We recently got our hands on ValveTrain Amplification’s newest amp, the ValveTrain 427. Like the majority of their amps, this beast gets its inspiration and foundation from the early Fender tweed circuits. ValveTrain’s designer/owner, Rick Gessner, told us to expect something reminiscent of the 5E3 Deluxe, but with more tonal control and more power, saying that ValveTrain takes a few liberties in order to provide today’s musician with tonal choices that the original amps just didn’t have.
The 427 is powered by a cathode-biased pair of Groove Tube 5881’s with heavy-duty transformers and makes a very conservative 27 watts. When driven to saturation, the tubes yield a tone that crosses the bridge between the smaller tweeds and the early Marshalls.
Aside from the heavy duty power section, the controls are another departure from the amp’s tweed heritage. Depending on how you look at it, there are either four or six controls on the front panel. Starting from the business end of the signal chain, there is a post-phase splitter Master Volume. At a setting 5 or higher (out of 10), this control provides the ability to reduce the overall level of the amp without sacrificing much of the tone or gain produced by the front end. Below 5, the amp produces a smooth overdriven tone from the preamp. The single-knob “Tone” control works well, allowing users to roll off the high end and darken up the overall tone of the amp. When used with the two volume controls, a wide variety of tones can be drawn out of the unit.
Probably the most interesting aspect of the 427 is the design of the initial gain stages. There are two volume controls, one for the “Normal” channel and one for the “Bright” channel – pretty much what one would find on the early Marshalls or Tweeds, but that is where the similarity stops. Instead of the traditional four input jack setup, there are only two. The channels are internally isolated and “jumpered,” meaning that the player is able to blend the tonality of each channel into the overall mix. Because the channels are both active, the preamp tube is running in parallel operation, producing more gain than is normally found in an amp of this style.
Keep in mind that this is not a cascaded gain circuit found in Mesas and others, but reacts more like a split cathode early Marshall. Turning either volume control down, which eliminates that channel, returns the tone of the amp back to its tweed roots. There are also two boost switches that activate a gain and low frequency boost on each channel. These act similarly to a “Loudness” switch that you would find on a stereo receiver.
By controlling the boost on one channel or the other (as well as using neither or even boosting both at the same time), blending the two distinct voices of the channels really opens up the tonal palette of this amp.
Besides the sounds and features, the ValveTrain 427 looks slick as well. ValveTrain uses a two-tone tolex covering that blends a dark color on the sides with a lighter color in the center of the amp – in this case, a dark green with tan contrast.
ValveTrain Amplificationvalvetrainamps.com407-0886-7656