45W Tres Leches

ABOUT

The Tres Leches amplifier is the first in a series of amplifiers integrated with the Milkman Alnico speaker, the new production JBL K120 speaker that Milkman recently released. The amplifier is designed to take full advantage of the fidelity of the speaker, providing more power and headroom than the lower wattage models without sacrificing any of the versatility

The power attenuator circuit in the Tres Leches is very unique. In the lower wattage models Milkman uses a mosfet based "variable voltage" attenuator circuit which works quite well in cathode biased amplifiers with a tube rectifier. However in order to maximize the headroom and power of the Tres Leches, a solid state rectifier and adjustable grid bias are used.  In place of a mosfet, Milkman uses a 6L6 tube (this circuit has been graciously shared by Chris at Benson Amplifiers) to adjust the internal voltages. The benefit of a 6L6 power tube is that there is plate resistance similar to what a tube rectifier so the amplifier never feels stiff, but at the same time it can deliver a huge high bandwidth output. At both the 15 watt and 5 watt settings, you can feel the 6L6 adding "sag" and compression which gives a very familiar low wattage feel.

The preamp for the Tres Leches is nearly identical to the 85W Pedal Steel model. It is designed to be full bandwidth, high headroom with high fidelity. Coupling that preamp to the custom designed Soursound transformer and a custom built high fidelity Alnico (or ceramic) speaker delivers amplifier tones that have been missing for more than a generation: 45 watts of 6L6 power with a JBL speaker is the classic American amplifier tone. Milkman sound is very excited to bring that tone back and also bundle in a modern amplifier feature: power attenuation. 

The 45W Tres Leches is hand wired onto a turret board with bespoke Soursound transformers and Jupiter capacitors.