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Everything posted by blacksheep

  1. I am actually trying to understand how to design a transistor stage :) I don't know much about it and i think it is very confusing -- i don't know where to start and where to end. I thought about transferring the theory about vacuum tubes to transistor design, because i understand it better. In tube stage designing, the anode curves (collector curves for transistors) is used to get parameters such as amplification, internal resistance and others. I think it is a nice way to design and understand a tube circuit. Why is it so different with transistors? Is it the because of the difference between transistors of the same part number or is it just a totally different way of designing amplifier stages? I could really use a good book about small (audio) signal amplifiers using transistors...
  2. I don't know why it is so difficult to find datasheet with collector curves for any general purpose transistor. I have looked for datasheets for bc547, bc549, 2n2222 and others . Does anybody know where to find good datasheets with the Uce - Ic curves and Ube - Ib curves included for standard general purpose transistors?
  3. No i didn't remove the diodes... maybe thats the problem ::) What do you mean about an emitter-follower? I've heard about it before but i don't know what it means... But thanks... i'll try that very soon :)
  4. The speaker was connected through a power-amp... I don't know anything about the impedance :-( but I still think it's the way that the preamp is made... you know, some guitarists likes distortion, but i want a clean pre-amp :-)
  5. I did build the pre-amp of this project: 100W Guitar Amplifier Mk II http://sound.westhost.com/project27.htm The problem was that almost nothing was comming out of the speaker unless i was turning up the gain-control, and then I got distortion. The Volume-control was as high as possible... then i looked on the project-site again, and changed some resistors but it didn't work very well.... I think its best if I start with a simple schematic... i think the dual opamp TL072 should be fine, but I don't know much about op-amps... so I need some help :-) I explain: I don't need big complicated schematics of already build guitar-amps, I more need some beginner-info about building pre-amps with op-amps (or maybe transistors) Thanks for helping me :-) - But I need more help :-( , so everybody is welcome to post some info :-)
  6. Ante, I've already tried building the pre-amp - the problem is, that the sound isn't clean. I wanted a clean pre-amp :-) But maybe i could use the power-amp schematic... Thanks :-) Really nice site, EDY, but it's still tube-amps :-[ hehe But, thanks for helping. I would really like some beginner-guides to build pre-amps with op-amps and/or transistors. Somebody in this forum must know something about that :-)
  7. Thanks for the links, but it seems like its only tube-amps, and thats not what i'm interested in... :-) hehe... Maybe somebody have some schematics of a (very) simple preamp with TL072 or similiar opams. I think, it could help me to find out how to work with opams...
  8. Hi :-) I want to build a guitar amplifier, but i haven't found any useful schematics yet... I want it to be powerful, maybe 100 Watt if its possible, it has to be a clean pre-amp (which means: no distortion), low-noise as possible (no hiss) and a 3-band graphic equalizer (low, mid and high-controls), look at my drawing. I'm a newbie in audio electronics, so i don't know that much about op-amps, transistors... you name it :-) If you think you know much about it to help me creating some schematics, you are very welcome to post in this forum or to my mail-adress: peter(@)gawis.dk
  9. It is easy to build a square wave-generator with a NE555, but it is possible to build a sine wave generator with the NE555? If not, i would like if somebody have some ideas, how to build a sine wave generator
  10. mixos: Thank you very much for your reply... i have one more question: I've made a digital amperemeter with a voltage-to-frequency-converter (LM131), an amv (NE555), some mmv's (MC14538), some bcd-counters (MC14518) and some bcd-to-7segment's (MC14511).... is it possible to build an ampere meter in the same way, or do i need a "ampere-to-frequency-converter"? ;) sounds a little funny...
  11. Does somebody know how i can make a digital amperemeter? It's for a power supply...
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