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What is the upside?

I've scratch built several power amplifiers and a fairy sophisticated pre-amplifier, fairly often just from schematics. I was guided in the beginning by excellent threads in this forum on some of the builds, particularly Dave Gillespie's projects. One other notable one was Mark's Blueglow/Kegger KT88 SE amplifier, which also introduced me (in an excellent way) to single-ended designs. Following the "guided" ones helped me develop proper construction techniques, particularly around noise/hum control, proper placement of components and the like. This then helped make my "unguided" builds a success. Morgan Jone's excellent books were also a great resource.

I really enjoy the process of scratch building. The metal working is probably my least favorite part, but I learned from these sources how to do it reasonably well.

My favorite personal example is the Gillespie Fisher SA-100 clone which, like the above "semi-vintage" examples, used re-purposed Heathkit AA-100 output transformers and Dave's circuit improvements to produce a really great-sounding EL84 power amplifier. I built the first one and sold it to a fellow who loves it and built a second one as a keeper for myself. Another very satisfying build was Dave's re-work of the Heathkit W4M to class A triode push pull service that sounds great and uses a vintage design as a stepping off point for something special. (Do you detect a "Gillespie" theme in this work? );)

I really enjoy restoring vintage gear as well, but the scratch builds taught me a lot and gave a lot of satisfaction in the process and the end product ("I built this one from a pile of parts!").
 
Dave451 said:
I've scratch built several power amplifiers and a fairy sophisticated pre-amplifier, fairly often just from schematics. I was guided in the beginning by excellent threads in this forum on some of the builds, particularly Dave Gillespie's projects. One other notable one was Mark's Blueglow/Kegger KT88 SE amplifier, which also introduced me (in an excellent way) to single-ended designs. Following the "guided" ones helped me develop proper construction techniques, particularly around noise/hum control, proper placement of components and the like. This then helped make my "unguided" builds a success. Morgan Jone's excellent books were also a great resource.

I really enjoy the process of scratch building. The metal working is probably my least favorite part, but I learned from these sources how to do it reasonably well.

;)
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Yes, it should ultimately be a learning experience.

:thumbsup:
 
Agree that chassis work is a huge time drain and one of my least favorite parts. However I recently bought a drill press and that made it suck 100x less for me. I always dreaded hand drilling and the results often required clean up, whereas my holes with a cheap drill press are clean and professional every time.
 
The chassis work for me is the easy cheap part as where I work we are aero space fabricators so I have access to plenty of scrap, a water jet table, machine shop, blast shop, welders, paint shop, shears, and brakes and all the manpower to do what I need at no cost if were slow and I keep it to a limit. Although I did buy a few Hammond chassis, and transformer covers just because they are cheap and saves time.
 
Ken Boyd said:
Currently I am working on my first scratch build project and as I progress, I can see I doubt I will be able to keep the budget to where it will be less than what I can buy a nice condition used really nice amp. So all said I am wondering what is the upside of scratch building an amp. I can buy amps that are used that need work and stay within a good margin in most cases. But starting fresh, buying the chassis, transformers, OPT's tube sockets, turrets, tubes, caps, resistors, chokes, and all the other little items needed, I can go out and buy a really nice pair of amps that hardly need any work on the used market. And then you have to take into account will the project sound as good. I am still going to go forward, but this might be the last of this kind of projects for me. I think I would be better off just buying an old used amp that has good iron and repurpose it.

So I am wondering what is the upside of building a new amp from scratch? Am I missing something?
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ConradH said:
I don't do tubes but could probably find half what's needed in my 50-year-old stash of stuff. Starting from scratch would be expensive unless I could find parts on Alibaba or similar.
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I dunno, I've built a few amps from scratch that would have cost me twice as much if I had went out and just bought one ready to go. It kind of depends on the types of amp and how fancy you want to go with some parts. There isn't any reason to spend hundreds on boutique capacitors, etc.
There's mild to wild when it comes to scratch builds.
 
For me,, I enjoy building stuff!! It was cars when I was younger and had teh connections,,, but then found other hobbies that came and went,,, I got into amps when I retired and went to radio shows and then hamfests and got hooked,,,,, Just about everything I use (other than consumables,,, resistors caps, solder) came from these meets and usually for pennies or free from guys that just want to clear out stuff... I only bought 2 pair of OPTs new,,, as I built everything else I've posted here from transformers, pots, switches and other parts I collected,,, same with chassis,,, tubes,,, sockets,,, knobs etc,,, The hunt is a big part of teh build,,,,
We have a huge 2 day antique radio show next weekend and I have lists and empty boxes for parts and new projects ready to go!!!
I'll see some of you there!!!
 
A big part of why I stalled on my W4 clone build is I screwed up the chassis work. Its not tragic, but I put the power transformer 90 degrees from where I should have. I can fix it, or probably ignore it but it annoyed me so I set it aside and haven't gotten back to it. Got a little ahead of myself and didn't pay quite enough attention to a detail.
 
Ken Boyd said:
Currently I am working on my first scratch build project and as I progress, I can see I doubt I will be able to keep the budget to where it will be less than what I can buy a nice condition used really nice amp. So all said I am wondering what is the upside of scratch building an amp. I can buy amps that are used that need work and stay within a good margin in most cases. But starting fresh, buying the chassis, transformers, OPT's tube sockets, turrets, tubes, caps, resistors, chokes, and all the other little items needed, I can go out and buy a really nice pair of amps that hardly need any work on the used market. And then you have to take into account will the project sound as good. I am still going to go forward, but this might be the last of this kind of projects for me. I think I would be better off just buying an old used amp that has good iron and repurpose it.

So I am wondering what is the upside of building a new amp from scratch? Am I missing something?
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I haven't done a new scratch build in years, on account of this. Closest thing was buying an older set of partially complete kit amplifiers, which I wanted but didn't have the funds to buy back in the 90s, and finishing them off.

On the other hand, you say it's your first, and there's some things you can only learn by doing. I find that having designed and built amplifiers from scratch helps me to understand and troubleshoot amplifiers, not to mention evaluate their relative merit. For me, it is a little hard to justify making one after another though - both in terms of cost, and also, well, I don't need so many amplifiers!
 
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knockbill said:
For me,, I enjoy building stuff!! It was cars when I was younger and had teh connections,,, but then found other hobbies that came and went,,, I got into amps when I retired and went to radio shows and then hamfests and got hooked,,,,, Just about everything I use (other than consumables,,, resistors caps, solder) came from these meets and usually for pennies or free from guys that just want to clear out stuff... I only bought 2 pair of OPTs new,,, as I built everything else I've posted here from transformers, pots, switches and other parts I collected,,, same with chassis,,, tubes,,, sockets,,, knobs etc,,, The hunt is a big part of teh build,,,,
We have a huge 2 day antique radio show next weekend and I have lists and empty boxes for parts and new projects ready to go!!!
I'll see some of you there!!!
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The enjoyment is the biggest part of it. I started with cars in high school and kept building muscle cars into the 80's. Back then all my audio equipment was bought new ready to go out of the box. I started collecting and restoring older SS gear around 2000 after I got side lined with a broken back. Then switched to tubes.
It's been a lot more fun building tube equipment than it was just cleaning up and replacing parts in SS gear. The hunt for parts new and used along with keeping an eye out for old tube junk to scavenge parts from is fun to me also.
I have a larger Toroidal transformer next to my bench I keep looking at trying to decide what to build around it at the moment. Maybe a 6L6 PP amp, or another guitar head amp for my son?
 
Ken Boyd said:
Currently I am working on my first scratch build project and as I progress, I can see I doubt I will be able to keep the budget to where it will be less than what I can buy a nice condition used really nice amp. So all said I am wondering what is the upside of scratch building an amp. I can buy amps that are used that need work and stay within a good margin in most cases. But starting fresh, buying the chassis, transformers, OPT's tube sockets, turrets, tubes, caps, resistors, chokes, and all the other little items needed, I can go out and buy a really nice pair of amps that hardly need any work on the used market. And then you have to take into account will the project sound as good. I am still going to go forward, but this might be the last of this kind of projects for me. I think I would be better off just buying an old used amp that has good iron and repurpose it.

So I am wondering what is the upside of building a new amp from scratch? Am I missing something?
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Upside is the sheer joy of building something that works well, and you gits to say, "Made it muhself!.
 
Lavane said:
I dunno, I've built a few amps from scratch that would have cost me twice as much if I had went out and just bought one ready to go. It kind of depends on the types of amp and how fancy you want to go with some parts. There isn't any reason to spend hundreds on boutique capacitors, etc.
There's mild to wild when it comes to scratch builds.
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I won't be using any boutique caps just reputable ones, And I thought the amps I want to build would be simple and low cost, a pair of amps built off the drawings of RCA SP20 amps. A simple basic PP amp using 6L6 tubes and nothing really exotic. When finished they won't be worth a whole lot, not near as much as some old amp that I find for sale, good deals are easy to find.
 
Ken Boyd said:
the amps I want to build would be simple and low cost, a pair of amps built off the drawings of RCA SP20 amps.
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I think you answered your own question. You can't just go buy a new SP20, and they're not exactly plentiful on the used market either. I actually have a pair of output transformers reserved for a future SP20 build, and will follow your build closely if you post it here.
 
maxhifi said:
I think you answered your own question. You can't just go buy a new SP20, and they're not exactly plentiful on the used market either. I actually have a pair of output transformers reserved for a future SP20 build, and will follow your build closely if you post it here.
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See there is another reason to build your own....you can help others when they go to do the same thing!!!
 
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