Akai SS-1 Universal Synthesizer

[Soundfield]

.... I’m next going to use par4ken’s modern variant of the Akai SS-1. Interesting that you should post the EA 1972 design as it’s also fundamentally the same thing. As I mentioned above, my slightly simplified version of par4ken’s circuit will dispense with the front channel mixing facility:

View attachment 56706

I've just designed a Veroboard layout and cut the tracks-

I now need to go and check if I've some suitable close tolerance metal film resistors.

 

[Sonik Wiz]

I've just designed a Veroboard layout and cut the tracks-

View attachment 58385

I now need to go and check if I've some suitable close tolerance metal film resistors.

Nifty little circuit! And certainly a minimum of parts to accomplish your goal.

Might I suggest adding a remote control to adjust the blend from the sweet spot? I've seen variations on that type of kit, some cheaper. You would need to replace the log volume pot with a linear one. Alps motor driven pots are pretty easy to find.

 

[chucky3042]

I've just designed a Veroboard layout and cut the tracks-

View attachment 58385

I now need to go and check if I've some suitable close tolerance metal film resistors.

Have you included HDMI, Bluetooth and optical???

 

[Soundfield]

Have you included HDMI???

You of all people!!

 

[J. PUPSTER]

Have you included HDMI, Bluetooth and optical???

Better check your temperature Chucky

 

[chucky3042]

Better check your temperature Chucky

The devil made me do it!

 

[Soundfield]

I've just designed a Veroboard layout and cut the tracks-
I now need to go and check if I've some suitable close tolerance metal film resistors.

Found the box with the 0.1% resistors I was looking for, so I've been able to populate the board-

Next I have to decide what I'm going to do about the dual rail Power Supply. Could use an off the shelf one but as time isn't really an issue (!) I'll probably build one myself.

 

[par4ken]

Found the box with the 0.1% resistors I was looking for, so I've been able to populate the board-
View attachment 58727
Next I have to decide what I'm going to do about the dual rail Power Supply. Could use an off the shelf one but as time isn't really an issue (!) I'll probably build one myself.

Two 9V batteries will also do in a pinch.

 

[Sonik Wiz]

Found the box with the 0.1% resistors I was looking for, so I've been able to populate the board-
View attachment 58727
Next I have to decide what I'm going to do about the dual rail Power Supply. Could use an off the shelf one but as time isn't really an issue (!) I'll probably build one myself.

RE: power supplies. I got tired of building a new one eveytime for a new project. So I built 2 free standing PS's, one for the workbench & one to power multiple DIY projects in the Hi-Fi stack.

RE: Veroboard. I have never used that or heard of before. Do I understand right; you actually have to cut or scratch away the copper to break conduction where you don't want it it? Seems like a pain to me.

I used to use Global Specialties Prototype boards but a few years ago when I ordered some more it looks they've been bought out by BusBoard. This layout makes it really easy to work with bipolar voltages & easy ground decoupling, etc.

 

[par4ken]

RE: power supplies. I got tired of building a new one eveytime for a new project. So I built 2 free standing PS's, one for the workbench & one to power multiple DIY projects in the Hi-Fi stack.

RE: Veroboard. I have never used that or heard of before. Do I understand right; you actually have to cut or scratch away the copper to break conduction where you don't want it it? Seems like a pain to me.

I used to use Global Specialties Prototype boards but a few years ago when I ordered some more it looks they've been bought out by BusBoard. This layout makes it really easy to work with bipolar voltages & easy ground decoupling, etc.

Scott, I'm shocked, a long-time DIY'er like yourself has never heard of "Vero Board"? Sometimes cutting the traces can be a pain; so often a plain perfboard is easiest. I've used both. Best (easiest of all) is a ready made PC board for your project, thus leaving the hard work to someone else!

 

[Sonik Wiz]

Scott, I'm shocked, a long-time DIY'er like yourself has never heard of "Vero Board"? Sometimes cutting the traces can be a pain; so often a plain perfboard is easiest. I've used both. Best (easiest of all) is a ready made PC board for your project, thus leaving the hard work to someone else!

True, that. Never heard of Vero Board. This is partly because of what's been available with local retail. Until a few years ago there were multiple Radio Shacks and a couple of much more advanced electronic supply shops are still around. What they stocked is what I bought. Now I use the local for stuff I need fast. Otherwise it's Allied, Mouser, or DigiKey.

And I've done my fair share of making my own PCB layouts with rub downs & tape. Working in photography it was always easy to make Kodalith negs to expose, develop & etch my boards. What seemed like fun then would be drudgery now.

I've never really delved into PC schematic drawing much less the programs for PCB layout. The latter esp seems cumbersome as you must specify the exact part you'll be using so it knows spacing, etc. I'm just a little too seat of the pants for that.

 

[Soundfield]

RE: power supplies. I got tired of building a new one eveytime for a new project. So I built 2 free standing PS's, one for the workbench & one to power multiple DIY projects in the Hi-Fi stack.

RE: Veroboard. I have never used that or heard of before. Do I understand right; you actually have to cut or scratch away the copper to break conduction where you don't want it it? Seems like a pain to me.

I used to use Global Specialties Prototype boards but a few years ago when I ordered some more it looks they've been bought out by BusBoard. This layout makes it really easy to work with bipolar voltages & easy ground decoupling, etc.

I was brought up on Veroboard, can’t imagine life without it! It was THE prototyping stuff here and in Oz I think for donkey’s years. Vero is an electronics supplies company but I guess this board was / is its best known product. Other companies make it, but it’s all known generically a ‘vero board’. I assumed you had similar stuff, I thought you called it ‘stripboard’ or some such. It comes in various flavours of track pattern, I’ve got a couple here-

And yes, you cut the tracks as required, using that tool above, rather grandly called a “spot face cutter” but is in reality just a 3mm drill bit stuck in a plastic handle! It is a bit tedious but in the current circumstances strangely therapeutic!

 

[Sonik Wiz]

I was brought up on Veroboard, can’t imagine life without it! It was THE prototyping stuff here and in Oz I think for donkey’s years. Vero is an electronics supplies company but I guess this board was / is its best known product. Other companies make it, but it’s all known generically a ‘vero board’. I assumed you had similar stuff, I thought you called it ‘stripboard’ or some such. It comes in various flavours of track pattern, I’ve got a couple here-
View attachment 58737
And yes, you cut the tracks as required, using that tool above, rather grandly called a “spot face cutter” but is in reality just a 3mm drill bit stuck in a plastic handle! It is a bit tedious but in the current circumstances strangely therapeutic!

It's always a good day when I learn something new. Today it was Veroboard & "donkey's years".

 

[Soundfield]

Next I have to decide what I'm going to do about the dual rail Power Supply. Could use an off the shelf one but as time isn't really an issue (!) I'll probably build one myself.

PSU decision made. I was having a rummage this morning and unearthed some nice little blank power supply PCBs-

Just need to buy a couple of linear regulators and I can make one up.

 

[Soundfield]

PSU decision made. I was having a rummage this morning and unearthed some nice little blank power supply PCBs-
View attachment 58755
Just need to buy a couple of linear regulators and I can make one up.

Linear Regulators obtained and PCB assembled-

 

[Sonik Wiz]

Linear Regulators obtained and PCB assembled-
View attachment 59315

Sweet!
And nice sized heat sinks for those TO-220 VR's. Their usual max 1.5 amp rating only happens if you can keep them from running too hot.

 

[Wagonmaster_91]

Speaking of the Akai SS-1 (way back a few pages) ....

https://www.ebay.com/itm/Akai-SS-1-...154181372671?_trksid=p2385738.m4383.l4275.c10

 

[Soundfield]

Sweet!
And nice sized heat sinks for those TO-220 VR's. Their usual max 1.5 amp rating only happens if you can keep them from running too hot.

Thanks, yes, I cut the heatsinks down from some suitable Alli extrusion, but only because I had time on my hands! In all honesty if the decoder takes more than a few mA something will have gone horribly wrong!

 

[Soundfield]

Speaking of the Akai SS-1 (way back a few pages) ....

https://www.ebay.com/itm/Akai-SS-1-...154181372671?_trksid=p2385738.m4383.l4275.c10

The description of its condition made me laugh - "Condition is overall nice but does have some scratches wear ". If he thinks that battered and corroded thing is 'nice' I'd hate to see one he thinks is 'poor'. He must be a used car salesman by day!

 

[Soundfield]

Thanks, yes, I cut the heatsinks down from some suitable Alli extrusion, but only because I had time on my hands! In all honesty if the decoder takes more than a few mA something will have gone horribly wrong!

With the PSU and Decoder boards connected up and under test I can confirm that the current draw is just 18mA per rail (and that includes 10mA for the PSU monitoring LED!).