Feeler: 'Easy' He69

frazzman said:

Would it be possible to use standard 12pos LORIN type rotary switches on this EQ, like whats commonly used on the SSL clones?

Click to expand...

Maybe, maybe not. There are two potential problems.

The first is; the switches you are thinking of only come in single decks for 12 positions. Thats not necessarily a problem though as Lorlin has the 'PT' series which is extensible up to 5 decks.

The second potential problem is the size of Lorlin's switches. Whether they will fit in a single 500 series module space or eurorack 7HP I dont know. The shaft diameter tends to be 6mm or so, which increases the total diameter of knobs you would need...As this EQ will be fairly front-panel crowded already (2 switches, 2 pots, 3 rotary switches) this could be a problem. You can always go to 2 module spaces

I have a couple of PT switches on the way so I will investigate....

Hi James,

I noticed another small point on your PCBs. In the euro rack system there is usually a 2mm gap between the front edge of the PCB and the front panel. This means if you want your switch bushes to touch the front panel you have to mount them 2mm further forward on the PCB. I cannot tell if you have already accounted for this by looking at your footprints but I thought you should know.

Cheers

Ian

ramshackles said:

frazzman said:

Would it be possible to use standard 12pos LORIN type rotary switches on this EQ, like whats commonly used on the SSL clones?

Click to expand...

Maybe, maybe not. There are two potential problems.

The first is; the switches you are thinking of only come in single decks for 12 positions. Thats not necessarily a problem though as Lorlin has the 'PT' series which is extensible up to 5 decks.

The second potential problem is the size of Lorlin's switches. Whether they will fit in a single 500 series module space or eurorack 7HP I dont know. The shaft diameter tends to be 6mm or so, which increases the total diameter of knobs you would need...As this EQ will be fairly front-panel crowded already (2 switches, 2 pots, 3 rotary switches) this could be a problem. You can always go to 2 module spaces

I have a couple of PT switches on the way so I will investigate....

Click to expand...

Makes sense... sorry I was under the impression the design was intended for a standard 1RU rack enclosure, making front panel real estate a little less critical, but I can see now its intended for 500 series. Damn, I need a lunchbox...

I was hoping to build a stereo 1u of this. It can be done. Ramshackles sells something for this very purpose.  rackit!!!!!

ding said:

I was hoping to build a stereo 1u of this. It can be done. Ramshackles sells something for this very purpose.  rackit!!!!!

Click to expand...

True! But I think that kinds of adds unneeded expense and complication ... Maybe ramshackle can offer a design for each format.. That'd be great   

At the moment the design is on a eurocard, which can easily be put in a 1U rack without any additional interfacing (it commonly mates to a backplane via a DIN connector rather than fingers, so you can just replace the DIN connector with 5.08mm spaced headers for 19" racking...).
It can also of course be used in a eurorack, where it would be placed vertically (like 500 series) and mate with a custome backplane (see here: http://groupdiy.com/index.php?topic=54418.0)

I'll also do it in 500 series provided there is enough interest. As eurocards and 500 series boards are of a very similar size, nothing much will have to change layout-wise.

Started building this thing finally:



Most of the components are available from Farnell (Newark). There is 1 capacitor unavailable, so I'll modify the PCB for the final version to take two in pll...

I may improve the input stage for the final version which is currently a 'simplest possible' approach to using the 1240 chip..

Hi,

how is it going on the build? I've got to gather missing parts for mine.

Sorry for late reply. Im in and out of the house at the moment...


My build is going well. All pieces in place and I have been doing some prelim tests (before attaching to power).

I've also put together a power supply on a eurocard (just using readily available kits) that should be enough to power a single eurorack of modules and have almost got the backplane ready for prototyping. Backplane only needed if you are planning on making a lunchbox-style rack or mixer system.

I'll try to get some photos up tomorrow.

A couple of issues to watch out for:

- The DIN connector is very tight to the edge of the eurocard. It fits, but ideally needs repositioning by half a mm or so.

- There is very little space between the electrolytic capacitors and the DOA. In fact, I had to file away the corners of the DOA PCB I'm using to get it in. I would recommend putting a DOA in place (but dont solder) while you put the caps in and bend them away slightly.

Apart from that the layout is ok. Put the small parts in first

Do you still need prototype testers? Got my hands on some 19" eurocard housings (for free ;-) ), that want be filled up.  They got their PSUs already build in so it would be peace of cake to build your Easy He's  into them.

Cheers.

Hey James,

Are these 2 decks from Digikey compatible?

http://www.digikey.com/product-search/en?mpart=71ADF30-02PAJN&vendor=136 

They have an "N" at the end so are non-shorting, is that alright?

It just makes it easier for us stateside gents.
Nice boards by the way.
Cheers
Dylan

Non-shorting would be ok, but there is a possibility of hearing clicks when you switch positions.

Realistically, I don't think it should be a problem, so give it a try with the non-shorting.

If there are clicks, put resistors in series with the switch and it's sources.

ramshackles said:

Non-shorting would be ok, but there is a possibility of hearing clicks when you switch positions.

Realistically, I don't think it should be a problem, so give it a try with the non-shorting.

If there are clicks, put resistors in series with the switch and it's sources.

Click to expand...

Excellent.  Hopefully its not too much a hassle.  Thanks.

Dylan

start of a small power supply for the easy69/eurorack:





A nice little pcb from diypartssupply and a stock trafo from Farnell fit just nicely on a eurocard..

I am slowly putting together some more-readable documentation for all this. At the moment I'm just flinging it on the venerable readthedocs:

helvellyn.rtfd.org

Hopefully by the new year the project will be nearing release...