Post by Steve Deckert on 06/20/12 at 12:39:01
Hi guys,
The change in the SE84C+ had nothing to do with cost cutting. We don't do that here. Specifically, it was done because it makes the amp sound better. By increasing the plate resistor to 56K and eliminating the last section of the power supply filter (10K and 3.3uf 400V Poly caps) there is a noticeable increase in musicality. The reason for this is speed, a function largely controlled by the power supply. This mod slows down the front end of the amp slightly compared to how it was. So why was the Zen designed with the poly caps in the first place? Because the original Zens, back in the day, were designed around a Hammond Power transformer. In those amps it was a better sound. We have since made our own proprietary power transformers here in the USA and they are a superior product compared to the hammond. A few years ago we re-designed the power transformers and gained a far better efficiency as a result of using even higher grade steel. We made the discovery with the SE84C+ this year by mistake, after all these years of building zens with the upgraded power transformer, we never thought to make such a serious change to it's design. Just goes to show, you change even the smallest thing, a power transformer with nearly identical specs, and everything must be re-voiced. In fact I remember this was the reason for the TORII MKIII. After improving our power transformers for the third and final time I lost the voicing on the TORII MKII and had to completely redesign and re-voice it. It was impossible to get it to sound the way it was, because it wanted to be something better.
So basically if you have an SE84C+ in the white chassis using our latest power transformer shown below and it was built prior to this Spring, we can modify your amp in the same way.
As you can see, the newest power transformer can be identified by the end bells which now wrap slightly around the sides. It also has a textured powder coat finish.
Steve