Restoring Vintage Equipment

[Sovkiller]

I was not talking of tube amps, just solid state, not sure Ari where did you get that insane idea that the 70-80 are the worst era for SS amps. I grow up on that era and I can tell you that you are absolutely wrong on that, still have a Pioneer under the bed, working fine, and sounds fabulous. Just go to audio circles and you will get recos all the time about Sansui's, Marantz, Pioneer, Kenwood from the early seventies, as the best choices, again tubes aside, which you know I do not like too much....Maybe I extended the time frame too much, let's reduce it to 70's and early 80's, only, it is true that in the late 80's there was a lot of crap produced...

It is funny how people mention in inefficiency of class-A SS as down point, while tubes are far less efficient, and they are still used, and consume a huge amount of energy in comparison to any Class-A SS amp...

You do not need black gates, of course, you can use any cap and being a decent brand, with the appropriate ratings, and you will not hear any difference, but that is what people like to use all the time, and reco all the time, since I joined Head fi the first day, they like to pay premium prices for nothing, same as those so mentioned as an upgrade, Jensen paper in oil caps from the 50's, etc...

The problem with the wires is that on those vintage amps they manufacturers tend to use solid core wires, the rosin core of the solder used at that time was corrosive enough and sometimes it corrode the cooper, and sometimes you get broken contacts and broken wires internaly, even while they look fine externally, the case that crossed my mind was once with a CTF4140 Pioneer deck long time ago, I was crazy trying to hunt an oscialltion after replacing the permalloy heads and adjusting the bias for some glass ferrite heads, and all was due to the freking broken wire in one board...

As per class A, well just get efficient speakers, no need to use inefficient ones, what for? But even using the worst speakers, in your home, would you be able to use more than 10-15 Watts per channel? Unless you live in a jungle, your neighbors will put you out of town soon...
As a reference I have never used my Marantz in any region close to half a volume yet in Class-A...

BTW the Maratnz is 25 watts per channel in class A, but if you want to run it class AB, you will get 95 watts per channel, IMO not bad at all for a 250 watts AC power consumption rated amp...otherwise then where did you leave those absurd 8 watts tube mono-blocks that can keep the room warm on the wintertime...Is there any logic behind those???

 

[Tridacnid]

Quote:

Originally Posted by Telynau /img/forum/go_quote.gif There is a reason some old timers would only test live equipment with their left hand in their pocket. If you don't know what that reason is, find someone to help you do the work or do it for you.

I always assumed because you don't want to ground anything with charge across your heart by accident (it needs something like 50mA to stop it, correct?). With one hand in your pocket, you couldn't touch the metal case, or something else, so if you did receive a shock, it would go through your leg, not through your heart and into your other arm, to get to ground.

Thanks all.

 

[silencewithin]

That's for the great advice in this thread, especially Uncle Erik. I am eagerly awaiting the holidays so I can begin to restore a vintage "stereo" I acquired. Tube radio and preamp, turntable, 3 speakers per channel (inlcluding electrstatic tweeters), 2 channel input and output. It was built for diy repair and will be a fun learning experience for me. I'm new to it all and this thread will definitely help me with where to begin

Thanks for all the advice.

 

[alamakazam]

Quote:

Originally Posted by Uncle Erik /img/forum/go_quote.gif Start with the power supply. Put on a new cord if it has an integral one. If it has an integral cord, you might want to think about modifying it to use an IEC jack. Especially if the original cord isn't ground. Gear wasn't always grounded. So if it isn't, ground it.

sorry more of theory guy... so the ground will just tie to the casing?

 

[Uncle Erik]

Yes, ground the case. Sometimes you'll get a ground loop from that. However, you're better off hunting down the ground loop and dealing directly with it than having an ungrounded case.

Also, the above post is correct about why you keep a hand in your pocket. Still good advice, though if you're going to work on more equipment, a Variac and an isolation transformer are good to have and use.

Sov, Blackgates aren't the be all and end all of electrolytics. They've been discontinued for some time and the supply is drying up. I think they're nice, but others sound good, too.

I haven't had the same experience with wires. The oldest set I've worked on is my Atwater-Kent neutrodyne from around 1927. Left most of the originals in there since they were fine. Also have a 1918 GE fan that had been left outside a few years. It ran with fresh oil, but the wires were still marginally OK. They've since been replaced. Haven't seen much damage from flux in older sets, either. The worst damage comes from mice and rats that get into stored sets.

Some of us love inefficient speakers. If you haven't had the pleasure of owning a planar, electrostat or ribbon, I highly recommend it. They're awful with amps, but there's a considerable reward. Same with the fleawatt SET amps - they have a magic to them.