Suggestions for testing a never installed, 20-year boxed amp.


I have a new Pass Labs X5 power amp that has never been installed (boxed up for over 20 years). I'm looking for suggestions about powering this unit up. I'm concerned about connecting it up to my current speakers the first time I power it up. Should let it cook while connected to some load resistors? Should I leave the inputs unconnected or loaded? 

philliprcook

I used a Variac and 2, 8ohm 10watt resistors on the output with volt meters across them.  Short the inputs.  Take the covers off.  As I easy up the variac, I watch the meters, sniff around and look for smoke.  Now I would use an infrared thermometer.  Before I used to use my trusty finger.  Hoping B+ doesn't get me.

I had a laughed watching Vice Grip Garage.  When he connects a battery to a car he's resurrecting, he sniffs around and looks for smoke.

OK - I took your advice and contacted Pass Labs. Someone actually answered the phone and referred me to Kent who was very helpful. His concern was with the capacitors as some of you mentioned. Kent recommended a "current limited power up" using a 120vac current limited power supply. I asked if a light-bulb limiting circuit would be Ok and he said to cook the amp for a day with a 60w bulb then move up to a higher wattage bulb for another day. Of course, he cautioned me about safety concerns. No connections to inputs or outputs are necessary. 

Kent offered to do this for me if I wanted to ship it to them for a nominal fee. He said he could also re-cap the amp if it becomes necessary. He also offered to send me instructions to make the speaker connectors banana plug ready. 

I don't have any decent speakers for this amp. If this amp tests ok I will have a tough decision to make. Do I keep it and build a system around it or get rid of it? Either way, I need to know if it works.