Ok, back again. After frying a couple of ne570's ( :applause: :slap: ) I've finally got my hands on a few more to fiddle with. I found a tone burst program - and are using my sound card to send the signal to the breadboard. If I understood correctly, I should make adjustments to VR4 untill the dc vo...

Thanks for your guide, I'll try that. I actually came across some software that should be able to work as both a scope and spectrum analyser using a good quality soundcard: Visual Analyser http://www.sillanumsoft.org/ From looking at the program, it seems it might be able to measure THD. I've been t...

VR4 trim for lowest THD @ IC2's pin 7 Ok, I'm trying to read up on how to measure THD - and it seems like it's a bit complicated, and requires special equipment. But most of what I read also seems to be aimed at hifi amps. Is there an easy way to do this trimming in this circuit? Can it be done wit...

Good news. I had one NE570 chip left. This one was slightly different from the others, and has "philips" written on it. I was a bit unhappy about trying out my last chip that was known to work, but anyways.... I disconnected the trim controls for pin 8/9 and put a 220pf to ground from both...

At pins 8 and 9 you may safely supply 3.6V (chip's internal bias voltage), with 330K series resistor(s) I guess you may raise this voltage Yeah, that's what I was guessing at, from what I could find in datasheets etc. But could I have damaged the chip by supplying above 3.6v? D2 and D3 work in a tu...

ok, my first two ne570 are fried. I have a pt80 delay that I checked them out in, and they give a nasty hum, and there's no delay. Before I use my last ne570 I really want to try to figure out why they died. Would the chip be damaged by supplying higher than 3 volts at the trim pin 8 and 9? I'm glea...

Well, I started trying to find what uses all the power, so I lifted the power for the various parts of the circuit. Turns out the NE570 was the culprit. Out of curiosity I put a 1R resistor from pin 4 to ground, and measuered how many milliamps was pulled through it... ... ehm.,.. ... just about 560...

I'm almost done with the breadboard layout. Now I'm getting some funky problems with powering it. At first I used a 2x15V trafo (2 x 1,3 VA) - and paralleled the secondaries. Rectifier bridge -> 220µF cap -> TS7815 -> 100µF Unfortunately I was unable to get the supply voltage to the 7815 high enough...

Ok, sorry for my misunderstanding - and again, thanks a LOT for your help this far! :) Actually I'm trying to follow what you wrote some posts above: First I need to understand the BBD chip... this is still what I'm working on. Just your recent tips shows that TC made some decisions on the Vgg suppl...

Fender3D : First: Thanks for your tips - I'll try to wrap my head around them. Second: Your first remark sounds like you wont give any more tips/hints or answer any more questions of mine. That's actually ok - you have no obligation to do so! But, forgive me if I'm wrong, it also sounds like you th...

Ok, I've been reading up some on BBD's and studying both the MN3007 datasheet, and the SCF schematic. I'm trying my best to wrap my head around it, but I have a few questions that I hope you guys can answer. I'm reading a book called "audio IC users handbook", which among other things desc...

First you must know how BBD works... If you knew how BBD works Thanks for the info. I actually am reading up on BBD's... found this site which seems quite informative: http://www.electrosmash.com/mn3007-bucket-brigade-devices Of course there's a lot to learn, so it takes a little time to understand...

well, it's a big challenge indeed.... which makes iznogouds comments about "not worth it" understandable. But I guess I'm to silly / stupid to give up :-) It's just going to take time and learning - though I'll of course be very thankfull for all the nudges in the right direction I can get...

Ah ok, I see. So this is the case for three resistors, as far as I can tell: R4, R8 and R18. I do have an oscilloscope, but so far I only used it to work on my tube amp builds - and in honesty I don't know how to use it for the application you mention. (Tube amps are quite simple circuits - this ped...

Awesome man - Thanks a bunch. I've been looking over the schematics for a few days, and I'm in the process of making a clean version in eaglecad. There are a few missing values in the schematic, but for the most part I've been able to find them on the sketch posted earlier in this thread. Now I fina...

anyone?

Hey. I just built a clone of the xotic ac booster, and used a millenium 2 bypass for the led. The led shines nice and brightly when the effect is on. When I switch it off, the light intensity decreases drasticly, BUT the led is still shining. I'm using a BS170 (fairchild I think), 2n3904 and 1n914. ...

Bernardduur wrote:I'll try to add the guts tonight!

Any chance for them?

DLY.JPG Looking forward to the guts :-) I'm a little confused about the connection "bubbles" on the cd4520's Does those cirkles just mean that those pins are connected, or do they signify something else? Regards Anders The bubbles are in the datasheet of the IC; the numbers on the bubbles...

Bernardduur wrote:

DLY.JPG

Also, I think maybe you forgot the power pins on the cd4066's..??