Repurposing Old/new Amps & parts

[Mrd34d]

I've apparently gotten off on the wrong foot with some members based on this topic. Thought it would be a good & educational idea to start a discussion on this.

SO: is it a good idea to repurpose parts from both old & new amps? Are some parts better left alone and should be replaced? Are there are parts that are better to reuse?

Why is it ok to repurpose old vintage amps, but not the parts contained?

Personally I think it's ok to reuse old parts...whether it be because of a tight budget, or the parts are actually in very good condition for their age.

Maybe an amp (or even pedal) sat around for 10, 20, or 30 years and never saw any action. At that point I'd think it'd be perfectly fine.

 

[waltdogg]

Techs repurpose good transformers, chassis, and tubes.

Cannibalizing old pedals and amps with funky circuits for their germanium, etc. That's all good fun as well. But as parts age, unused or not, they get out of spec and decay and don't function the way they should and a lot of them are ultimately a shock or fire hazard waiting to happen. Just because something looks good, doesn't mean it functions as good.

 

[seamonkey]

Go for it.
Recycling is good.
Circuit bending has a huge fan bass. Great music being made with bent circuits.

Through the years, plenty of people have re-purposed gear. Entire companies have their roots from re-purposing gear. Any company making a new product should study what has been on the market through the years and why.
Reverse engineer what's out there, mod it, and make it better.

Unless you do the research, really old gear you should stay away from as it may include some dangerous compounds.

Some old parts like caps are consumables and don't stand the test of time but are cheap and easy to replace with modern ones. But don't expect the modern matches the characteristics of the old, as things like caps are much better today with lower unexpected artifacts. Some things you can try is to degrade a modern cap by adding some series resistance or inductance.

 

[BassmanPaul]

Old parts are just that OLD. Many will be off spec or already close to the end of their life span. (Gawd!! That sounds a bit like me!!!)

If you are going to the trouble of building something using fresh modern parts will save you grief down the road.

 

[waltdogg]

Old parts are just that OLD. Many will be off spec or already close to the end of their life span. (Gawd!! That sounds a bit like me!!!)

If you are going to the trouble of building something using fresh modern parts will save you grief down the road.

+1

This is the bottom line.

 

[agedhorse]

There are indeed some parts that can be successfully re-used. They include unique switches and hardware, tubes, unique semiconductors, some wire wound resistors, transformers, chokes and unique jacks-sockets.

 

[spankdaplank]

In 1963 (13 years old) when I started playing bass I needed an amp but had no money. There was a moldy old black&white TV sitting in our basement. Emerson brand, I think. This thing had a huge (to me at the time) speaker; probably a 10. The best part was this beast of a TV had, separate from the video chassis, a power amp mounted in the bottom of the cab, tube of course. 6V6 output tubes. I took out the speaker and amp chassis and mounted them in an old kitchen drawer that was being thrown out after some remodeling. I cut a hole in the bottom of the drawer to mount the speaker and stood it on edge. It still had the handle on it. The whole mess needed some kind of preamp, though. It just so happened that I had built a phono preamp kit made by Lafayette Radio. I used this as the preamp. It really ruined the potential of this setup as the preamp had a built in RIAA eq curve which made it very bassy and muddy. I did have fun building it and, I guess learned a few things along the way. I still cobble stuff together to this day as a hobby. The best part of the adventure was that my parents saw I was serious about playing bass and bought an Ampeg SB-12 for me. My first real bass amp.

 

[beans-on-toast]

In 1963 (13 years old) when I started playing bass I needed an amp but had no money. There was a moldy old black&white TV sitting in our basement. Emerson brand, I think. This thing had a huge (to me at the time) speaker; probably a 10. The best part was this beast of a TV had, separate from the video chassis, a power amp mounted in the bottom of the cab, tube of course. 6V6 output tubes. I took out the speaker and amp chassis and mounted them in an old kitchen drawer that was being thrown out after some remodeling. I cut a hole in the bottom of the drawer to mount the speaker and stood it on edge. It still had the handle on it. The whole mess needed some kind of preamp, though. It just so happened that I had built a phono preamp kit made by Lafayette Radio. I used this as the preamp. It really ruined the potential of this setup as the preamp had a built in RIAA eq curve which made it very bassy and muddy. I did have fun building it and, I guess learned a few things along the way. I still cobble stuff together to this day as a hobby. The best part of the adventure was that my parents saw I was serious about playing bass and bought an Ampeg SB-12 for me. My first real bass amp.

I did much the same thing back then but in my case it was an old console radio conversion. It had a 15" speaker and sounded great.

Finding an old amp in rough shape or anything similar that is tube based can serve as a great platform for building something else. You have a chassis, tube sockets, pots, power and sometimes a useful output transformer all available. I've used HP200CD signal generators that I bought for under $25 at hamfests. Throw in an output transformer and a bit of rewiring and parts and you have a nice little amp.