Building a Ge SkyRipper

[BetterOffShred]

Well the box and everything else came last night, so I'll be hopefully taking a trip to soldering town tonight and see if I can get some sound out of it.  I am trying to use the "XX" size boxed, so I may go 4 and 3 across the top for knobs and then the toggles next to the 3 on either side.   I think I'm definitely going to implement the range input cap selector as Dino added to his unit, though I may only have a 1P6T rotary, but 2 extra wouldn't hurt.  So I'd just replace "C3" to the right of Q2 with a jumper and stick my rotary between the rangemaster bypass lug and the 3rd row up connection ?  That's what it looks like to me  

So looking at the schematic and layout, if I use the voltage inverter, I'll just hook the "Ground" off the inverter board to Bias pot 1 and 2, and then the -9VDC leg to the top left corner of the board where it says "-9VDC"  ?  Then my indicator LED's will have a total of 9V potential from -9V to 0V?

It's obvious I don't understand voltage 
Thanks for looking guys

[PRR]

> Does it produce a reasonable sized image or just a thumbnail you need to click on to get to something you can see detail in?

Try it on my message.

That's the default action. If you care (and the image is not so big it blows-out the forum formatting), in Preview you can click-through to the actual image, get the URL, and put it in IMG tags, delete the thumbnail code.

I noted this offer from PostIMG some months back and Aron implemented it.

[davent]

Thank you Paul, i now see you can size the image that you're attaching so that's a major help to me!
Thanks!
dave

[BetterOffShred]

Measured out a couple of AC128's that seem to fit the bill.  One is 100 hFE and the other is 159.   Should be right in the spot.  I don't trust the leakage on my current tester, so I'm not 100% sure there, but I'll just try them out and go from there.   I only had a few minutes last night so I soldered the jumpers on the board and got all my parts out, so It should just take a few minutes tonight to get the board soldered up and start stringing wires.   

[BetterOffShred]

Now for wiring

[BetterOffShred]

Also figured I'd assemble it in the box.. that way I can try to keep the wires clean.  Haha

[BetterOffShred]

Mocked everything up, now to finish it up.. I just don't have the time during the week haha.  I went looking for a set of 8 string strings.. 3 places.. nobody had them. Waste of time

[BetterOffShred]

Ready to wire it all up 

[davent]

If you can make an assembly jig, simply a thin piece of cardboard/plywood drilled to match your enclosure layout, mount all your externals to it, you'll make the wiring up much easier and neater. You have much greater access to all the solder connections when you don't have the enclosure sides in the way.

dave

[BetterOffShred]

I've seen that!! I will do that.  Thanks for the tip

[davent]

This was done years ago and i used a chunk of wood, an early attempt with a jig.

And first attempt using the "Add image to post" button. OK you have click on image for the bigger picture.






edit; More playing with Postimage... thanks Paul!




dave

[BetterOffShred]

That's so cool Dave,  thanks for sharing that. It looks really good,  I'm hoping my pedal looks halfway as good hah

[PRR]

> OK you have click on image for the bigger picture.

For people who post 3,000 pixel images of a one-transistor sketch, thumbnail and new tab is safest.



You did size your images appropriately for in-line viewing.

[davent]

> OK you have click on image for the bigger picture.

For people who post 3,000 pixel images of a one-transistor sketch, thumbnail and new tab is safest.



You did size your images appropriately for in-line viewing.

My monitor will show a 600 pixel high image full screen on forums so if i need to resize for a forum i'll set the size based on that. I really hate to scroll to view an image.

For anyone that hasn't tried the Postimage button, it gives you a bunch of sizing options for uploading, i have an avatar again size, up to giant, uncompressed images, very handy! I've been resizing with Irfanview before uploading.

dave

[BetterOffShred]

Well it works. Sort of.  I have nice smooth fuzz and it gets pretty beefy with the pre all the way up.  The buffer works but you have to have it basically turned all the way up (buffer pot) and then the rangemaster part doesn't work and kills all volume when engaged.  So I have some troubleshooting to do, and biasing the transistors too.  I built the 7660 voltage inverter and had to clip the grounding kind of like I thought I would.  I got some good 7660's from Mouser so it's super quiet.. I may try the noisy ones to see how they behave in a voltage inversion circuit rather than the voltage pump. Anyway it's not pretty, but I managed to keep it kind of clean.. for me 

[BetterOffShred]

I built the Geofx germanium transistor tester. It works great. Had to use 3 resistors in series to get 2473R... one ohm over but hey, pretty close!

[BetterOffShred]

If you're really observant you'll notice that I missed the 5n capacitor between Q4 and Q3.. but it's part of the fuzz circuit.. still working on the rangemaster.   

For someone who has one of these... what is the purpose of the buffer and how is it used?  Does it sound like mine is operating correctly? 

[BetterOffShred]

Ok so I had a 500k pot in range somehow instead of a 25k .. so everything seems to work now.  Going to put it all back In the box and see if I can get it to behave as expected

[duck_arse]

you may well need "something" to hold/support/locate those K-case germs. if they are hanging upside down in sockets, their unsupported extra mass will like to jump out every footswitch stomp.

[BetterOffShred]

Haha!  Yes thank you. I was going to shorten the leads and solder then in once I audition a few more.  Those are 89 hFE in the rangemaster circuit and 144 hFE in the fuzz side.  They sound good but I'm not sure if they are too leaky. I have some other ones on order but they haven't arrived yet.