Hello all
In my part of town we are about to have a "Curb side pickup" day, where everyone puts all there large junk out on the street to be picked up and taken away. There are always a lot of old TVs and stereos thrown out and I would like to know what should I look out for if I want to salvage some transformers for use in chip amps?
Cheers
Jye
In my part of town we are about to have a "Curb side pickup" day, where everyone puts all there large junk out on the street to be picked up and taken away. There are always a lot of old TVs and stereos thrown out and I would like to know what should I look out for if I want to salvage some transformers for use in chip amps?
Cheers
Jye
forget the televisions. do not open televisions. that's high voltage territory.
look for 70s stereo components from the better brand names like yamaha and technics and even kenwood. these are the ones that weigh a fair bit and usually have a little wood trim.
look on the back and you may see a rating like 260va right there where the power cable goes in.
i'd grab these. however, the transformers tend to be center tapped and in the 30-0-30 range. that's getting a little high for a lm3875 gc, and you can't do the dual bridge. you're not likely to get a 20v dual secondary.
you might in newer gear -- i don't know. i've only salvaged the older gear. the only newer amps i've opened tended to have small transformers and a heck of a lot of secondaries (possibly for the digital display and whatnot).
you might also look at salvage for useful chassis.
you might also look in the vents of equipment you're not sure about. if it's really heavy and has a big pair of caps staring at you, then that might be good to grab. you can always chuck it out next "curb day".
and keep an eye for really good brand names. sometimes it's just amazing what people toss out. it can be very good gear that just needs the pot cleaned.
once you have something, you can often find out a fair bit about it with google.
i wish they still had "curb day" here.
look for 70s stereo components from the better brand names like yamaha and technics and even kenwood. these are the ones that weigh a fair bit and usually have a little wood trim.
look on the back and you may see a rating like 260va right there where the power cable goes in.
i'd grab these. however, the transformers tend to be center tapped and in the 30-0-30 range. that's getting a little high for a lm3875 gc, and you can't do the dual bridge. you're not likely to get a 20v dual secondary.
you might in newer gear -- i don't know. i've only salvaged the older gear. the only newer amps i've opened tended to have small transformers and a heck of a lot of secondaries (possibly for the digital display and whatnot).
you might also look at salvage for useful chassis.
you might also look in the vents of equipment you're not sure about. if it's really heavy and has a big pair of caps staring at you, then that might be good to grab. you can always chuck it out next "curb day".
and keep an eye for really good brand names. sometimes it's just amazing what people toss out. it can be very good gear that just needs the pot cleaned.
once you have something, you can often find out a fair bit about it with google.
i wish they still had "curb day" here.
jackinnj, no offense at all, but if you're going to suggest that then you should also talk about discharging it. there's serious danger for the novice here. it's not just an implosion hazard.
i really think discharging should only be learned hand-ons from someone experienced, rather than on-line. the cost of a mistake is too high. tv stripping is not something for someone just starting on gc's. experienced tube folk are much better placed to make that step.
i do appreciate the tip on trans source, though. good iron is pricey.
general note for others: the leaded glass shards may be classed as dangerous waste in your area. check with your local facility. this may make the free transformer less worthwhile.
i really think discharging should only be learned hand-ons from someone experienced, rather than on-line. the cost of a mistake is too high. tv stripping is not something for someone just starting on gc's. experienced tube folk are much better placed to make that step.
i do appreciate the tip on trans source, though. good iron is pricey.
general note for others: the leaded glass shards may be classed as dangerous waste in your area. check with your local facility. this may make the free transformer less worthwhile.
What do you mean by discharging it?
When I took apart a broken TV, it held a HUGE amount of charge.. I ground the cable that enters the glass many times, getting a spark each time.
Is that what your talking about?
It is dangerous.... be sure to take all the proper precautions.
If the transformer voltage is too high, see if it has seperate primary hookups for 220V. Or maybe you can regulate it too.
When I took apart a broken TV, it held a HUGE amount of charge.. I ground the cable that enters the glass many times, getting a spark each time.
Is that what your talking about?
It is dangerous.... be sure to take all the proper precautions.
If the transformer voltage is too high, see if it has seperate primary hookups for 220V. Or maybe you can regulate it too.
renkus-heinz lpa2 anybody know this one?
i've come across what must be an old power amp.
it could be worth all the hassle of dragging it home. it's got an ulveco trans that says😛rim1/2- 117v 50hz, sek1/2 36,5v 7a, sek3/4 21,5v 7a,sek5/6 24,7v 1a. it also has 4elna caps 50v 10000µ and 6 63v 6800µ caps that look good. i took it thinking i could use the trans, heatsinks, speakerterms and some other parts.
anything worth taking care of?
i've come across what must be an old power amp.
it could be worth all the hassle of dragging it home. it's got an ulveco trans that says😛rim1/2- 117v 50hz, sek1/2 36,5v 7a, sek3/4 21,5v 7a,sek5/6 24,7v 1a. it also has 4elna caps 50v 10000µ and 6 63v 6800µ caps that look good. i took it thinking i could use the trans, heatsinks, speakerterms and some other parts.
anything worth taking care of?
take it!!!
its probly 120v primary with a stepped secondry tap. probly single supply, ie, +v and 0v and you can probly onlt use one set of secondrys. those caps are the big thing. they cost a lot to get these days, if they have the screw terminals on them. good trans for single supply GC, if slightly low on volts, but good amp rating. better off using it for an N channel amp, look in solid state for some good, simple and powerful amps. c u later bud, steve.. ..
its probly 120v primary with a stepped secondry tap. probly single supply, ie, +v and 0v and you can probly onlt use one set of secondrys. those caps are the big thing. they cost a lot to get these days, if they have the screw terminals on them. good trans for single supply GC, if slightly low on volts, but good amp rating. better off using it for an N channel amp, look in solid state for some good, simple and powerful amps. c u later bud, steve.. ..
are you sure sek with 24.7 v is 1a (one amp) if it is it may be that you can use all the secondrys together? dont know with out seeing it. c u later, steve.. ..
CAUTION
A word of warning!
Most UK TVs old enough to use large TXRs have a live or 'half live' chassis. In this case, the transformer DOES NOT provide mains isolation (it's an autotransformer), and is definitely unsuitable for providing LT for amps, etc.
They do have their uses, but if you know how to use one safely, you'll also know where it could be handy.
Even in the case of second-hand isolating transformers, be VERY careful when experimenting - the old gear might have failed because of a pri - sec short, and you might find HT on the LT side!
A word of warning! Most UK TVs old enough to use large TXRs have a live or 'half live' chassis. In this case, the transformer DOES NOT provide mains isolation (it's an autotransformer), and is definitely unsuitable for providing LT for amps, etc.
They do have their uses, but if you know how to use one safely, you'll also know where it could be handy.
Even in the case of second-hand isolating transformers, be VERY careful when experimenting - the old gear might have failed because of a pri - sec short, and you might find HT on the LT side!
Jack,
While there is no doubt that there are useful things in old TV's , and that people who are knowlegeble could possibly deal with these dangers. It is absolutely prohibited on these forums to suggest that people open old television sets, because of the high voltage dangers therein, that remain even if the mains cord isn't connected. This isn't my rule, it is universally applied here.
ofb dnsey thomas997 should be listened to.
Sorry
variac, thanks for the tip. i hadn't realized that myself.
anyway, jye has the good fortune of "curb day" coming up. i was only able to comment on 70s amps. can anyone give him specific info on other types of treasure he should look for? (i'm resisting talking about speakers; he's asking about gc parts.)
some car amps have nice finned heatsinks across their backs. those are worth grabbing.
anyway, jye has the good fortune of "curb day" coming up. i was only able to comment on 70s amps. can anyone give him specific info on other types of treasure he should look for? (i'm resisting talking about speakers; he's asking about gc parts.)
some car amps have nice finned heatsinks across their backs. those are worth grabbing.
Thanks for the help ofb, I hadn't thought about car amps and using their heatsinks.
And feel free to talk about speakers 😀
And feel free to talk about speakers 😀
... i predict a long thread.
you likely already know to be curious about anything that's old and heavy, so i'll just add this less obvious one.
http://www.t-linespeakers.org/drivers/tunnelreflex/
after that, maybe it's best to suggest you just grab what you're pretty sure is useful so you don't get loaded down with junk. one you sort through this year's haul, you'll have a much better eye for next time.
maybe you should google a bit with "vintage hi-fi" and the like. that may give you some practice. things like noting slightly taller gear can be late model tube amps.
http://homepage.mac.com/urbanradio/Vintage.HiFi/Fisher.800c.html
that's not gc territory anymore, but it's a great score if you want to get into tubes.
They took away "Big Garbage" day in San Francisco- Now we have to call for a private pick up (free) BUT the garbage day was a social event-packs of people cruising each others discards. I'm sad to see it go- although I certainly brought home some useless stuff!!
OK Heatsinks - Absolutely! Also thick pieces of metal that can be used as heatsinks- like thick aluminum pots: remove the handle turn them upside down on a wood base and bolt the chips on the inside of the bottom. Run a large bolt through the middle from underneath and put an acorn nut on the end! run the wires in the holes from the handle. I'm still looking for just the right one, probably would require a buffing wheel to polish off the food 🙁
Wood to make bases. ALso, most speakers are indeed garbage- BUT one can use old speaker boxes with new components- just cut a piece of MDF the size of the front baffle, spray it black semigloss, and glue it on the front, cut new holes and viola!
Puttting a few braces inside first is a good idea.
OK Heatsinks - Absolutely! Also thick pieces of metal that can be used as heatsinks- like thick aluminum pots: remove the handle turn them upside down on a wood base and bolt the chips on the inside of the bottom. Run a large bolt through the middle from underneath and put an acorn nut on the end! run the wires in the holes from the handle. I'm still looking for just the right one, probably would require a buffing wheel to polish off the food 🙁
Wood to make bases. ALso, most speakers are indeed garbage- BUT one can use old speaker boxes with new components- just cut a piece of MDF the size of the front baffle, spray it black semigloss, and glue it on the front, cut new holes and viola!
Puttting a few braces inside first is a good idea.
i'll mention skipping old computer gear. there's not much interesting in them for the effort. better to concentrate on actual audio gear on the day.
an exception is old modems. remember some had an extruded aluminum case? pair of those would make nice monoblocks.
i'd also skip ghettoblasters. tends to be light and cheap parts.
old ham radio gear might be interesting. certainly excellent cases, maybe useful iron and heatsinks, and probably good switches. and some of it will be worth restoring and selling whole, rather than using for parts.
another source of nice aluminum shapes is engine parts for bikes and cars. i'd love to still have the head from my old matchless. plenty of finned area, stick the circuits under the valve covers, put the cables out the exhaut ports, and set volume knobs through the spark plug holes. power cable can go in the intake. set it on a base just high enough to conceal a pair of toroids under the compression chambers.
an exception is old modems. remember some had an extruded aluminum case? pair of those would make nice monoblocks.
i'd also skip ghettoblasters. tends to be light and cheap parts.
old ham radio gear might be interesting. certainly excellent cases, maybe useful iron and heatsinks, and probably good switches. and some of it will be worth restoring and selling whole, rather than using for parts.
another source of nice aluminum shapes is engine parts for bikes and cars. i'd love to still have the head from my old matchless. plenty of finned area, stick the circuits under the valve covers, put the cables out the exhaut ports, and set volume knobs through the spark plug holes. power cable can go in the intake. set it on a base just high enough to conceal a pair of toroids under the compression chambers.
If you live in or near a college town, go dumpster diving at the university physical plant or any place where electronic repair is done. They constantly throw away old PA equipment, stereo equipment, and speakers. I know from personal experience from working as a technician while going to school. I salvaged so many cool parts it's ridiculous!
Find a fellow enthusiest with a pregnant wife. I got a case of about 500 tube sockets, 1000 pots, 20 chip amps, and 100 high voltage caps from a co-worker with a ****ed-off wife who was "tired of all that junk."
Solid-state guitar amps usually have pretty good transformers for chip amp use(and usually some other goodies as well!). Find an unused Peavey in someones garage.
Find a fellow enthusiest with a pregnant wife. I got a case of about 500 tube sockets, 1000 pots, 20 chip amps, and 100 high voltage caps from a co-worker with a ****ed-off wife who was "tired of all that junk."
Solid-state guitar amps usually have pretty good transformers for chip amp use(and usually some other goodies as well!). Find an unused Peavey in someones garage.
trash!! give me trash!!
talk to hi-fi repair shops as well, if you talk nicely they may throw some things your way, most of the realy good stuff they keep for them selves, they do know how to repair the stuff after all. but you should get enough to make a few good amps with. the exeptions with computer stuff are servers they have some realy good caps and some power distribution stuff like current ballance chokes great for cleaning supply lines, and psu units, not for the power supply its self, but case and fan, power conector, stuff like that. old style desk top cases make good amp boxes. happy hunting, c u later, steve.. ..
talk to hi-fi repair shops as well, if you talk nicely they may throw some things your way, most of the realy good stuff they keep for them selves, they do know how to repair the stuff after all. but you should get enough to make a few good amps with. the exeptions with computer stuff are servers they have some realy good caps and some power distribution stuff like current ballance chokes great for cleaning supply lines, and psu units, not for the power supply its self, but case and fan, power conector, stuff like that. old style desk top cases make good amp boxes. happy hunting, c u later, steve.. ..
BbbyBld
Funny you should say that, I am a physics PhD student and also work in the physics department 🙂 We don't throw out as much stuff as the engineers but I am always looking.
The pickup day is Monday week and I noticed today that people are starting to put stuff out, so I think I will go for a look this weekend 😀
Funny you should say that, I am a physics PhD student and also work in the physics department 🙂 We don't throw out as much stuff as the engineers but I am always looking.
The pickup day is Monday week and I noticed today that people are starting to put stuff out, so I think I will go for a look this weekend 😀
excellent. university departments can have very good clear-outs once in a while. can't hurt to chat up your department head too. once he knows what you're looking for, he might mention the odd bit of obsolete lab kit that's gathering dust. (or 'she', of course.)
The first find of the week is a Rank Arena stereo receiver/amplifier, model RA402, 90W into 8ohms. I pulled the transformer out and measured the output to be +-22v. It is also a good source of pots and knobs. The amplification stage still looks in good shape so i will hang onto that.
I just hope I find some more stuff in the week to come 😀
I just hope I find some more stuff in the week to come 😀
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