Jürgen Haible Krautrock phaser BUILD THREAD

[jfloftin]

After going through the PCB with a magnifying glass, i noticed my BC560 was badly soldered, so replaced that and tidied up other soldering areas and lo and behold the lights are now pulsing and I do have phasing, albeit with different LDR's, the ones i am using are not the correct ones, but they do at least work now, One day, perhaps i will find the correct LDR's and hear how it is supposed to be heard, but i am happy that it is finally working and I do have some phasing at least.
Only odd thing is that some instruments sound lovely and some sound terrible.
My JP08 though it sounds awesome, Model D and Juno 106 just make horrible feedback type noises depending on the rate of phasing.

I am not using anything into my rate connector, i am just leaving that open

kagey3001,

I actually still have the original Krautrock Phaser board set I purchased for Jurgen Haible back in the 2000s. I have the correct LDR's however, they are not for sale (and neither is the circuit board).

I had a problem once when I built the 258j Buchla Clone I bought from Thonk. He doesn't stock that kit anymore but if you can get the faceplate and all of the components from a trusted vendor, it sounds great! I mention this because I had an issue with the 2nd oscillator not working. I found a bad solder joint with magnification and just resoldered it with a slight amount of additional solder. I then powered it up and both of them were working fine. I only had to do a slight adjustment for 1v/oct calibration. It is now one of my go-to oscillators...

[hamildad]

great to hear we have another successful build.

hopefully mine will be fixed soon.

strange that some things dont sound good, could it be input levels that make some synths sound bad?

post an audio example if you think there might be something faulty.

[Zek]

Hi,
I'd like to build one also, but the LDR's seem to be obsolete. Is there any replacement ref? Thanks

[LED-man]

I used in few builds adafruits, it’s described somewhere in this thread too.
It’s better to select the LDR otherwise you have to change the capacitors later.
In my case I selected all LDRs (resistance under a LED lamp with the same posistion) and I used matched capacitors within a range of 1%.
Furthermore I installed headers for the capacitors, some customers preferred 33nF and some customers the sound with 47nF caps.

[Zek]

Ok thanks! So you mean whatever ldr can fit if you find the good combination between resistor of the ldr and the capacitors?

[LED-man]

I used this LDR,which is still available:
https://www.mouser.de/ProductDetail/Ada ... qKUw%3D%3D
You can’t use every LDR.
Just order 8 and order 5% tolerance filmcaps with 33nF and 47nF for the LFOs and use milled ic socket pins to swap the capacitors to your favorite sound.

[Zek]

Thanks a lot!

[Zek]

And also: is it better to put it in a separate enclosure as it uses ldr? To avoid light leakage from the case?

[bengarland]

I just ordered the PCB for this phaser -- looks like I'm in for a rollercoaster ride! I'll be sure to document my build and post again when I do (or don't) get it working.

[breadman]

And also: is it better to put it in a separate enclosure as it uses ldr? To avoid light leakage from the case?

Definitely use an opaque enclosure for this--the phasing modulation won't be deep at all if there is significant light leakage.

[Zek]

Ok thanks, I will do it in a separate box. I just need to order the pcb...

[clickmrmike]

Anyone know a source for the bulbs and sockets in the US? I haven't been able to find any, and Reichelt wants $33 to ship $4 worth of parts....

clickmrmike

[breadman]

Anyone know a source for the bulbs and sockets in the US? I haven't been able to find any, and Reichelt wants $33 to ship $4 worth of parts....

clickmrmike

PM me if you want, I have a bunch.

[manymachines]

Hi All!

I've been building this and have a question. I powered up the board without populating ICs to take some voltage measurements without frying anything. All good, expected voltages on IC power pins and indicator lamp working. then populated ICs, power up again and the fuse blows. I replaced the fuse twice more and blows twice more.

I did some reading here and as I'm using a wall wart and half the supply, replaced fuse with 500mA. Blows again. I started looking for shorts, noticed pin 8 and 13 of the cd4007 have continuity.

I checked the schematic and these look like they're connected so maybe that's OK? I'm not knowledgeable enough with electronics to know. I took the IC out and replaced the fuse, powered up again and things look good, lamps are pulsing and respond to rate control.

so the question is, I have one more cd4007 and two more fuses, shall I just stick that one in assuming the other chip was bad/damaged or should I be looking for something else wrong?

sorry for the long post but I wanted to give as much background info as possible,
ta
g

[FactoryDefault]

You’re correct - cd4007 pins 8 & 13 are connected so that’s normal.
Do you have a multimeter? Maybe check the current across the fuse in a working configuration to see how close you are to 500mA.
Also which relay did you use? The one in the bom only draws 40mA max across the coil when actuated. If you bought something else it might be pulling more current. Don’t know if mine’s unique but it always powers up with the flip flop powering the relay so it would blow the fuse before hitting the bypass switch if it were pulling too much current.

[manymachines]

OK will check current across the fuse without the CD4007 plugged in tomorrow.

I ordered the relay from reichelt using the part number from the BOM but I did notice the one in JH's pictures is white and mine is black (although the one the guys at dragonfly alley use is also black). At the time I assumed same part just with a different package. Which pins can I measure the current across? Also I haven't wired the momentary switch yet, would that make a difference? I assume like your it's already switched when I apply power as the lamps are pulsing but I'm guessing here :0

thanks for your help!
g

[FactoryDefault]

Manymachines, if your relay part number matches the bom then you're probably good. Is it the finder 30.22.9 12V ?
That draws 40mA or less so it's probably not what's blowing your fuse, unless it's faulty.
The white relay in JHs pictures is the other relay he mentions in the bom - a Meder TC12 K002.
If there's any doubt as to which one you have, attach a pic so we can check the specs. It will be hard to measure current through the coil since the meter needs to be in series, so you'd need to desolder it and connect via wires or mount it on a separate strip board etc to get your probes connected.

Your initial instinct to swap the 4007 was probably a good one. You sure it was oriented correctly before? (No offense intended by that question - I'm sure we've all done it )

Might be worth checking current draw for the rest of the circuit to eliminate that from the equation.
If current's normal with the just the 4007 removed, that points to the 4007 or something downstream of it being the problem.
See pic for how to attach probes.
I just measured mine in a single supply config (just removed 1 fuse) and it draws just over 200mA with the lamps at full brightness and the relay on.

BTW, the lamps will pulse regardless of the state of the relay. The relay just switches the input signal or the phaser output to the output jacks.

haible-current.JPG

[LED-man]

Please share a picture of your populated PCB.
Make sure the big 5W resistor pin is isolated - it’s easy to get a short to the heatsinks.

[manymachines]

My relay is the right one, after my last post I checked JH's again and noticed the different brand.


'Your initial instinct to swap the 4007 was probably a good one.'

Haha, you give me too much credit! As everything was OK without ICs I guessed that they might be the problem. The CD4007 was the first to go in
so I took it out first and then the fuses stopped blowing so more luck than skill It manage to put in the right way, I'm always paranoid I'm going to do that! I had some transistors in the wrong way once and couldn't figure out why nothing was happening for awhile

I might have damaged it getting it in there in the first place, the board is so tight between the heat sinks it took me a few goes and I bent the pins a few times. Next time I am going to form the pins using a socket I've got lying around before I try and get it in there! Are 4007s particularly vunerable to static?

Without the 4007 in mine draws 120mA, not sure if I had the relay on to be honest.

I checked the 5w resistor, as suggested by LED-man. The lead was very close to the heat sink bolt but not touching but I slipped some heatshrink
over it just in case. Thanks for your help, your page on building this was really useful in preparing to build this.
I've attached some pics any further ideas are much appreciated,
g

btw way I removed the top right heat sink to get the 4007 out.

[manymachines]

UPDATE!! I put a new 4007 in today and it's phasing. Sounds sooo good! Can't stop playing with it.

Will post some pics when I get it boxed. Thanks again to factory Default and LED man ofr the advice and guidance!

[FactoryDefault]

manymachines, that’s great news!

Just in time to play Kraftwerk covers all weekend!

[Hermetech Mastering]

Is anyone currently offering these already built? Would love one for my Super 6, but have zero DIY chops.

[FactoryDefault]

Is anyone currently offering these already built? Would love one for my Super 6, but have zero DIY chops.

Looks like Vandaal Electronics has some.

https://vandaal-electronics.com/product ... ng-x-case/

That’s actually a really good price considering all the work that goes into sourcing parts, building Etc

[Hermetech Mastering]

Thank you, I'll give it a look.

[hamildad]

Is anyone currently offering these already built? Would love one for my Super 6, but have zero DIY chops.

Looks like Vandaal Electronics has some.

https://vandaal-electronics.com/product ... ng-x-case/

That’s actually a really good price considering all the work that goes into sourcing parts, building Etc

If I had a time machine, I'd go back and buy a ready built one.

360 Euro is a great price and I HATE the Yamaha PA20 PSU I have for it...