Amp Turn On After Seven Years

Waker · « **on:** 7 Nov 2018, 02:01 am »

I have a pair of 7BSST-2 amps I have not had on since 2011. Is it safe to power these up at full AC line voltage? I am excited to get these amps back into use--thanks!

FullRangeMan · « **Reply #1 on:** 7 Nov 2018, 02:17 am »

Do you have a Variac to soft start the caps?
If so I like the procedure of
20/30 mins at 30V,
20/30 mins at 60V,
20/30 mins at 90V,
and after 120V, supposing your mains are 120V.

jtwrace · « **Reply #2 on:** 7 Nov 2018, 02:19 am »

Quote from: FullRangeMan on 7 Nov 2018, 02:17 am

Do you have a Variac to soft start the caps?

Probably not since he asked the question. Just power it up and and turn your head away from the unit and use the opposite arm to keep your face protected. Safety glasses are never a bad idea either. You're probably fine though.

Waker · « **Reply #3 on:** 7 Nov 2018, 02:43 am »

I do have a nice variac that I have used to start a NOS subwoofer. I recall James saying that the Brystons have a soft-start feature, but just not sure if that is enough after seven years. I will try the variac at the stages described.

Elizabeth · « **Reply #4 on:** 7 Nov 2018, 02:12 pm »

The 'poor man's Variac' is to turn on very briefly. Quick on, then immediately off.
Wait a few minutes. Do it again. Wait a few more minutes. then turn on.
This gives the capacitors just a brief jolt, not a full blast at first turn on. Allowing them to work OK when you finally turn it on for real.

Goosepond · « **Reply #5 on:** 7 Nov 2018, 04:02 pm »

Hi Waker,

No way you can not tell us why in the hell did you leave these great amps unused for 7777777 years!!!

Gene

CanadianMaestro · « **Reply #6 on:** 7 Nov 2018, 05:49 pm »

Quote from: Goosepond on 7 Nov 2018, 04:02 pm

why in the hell did you leave these great amps unused for 7777777 years!!!

Gene

Hey Gene,

Hedy would have designed an auto-starter with programable timer....

FullRangeMan · « **Reply #7 on:** 7 Nov 2018, 08:21 pm »

As a poor man Variac one can use a general purpose transformer, lowering from 120V to 60V, I have 2 transformers and have lowering to 30V, Variacs are not cheap here.

avahifi · « **Reply #8 on:** 7 Nov 2018, 08:54 pm »

We have a BIG variac (1000VA) we use every day here to bring new and repaired equipment up very slowly to line voltage. We can also handle 240V equipment by putting a big step up transformer in series.

If any one has a hibernating unit that needs to be woken up slowly, we would be happy to do it for you.

It won't cost much other than shipping.

Frank

Jonathon Janusz · « **Reply #9 on:** 8 Nov 2018, 03:18 am »

Okay, I'll show my ignorance on this one.

Why is this a thing? Sure, I could understand if we were talking about a piece of equipment that is 70, 80, 100 years old that has some components that might have physically deteriorated to the point of potential fire hazard (not just the magic blue smoke escaping, but a real call the fire department fire), or something of similar vintage/physical condition that might only have one last hurrah in it that someone might want to see alive that one last time just to say it did it before it dies the above mentioned ancient technology death, but a piece of equipment seven years old? I thought (maybe incorrectly?) that the general position on such matters is that technology and manufacturing of components has gotten such (particularly after the 1990s) that other than some audiophile "performance" degradation, electronics are built to more or less just keep on keeping on.

All that aside, absolute worst case, considering we're discussing Bryston amps here, aren't they still under warranty?

Thanks to those smarter than I who might give me a chance to learn another new thing today!

FullRangeMan · « **Reply #10 on:** 8 Nov 2018, 04:31 am »

Well, this is a audiophile thing, audiophiles like to care his equipment, mainly expensive and good sound as Bryston, a visit to factory for repair not cheap due the heavy/big box.

Doublej · « **Reply #11 on:** 8 Nov 2018, 11:48 am »

I'd take the cover off first and give it a thorough visual inspection to make sure there is not anything visually which might indicate a problem.

CanadianMaestro · « **Reply #12 on:** 8 Nov 2018, 12:18 pm »

Wonder if the 20-yr warranty covers shipping to/from factory for repairs.

Elizabeth · « **Reply #13 on:** 8 Nov 2018, 02:27 pm »

My phono box, BP 1.5 would not come off mute. Took to dealer, they sent it in to Bryston, They got it back workng. I paid zero.
I suppose if you bought it used, and the dealer was not in your area (assuming you got the purchase receipt) you would pay to ship to Bryston, Bryston would pay return ship IF it was covered under warranty
In my case I assume the DEALER paid for the shipping to Bryston.

CanadianMaestro · « **Reply #14 on:** 8 Nov 2018, 03:09 pm »

Can't imagine shipping something like a 7B (or two). Special crate/box needed.

Waker · « **Reply #15 on:** 9 Nov 2018, 03:43 am »

Thanks all for the comments. The story of these amps: I bought them new in '09 and used my 7BSST-2 amps for two years, then got a deal on a pair of tube amps. I sold the 7Bs to a guy via Audiogon, and he said they arrived DOA. They were double-boxed, so I was shocked and perplexed--just gave him a refund without question. He offered to send them on from Ohio to Bryston's NY repair center. I said sure--what else was I supposed to do? I later received the amps back in MN via Fed Ex courier. Invoice said: "Could not find a problem." The buyer was a bit reticent from the start about making the purchase---I feel he just didn't want them when they arrived---did not follow up with him at all. I was only out the shipping costs. We bestowed gentlemanly praise upon one another via the A'gon feedback system. I had the ARC Refs in place by then, so I shelved the 7B's---haven't even tried them. If I sell them again, there will be no shipping---pick up only.

FullRangeMan · « **Reply #16 on:** 9 Nov 2018, 02:40 pm »

This is a awful sale, in this case the buyer most proof its DOA, usually by a POV video with real time sound, or YT posted video etc

avahifi · « **Reply #17 on:** 9 Nov 2018, 04:03 pm »

The issue with equipment that has been in the Rip Van Winkle mode long term is the state of its large power supply capacitors.

As they age in an off state over the years, they slowly "deform" loosing all of their residual charge.

When totally discharged, they tend to fail destructively when full rectified power voltage is applied to them rudely. Kind of like dropping a wet washcloth over the face of a sound sleeper.

The fix is simply don't do that!

Bring the equipment up very slowly with an AC Variac to apply power supply voltage to those capacitors gently.

With equipment that has "standby" circuits that don't apply power supply voltage until the voltage ahead of the standby circuits reaches some pre determined value, the "use a variac" trick might not work. Then you will need to contact the manufacturer for help.

Frank

stonedeaf · « **Reply #18 on:** 10 Nov 2018, 03:41 am »

First off - power supply capacitors have the toughest demand made on them in the fraction of a second after they are first turned on -cycling them on and off for brief period of times won't "form" them. Soft start circuits were a big surprise for me - I'd replaced relays in a amp years ago-and still couldn't bring it up on a variac. Was getting ready to curse out and replace the relays again when a know it all friend (it is so disappointing that there are some folks who are

- pointed out the function of a few other parts and demo'd just plugging the amp into plain jane 120V and it worked just fine. I'd suggest waiting until either James or Mike gets back with their idea as to how best to deal with this in one of their products - otherwise -taking Frank up on his offer of using their very large variac seems like a good idea.

Waker · « **Reply #19 on:** 10 Nov 2018, 09:06 pm »

I have not tried anything yet with the 7BSST-2 amps---hoping for guidance from a Bryston official.