Amp Module: Transformer

Transformer

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This module has two sections: Power Supply (controls on the left side of the module) and Transformer (Transformer Type selector on the right side of the module).

Power Supply

This section of the Transformer module models the power supply sag effect. Voltage or power supply sag is a major contributor to an amp’s organic sound. The heart of the amp, the power supply is the foundation where the amp’s soul is born.

Rectifier Type (Solid State vs. Tube)

A tube rectifier has internal resistance. The more current that travels through a tube rectifier, the more the voltage drops. When the voltage drops, the power of the amplifier also drops. This results in an amp with less headroom, but one that provides flattering compression.
A solid-state rectifier has no internal resistance whatsoever. It has a very consistent, fixed voltage drop that occurs both at zero and full current. When an amplifier needs power at low frequencies, there will be no limit to the current that travels through the rectifier. This results in an amp with more headroom for a punchier, more in-your-face sound.

Rectifier Tube Type

Different types of rectifier tubes provide different levels of AC-to-DC conversion. The most common small-amp rectifier tube is the 5Y3, used in older amps. This tube works fine in small combos that put out 15 watts or less, but when pushed hard it can start to sag noticeably—great for certain sounds!
At the other end of the scale, the GZ34 (equivalent to the 5AR4 in the USA) has long been considered the king of the rectifier tubes. This powerful, sturdy rectifier tube makes more DC out of the AC it’s fed—and does so very elegantly and with great efficiency—while inducing many of the most-loved characteristics of tube rectification in the amplifier’s performance.

Input Knob

This knob adjusts the input gain within a +/- 12dB range. The INPUT knob together with the COMPRESSION knob controls when the amplifier will start to sag. Lower settings produce less compression, higher settings more.

Ratio

Sets the amount of compression: the higher the setting, the greater the compression effect.

Attack

Sets how quickly the power supply sag will kick in in response to the guitar signal.

Release

Sets how quickly the power supply sag will return to its normal condition.

Compression

This knob sets the threshold at which the power supply sag will kick in. The higher the knob setting, the greater the compression effect that will be produced.

Reduction Meter

This virtual analog meter displays the current amount of compression (in dB).

Output

This knob adjusts the output level within a +/- 12dB range. It provides a way to compensate for loudness increased or reduced by the power supply sag effect.

Transformer

This section of the Transformer module models the response of different types of transformers. The transformer’s function is to convert the high-voltage, low-current signal from the amplifier’s power tubes into a low-voltage, high-current signal to power the speakers at a low impedance. The transformer is responsible for how efficiently the audio power of an amp will transfer to the load of the speakers, and it prevents hundreds of volts (DC) from passing to the speakers.

An output transformer does not change an amp’s character. A different transformer will not change an amp’s DNA or make a British amp sound like an American one. It takes what the amp already is, and then enhances it.

American Style

This transformer produces the leanest bottom end and spotlights the upper midrange, helping your guitar cut through a dense mix with excellent presence.

British Style

Producing a slightly fuller low-midrange band and enhanced highs compared to the American Style transformer, this British classic offers the perfect balance of presence and warmth.

Fat Style

This custom-designed transformer has a boatload of iron in its mammoth core. It extends both the bass- and high-frequency responses and broadens the midrange band, producing terrific saturation and a full, in-your-face sound.

This custom-designed transformer has a boatload of iron in its mammoth core. It extends both the bass- and high-frequency responses and broadens the midrange band, producing terrific saturation and a full, in-your-face sound.

 

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