tahitibub Posted May 25, 2012 Share Posted May 25, 2012 Hi, I'm french, I live in Tahiti (French Polynesia / South Pacific Ocean). My native language is French, so I apologize for my poor English style and I hope you'll understand me ! I just grab an old "SCOTT 233" amplifier. When I look at it, I can see that some tubes are totally unusable (they have "inhale" air, there is a leak inside, they became white). I'd like to know if someone could give me a kind of checklist in order to restrore this old amplifier. Kind regards. Quote Link to comment Share on other sites More sharing options...
tube fanatic Posted May 25, 2012 Share Posted May 25, 2012 Looking at the rust on the transformers there may be many problems with this amp resulting from moisture/salt exposure. Do you have experience in working with high voltage electronics? If not, please don't try it as there's a definite risk of electrocution with such equipment. Tahiti seems like the kind of place where I'd like to live!!! Quote Link to comment Share on other sites More sharing options...
NOSValves Posted May 25, 2012 Share Posted May 25, 2012 Start off with doing a good quality cleaning. What ever you do DO NOT PLUG IT IN. Once cleaned take some more photo's and post them up and I will help you bring the amp back to life. I will need good detailed photo's from above, under the tone control cover and under the bottom cover. You will also have to realize that I am a busy guy so be patient it may take me a day or two to pop in here. If the arm chairs brigade keep from confusing the project we can do this right here on the forum. If not it will have to go to private email. Not to be rude but I just do not have the time to be debunking BS from folks that possess generalized information about amplifier rebuilding. Craig Quote Link to comment Share on other sites More sharing options...
Boxx Posted May 25, 2012 Share Posted May 25, 2012 Hi,I'm french, I live in Tahiti (French Polynesia / South Pacific Ocean). My native language is French, so I apologize for my poor English style and I hope you'll understand me !I just grab an old "SCOTT 233" amplifier. When I look at it, I can see that some tubes are totally unusable (they have "inhale" air, there is a leak inside, they became white).I'd like to know if someone could give me a kind of checklist in order to restrore this old amplifier.Kind regards. Bienvenue sur le Forum Klipsch. Bonne chance avec votre projet. Cordialement, Boxx Quote Link to comment Share on other sites More sharing options...
Guest " " Posted May 25, 2012 Share Posted May 25, 2012 first thing on the check list......do not trust anyone who likes to discredit folks who respond to your request for input...if someone makes a request for assistance on an open forum...and our good forum members respond....they should not be badgered and harassed. I have no problem with private emails being sent making recommendations. But let's have some tac and respect for the folks who respond to request for assistance. Quote Link to comment Share on other sites More sharing options...
NOSValves Posted May 25, 2012 Share Posted May 25, 2012 The King of the clueless arm chair brigade pipes up..... what a card. No one is discrediting anyone. I am simply offering to help..... if and only if my time is not spent debunking information from armatures like you. So the offer stands to the originator of this thread but now (thanks to "king arm chair") the offer is only available via private email. Free professional advice is a VERY GENEROUS OFFER.......... and on a open public forum its even a more generous selfless offer..... I have no way of benefiting from a private email correspondence and would actual prefer it that way... in public I stand just as much to lose and to gain. It's really too bad it's so hard to share my extensive experience on the Internet because a few arm chair types refuse to just step back and learn a thing or two probably out of some wierd ego trip...... Quote Link to comment Share on other sites More sharing options...
thebes Posted May 25, 2012 Share Posted May 25, 2012 Welcome aboard. Believe it or not you will like it here. First what Tube Fanatic said, second what Craig said. The first and most obvious thing from your picture are those cloudy tubes. That means they have lost their vacuum and are no good anymore. Second is all the rust which means that almost everything, wires, caps resistors etc. has spent too much time where it should not be. The wiring could be rotten, the Caps leaky and the resistors open. In short, right now it's in about in bad a shape as an amp could be. Craig, and several others hear can walk you through the initial testing to see if number one, the transformers are still OK. Go from there. Quote Link to comment Share on other sites More sharing options...
George O. Posted May 25, 2012 Share Posted May 25, 2012 Hi Tahitibub, Because of its condition, it is simply not worth the trouble and expense to restore. Quote Link to comment Share on other sites More sharing options...
gnatnoop Posted May 25, 2012 Share Posted May 25, 2012 Hi Tahitibub, Because of its condition, it is simply not worth the trouble and expense to restore. to who? Quote Link to comment Share on other sites More sharing options...
tube fanatic Posted May 26, 2012 Share Posted May 26, 2012 Hi Tahitibub, Because of its condition, it is simply not worth the trouble and expense to restore. George may be correct if in fact the amp has had significant salt air/moisture exposure. I've serviced hundreds of TVs, amps, and other equipment which were kept near open windows of homes close the ocean. The corrosion in switches and controls can be awful. Wafer switches in particular are prone to such damage, and having to totally disassemble them for cleaning and restoration is not a task for someone inexperienced. And, as I asked before, what is your level of experience in doing electronic repair? Restoring an amp like this is not something that one should tackle without a solid experience base in working with this type of equipment. There's too much potential for a catastrophic outcome. It would be helpful to all of us forum members if you let us know your background in this area. Regards--- Maynard Quote Link to comment Share on other sites More sharing options...
tahitibub Posted May 29, 2012 Author Share Posted May 29, 2012 Hi everybody, I thank you very much for all these contributions. In order to answer to some questions about my skills, I'm an electronic hobbist : I think I'm able to do this restoration with the help of the community. Following Craig advice, I've cleaned the amplifier. You'll find attached the "map of the tubes" (Stereomaster 233.pdf). I'll post photos in the next 2 posts. Many many thanks to all of you. SCOTT Stereomaster 233.pdf SCOTT Stereomaster 233.pdf SCOTT Stereomaster 233.pdf Quote Link to comment Share on other sites More sharing options...
tahitibub Posted May 29, 2012 Author Share Posted May 29, 2012 Photo 1 ... Quote Link to comment Share on other sites More sharing options...
tahitibub Posted May 30, 2012 Author Share Posted May 30, 2012 Photo 2 ... Quote Link to comment Share on other sites More sharing options...
tahitibub Posted May 30, 2012 Author Share Posted May 30, 2012 In order to do this restoration, I have got these test equipments: - Digital oscilloscope RIGOL DS1052E (hacked to 100 Mhz) - Lamp meter METRIX (but I'm not sure if it works) - ATLAS ESR 70, ATLAS DCA, ATLAS SCR - Multimeter Quote Link to comment Share on other sites More sharing options...
tahitibub Posted May 30, 2012 Author Share Posted May 30, 2012 Tahiti is a magic place ! Quote Link to comment Share on other sites More sharing options...
jtnfoley Posted May 30, 2012 Share Posted May 30, 2012 Hi Tahitibub, Because of its condition, it is simply not worth the trouble and expense to restore. Finding ANY well regarded tube integrated amplifier could be troublesome and expensive in some places in the world. Tahiti, for example. Quote Link to comment Share on other sites More sharing options...
jtnfoley Posted May 30, 2012 Share Posted May 30, 2012 I'd like to know if someone could give me a kind of checklist in order to restrore this old amplifier. I believe everybody here will agree that electrolytic capacitors should be on the checklist for replacement, certainly in the power supply. Ceramic and signal-path capacitors will be a matter of much debate (like anything in audio) but electrolytic capacitors should all be replaced. Quote Link to comment Share on other sites More sharing options...
tube fanatic Posted May 30, 2012 Share Posted May 30, 2012 Frankly, looking at the pictures in close up I'd advise you not to even bother trying to restore this unit. Judging from the rust on the speaker terminals and bottom of the transformer housing, rust/corrosion on the chassis, etc, you are likely to encounter too many problems. Even if the transformers test ok for resistance, there's the possibility that the internal wiring has been attacked by moisture/salt and will fail when voltage is applied and current drawn for some length of time. It's also likely that every solder connection will have to be re-flowed, riveted chassis grounds drilled out and redone, rotary switches taken apart (as mentioned before) and rebuilt, potentiometers replaced, and lots more. It just isn't worth the expense of buying all the needed replacement parts and tubes only to wind up with an unusable amplifier. I speak from many years of experience working on equipment which has seen service in a moist, salt laden environment. You will be better off buying an amp which has already been restored or, given your location, possibly considering one of the Chinese amps like Yaqin which have a good reputation. There are some self-appointed arbiters of "good taste" on this forum who will attack this advice vehemently by asking why I should care how you spend your money, so it's up to you to consider all sides and make a decision. Isn't there a French expression to the effect "Il pete plus haut que son cul?" You will find that it's quite applicable here, so beware! With all that said, we are really a nice bunch of folks with many years of collective experience (52 in my case) in audio or electronics. Quote Link to comment Share on other sites More sharing options...
NOSValves Posted May 30, 2012 Share Posted May 30, 2012 Any bets with some guidance he can get it up and running for about $150 plus tubes.... if it passes a few innitial tests that will cost nothing beyond replacing the bad tubes it will work fine long term. Scott's are pretty darn tough. I bet nice vintage amps are really hard to come by and very expensive in this posters local. By the looks of his location of the shots he likes to tinker on electronics anyway so why not? Quote Link to comment Share on other sites More sharing options...
Marvel Posted May 30, 2012 Share Posted May 30, 2012 The pics show a rather funky looking amp. Definitely would be a lot of work for possible failures when you are done. However, most of the major rust looks to be on the top/outside. There may not have been much leakage/penetration into the transformers. Switches on teh front would surely need to be cleaned and/or replaced. Bruce Quote Link to comment Share on other sites More sharing options...
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