1 SE on a strong, level equipment support with sufficient open space for heat to escape.
Do not install it in a sealed cupboard or place another component directly over its ventilation openings.
Allow additional rear clearance for interconnect, loudspeaker and mains cables.
Power-Up and Shutdown Sequence
When starting a system, switch on source components first, followed by the preamplifier and then the P1 SE.
When shutting down, switch off the P1 SE first, followed by the preamplifier and source components.
Reduce the preamplifier volume before switching the system on or off.
Valve Replacement
Switch the amplifier off, disconnect it from the mains and allow the valves and chassis to cool completely before touching a valve.
Replacement EL84 output valves should be suitable for the amplifier and supplied as an appropriately matched set.
Contact Audio T if there is any uncertainty about valve type, condition, matching or installation.
Anodised Aluminium or Black Acrylic Fascia
The standard fascia choices are anodised aluminium and black acrylic.
Audio Note also lists custom-colour fascias on request, subject to current production availability, cost and lead time.
The fascia choice is cosmetic and does not alter the amplifier's circuit or component specification.
Key Features
- P1 SE 35th Anniversary Edition
- Dedicated stereo valve power amplifier
- Audio Note Level 2 design
- Pure Class A operation
- Parallel single-ended EL84 output stage
- Approximately 8 watts RMS per channel
- 4O and 8O loudspeaker outputs
- Four EL84 output valves
- Two ECC83 input and driver valves
- Six-valve total complement
- 100kO line input impedance
- 220mV input sensitivity for full output
- BA C-core mains transformer
- In-house designed choke power supply
- M6 lamination output transformers
- Standard and Seiryu electrolytic capacitors
- Tantalum resistors in critical areas
- 15kg current published weight
- Anodised aluminium or black acrylic fascia
Frequently Asked Questions
Is this the current 35th Anniversary P1 SE?
Yes. This description and specification are for the redesigned P1 SE 35th Anniversary Edition.
Is the P1 SE an integrated amplifier?
No. It is a dedicated stereo power amplifier and normally requires a separate preamplifier.
Does it have a volume control?
A conventional user volume control is not part of the published power-amplifier specification. Listening level should be controlled by a suitable preamplifier or verified variable-output source.
How much power does it produce?
The current anniversary model is specified at 8 watts RMS per channel into suitable 4O or 8O loads.
Why does the previous specification say 10 watts?
Ten watts was the published output for the discontinued P1 SE. The redesigned 35th Anniversary Edition is specified at 8 watts per channel.
Will it drive any loudspeaker?
No. Its output requires a sufficiently efficient and electrically compatible loudspeaker.
Does it have a phono stage?
No. A turntable requires a suitable external phono stage and preamplifier, or a preamplifier with the correct phono input.
Can I connect a DAC or streamer directly?
Only if it has a properly engineered variable analogue output and dependable level control. A fixed-output source should connect through a preamplifier.
How many valves does it use?
It uses six valves: four EL84 output valves and two ECC83 input and driver valves.
What does the Signature version add?
The P1 SE Signature adds niobium resistors in selected positions and I HiB-core output transformers.
Can it be operated without loudspeakers connected?
No. A suitable loudspeaker load should be correctly connected before the amplifier is switched on.
Can it be bridged for mono operation?
Audio Note does not publish a bridged operating mode for the P1 SE. Do not combine its outputs or attempt to bridge the amplifier.
Should it be left switched on permanently?
No. Allow it to warm up before critical listening, but switch it off when it will not be used to avoid unnecessary heat, power consumption and valve wear.
What fascia finishes are available?
The standard choices are anodised aluminium and black acrylic. Custom colours may be available on request.
Why Buy From Audio T?
- Experienced Audio Note valve-amplifier specialists
- 35th Anniversary and discontinued-model identification
- Preamplifier and system-gain matching
- Low-power amplifier and loudspeaker matching
- 4O and 8O loudspeaker connection guidance
- Standard and Signature model comparisons
- Valve replacement and ownership advice
- Equipment-support and ventilation planning
- In-store demonstrations through participating branches
- Ongoing system setup and servicing support
Contact your local Audio T store
to confirm the current P1 SE version and arrange a demonstration with a suitable preamplifier and loudspeakers.
Audio Note's current public specification does not state the exact input connector, output-terminal layout or supplied interconnects.
Specifications may change as Audio Note continues product development. Current connections, supplied valves and accessories should be confirmed when ordering.