EMI RS124

[alphasnk]

So cool to see you having fun making these beauties!

I've done two RS124 with a 1mA Simpson vumeter and left a potentiometer inside as well, and same thing with the threshold potentiometer..

It's a great circuit for experimenting as well, you can try putting the timing capacitor on a lorlin and adding different values, different kind of material, ceramic, plastic

The input potentiometer was always weird..

 

[Brian Roth]

Today I silkscreened my two panels with a friend. Friday will be drilling day… and final assembly to follow.

Happy about how it turned out !

So cool to see someone doing DIY silkscreening! Decades ago I taught myself screening of panels with assistance from a local company that sold the supplies.

High contrast "Kodalith" print of the "artwork" transferred onto a photosensitive emulsion on the fabric. Using the correct ink for adhesion to the metal and durability. The friendly rep at the supply company directed the long haired kid <g> to the ink used to make outdoor signs...speed limit, stop, etc. signs.

Unlike many things these days, the ancient art of screen printing is still in wide usage. My closet is full of screened t-shirts!! lol

Bri

 

[thomasdf]

Cool story ! Mine implied computer work of course so it is a little less charming I was hesitating re insulating the screen myself, because I do a lot of film photography and did a some photo engraving for a while so it wasn’t completely unfamiliar, but in the end I found a great deal with a local supplier providing the insulated screen and when that route. I then did the printing with a friend at his workshop, using Nazdar black ink.
Very happy how it turned out, even if it was a lot of work for « just » two front panels.
If I had to redo it, I’d add the vu meter design and maybe rear panel to the screen. (There was a lot of room left)

 

[Brian Roth]

We didn't have consumer access to computers in the 1960's and 1970's; those were owned by the banks and government! <g>

I laid out the panels with rub-on letters and (as needed) a Rapidograph ink pen onto a piece of white artist's board (a semi-thin cardboard). I discovered a local shop with a large photostat camera that could accept a 2x size original from me and reduce it 2:1 onto Kodalith film. Then, it was a sort of "contact printing" of the Kodalith image onto the emulsion coated onto the "silk". Lots of trial and error!

Nazdar was a brand of ink I recall, but the local folks directed me to the "stop sign" ink they sold.

I originally screened the fronts of the Roth Fuzz (yes...) stomp boxes in my parent's garage. Did a total run of maybe 10. Later the front rack panel and rear overlays for an electronic crossover I was selling. I'd run maybe a dozen panels at a time totaling maybe 100-125 over several years of production.

Wish I had a better copy of this "artwork"....

 

[vitopower]

This is so cool! Any chance we get to hear the Roth Fuzz / see the layout? GE or SI?

 

[Brian Roth]

This is so cool! Any chance we get to hear the Roth Fuzz / see the layout? GE or SI?

I built the few that existed over 50 years ago when I was in High School. AFAIK none are still around.

It had two SI transistors and was based on a circuit I saw in Electronics Illustrated magazine.

Bri

 

[thomasdf]

Cool logo Brian ! Simple and effective

Today was drilling day, here are some work in progress pictures

Edit : as anticipated, the VU hole is a bitch, in this steel panel !

 

[thomasdf]

Build is almost over ! They need proper meter scale, as well as a 12V light bulb because the 6.3V is way too bright
Sound is glorious !!

 

[rock soderstrom]

Build is almost over !

Wow, impressive builds

 

[anvl]

Really Beautiful !!! Bravo !!!!

 

[tomas1808]

Build is almost over ! They need proper meter scale, as well as a 12V light bulb because the 6.3V is way too bright
Sound is glorious !!
View attachment 132978

Thomas, where do you get the "bypass" and "stereo link" indicator buttons? Are they NOS? Or can they be purchased new? Thank you!

 

[thomasdf]

These are NOS, from my stash but you can buy them new from RS and everywhere else. They are ITT Schadow switches. They come in a variety of gangs, colors, bezel type etc