freestompboxes.org

This is my first, but I'm trying to put two in one box, a 1590XX, so I need to save every single milimeter

destro wrote:The first one I built, I just used four 2.2k resistors and put them in place of the trims

Tell me if I understand you correctly: you put one 2k2 resistor on each side of the divider, simulating that your trimms are in a center position? Am I right?

If that's the case, I can add 2k2 (more or less) to each resistor of the divider and save some space, right?

Yup. You got it!

Well, seems that 2) is solved

Thanks, destro

destro,

to be honest i can't remember, I did put sockets (cut down IC strip) so I could swap them around.

I think I used 0.015, 0.1, 2n2, 470pf

cheers

Frank

Got my second one finished and I do have to say that there is a noticable difference in rolling your own led/ldr compared to the vactrol. I ordered the 5mm clear tinted yellow but they ended up being red. I used 2506A photocell. Bias control functions much better than what I remember with the vactrols. The modulation sounds smoother/deeper so I highly recommend using the led and photocell approach. Can't help but wonder what the yellows would sound like, but I am happy with this one. Trem and chorus sound a hell of a lot better. Vibe gets nasty quick.

Hey destro, 2506A it's an internal code from Small Bear, generic for all photocells. Wich one you buy?

I got the 9200 as it specd closest to the other photocells used for univibe projects on the smallbear site.

Are there any differencies between the XR8038A and ICL8038CC ?
I can get some Xr's for a reasonable price , will they eventually change something about the final result/sound ? I haven't found ICl8038 anywhere but on ebay and the prices go from 10 to even 50€ for a single piece...and I have some doubts about their authenticity since there is a lot rebranded crap out there...

Thanks

Since I have to place an order from musikding , which LDR are recommended ? I read they should be like around 30k when led's off ...will this work ?

FloydFan wrote:Are there any differencies between the XR8038A and ICL8038CC ?

I don't know, but... you can check datasheets. I bought some ICL8038CC from Small Bear, around $3,50.- each, not so bad, uh?

FloydFan wrote:Since I have to place an order from musikding , which LDR are recommended ? I read they should be like around 30k when led's off ...will this work ?

I made mine with some Photocells I found in my "near"store. If I remember well, something around 5M or 10M (or was 2M ) Check destro answer two or three post above, about the 9200 model he found in Small Bear.

:S forgot to check smallbear ..shame on me However I bought an handful of them on ebay in europe since I didn't want to mess with lost packages or long delays (i'm from italy). I got a pair of xr8038 from a store near Rome and 4 icl8038CC from uk . the former 10€ and the latter 12€ both shipped.
I'll keep you up to date if I notice any differencies between them

about the ldr's (i'm a newbie )
I see they have min-max resistance when led is on and a bigger resistance after a while (decay 25-35ms) in the range from 300-500k to even 15M..could you help me ? Should I just pick the ones which for min-max res. give me like 25-60 for min-max or lower minimum resistance like 10-40? And what about the Max when led's off ?
PS: I've checked the whole thread but i haven't found any precise info about the specs...

thanks

I'm not an expert, but check this:

destro wrote:I got the 9200 as it specd closest to the other photocells used for univibe projects on the smallbear site.

Then you can see in Small Bear stock list that the 9200 rates are: Light: 10k<50k, Dark: 5M
Steve, at Small Bear, also recommends the 9203: Light: 5k<20k, Dark: 20M
Rise time 50<70 ms, Fall time 25 ms
http://www.smallbearelec.com/Detail.bok?no=711
So, what you got is a "zone" to move and test for your best option.
I'm 99% sure that mines are 10M; 25k<50k and did the job (with 3mm yellow clear LED's)

Hope that helps!

Need some help, please!
I made two and the first one works perfectly, but the second... not.
Tremolo = low gain, a little distorted
Vibrato = no vibrato, subtle tremolo, some motorboating (only when guitar is strummed strongly)
Chorus = no chorus, heavy motorboating without playing anything...
Where do I start?
All components well oriented, all solders and possible trace bridges cleaned and double checked, triple checked, quadruply checked under a magnifying lens...
I need some advice before I start to change every component!

Nobody?

If you have one that is working than shouldn't be too difficult to audio probe and figure out where things are going south. If you don't have an audio probe, you can take voltages from the working one and compare and that might help you narrow it down as well. My pedal builds would be fe if i didn't rely on being able to audio probe to debug.

Hello, I'm new here and was following the thread. I can't get the schematics to load from the first third of the post, so I had a question or two:

1) What schematics were acutally used and were all the mods mentioned successfully done (variable speed rates, stereo output, etc...) on one version?

2) is there a complete set of schematics, PCB and board component layouts available for download somewhere.

Most of the links I click on are dead links. Any help would be appreciated. Thanks!

Where can I download the files? Tried the links at the start and it may well be that I'm a noob and can't figure out computery stuff...

Man would love to build this....but as said before....most of the links are dead.
The Bigupload link leads to an mp3 of Arabic muttering....not the sound I'm looking for

So please if anyone finished the project (mono or stereo) could they please upload the files....pretty pleasy

That's all I got. No mods, just the Kaputepalla version, redrawn by me in .shc
Mods are all in the thread, easy to find

Here's what i've got. There's everything to build a fully functional pedal. I included the cap switcher mod (switches between RT-18, Univibe e Voodoo Vibe caps).
Enjoy
Matteo