Intro and a question on parts havesting.

[Gundecker]

New guy here. I have yet to build anything. I want to get my feet wet with a boost or OD stomp. I will start with the basic beginner project using the recommended parts, and I have a question about old amps. Specifically old Peavey bass and PA amps. These things can be had for free or very cheaply around here and most are not working. I am talking late '60's-early '70's. They are full of Motorola and RCA transistors,caps,resistors,diodes etc. With a lot of time on my hands, is it worth it to harvest these components for future designs of "Homebrew" vintage stomps? I hate to throw stuff away. Thanks, Dana

[joelindsey]

If I were you, I wouldn't tear them up. I wondered the same thing as you when I first got into this. There's probably some value in that gear, just because it's vintage. It's most likely not worth your time to pull all the parts. Electrolytic caps deteriorate over the years (sometimes to the point of spilling chemicals out the sides), so the ones from that old equipment won't be of much use. Passive components are pretty cheap. I would get some of those grab bags from http://futurlec.com/ValuePacks.shtml. A few bucks there and you'll have plenty of components to start with. Old transistors are cool, but if this stuff is of late 60's/early 70's vintage they are most likely silicon anyways.

You would probably be better off fixing (if needed) and flipping the old equipment, then using the money to buy parts and enclosures. Plus, P.A. heads can make really cool guitar amps, especially ones with spring reverb. I have a late 60's Ace Tone PA head and it sounds righteous with guitar.

[Govmnt_Lacky]

If some of those Moto and RCA transistors are Germanium, then those would be worth a little effort.

Google the part numbers and do a little research. May just be worth it 

[amptramp]

The power transformers alone may be worth the investment.  The amplifiers may have value, but if they are beyond rebuilding, this is the most important component I would save.  As you can see, I don't go in for any of this old part mojo stuff, but transformers are never cheap new.

[Gundecker]

Thanks for the advice. I have plenty of guitar amps and am partial to Peavey twins. There is some vintage value to some of the old bass and pa amps but the ones I stumble on are either beyond rehabing or flood victims. I will investigate the numbers on the transistors. They do want some big bucks for vintage components but they are NOS. I just want to recycle and say " I made this out of that".

[PRR]

Peavey started with Silicon transistors; Hartley was wise enough to avoid messing with Germanium.

In general you are very unlikely to find any "exotic" part in a Peavey.

In general, "salvage" leaves you with a box of mystery parts you will never use. By taking-apart you lose valuable clues of how the parts work together. I've seen buckets of transformers the owner didn't know what they were, what they came out of, what wire went to what. In an ideal world, some of these could be worked-out with research and testing. IME, this (almost) never happens.

I do recall buying boxes of ex-military circuit boards and used maybe a dozen transistors pulled from them, after much study. In retrospect it would have been just as cheap and much less distracting to just buy the transistors, even at 1970s prices (50X what a transistor costs today).

[LucifersTrip]

New guy here. I have yet to build anything. I want to get my feet wet with a boost or OD stomp. I will start with the basic beginner project using the recommended parts, and I have a question about old amps. Specifically old Peavey bass and PA amps. These things can be had for free or very cheaply around here and most are not working. I am talking late '60's-early '70's. They are full of Motorola and RCA transistors,caps,resistors,diodes etc. With a lot of time on my hands, is it worth it to harvest these components for future designs of "Homebrew" vintage stomps? I hate to throw stuff away. Thanks, Dana

If the amps are beyond repair and you think you would have fun tearing something apart and desoldering, then I'd go for it.
Otherwise, as someone mentioned above, the vintage equipment would be worth more.

Also, even if you did get some exotic parts, germaniums, etc, you probably wouldn't want to start there as a beginner. It's a good idea to go silicon first. Additionally, if you're not accustomed to tearing something vintage apart, you will get your hands dirty....very dirty.

A very simple, clean and  cheap way you can get a bunch of useable transistors, caps & resistors (before you put in a "real" order) is to tear apart plastic children's/baby's toys. Go to a thrift shop and buy a few for a couple bucks. Try to find the older ones (80's) or you'll wind up with micro components. Ironically, I recently finished a Fuzz Face with transistors from a toy that everyone chose over the one I made with BC108's....funny.

good luck

[waltk]

Yeah, recycling parts is cool, but you might find it quickly gets tedious.  I would suggest sticking to high-value parts like transformers (as suggested above).

If you decide to salvage a Peavey, check it for TL604 chips.  These are impossible-to-find/expensive analog switches in an 8-pin DIP package.

[DavenPaget]

New guy here. I have yet to build anything. I want to get my feet wet with a boost or OD stomp. I will start with the basic beginner project using the recommended parts, and I have a question about old amps. Specifically old Peavey bass and PA amps. These things can be had for free or very cheaply around here and most are not working. I am talking late '60's-early '70's. They are full of Motorola and RCA transistors,caps,resistors,diodes etc. With a lot of time on my hands, is it worth it to harvest these components for future designs of "Homebrew" vintage stomps? I hate to throw stuff away. Thanks, Dana

If the amps are beyond repair and you think you would have fun tearing something apart and desoldering, then I'd go for it.
Otherwise, as someone mentioned above, the vintage equipment would be worth more.

Also, even if you did get some exotic parts, germaniums, etc, you probably wouldn't want to start there as a beginner. It's a good idea to go silicon first. Additionally, if you're not accustomed to tearing something vintage apart, you will get your hands dirty....very dirty.

A very simple, clean and  cheap way you can get a bunch of useable transistors, caps & resistors (before you put in a "real" order) is to tear apart plastic children's/baby's toys. Go to a thrift shop and buy a few for a couple bucks. Try to find the older ones (80's) or you'll wind up with micro components. Ironically, I recently finished a Fuzz Face with transistors from a toy that everyone chose over the one I made with BC108's....funny.

good luck

Or even bloody annoying lead free solder even if you bought today's stuff with through hole components .

[edvard]

If it's a total loss, as in board cracked, wood rotted, fire damage, etc. then I agree with looking it over for hard-to-find parts.
Otherwise, I would lean towards the fix-it and flip-it camp, especially for older, more well-known models.

Although, it might be worthwhile to hang on to a couple until after you learn a thing or two from building some pedals, and then try your hand at modding.
I remember Peavey pumped out all kinds of crap in the 80's that you wouldn't take a second glance at, but if the basics are still sound (cabinet, hardware, board) you could make a few well-placed tweaks, label it 'custom' and see what you can get from it.

Hell, maybe I should drink my own Kool-Aid and keep my own eyes peeled for some 'handy-man specials'.
Where do you usually find these things?

[joelindsey]

Although, it might be worthwhile to hang on to a couple until after you learn a thing or two from building some pedals, and then try your hand at modding.
I remember Peavey pumped out all kinds of crap in the 80's that you wouldn't take a second glance at, but if the basics are still sound (cabinet, hardware, board) you could make a few well-placed tweaks, label it 'custom' and see what you can get from it.

+1 on that. Over the past few years I've acquired a handful of broken or beat up old solid state amps. It's always handy to have a little beater amp sitting by the workbench or for lending to friends. You never know when a speaker on your main amp is going to blow... having those beaters around to temporarily pull stuff from in a pinch is handy.

Where do you usually find these things?

Try craigslist, in the trash, yard sales, friends of friends parents cleaning out the basement, etc.

[DavenPaget]

+1 on that. Over the past few years I've acquired a handful of broken or beat up old solid state amps. It's always handy to have a little beater amp sitting by the workbench or for lending to friends. You never know when a speaker on your main amp is going to blow... having those beaters around to temporarily pull stuff from in a pinch is handy.

That's why i stuff me 3 replacement speakers under my bed   
Okay , they aren't really exactly replacement , but they are 8" subs that obviously is smaller then my 10 incher .

[petemoore]

1  Plugged in: What does it do ?
  a: Works...use it or sell it.
  b: Needs work but works, fix it and refer to 'a'.
  c: Doesn't work...either fix it or use the chassis/power hardwares to supply a different circuit...in cases where say the whole 'back end' is toasty.
  ...Old PV400 amp/PA sits in the garage [need to bring it in before it freezes...
  Perfect example of what these things can go through...freezing, baking, water...who knows what 'it'll do until it is caused to do something...if blue smoke comes from the transformers, don't inhale and you can still get the ''bums rush'' effect from it.
  Basically it's either a pile of good and or bad parts or it works, getting to know the parts helps keep it working.