Whitestone Audio Instruments Add an EVL Version of their P331 Tube Loading Amplifier

Both the Whitestone Audio P331 Tube Loading Amplifier and its “EVL twin” were developed to bring professional tracking, mix and mastering engineers versatile, elegant, precise and repeatable audio circuit variation. These are high-fidelity, hybrid vacuum tube /solid-state audio enhancement devices. They’re identical in their signal flow and control circuits, however we designed the P331-EVL to be more direct…more forward…less “polite” in its presentation.

So what are the differences?

Well let’s start with what’s the same. Like the original P331, the EVL version utilizes digitally controlled analog for all controls. Left/Right coherence is every bit as precise. The fully-differential solid-state output amplifier is unchanged. The LIFT circuit is also identical in both units, however, since the lifted frequencies are affected by the harmonics generated by the LOADING section…LIFT on the EVL will not sound exactly the same as the original P331.

The fully-differential tube LOADING amplifier in the EVL starts from a much different point. While the LOADING control is functionally the same as the original P331 in that it controls the 6SN7 tube’s operating point, it’s being pushed much harder from the start. It’s not like a distorted guitar amp…it’s still “mastering appropriate”. It’s simply a different, more forward “feel” than the original P331.

The XFORMER section is where the most differentiation occurs. We’re driving WAY more current at the transformers …forcing them much further into saturation. The result is a more pronounced low-end presence, thrust and punch without becoming stuffy or losing clarity.

https://www.youtube.com/watch?v=q8eTY0JSxV8