[James Tanner]

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

HI

Email Mike and he can assist

mpickett@brystoncom

james

[FullRangeMan]

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.

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.
+1.   The slow turn on with an Variac is the safest procedure imo, but I curious what Mike will recommend.

[gbaby]

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!

I would not be concerned with not using the amps in seven years and I'd just fire them up. Think positive. There is no reason for them not to work unless you've stored them in a damp environment.

[paul79]

They are fine. 7 years is small potatoes, assuming the storage environment has been sufficient. I restore vintage audio for a living. Never a bad idea to power it up slow though, if the means are obtainable.

[Elizabeth]

I still stand by my cheapskate means of turn on. Which is to plug in, turn on for the briefest moment and turn off.
This charges the caps only partially. But if thye get a quick bit of 'juice' it helps them.
Second time again same thing after a few minutes.
Then a third time perhaps a little longer, but still no more than a full 2 seconds on.
After than wait again a few minutes and TURN ON. no problem.
FREE. did I mention FREEEeeeeeeeeeee. 

[Waker]

I have emailed Mike Pickett with a description of the situation--will post his advice here. 

[RDavidson]

I would be surprised if a modern Bryston amp with a 20 year warranty would have trouble turning on after 7 years of storage. I understand the caution. Just sayin' I'd be surprised.

[stonedeaf]

Free is sometimes the right price. The problem is you are thinking about a power supply capacitor as a battery (this analogy is frequently used to describe capacitors -it's only slightly accurate). Unlike charging a battery which is done with limited current applied to the battery over extended time - a power supply capacitor gets a kick in the head as soon as you apply power to it. It's a tough life. Short cycling the power switch isn't going to protect the power supply capacitors or form them - it's in no way equivalent to bringing up a amp on a Variac. Part of the procedure for bringing up a amp on a test bench is watch the current draw as you bring the amp up to full AC  (120V) power - if it suddenly starts to really suck current you can stop and go back to figure out what you missed before ya blow up the new parts ya just put in (OK -if you're lucky).Short cycling does nothing to either protect the amp or form the power supply capacitors.

[Stu Pitt]

I would be surprised if a modern Bryston amp with a 20 year warranty would have trouble turning on after 7 years of storage. I understand the caution. Just sayin' I'd be surprised.

I didn’t want to say it, but yeah.

And an SST2 amp should still be under warranty too, right? So long as you have a receipt from an authorized dealer.

[Russell Dawkins]

I suppose a cheap way of handling this (if you have a few basic electrical assembly skills) would be to rig up a board with a lamp socket in series with one of the conductors of an extension cord. You could start with this in circuit and power up with a 7 or 15 watt incandescent bulb, then power down and go to a 40 w, then a 100 w bulb. That should pre-condition the caps. I guess if you wanted to get fancy, you could use a dimmer switch in series with the bulb.

That's what I would do considering I don't have, nor do I have access to, a variac.

[stonedeaf]

I like the multiple dim bulb idea except these are beasts of amps -my guess is that you'd go thru a series of light bulbs being converted to very bright short lived flashbulbs at the lower wattage ratings ? The dimmer is a interesting idea - audio techs ( I was one) are cheap and some of my cheap buddies would of come up with a dimmer as a alternative to a big honkin expensive variac - somehow i think the inrush current would probably take out a dimmer - but haven't tried it ???
BTW- please note -the dim bulb hook up only works with incandescent (old fashioned) light bulbs .

[Elizabeth]

Actually the low wattage light bulb in series on AC line is a GREAT idea.
The bulb is the controlling element NOT the amp. So the notion the bulb will self destruct is completely wrong. (Consider without the amp the line is a dead short! yet every light bulb survives this.

[Waker]

Mike from Bryston advises to start at full power because a variac would need to be at 100V initially, anyway, and that he would worry more about a much older amp than these.  Those of you who said not to worry got it right---now I just have to do it---will be awhile before I take my current system apart, though.       

[FullRangeMan]

Incredible, I hard could believe it, it not a softstart.

[greyscale]

I have a pair of 7bST amps which have not been powered on in at least 10 yrs. Couple of weeks ago, I decided to try to use them. The Right amp years ago blew a speaker( smoked). But I did hookup the left amp to my BP25 and used a cheap outdoor speaker from Amazon. The amp came on without a hitch. I left the amp on for 72hrs, no problem. The right speaker is now in its original shipping carton and is awaiting UPS pickup to Vermont repair shop. These amps just keep on goin.
UPDATE, I received the 7BST i had sent to Vermont for repair on Friday. Unpacked the amp and connected it to my BP-25 and the outdoor speaker. After 36hrs always on, the 7B sounds great. Thank you Bryston ,especially the Bryston techs at the repair center in Newport, Vt.

greyscale

[Calypte]

Partly inspired by this thread, and also to test an unemployed preamp that I'm thinking of selling, I tested a power amp (not Bryston) that's been sitting for six years.  It worked fine.

[FullRangeMan]

Partly inspired by this thread, and also to test an unemployed preamp that I'm thinking of selling, I tested a power amp (not Bryston) that's been sitting for six years.  It worked fine.

It always works fine, the softstart will enlarge the caps life.