Last year shortly after I got my Darkvoice Figaro I replaced the stock fuse with one from ISOCLEAN POWER. I could tell a slight difference, a level of clarity. The Figaro went up in smoke a few months ago and so I have a few cool parts to salvage from it and one is the Isoclean. OK, a couple weeks ago I got a 336se. Did my normal partswapping and installed the Isoclean. Didn't think nothing of it. I bought a HiFi-Tuning Fuses - Small Gold FAST Blow F by Revolution Power and didn't install the fuse. I wanted to make sure I was familiar with the sound of the amp. Settled on the tubes I'm using at the moment so figured was comfortable with the sound. So today I installed the Hi-Fi Tuning fuse. The sound was completely different from what I was used to. It lost a few DB's. I can turn the the volume knob up a little more than previously. Thinking the Isoclean was completly broken in compared to a brand new fuse. The sound was a little laid back but there was sense of a little more clarity with the guitars and cymbals. Vocals are pushed back a bit. Soundstage seems a tad bit smaller. Never thought that there would be such a difference in two gold plated fuses. Who new? Have to try the Rhodium Plated fuse from Furutech now to see if there is a difference? A cheap can of worms to me. Cheaper than some tubes. See what happens after a week or two. Just giving impressions on something that was unexpected but found interesting to me.