Neil. Posted January 3, 2015 Share Posted January 3, 2015 nah dont need to do that. Just put a 10k across the 100k. Link to comment Share on other sites More sharing options...
james90 Posted January 4, 2015 Share Posted January 4, 2015 Fair enough. Not sure if I have a 10k resistor (or anything close to it) though YET I have nearly every value of NOS caps you could imagine, some of which don't even seem to be standard values anymore Link to comment Share on other sites More sharing options...
Neil. Posted January 4, 2015 Share Posted January 4, 2015 Anything less than 10k. Its a law of averages, and you wanna get around 47k-56k Link to comment Share on other sites More sharing options...
james90 Posted January 4, 2015 Share Posted January 4, 2015 I found a 5.6k (it isn't NOS carbon comp though), so I guess that will have to do for now I still don't know about the voltages though. What should Q1's collector generally be around? With the 100k, it was at -3v or so. Yes, I know, ignore all the voltages, but just wondering if that's around normal Also, I'm curious how much this high humidity overnight affected my transistors. Will it enhance my tone and make it sound less dry? Probably didn't do a thing, but I need to reset the trim pot for Q2 anyway Will this pedal be able to hide the fact that I'm using 6550 valves? https://www.youtube.com/watch?v=lXub-vOB640 http://www.thegearpage.net/board/showthread.php?t=221526 Link to comment Share on other sites More sharing options...
james90 Posted January 4, 2015 Share Posted January 4, 2015 Will this pedal be able to hide the fact that I'm using 6550 valves? KT66 valve best valve https://www.youtube.com/watch?v=rqFXerXDodY Link to comment Share on other sites More sharing options...
Neil. Posted January 4, 2015 Share Posted January 4, 2015 I found a 5.6k (it isn't NOS carbon comp though), so I guess that will have to do for now I still don't know about the voltages though. What should Q1's collector generally be around? With the 100k, it was at -3v or so. Yes, I know, ignore all the voltages, but just wondering if that's around normal Also, I'm curious how much this high humidity overnight affected my transistors. Will it enhance my tone and make it sound less dry? Probably didn't do a thing, but I need to reset the trim pot for Q2 anyway Ok, a few things to point out here. 1. Voltages don't matter. 2. Voltages don't matter. 3. Voltages don't matter. 4. There is no such thing as "normal" voltages. They will always vary a little bit. For example, if you take a DC power supply and measure it, it's almost never at exactly 9V. Mine, for example, supplies at 9.4V. Does that extra .4V add toanz? No. Does it affect the transistors? No. Does it accidentally the whole volt? No. If voltages really made that much of a difference, wouldn't every single pedal be fitted with a 9V voltage regulator? If you want to know what the "normal" voltages are, you'd have to build one EXACTLY like whatever "normal" voltages you're referencing, and check that. So for example, if you wanted to build an original fuzz face, it would have to be part for part identical, then check the voltages. I'd still be very surprised if you get exactly the right value of voltages. 5. I've never heard of humidity affecting transistors. 6. In my own opinion, that 1k trimmer that seems to be the cool thing to do with fuzz faces is pointless. how much it affects it is negligible imo. 7. Again, read through this if you want to learn more about modding your FF. http://www.geofex.com/article_folders/fuzzface/fftech.htm 8. Voltages don't matter. Link to comment Share on other sites More sharing options...
Don'tPostThePear Posted January 4, 2015 Share Posted January 4, 2015 I found a 5.6k (it isn't NOS carbon comp though), so I guess that will have to do for now I still don't know about the voltages though. What should Q1's collector generally be around? With the 100k, it was at -3v or so. Yes, I know, ignore all the voltages, but just wondering if that's around normal Also, I'm curious how much this high humidity overnight affected my transistors. Will it enhance my tone and make it sound less dry? Probably didn't do a thing, but I need to reset the trim pot for Q2 anyway Will this pedal be able to hide the fact that I'm using 6550 valves? https://www.youtube.com/watch?v=lXub-vOB640 http://www.thegearpage.net/board/showthread.php?t=221526 As your collector voltages drift away from -4.5V (aka half supply voltage) your clipping gets more asymmetrical. I think no one is really concerned with the voltage on the first collector but if you see it getting moving below -3V as you mess with the feedback resistor you should except even more asymmetrical clipping and less headroom. Sometimes when we mess with the voltages in the power amp section of our tube amps we try to get our cathode/whatever voltages to half supply for maximum headroom/voltage swing and symmetry. As you lower the feedback resistor value you theoretically should get less fuzz and more tonesuck. Putting a 10k across it will lower the resistance to below 10k, check parallel resistance calculators. Of you want it around 50k you need to put a 100k across the 100k res. Btw the output volume is deliberately lowered/damped by that resistor voltage divider on the output, it could be made much louder by changing the ratio of those resistors. (but not their combined value) Link to comment Share on other sites More sharing options...
Crowella Posted January 4, 2015 Share Posted January 4, 2015 Funny you mention voltages from the V+ Neil. I have been looking at using a polarity protection system in my pedals as well as some crude power filtering and one of the issues I am having is voltage losses which make a difference when you're talking about fuzz pedals but not really much else. Doing that more so to protect CMOS and IC's. I'm thinking going the MOSFET route for polarity protection which counts for losses ~0.01-0.2V over the silicon diode protection method which is about 0.6-0.7V. Also bonus hipster points for MOSFET. James, you can just google a calculator for parallel resistors if you can't be bothered doing the calc (it's not that hard but still...). The only voltages that really matter with transistors is that the Collector, Base and Emitter are all at operational voltages. When you think about how you debug a pedal, the transistors make the easiest point to measure simply because... "For linear amplifying, the collector must be more positive than the base; the base must be more positive than the emitter by about 0.4 to 0.7V for silicon, and 0.0 to 0.3 for germanium; the emitter should be the most negative pin." http://www.geofex.com/fxdebug/bias_prob.htm That said, depending on what you want to push, a bit of assymetrical clipping sounds divine. It wasn't uncommon to have some to get more out of a tube amp. I'm more of a symmetrical guy myself but that could be an OCD thing. Also, I'll have to take a picture of the parts that arrived from China. With the exception of the enclosure screw holes being drilled after painting, they all seem very well painted in white. Perfect test bed for pedals considering they cost me $2.50USD a case. Also got about 50 3PDT switches, 100 jacks and about 100 of those 1900H Davies knobs. I'm missing making pedals at the moment. 40+ hours of work over the past 4 days. :'( At least the money from this will get equipment for a small production line to be feasable. Link to comment Share on other sites More sharing options...
james90 Posted January 5, 2015 Share Posted January 5, 2015 Were you buying from a specific company? (I'm guessing you are if you're having custom enclosures built) I see loads of sellers on eBay for example, and it's often difficult to find a US seller that has the parts I want. I've avoided them so far though. So i haven't changed anything yet (besides removing the 33k), but i'm going to make a sound clip soon/someday to see if you lot have any suggestions. Unfortunately I burned through part of the film cap yesterday, and I already replaced it once (damaging the PCB in the process) so it's going to stay for now. seems to still work the same at least. Link to comment Share on other sites More sharing options...
Neil. Posted January 5, 2015 Share Posted January 5, 2015 Also, I'll have to take a picture of the parts that arrived from China. With the exception of the enclosure screw holes being drilled after painting, they all seem very well painted in white. Perfect test bed for pedals considering they cost me $2.50USD a case. Also got about 50 3PDT switches, 100 jacks and about 100 of those 1900H Davies knobs. I'm missing making pedals at the moment. 40+ hours of work over the past 4 days. :'( At least the money from this will get equipment for a small production line to be feasable. this is relevant to my interests. I'm looking at getting a bunch of white enclosures soon, but I'm going to need at least 2 sizes. Best option so far has been some supplier on that aliexpress site, but i've never used it before. Link to comment Share on other sites More sharing options...
Neil. Posted January 7, 2015 Share Posted January 7, 2015 As many of you will know, I like both Jack White and Sigur Ros. Following on from my old amp based preamp, I have a new one. I call it the "Reverb Channel." It's based on the Fender Twin Reverb. Currently, I'm using an Accutronics BTDR-2H chip, which isn't a great reverb, but this seems to be the best sound I can get out of it. In hindsight, I think a medium-length chip would have been better, as that would probably be closer to Fender's reverb tank in the Twin. I have this breadboarded at the moment, and I quite like it. It's a little treble heavy, which is why I've added in an optional tonestack section. I'll be adding this to my own one once I go to build it. Even at that, I might go for a different tonestack. The effect can be quite gainy, but by no means high gain. The plan is to put this into a Hammond 1905BB sized box, which I will be ordering many of in a week or so. Like I said, it's not the greatest sounding reverb, so it might be a case for 2 foot switches, one of which will be a true bypass, and the other to bypass the reverb. Turning Reverb to 0 will also cut out the reverb, but a footswitch might be more useful. Anyway, sharing is caring, so here's the schematic if anyone wants to give it a go. I will post soundclips in due course, but not till it's built. Link to comment Share on other sites More sharing options...
james90 Posted January 10, 2015 Share Posted January 10, 2015 Pear... https://drive.google.com/folderview?id=0B9SHlVWM7PoHZHY5SDlPY2hReUU&usp=sharing#list play/download the second to last file. What do you think? Link to comment Share on other sites More sharing options...
Don'tPostThePear Posted January 11, 2015 Share Posted January 11, 2015 Pear... https://drive.google.com/folderview?id=0B9SHlVWM7PoHZHY5SDlPY2hReUU&usp=sharing#list play/download the second to last file. What do you think? that fried my brain am i on the right track if i plan to spend the day reading this tread instead of doing something productive? Link to comment Share on other sites More sharing options...
james90 Posted January 11, 2015 Share Posted January 11, 2015 Heh yep, that's where it came from. Seems like that guy is legit, and there's something about a fuzz circuit towards the end there which I'm very interested in Link to comment Share on other sites More sharing options...
Neil. Posted January 15, 2015 Share Posted January 15, 2015 Crowella/Pear/Other I've been busy. I have a fuzz face variant that I could benefit from someone else breadboarding and testing. Any takers? Special required components: 1 x Mid-high gain NPN, 2 x Mid-low gain PNP (germanium?) 3 x 10k pots. other than that, a few standard value resistors and caps. Nothing wild. Link to comment Share on other sites More sharing options...
Crowella Posted January 15, 2015 Share Posted January 15, 2015 PM me, I'll have a squizz. Might perfboard it if I get a chance. Sadly I'm hella busy though Only germs I have are some 80-120 AC128's... Link to comment Share on other sites More sharing options...
Neil. Posted January 15, 2015 Share Posted January 15, 2015 PM me, I'll have a squizz. Might perfboard it if I get a chance. Sadly I'm hella busy though Only germs I have are some 80-120 AC128's... they'll do perfect. I'll pm you now. Link to comment Share on other sites More sharing options...
james90 Posted January 19, 2015 Share Posted January 19, 2015 Heh yep, that's where it came from. Seems like that guy is legit, and there's something about a fuzz circuit towards the end there which I'm very interested in here it is http://imgur.com/a/iPVSE any thoughts? 3rd image is the current revision of the schematic Link to comment Share on other sites More sharing options...
james90 Posted January 25, 2015 Share Posted January 25, 2015 you lot will never guess what i'm building no idea if those transistors are what the seller claimed they are, but hopefully they'll sound good Link to comment Share on other sites More sharing options...
Don'tPostThePear Posted January 25, 2015 Share Posted January 25, 2015 you lot will never guess what i'm building no idea if those transistors are what the seller claimed they are, but hopefully they'll sound good dat purple did you test the leakage on those transistors? Link to comment Share on other sites More sharing options...
Crowella Posted January 26, 2015 Share Posted January 26, 2015 That reminds me, I need to create my Germanium Transistor rant. For an idea why... check this. 2/100 germs are usable! http://www.muzique.com/news/ac176-germanium-transistors/ Also, got a few things I've been working on, more of a technical thing. Using some logic circuits with PNP/NPN transistors to use a momentary switch and a relay to do the effects off/on switching. Just trying to hunt down a relay that will be good for audio signals. I'll do a video/write up of how it goes. If I hit +100,000 cycles, I will be happy... Just need to find my PICAXE to program the switching code to test it. Link to comment Share on other sites More sharing options...
james90 Posted January 26, 2015 Share Posted January 26, 2015 dat purple did you test the leakage on those transistors? I wish I knew where that PCB came from (it was from eBay, but I can't find them now) And no, but I have some numbers written down on the package they were sent in. I know it was the hfe, but I think there might have been something else too. The last transistors I got from this seller seemed to work fine anyway Link to comment Share on other sites More sharing options...
Neil. Posted January 26, 2015 Share Posted January 26, 2015 Erm, starting to notice a colour theme creeping into my builds... Especially when it ends up being red and white DC jacks... Relevant, started properly putting work into getting my 3d printer back working. I now have all the parts I need for it, so I'm hoping to be back printing by the end of the week. However, before then, I have to wire the power supply, relay, new heatbed, electronics board and cooling. But once that's done, I'll be starting on printing boards. No srsly. The other... setback... that I've had is that a company that I was in talks with over a new job has decided they want to hire me, but in a different location to what was planned. It's an ideal company to work with, but it means that this current batch of pedals will be the last for the forseeable future. That being said, I'll be selling off most of them in due course. Link to comment Share on other sites More sharing options...
Crowella Posted January 26, 2015 Share Posted January 26, 2015 Colour schemes <3 You've reminded me I need to find somewhere that produces aluminum knobs otherwise I'm settling on those davies 1900H clones which are good, even if a bit vanilla because they fit on the pots snug, actually coloured well and I have about 400 in black right now which I'll use on the future builds... That 3D printer is pr0n. I'll have to buy a printed board off you as well as a pedal just to see what they are like. Link to comment Share on other sites More sharing options...
Jaicen Posted January 29, 2015 Share Posted January 29, 2015 James, they're most likely rebranded AC128's I would imagine. Never seen a genuine NKT in one of those packages. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.