Greg, I found this forum & this topic by doing a google on 'do Synergistic fuses really sound better'.  On another forum I no longer frequent I read more than 2 members swearing by them, and since then I have always been interested/tempted.

I recently upgraded from a SLP 90 to a preowned (from Cary) SLP 05 that I had them put "The Ultimate Upgrade" on before they shipped it, and this was the unit I was most interested in re-fusing with Synergistic (especially now, as they are on sale).  What you have discovered about turning on the power supply last is advice I will heed whether I refuse or not, but I do have a question about this:

What direction did you find sounded best on your Cary preamp? I I have the hot end going in from right to left.

Am I missing something?  I believe on mine, the fuses plug into the back of the power supply from back to forward?

And I agree with just about everything you have typed about this "hobby."

Matthew,

I did the SLP 05 Ultimate Upgrade as well, along with the older Tungsten tubes.  Maybe that combo with the fuses is the improvements we are hearing. I was afraid to try different directions on the fuses after the original problems so I never tried reversing them. They are as you say hot end going in right to left. fuse info/writing reads from left to right going in to back of power supply. I'd be interested to heare if anyone has tried them reversed and has any opinion. They sound right to my ears the way they are. 

Greg

They are as you say hot end going in right to left

Greg, thanks for getting back to me on that.

But this is where I am confused (and maybe it is me, because although I can solder & de-solder, the theory of electronics is beyond me); in mine, the fuse inserts in the fuse holder and then the fuse holder plugs straight back into the back apron of the power supply, which actually seems more 'forward and aft' than 'right and left', but as I typed, maybe I am missing something?

Also, keeping in mind my limited grasp on electrical theory, tonight I did turn on my pre-amp as was suggested above . . . turned the pre-amp/6sn7s to 'on' and then turned the power supply on so everything powered up at once.  Why is that a softer start than turning the power supply on and getting the rectifier tube  going and then firing up the 6sn7s?  I believe you that it is, but I am not understanding why.

Hey, thanks again for getting back to me!

Matt

Hi again Matt,

I'm no expert either but unless I'm mistaken we have it right. The hot end is the forward end of the fuse which as you say goes straight in to the power supply. The SR is on the other end which is the fuse holder itself with the fuse values showing left to right as we read. Also, I think the power supply rush when turning on the unit first before the power supply eliminates the current rush because the rectifier tubes warm up slower. Again, someone else is the forum like HeavyMech knows way more on this stuff.

Happy listening

Greg

Thanks!