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

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.

This is result of inrush current, I had the same issue with my Coincident 845 SET amp and former Cary push pull. I went up a couple values both times, no more failures. My take is as long as fuses are blowing they are doing job intended to do.

 

Perhaps they are undervalued to whats stated on fuse. If they are blowing on startup, they'll also blow if equipment suffers some other failure.

Thanks everyone for all your input and great advice? Since Cary just did a complete factory overhaul on my SLP-05 I and I retubed it as well I think I will try a higher value slow blow after double checking with Cary first. I'm going to confirm if they changed the caps and fix if they didn't. Also I will try turning the preamp on first before the power supply and see if that solves it. Thanks Ted and Synergistic. You have been great incidentally at trying to help resolve this and even replaced the popped fuses , no questions asked. Very refreshing when you consider the feeling you get with a $400 pop with these new purples.

Greg

Not coupling/decoupling caps, FILTER CAPS. 

Here is the rub. There was a thread about V12i blowing fuses on the forum, HE had sent it to Cary, They did a (so called) complete rebuild and they started blowing coupling caps.

I told him my story and sure enough Cary had NOT replaced the filter caps but everything under the sun including one transformer.

Cary gets it back and replace ONE bad filter cap and one blown coupling cap.

The tech, was assuming the guy before him (AT CARY) did replace the filter caps (He didn't). The customer gets it back again and this is when I read his thread complaining about Cary. I would too.

He post a pic off site you can see they didn't even do a Hexfred upgrade but changed all these big old honkin' coupling caps. You know what it takes to charge big caps? Ask the filter caps that blew.. LOL

The whole story is He had 3 V12i. 2 mono one stereo. ALL started doing the same thing.

After Mr. Ralph, chimed in and confirmed my suspicion, the guy quit posting about his amps.

I have no idea what he spent, but V12i mono blocks or stereo amps are a sight to behold and listen to if they are done right. Blown up they are just a sight.  A Cary V12 - V12r should outlast my grandchildren. I paid 165.00 plus postage and tax for all 4 560uf filter caps. I paid almost that per coupling/decoupling cap combo. Copper foils and teflons. Magic!

It takes me about the same amount of time to swap and bias valves, (10 minutes) vs. swap out all 4 FILTER caps.

BTW I offered to fix his Cary for FREE, if he would pay for the parts and shipping. Silence!!! :-) I am still looking for a second V12r. My wife won't give me mine back. I'm using a MC225 and a MX110. Women. :-)

Regards