I went from the sock Tempest to the Magnum Tempest . The Tempest is the integrated that uses the 88 amp. The improvement was very impressive. The extension in the highs and the bass from the 50% larger output tranformers is impressive as is the added authority from the doubled power supply. There are also some nice improvements in detail and resolution and complete freedom from any grain allowing the soundstage to really open up. It really transforms the amps into one of the best and uses the best parts available. The Electro Harmonix 6550's are great. Highly recommended. Have fun.
