bloke_zero Posted January 6, 2023 Share Posted January 6, 2023 Like Luke I was out by a magnitude of 10/100/1000 - so most of the bands were correct but not all. And also I had a mix of 2%, 5% and 20% tolerance as I'd had to source the parts from 4 or 5 suppliers. And I can be deeply stupid at times! Quote Link to comment Share on other sites More sharing options...
tauzero Posted January 6, 2023 Share Posted January 6, 2023 32 minutes ago, bloke_zero said: Like Luke I was out by a magnitude of 10/100/1000 - so most of the bands were correct but not all. And also I had a mix of 2%, 5% and 20% tolerance as I'd had to source the parts from 4 or 5 suppliers. And I can be deeply stupid at times! Resistors can be 3-band or 4-band. They're normally 3 plus a tolerance band but you can get 4 plus a tolerance band. Might this have caused confusion? Quote Link to comment Share on other sites More sharing options...
SamIAm Posted January 6, 2023 Share Posted January 6, 2023 16 hours ago, LukeFRC said: You know everyone says “check every part” and you think “I should check every part” but don’t and sometimes you get away with it and sometimes the 2m resistors turn out to have been labeled wrong and are 2k so that doesn’t work there’s a lesson there for us all, which lets be honest, we probably won’t all do! I feel you! The "Big Boys Race Our ..." mnemonic is etched in my head since my early exploits with breadboards, a cheap and nasty soldering iron and a stack of Babani books ... but these days (as you) I just bung a multimeter on them ... it has the secondary advantage of allowing me to pick one from the strip that is closest to the nominal value. S'manth x Quote Link to comment Share on other sites More sharing options...
KingBollock Posted January 6, 2023 Share Posted January 6, 2023 18 minutes ago, Smanth said: I feel you! The "Big Boys Race Our ..." mnemonic is etched in my head since my early exploits with breadboards, a cheap and nasty soldering iron and a stack of Babani books ... but these days (as you) I just bung a multimeter on them ... it has the secondary advantage of allowing me to pick one from the strip that is closest to the nominal value. S'manth x The mnemonic that I learned in college is rather unsavoury, but it is the one that has stuck in my head. It’s done it’s job, I suppose. 2 Quote Link to comment Share on other sites More sharing options...
SamIAm Posted January 6, 2023 Share Posted January 6, 2023 6 minutes ago, KingBollock said: The mnemonic that I learned in college is rather unsavoury, but it is the one that has stuck in my head. It’s done it’s job, I suppose. The mnemonic I learned in medical school for remembering the 12 cranial nerves was also rather risque! Helped it to stick tho; oddly that and the resister colour codes one (which was totally clean) are the only two I can recall. S'manth x Quote Link to comment Share on other sites More sharing options...
LukeFRC Posted January 6, 2023 Share Posted January 6, 2023 1 hour ago, bloke_zero said: Like Luke I was out by a magnitude of 10/100/1000 - so most of the bands were correct but not all. And also I had a mix of 2%, 5% and 20% tolerance as I'd had to source the parts from 4 or 5 suppliers. And I can be deeply stupid at times! I wish my mistake was that complex. Musikding is great for labelling your resistors. After you test 20 diff values without mistakes you kinda stop... Apart from this time the 2M were actually 2k Quote Link to comment Share on other sites More sharing options...
LukeFRC Posted January 6, 2023 Share Posted January 6, 2023 (edited) Random question- what are the 2m resistors doing here? One I think is to stop a pop on switch on? Other set input impedance? should if work without them? Edited January 6, 2023 by LukeFRC Quote Link to comment Share on other sites More sharing options...
tauzero Posted January 6, 2023 Share Posted January 6, 2023 It looks like a passive R-C filter network. I'd have to dig out Horowitz and Hill to find out any more though. 1 1 Quote Link to comment Share on other sites More sharing options...
nekomatic Posted January 6, 2023 Share Posted January 6, 2023 R3 makes sure Q1 is biased correctly, otherwise there would be nothing keeping the gate at the right voltage. R1 makes sure the input has a reasonable input impedance at DC which should reduce noise pickup and as you say reduce thumps on connecting the input. 1 1 Quote Link to comment Share on other sites More sharing options...
LukeFRC Posted January 7, 2023 Share Posted January 7, 2023 I’m now at the FFS it doesn’t work - let’s check everything stage of my builds. Both with no output thing is the only major difference between these two boards and others I’ve made is that these have surface mount J201 jfets - i made a test rig and checked the ldss of them - then soldered them in carefully - the board has space for a leaded version of them too so checked for continuity of my soldering … have I killed my jfets somehow? (Other thing I need to test is try a different power supply ) Quote Link to comment Share on other sites More sharing options...
Woodinblack Posted January 7, 2023 Share Posted January 7, 2023 Should be easy enough to check. If you don't have an oscilliscope, then just check the voltage at TP1 while putting a voltage on R2. Quote Link to comment Share on other sites More sharing options...
LukeFRC Posted January 7, 2023 Share Posted January 7, 2023 6 minutes ago, Woodinblack said: Should be easy enough to check. If you don't have an oscilliscope, then just check the voltage at TP1 while putting a voltage on R2. How? How much voltage on r2? Quote Link to comment Share on other sites More sharing options...
Woodinblack Posted January 7, 2023 Share Posted January 7, 2023 23 minutes ago, LukeFRC said: How? How much voltage on r2? Doesn't really matter - if you put a pot over the input voltage with the centre of that pot going the C1/R2 junction (and the pot wound closer to the 0 to start), changing the position of the pot (ie, increasing the voltage) should change the output on TP1, which is connected to the drain of the fet - if it doesn't, the fet is no longer a fet. Actual values of the voltage don't really matter unless you are working out if the gain is what you expect, but currently you are just trying to see if it works. 1 Quote Link to comment Share on other sites More sharing options...
LukeFRC Posted January 10, 2023 Share Posted January 10, 2023 First of all - thanks to @Woodinblack for the above help… might be useful for folk more at my level (Ie idiots) to go through how I got it going… Stuck a drum beat or demo from toy keyboard through it. Measured small voltage on input measured slightly larger at test point 1, bigger again test point 2 none at the volume or output tiny numbers wobbling around weren’t telling me much, so made an audio probe out of a Jack socket, a cap and two wires …. Ran that into my compressor at fasted and highest ratio… and into preamp to headphones… followed the toy keyboard beat around the circuit - figured the third stage 2n2222 wasn’t working switched it out for another one soldered it together, followed the beat to the end plugged in a bass and played!! 3 Quote Link to comment Share on other sites More sharing options...
LukeFRC Posted January 10, 2023 Share Posted January 10, 2023 So fixed the pedal with 20 components… onto the one with 131 components 🤯😬 1 1 Quote Link to comment Share on other sites More sharing options...
Passinwind Posted January 11, 2023 Share Posted January 11, 2023 On 29/12/2022 at 15:40, tauzero said: Are there no DIP equivalents? I'm incompetent enough at soldering .1" spacing (I probably bridge strips 10% of the time), I'd have no chance with spacing half that. As a followup, out of the blue I found someone who's keen on doing through-hole PCB layouts for some of my designs and sharing them freely. I've built up five different standalone HPF versions recently and am just waiting on some new PCBs to show up in the next day or two to try a few more design swerves. Meanwhile, feature creep never sleeps: 1 Quote Link to comment Share on other sites More sharing options...
Wilson_51_ Posted January 11, 2023 Share Posted January 11, 2023 I ordered a couple of enclosures from Tayda between Christmas and new year for a couple of projects I have on the go. I went for the custom drill and uv printing service. took me a while to actually wrap my head around it all. I usually drill, paint and design myself but wanted to find out if their any good. They arrived yesterday and I have to say the quality is impressive. The purple one is a megalith clone from a pcb, i already have one but I built this one to reduce the footprint and remove the heavy button. The green is stripboard version of a Dunwich D-120 for my guitarist. Which is based on a matamp. Hence the look. And the band logo. 5 Quote Link to comment Share on other sites More sharing options...
LukeFRC Posted January 12, 2023 Share Posted January 12, 2023 If you installed an MN3207 upside down … would it kill it? Quote Link to comment Share on other sites More sharing options...
Wilson_51_ Posted January 15, 2023 Share Posted January 15, 2023 So the Megalith clone is now finished. I had one in a larger enclosure with two footswitches (one for heavy mode) and never turned it off of heavy mode. So i made a new one with a 125b enclosure. It sounds the same as my other one so i am happy with the space saving. The green one in my post above i am currently having a struggle with. It sounds brilliant but when muting the guitar i can hear an oscillation type noise which is really annoying. i have a feeling it is the 7660S i am using in the charge pump. The original circuit has a LTC1144 however i couldn't find any in the UK, The build doc suggested replacing with either a 7660S or Max1044. I don't know if it is not optimal 7660S or not so i am going to do a bit of experimenting with trying a few out. Quote Link to comment Share on other sites More sharing options...
bobbass4k Posted January 15, 2023 Share Posted January 15, 2023 On 11/01/2023 at 13:02, Wilson_51_ said: I ordered a couple of enclosures from Tayda between Christmas and new year for a couple of projects I have on the go. I went for the custom drill and uv printing service. took me a while to actually wrap my head around it all. I usually drill, paint and design myself but wanted to find out if their any good. They arrived yesterday and I have to say the quality is impressive. The purple one is a megalith clone from a pcb, i already have one but I built this one to reduce the footprint and remove the heavy button. The green is stripboard version of a Dunwich D-120 for my guitarist. Which is based on a matamp. Hence the look. And the band logo. Those look very good, may I ask what the final landed cost was, and how long it took? I've been tempted by them but I had a bad shipping experience from tayda many years ago and I've been hesitant to go back. Quote Link to comment Share on other sites More sharing options...
Wilson_51_ Posted January 15, 2023 Share Posted January 15, 2023 13 minutes ago, bobbass4k said: Those look very good, may I ask what the final landed cost was, and how long it took? I've been tempted by them but I had a bad shipping experience from tayda many years ago and I've been hesitant to go back. All in price was about £41. That includes enclosures, drilling, coating, uv printing and shipping. I didn’t think it was a terrible price considering the quality and not having to do it all myself. it took 2 weeks from order to delivery so overall not too bad. I would certainly use it again. 3 Quote Link to comment Share on other sites More sharing options...
LukeFRC Posted January 15, 2023 Share Posted January 15, 2023 4 hours ago, Wilson_51_ said: All in price was about £41. That includes enclosures, drilling, coating, uv printing and shipping. I didn’t think it was a terrible price considering the quality and not having to do it all myself. it took 2 weeks from order to delivery so overall not too bad. I would certainly use it again. 20.5 each? For an enclosure that would cost you £5 or so anyway - sounds cracking to me! 1 Quote Link to comment Share on other sites More sharing options...
tauzero Posted January 16, 2023 Share Posted January 16, 2023 18 hours ago, Wilson_51_ said: The green one in my post above i am currently having a struggle with. It sounds brilliant but when muting the guitar i can hear an oscillation type noise which is really annoying. i have a feeling it is the 7660S i am using in the charge pump. The original circuit has a LTC1144 however i couldn't find any in the UK https://www.mouser.co.uk/c/semiconductors/power-management-ics/voltage-regulators-voltage-controllers/switching-voltage-regulators/?series=LTC1144 Also available from China on Ebay. Quote Link to comment Share on other sites More sharing options...
bobbass4k Posted January 16, 2023 Share Posted January 16, 2023 (edited) 20 hours ago, Wilson_51_ said: The green one in my post above i am currently having a struggle with. It sounds brilliant but when muting the guitar i can hear an oscillation type noise which is really annoying. i have a feeling it is the 7660S i am using in the charge pump. The original circuit has a LTC1144 however i couldn't find any in the UK, The build doc suggested replacing with either a 7660S or Max1044. I don't know if it is not optimal 7660S or not so i am going to do a bit of experimenting with trying a few out. Are you using the 7660s in boost mode (pins 1 and 8 connected)? Also the LTC1144 is available at farnell (search 4029296) - they are expensive though. Edited January 16, 2023 by bobbass4k Quote Link to comment Share on other sites More sharing options...
Wilson_51_ Posted January 16, 2023 Share Posted January 16, 2023 4 minutes ago, bobbass4k said: Are you using the 7660s in boost mode (pins 1 and 8 connected)? Yeah pins 1 and 8 are connected, I’m unsure if it fully is the charge pump but it’s a siren type sound almost like a flanger noise. 1 hour ago, tauzero said: https://www.mouser.co.uk/c/semiconductors/power-management-ics/voltage-regulators-voltage-controllers/switching-voltage-regulators/?series=LTC1144 Also available from China on Ebay. Thanks for this! The mouser ones have a £12 postage on them which feels massively steep. Quote Link to comment Share on other sites More sharing options...
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