SET Technology

Single Ended Triode amplifiers pass the entire audio signal through one tube.  The signal then proceeds intact through a series of tubes until the desired amplification is achieved.  This is opposed to push pull amplifiers where the signal is split with the positive half of the music being handled by one tube and the negative by another tube (think sine wave).  Or Class D amplifiers that chop up and reconstruct the entire signal.

The advantages of SET amplifiers are that there is no distortion caused by putting the music back together and fewer parts in the audio path to color the music.  The disadvantage is limited power.

Swan Song Audio’s clean power technology, lack of “recombining the music distortion”, and lack of feedback brings out the music’s dynamics and details.   The “music your way” technology (first made available in MAD No. 6) allows immediate rich / lean adjustment to bring out the most of a recording.   Built in startup procedures, controls, and thoughtful execution extend tube life and amplifier reliability. 

When paired with speakers rated at 91dB, or more, the limited power output of a SET amplifier is no longer a problem.  91dBs means that the speaker puts out 91dBs of loudness with 1 watt at 1 meter.  Every 3dB increment increase in power means doubling the power.  This means that a 4 watt amplifier can put out 97dBs of volume with a 91dB speaker.  As a comparison a jack hammer puts out 100dBs of noise.

Combining Swan Song Audio SET amplifiers with efficient speakers brings the most out of a recording.

6SN7 3.3 watt amplifier
Back with DAC option
Separation of signal (left) and power (right)

6SN7 SET - $11,000

The 6SN7 tube is the father of all modern dual triode tubes.  After 68 years of production it is still highly sought after for it’s unequaled linearity and power handling.  That is why it continues to be the input tube of choice for countless high end tube amplifiers.

Now it enters a new role in life as the only tube needed in a zero feedback SET amplifier.  Working in parallel configuration, the 6SN7 amplifier puts out 3.3 watts a channel.  This allows the 6SN7 to power any speakers with a sensitivity greater than 96dB.  And with a gain of 12 it does so with very little input required.  A signal of 0.238 volts provides 1 watt into 8 ohms.

Keeping in line with the, “it's all you need” theme, the 6SN7 takes the meaning of the words "integrated tube amplifier" to a new level.  Configuration options include:

  • 10 ohm speaker output transformers
  • Volume control
  • Choice of:            
    • DAC input module with 1 analog input OR
    • 4 Analog inputs

Monitoring and adjustments are made easy with top mount:

  • AC voltage and power consumption monitoring
  • Bias monitoring and adjustment
  • Logo color adjustment
  • Resettable hour meter

Hearing the 6SN7 by itself is a revolutionary experience in linearity and increased detail for both the speaker and headphone listener.  Combining the 6SN7 with the "analog focused" DACP or single ended phono preamplifier module takes the listening experience to a whole new level while adding the convenience of fewer components and cables.

Here is a download sample.

Original Download.wav

Here is the same download played through the built in DAC in the 6SN7, out of the 6SN7, and recorded by the ADC.

6sn7 Sample.wav

Here is the same song used for Sample 1 with the SE Phono.  This time it is played through the I to V phono, into the 6SN7, out of the 6SN7, and recorded by the ADC.


Here is another sample using the I to V phono and the 6SN7.


Click here to access documentation videos on youtube

1kHz Signal to Noise at 1 watt (10dB per division)


  • Power: 3.3 watts
  • Input sensitivity: 0.428 volts
  • Signal to noise: Better than 90dB
  • Sowter Transformer taps: 10 ohms (configurable)
  • Vampire Wire gold plated solid copper 5 way binding posts
  • DAC option 2 192kHz optical, 1 coaxial (configurable), 1 set of analog inputs
  • Chassis: Annodized but can be upgraded to powder coat
  • Chassis color: Customizable
  • Logo: Customizable startup and ready colors
  • Dimensions: 17” wide 13.5” deep 4.5” tall
  • Weight: 30 pounds