Good practice for the eyelet boards in DIY tube amp kits?

Mike M

New member
I would like at some point to start building amps (the Amplified Parts kits and Mojotone kits have my eye) and they seem to use eyelet boards for the boards almost exclusively, mirroring the real vintage construction. I've built something like 30 guitar pedals but they've all been PCB builds of varying source.

What's the best practice for getting sufficiently familiar with eyelet boards? Amplified Parts sells a number of "kits" for vintage style pedals that use eyelet board construction. Would those be good? E.g.: https://www.amplifiedparts.com/pedal-guides/build-project-one-knob-tonebender-mk2

I know there's way way more to building amps than just knowing how to solder components to an eyelet board but I definitely want to practice that specific skill before I start in on a $1000+ amp kit.

Thanks!
 
The soldering process for eyelet boards is similar to building a PPCB pedal. Basically you just bend the leads so they fit the holes then solder. Most eyelets will have more than one component lead. I prefer to fill the eyelet with solder, others just add enough solder to stick the component to the eyelet, IMHO either is fine. I assemble all components to the board prior to soldering any, this allows me to more easily make adjustments if necessary.

Having a decent soldering iron with a larger tip than used for pedal work is important. One melts a lot of solder quickly so the iron needs to be up to the task.

I see Amplified Parts has a 5E3 Board for $12 that would be good for practice, but TBH I just jumped in and started on my first amp and learned as I went.

The pedal kit you mention looks like good practice.

But seriously, IMHO, soldering eyelet boards is easier than soldering a pedal because there is much more room to work.
 
The soldering process for eyelet boards is similar to building a PPCB pedal. Basically you just bend the leads so they fit the holes then solder. Most eyelets will have more than one component lead. I prefer to fill the eyelet with solder, others just add enough solder to stick the component to the eyelet, IMHO either is fine. I assemble all components to the board prior to soldering any, this allows me to more easily make adjustments if necessary.

Having a decent soldering iron with a larger tip than used for pedal work is important. One melts a lot of solder quickly so the iron needs to be up to the task.

I see Amplified Parts has a 5E3 Board for $12 that would be good for practice, but TBH I just jumped in and started on my first amp and learned as I went.

The pedal kit you mention looks like good practice.

But seriously, IMHO, soldering eyelet boards is easier than soldering a pedal because there is much more room to work.
thank you! i think i'm mostly nervous about blowing up an amp board. i have a weller iron and half a dozen different tips of varying sizes and it hasnt failed me yet. the problem has been user-related when there has been a problem
 
I would add that you should definitely fill the eyelet with solder. Too easy to get a dry joint if you don't. You'll never see an old Fender amp without the eyelet being full of solder. It is good practice to hook components around the eyelet so that you are not just relying on the solder to hold everything in place. In other words, bend the lead at 90 degrees where it goes through the eyelet. Once you have got both ends of the component through their respective holes bend the excess lead poking through the back of the board flat against the back of the board and trim off the excess. You just want a little hook to hold the resistor, cap or whatever to the board. You don't want to much lead behind the board because then it's difficult to remove that component later if you need to.

Have a look at pics of old Fender and Marshall guts. You'll see how they lay things out. Try to avoid plate wires being close and parallel with grid wires. If they need to cross each other try to make them run at 90 degrees to each other.

And I would definitely recommend watching a bunch of Psionic Audio's Youtube videos. He is right about pretty much everything!
 
I would add that you should definitely fill the eyelet with solder. Too easy to get a dry joint if you don't. You'll never see an old Fender amp without the eyelet being full of solder. It is good practice to hook components around the eyelet so that you are not just relying on the solder to hold everything in place. In other words, bend the lead at 90 degrees where it goes through the eyelet. Once you have got both ends of the component through their respective holes bend the excess lead poking through the back of the board flat against the back of the board and trim off the excess. You just want a little hook to hold the resistor, cap or whatever to the board. You don't want to much lead behind the board because then it's difficult to remove that component later if you need to.

Have a look at pics of old Fender and Marshall guts. You'll see how they lay things out. Try to avoid plate wires being close and parallel with grid wires. If they need to cross each other try to make them run at 90 degrees to each other.

And I would definitely recommend watching a bunch of Psionic Audio's Youtube videos. He is right about pretty much everything!
i've been watching psionic audio for a little while now, his videos are great. before i went to build my first amp i was planning on reading building valve amplifiers by morgan jones at the absolute least.
 
The way Lyle on Psionic describes grounding has been a revelation to me. My amps have never been so quiet. Well, until I make them noisy.
do you have a specific video you can point me to where he talks about it? I've seen a lot of his videos and i know he talks about grounding but i dont recall one where he goes in depth
 
He did a video where he did up an old Marshall where he goes into it. Also some vids on older Fenders. I can't think of which ones of the top of my head.. The key bits are to ground the power section next to the PT and ground the preamp nearer the inputs. And if a pot has pin 1 to ground he recommends grounding that pin to the pot. But you must make sure that the pots are securely attached to the chassis with a star washer and that the nut is tight so that a good connection is made and kept. Don't attach PT grounds to eyelets bolted to the chassis via the PT mounting bolts. If possible solder the secondary's centre tap to the chassis.

Marshall's traditional ground buss along the back of the pots causes hum, so do as above.
 
Never built an amp but that's my wet solder dream.
However I've built a bunch of fuzz circuits on turret and eyelet boards and designed the layouts myself. I ended up cramming 5+ leads on the same turret. Amps usually avoid that.
I learned to place the leads carefully because you can't undo that mess and once done I never want to touch the board again.
Use a powerful iron with quick recovery and a large tip, 4mm flathead works very well.
 
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