Synergistic Orange and purple fuses popping


 

Synergistic Orange and purple fuses popping


I recently upgraded all my gear with the new Synergistic orange and purple fuses (15 in all) What a difference! My Cary SLP-05 preamp with 8 Vintage Tungsten  6SN7 tubes is having problems with the Orange and Purple Synergistic fuses in the power supply. For some reason when I turn on the preamp amp after warming up the powersupply unit, the 2 power supply fuses pop. So far Synergistic has been gracious and replaced them twice now. I increased  the 2 large slow blow fuses from 1amp to 2amps after asking Cary audio what I should try. I also spoke with Synergistic and they agreed their fuses are sensitive but all the stock fuses I ever used have worked flawlessly. Any body out there with any similar problems and maybe a solution? Any upgraded hi-fi fuses that may be less prone to popping? I think it may be due to a current rush (tube related) when I go from off to on. Help!

Thanks

gregtheis

I blew a blue in my preamp after a few months.  I got an orange and blew it in a new preamp from the same manufacture in a few months.  The orange was two increases over the stock.  

I put back in a common ceramic at the rated value and it has been fine ever since.  My opinion is that the fuses are not stable but lots of people like them, I don't.

I've had 5 different Cary tube products they all used the 560uf filter caps in the power supply. Mine all did the same thing they were all older units too. They would start running hotter and I had to be very careful flipping from standby to on. They would pop a fuses. I'd change the 2 or 4 560uf caps and the problem would go away. They will leak oil too. LOL I thought I had an old Harley the first time one took a dump. Left a puddle of oil. :-)

I was using ACME at the time in my Macs, Carys, VTL, Threshold. I was given SR to try. I wound up paying for blue and orange fuses. 10 or so..

Regards

Can you leave the preamp switched on and only use the power supply switch to power it up thus avoiding the surge?

@gregtheis if you’ve already received replacement fuses from the factory and the problem persists, than there’s one of a few issues at play here. As others have stated, Synergistic fuses are built to a very tight tolerance. They don’t blow unless there’s an issue. In this case, are you using a fast blow fuse but should be using a slow blow fuse? If so, that’s the problem (I see that you specified slow blow so this is not the issue). Otherwise, as Old Heavy Mech stated, you likely have one or more dried out capacitors and so a massive surge at start up. If this is the case, you are also burning through tubes faster than you should. It’s not a big deal to change out caps in a tube circuit, and one big bonus, you’ll get better sound as well as longer lasting tubes when you do. Lastly if none of these suggestions sound palatable to you, we will make certain you get a full refund through your dealer.

 

Yours and music,

Ted Denney III

Lead Designer/CEO Synergistic Research Inc.