frustrated by eyelet/turret board prototyping

[imaradiostar]

I've built quite a few "clones" of existing amps and I've rarely departed from existing designs. I now find myself wanting to try a bunch of new preamp ideas and I have a hard time deciding on an exact layout knowing things are likely to change.

I'm tempted to make a Hiwatt or Hoffman style board with an excess of turrets and just switch it around as needed till I'm happy. This doesn't seem to make for the best grounding or packaging for some circuits.

What do you do to try a new circuit or idea? Keep in mind I want something a little more permanent and transportable than a breadboard.

Jamie

[MWJB]

Terminal strips, I wouldn't use turrets for anything other than a finalised design, solder can collect in the turret & drip to the chassis. A generic, 3 row eyelet board could do the job, use an isulator board, less chance of any b+ suply wires coming loose & falling out of the board. Mounting tone circuit components on the tone post helps free up space on the board.

I might do a dozen drawings before I get to the stage of actually building anything.

[defaced]

I use poplar wood and copper coated nails. 10 bucks and all the prototyping fun you could ever want. More permanent than a "normal" plastic breadboard, but not as expensive as G10 and turrets. Plus I don't feel guilty when I tear the whole layout apart and re-do the nails because the design sucks.

[loudthud]

Making any eyelet or turret board work in a prototyping situation is a matter of luck. Don't crowd things too close together in the beginning to improve your odds. Place all B+ and ground wires on the top of the board under or over the components. You can move them to the back when things settle down later. The generic three row board is not a bad way to go. Another option is terminal strips. Need an extra couple of tie points at the tone stack or Dumble style right at a tube socket? A terminal strip will get the job done with one or two drilled holes or just solder to the chassis or back of the pots.

When I'm just trying out wild ideas, I tend to just tack things together willey nilley. If it works like I want it to, then I'll re-build it a little better until the design is finalized. The same goes when I'm doing a layout. I lightly sketch things in pencil so it's easier to erase and move things. The more confidence I have in the placement. the darker I draw it in.

[tubeswell]

I've done this (eyelet board prototyping) a few times now and I sketch out a few layouts and tease ideas around, then put in a few extra eyelets here and there to allow for things like changing stages from CF to normal inverting/vice-versa, or parallel triode stage, or leaving room for additional Rk/Ck combination or an additional/spare on-board filter cap and supply resistor, or a bias supply, or an optional tremolo or reverb circuit etc. I also put several eyelets side-by-side at the input jack end of the board, and run all the pre-amp grounds (by separate wires) to that 'terminal strip' for convenient grounding.

[jmaf]

A vector drawing program such as the free and open Inkscape can also be your friend in these cases. Drag things around, delete and change the layout at will before you even solder a single thing. Since a friend convinced me of drawing on the PC before diving into the chassis I've saved myself countless hours. Granted, you'll spend a little time on the program, but you'll save it back later during the build.

[R.G.]

Let's play history.

Do you know how the word "breadboard" came into electronics?

At one time, there was a woeful lack of electronic prototyping materials. As in none. An electronics hacker would take a flat plank, sometimes literally a breadboard used in the kitchen for keeping and slicing bread, and drive metal brads or nails into it where he wanted an electrical tie point. The extension to turrets should be obvious, as should the simplification of nails and turrets to hollow brass rivets, which is what eyelets are.

Get a plank. Figure out where you want tubes. Affix the sockets to the plank some way, perhaps by drilling a hole and then screwing the socket tabs/ears to the plank. Guess where you want parts laid out, then use a small hammer to place a small nail at the connection points, leaving about 1/2" sticking up. Wrap the leads/wires one turn around the nail and solder. Weller soldering guns are fine for this.

Leave yourself lots of room to add new parts. Don't like where the parts are? Pull the nails and drive in new ones.

It's not pretty, it's not elegant, and it's not long-term rugged. But it is fast, effective, and forgiving of placement mistakes. Once you get your own special sauce recipe done on breadboard, go to turret, eyelet, whatever. You can even use nails on boards as a prototype tester for turrets by placing nails where the turrets will go and developing the part layout and wiring layout that way as well.

Have I mentioned "let's get down to brass tacks"? Or "... aww, screw it." Brass tacks and screws work too.

[defaced]

A picture of how I do mine. Soldano Avenger preamp, bread board and finished version.

[R.G.]

You're all over it!! 8-)

[ivey]

I recommend that you do what we did back in WWII.

Make stencils of all your parts. In real life size pieces.
Lay them out on a piece of cardboard cut out to the size of your turret board.
Tape the pieces to the cardboard once you have them where you desire them to be.
Once that is done, use sewing thread as wire to connect your parts to tubes, pots, transformers etc.

Do not get rid of the stencils because you can use them again.

This will give you a good idea of the physical layout of your design.

A lot of good planning will save you a lot of money in the future. And headaches.

Take Care


Ivey

[imaradiostar]

Wow, I love seeing the comparisons. Thanks for the input.

I think I'm going to build a chassis with a pair of cathode biased EL84's, a LTPI, and appropriate transformers to go with them. I think I'll just leave a large area with a bunch of turrets so I can experiment. I happened upon a bunch (thousands) of military turrets so I think I'll just use some good old "swirly red" gpo3 from mcmaster and just try some things. I'll leave room for three or four preamp tube sockets and an abundance of holes for controls at the front panel.

I made a list of things I've been wanting to try and I stopped when I hit 15- time to stop planning and start building.

jamie

[Chuck H]

I now find myself wanting to try a bunch of new preamp ideas and I have a hard time deciding on an exact layout knowing things are likely to change.

Simple changes would be coupling cap values, load resistor values, cathode bias resistor and capacitor values, etc. And these don't require changes to the board at all. circuit and layout changes require changes to the board and this is extreamly hard to predict for myself. It's impossible for me to do it for you.

What do you do to try a new circuit or idea?

I build the board as I think it should be for the circuit and layout. I do sometimes include eyelets for curcuit changes like series resistors or jumper caps that may or may not end up in the circuit but only if their inclusion doesn't interfere with with the layout objectives. If it doesn't work out I make another board that hopefully fits within the overall design limitations of the chassis, control and tube layout.

Keep in mind I want something a little more permanent and transportable than a breadboard.

So you want something that will allow for full design flexibility for circuit and layout, look neat and tidy and perform with the same reliability as a fixed, idealized board, right? (just pokin' at you)

The closest I've seen would be the perf board and flea clip design used on Trainwreck amps. I don't even know if they make flea clips any more. But this system would allow you to change the circuit and layout at will with few limitations and minimum effort. When your done it would be almost as durable as any eyelet board amp.

Chuck

[ivey]

Jamie:

Building is good.
But building B.S., is not good.

You need input. Lots of input. You need layout ideas and layout patterns.
You can get all that you need at a EL84 site. You can download their designs and mod them to your liking.
Please do not go off half armed. You will need all your bullets.

Bread board your design of a piece of 10" wide pine wood. Lay it out like we use to do in the 1930's and 1940's. You can get ideas of the their lay out at vintage radio sites. This will allow you to photo the design and transfer the parts to your final build, without losing your parts or destroying them in your build.

I wish I was in the PENN State myself. They close down the naval shipyard there so all their old electronic materials went to surplus. God I am taking a trip!!!

Take Care


Ivey

[imaradiostar]

I wish I was in the PENN State myself. They close down the naval shipyard there so all their old electronic materials went to surplus. God I am taking a trip!!!

Take Care


Ivey

Not sure what you mean there- I got my excess of turrets from work and an ebay auction a year ago. Where is all the cool surplus stuff? I wanna know!

Don't get me started on EL84 sites- there are so many people talking about how great 18 watt marshall variants are and I just don't get it. I'm breadboarding because I don't want to do all that stuff over.

Jamie

[ivey]

I knew a great many of the yard workers at the Philly Naval Yard. They had so much stuff left over from the days of WWII, the nuclear start up periods, and Vietnam. You could get what you wanted.

In San Diego, there is a place called Murphy's Industrial Supply and Electronics. It was my favorite place. Spent hours in that place. They get so much stuff, it is unbelievable.

I notice one day the shipments were getting smaller, they told me that they were starting to have problems getting old electronics pcb's because of all the new companies that are recovering the gold from the old boards.

There are US Military auctions in Oklahoma, selling the stuff by the pallet load. As soon as I am feeling better, I get myself some.

But look around, it can not be far from Philly, one or two of the businesses that deal in surplus got some of the stuff. I know that surplus and used equipment dealers are getting far and few. But I feel that those guys be making a rebound soon if the economy continues as it has. And do not forget Pittsburgh. I will start checking over the internet, I will keep you informed.

There is a lot of buzz going on about EL84 amps. It is a load of Bull. But they are good sells men. They want to keep people into the tube thing, even thou they know it is a rip off.

Re-tubing amps can get expensive and in itself, is costly. We knew it in the 1950's and we know it day. But the electro-mechanical magic of the technology is a magnet in itself. It draws people to it like bees to blooming roses. People look into the inside of the tube and magically wait to see something happen or move.

I enjoy the tone of tube amps. But the dollar layout for tube equipment, is not worth the donation in dollars and cents. The heat, wears out the wiring, dries up the capacitors, and cause early failures in parts. Plus the tubes themselves wears out.

Like old cars, they are easy and a pleasure to fix, work on, and use. But it has its draw backs. And right now. That draw back is cost.

The makers of tube amps, hardware, and tubes, know that it is like Star Trek convection. Get your money while you can. They build these dreams into peoples heads, and then leave them with this very high cost for support, to continue on. Much like those groups of people that collect vintage sports cars.

I witness that first hand. I built a 240 mph Chevron in 1977. Mine was a rear engine driven 351 Ford Cleveland Engine, fully turbo blown. With 9" of boost. Z transaxle, interior was totally done in thin layers of stain Douglas Fir, steamed and wrapped around molding to take shape. With cloth padding, rolled and tucked. By 1990, I was own my own, with no support. And only the manual that told you how to put the thing together. No repair parts.

In 1997, my wife and I pack it up, shipped it Las Vegas, and drove it down the new and old stripe. The first day out, we started stopping at all of the lust hotels to show off the car. We leaving the front of the hotel, Sam's Club and Casino, when we were stopped and offered $60,000.00 dollars from these young Arabs.At least I think they were Arabs. Hell could have been Mexicans. So, I acted insulted about the price. But sold it minutes later.

I made $50,000.00 dollars on that car. Can you believe that. $50,000.00 dollars, sold as is, with no refunds. I even recouped the cost of shipping the car in the first place. I was hoping for $15,000.00 dollars. But what other people don't know will sometime be in your favor. If I had not been able to sell that kit car. I be stuck with a product with No support.
My biggest advantage in selling that car was that I built it like they do the British Morgans. I fitted every single piece and part together, so that it looked like came from the factory.

I did not do it on purpose, I did it because I was going enter it into the best Chevron kit car contests.

Take Care


Ivey