Members ej Posted January 5, 2013 Members Share Posted January 5, 2013 I designed this simple 1 transistor distortion with a switchable band pass filter for lowfi sounds. I would love some feedback on it.This is my first time trying my hand at anything like this. I left out all the switching and such. What do y'all think? Link to comment Share on other sites More sharing options...
Members ej Posted January 5, 2013 Author Members Share Posted January 5, 2013 The actual distortion part of the circuit it based on this from GGG:http://www.generalguitargadgets.com/...n/onetrans.pdf In case I copied some stuff down wrong, its my first time using CircuitMaker Link to comment Share on other sites More sharing options...
Members ej Posted January 5, 2013 Author Members Share Posted January 5, 2013 The actual distortion part of the circuit it based on this from GGG:http://www.generalguitargadgets.com/...n/onetrans.pdf In case I copied some stuff down wrong, its my first time using CircuitMaker Link to comment Share on other sites More sharing options...
Members Jack Deville Posted January 5, 2013 Members Share Posted January 5, 2013 I think a collector resistor would be a good idea. Link to comment Share on other sites More sharing options...
Members Jack Deville Posted January 5, 2013 Members Share Posted January 5, 2013 I think a collector resistor would be a good idea. Link to comment Share on other sites More sharing options...
Members ej Posted January 5, 2013 Author Members Share Posted January 5, 2013 Forgot some components and got some values wrong on my initial schematic. Revised: Link to comment Share on other sites More sharing options...
Members ej Posted January 5, 2013 Author Members Share Posted January 5, 2013 Forgot some components and got some values wrong on my initial schematic. Revised: Link to comment Share on other sites More sharing options...
Members Lanefair Posted January 5, 2013 Members Share Posted January 5, 2013 Originally Posted by ej Forgot some components and got some values wrong on my initial schematic. Revised: Will it be loud enough after clipping/filtering? Link to comment Share on other sites More sharing options...
Members Lanefair Posted January 5, 2013 Members Share Posted January 5, 2013 Originally Posted by ej Forgot some components and got some values wrong on my initial schematic. Revised: Will it be loud enough after clipping/filtering? Link to comment Share on other sites More sharing options...
Members macadood Posted January 5, 2013 Members Share Posted January 5, 2013 boost stage! Link to comment Share on other sites More sharing options...
Members macadood Posted January 5, 2013 Members Share Posted January 5, 2013 boost stage! Link to comment Share on other sites More sharing options...
Members ej Posted January 5, 2013 Author Members Share Posted January 5, 2013 what about an active filter instead of passive? I also made the switch DPDT so the filtering can be completely removed. Link to comment Share on other sites More sharing options...
Members ej Posted January 5, 2013 Author Members Share Posted January 5, 2013 what about an active filter instead of passive? I also made the switch DPDT so the filtering can be completely removed. Link to comment Share on other sites More sharing options...
Members amp_surgeon Posted January 5, 2013 Members Share Posted January 5, 2013 Either develop a passion for breadboards or use a simulator. A good sim will teach you an awful lot about how changes affect your circuit. You can use the simulator on circuitlab.com for free, and you don't have to download anything because it runs in your web browser. The downside is that it's all java script so it's really slow to run a simulation. I tried simulating only the octave amp of an FY-6 on circuitlab and it took more than an hour to generate 1000 sample points. There are lots of free Spice simulation engines but few with graphical interfaces. Writing simulation scripts manually isn't my idea of a pleasant afternoon, but I've done it before. I'm currently using 5Spice (5spice.com). The free demo version is very limited - very small schematic drawing space, and some of the simulation features are disabled, but it will give you an idea how it works. Once you register it (around $200) then it unlocks all the features, and you can draw very large schematics to simulate. I can simulate the entire six transistor FY-6 circuit and collect 10,000 sample points in a little over a second. It's very accurate, too. The waveforms I saw in simulation were exactly what I saw on the bench with the breadboard and o-scope. You'll need Spice models for every component you use in your circuit. 5Spice comes with some common components, and many more can be found on the internet. They're just text files containing a description of how the component performs, but they contain parameters you often won't find on a manufacturer's datasheet. For semiconductors, you can usually find Spice models on the manufacturer's website. Link to comment Share on other sites More sharing options...
Members amp_surgeon Posted January 5, 2013 Members Share Posted January 5, 2013 Either develop a passion for breadboards or use a simulator. A good sim will teach you an awful lot about how changes affect your circuit. You can use the simulator on circuitlab.com for free, and you don't have to download anything because it runs in your web browser. The downside is that it's all java script so it's really slow to run a simulation. I tried simulating only the octave amp of an FY-6 on circuitlab and it took more than an hour to generate 1000 sample points. There are lots of free Spice simulation engines but few with graphical interfaces. Writing simulation scripts manually isn't my idea of a pleasant afternoon, but I've done it before. I'm currently using 5Spice (5spice.com). The free demo version is very limited - very small schematic drawing space, and some of the simulation features are disabled, but it will give you an idea how it works. Once you register it (around $200) then it unlocks all the features, and you can draw very large schematics to simulate. I can simulate the entire six transistor FY-6 circuit and collect 10,000 sample points in a little over a second. It's very accurate, too. The waveforms I saw in simulation were exactly what I saw on the bench with the breadboard and o-scope. You'll need Spice models for every component you use in your circuit. 5Spice comes with some common components, and many more can be found on the internet. They're just text files containing a description of how the component performs, but they contain parameters you often won't find on a manufacturer's datasheet. For semiconductors, you can usually find Spice models on the manufacturer's website. Link to comment Share on other sites More sharing options...
Members ej Posted January 5, 2013 Author Members Share Posted January 5, 2013 Originally Posted by amp_surgeon Either develop a passion for breadboards or use a simulator. A good sim will teach you an awful lot about how changes affect your circuit. You can use the simulator on circuitlab.com for free, and you don't have to download anything because it runs in your web browser. The downside is that it's all java script so it's really slow to run a simulation. I tried simulating only the octave amp of an FY-6 on circuitlab and it took more than an hour to generate 1000 sample points.There are lots of free Spice simulation engines but few with graphical interfaces. Writing simulation scripts manually isn't my idea of a pleasant afternoon, but I've done it before.I'm currently using 5Spice (5spice.com). The free demo version is very limited - very small schematic drawing space, and some of the simulation features are disabled, but it will give you an idea how it works. Once you register it (around $200) then it unlocks all the features, and you can draw very large schematics to simulate. I can simulate the entire six transistor FY-6 circuit and collect 10,000 sample points in a little over a second. It's very accurate, too. The waveforms I saw in simulation were exactly what I saw on the bench with the breadboard and o-scope.You'll need Spice models for every component you use in your circuit. 5Spice comes with some common components, and many more can be found on the internet. They're just text files containing a description of how the component performs, but they contain parameters you often won't find on a manufacturer's datasheet. For semiconductors, you can usually find Spice models on the manufacturer's website. Thanks dude! I was actually playing around with CircuitLab this morning. Its currently trying to generate the output waveform, should be another 20 minutes Im gonna grab the free version of 5Spice. Link to comment Share on other sites More sharing options...
Members ej Posted January 5, 2013 Author Members Share Posted January 5, 2013 Originally Posted by amp_surgeon Either develop a passion for breadboards or use a simulator. A good sim will teach you an awful lot about how changes affect your circuit. You can use the simulator on circuitlab.com for free, and you don't have to download anything because it runs in your web browser. The downside is that it's all java script so it's really slow to run a simulation. I tried simulating only the octave amp of an FY-6 on circuitlab and it took more than an hour to generate 1000 sample points.There are lots of free Spice simulation engines but few with graphical interfaces. Writing simulation scripts manually isn't my idea of a pleasant afternoon, but I've done it before.I'm currently using 5Spice (5spice.com). The free demo version is very limited - very small schematic drawing space, and some of the simulation features are disabled, but it will give you an idea how it works. Once you register it (around $200) then it unlocks all the features, and you can draw very large schematics to simulate. I can simulate the entire six transistor FY-6 circuit and collect 10,000 sample points in a little over a second. It's very accurate, too. The waveforms I saw in simulation were exactly what I saw on the bench with the breadboard and o-scope.You'll need Spice models for every component you use in your circuit. 5Spice comes with some common components, and many more can be found on the internet. They're just text files containing a description of how the component performs, but they contain parameters you often won't find on a manufacturer's datasheet. For semiconductors, you can usually find Spice models on the manufacturer's website. Thanks dude! I was actually playing around with CircuitLab this morning. Its currently trying to generate the output waveform, should be another 20 minutes Im gonna grab the free version of 5Spice. Link to comment Share on other sites More sharing options...
Members ej Posted January 5, 2013 Author Members Share Posted January 5, 2013 So I spent the day tweaking the circuit in CircuitLab. Heres what I have:What do y'all think? Theres a significant drop in output, but that's to be expected when you're cutting out a huge range of frequencies. Link to comment Share on other sites More sharing options...
Members ej Posted January 5, 2013 Author Members Share Posted January 5, 2013 So I spent the day tweaking the circuit in CircuitLab. Heres what I have:What do y'all think? Theres a significant drop in output, but that's to be expected when you're cutting out a huge range of frequencies. Link to comment Share on other sites More sharing options...
Members Jack Deville Posted January 6, 2013 Members Share Posted January 6, 2013 You may want to include coupling capacitors between the clipping circuit and restoration amplifier. Link to comment Share on other sites More sharing options...
Members Jack Deville Posted January 6, 2013 Members Share Posted January 6, 2013 You may want to include coupling capacitors between the clipping circuit and restoration amplifier. Link to comment Share on other sites More sharing options...
Members amp_surgeon Posted January 6, 2013 Members Share Posted January 6, 2013 Originally Posted by ej So I spent the day tweaking the circuit in CircuitLab. Heres what I have:What do y'all think? Theres a significant drop in output, but that's to be expected when you're cutting out a huge range of frequencies. Where is R25 set? I seem to recall the default is 50%. Also, with emitter resistors that small you're going to be clipping in both transistor stages even with a pretty low level signal. Did you mean for this to clip in the transistor stages, or were you looking for the diodes to do the clipping?And seriously, 2Vpp is a pretty hot input, and 1kHz is pretty high frequency. Try it at 500mV and 100Hz or 500Hz. Link to comment Share on other sites More sharing options...
Members amp_surgeon Posted January 6, 2013 Members Share Posted January 6, 2013 Originally Posted by ej So I spent the day tweaking the circuit in CircuitLab. Heres what I have:What do y'all think? Theres a significant drop in output, but that's to be expected when you're cutting out a huge range of frequencies. Where is R25 set? I seem to recall the default is 50%. Also, with emitter resistors that small you're going to be clipping in both transistor stages even with a pretty low level signal. Did you mean for this to clip in the transistor stages, or were you looking for the diodes to do the clipping?And seriously, 2Vpp is a pretty hot input, and 1kHz is pretty high frequency. Try it at 500mV and 100Hz or 500Hz. Link to comment Share on other sites More sharing options...
Phil O'Keefe Posted January 6, 2013 Share Posted January 6, 2013 Originally Posted by ej What do y'all think? Theres a significant drop in output, but that's to be expected when you're cutting out a huge range of frequencies. I think someone already recommended a make-up gain stage to compensate for this. IMHO, it would be a good idea if you're going to use a fairly drastic bandpass filter on the signal. Link to comment Share on other sites More sharing options...
Members spentron Posted January 6, 2013 Members Share Posted January 6, 2013 Originally Posted by ej So I spent the day tweaking the circuit in CircuitLab. Heres what I have:[...]What do y'all think? Theres a significant drop in output, but that's to be expected when you're cutting out a huge range of frequencies. First of all this thread is cool, because of subject. But this has got problems. Also you're overdriving it hugely with that input level.The lack of a coupling cap distorts out D1 and D2 from Q4's bias.The bias on both stages is probably almost cutoff. Look at the collector voltages.If R25 is 100K etc. then in needs to be after the network. This would also eliminate C14, except reuse it on the first item. Link to comment Share on other sites More sharing options...
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