http://chrisgammell.com/2008/08/06/replacing-capacitors-on-my-wurlitzer-200a-electric-piano/ Combining renewable energy, analog design and some real life experience. A delicious stew of engineering! Sat, 06 Mar 2010 14:12:43 +0000 http://wordpress.org/?v=2.9.2 hourly 1 http://chrisgammell.com/2008/08/06/replacing-capacitors-on-my-wurlitzer-200a-electric-piano/comment-page-1/#comment-1002 When to Try Something vs When to Study Something | Chris Gammell's Analog Life Tue, 07 Jul 2009 11:48:38 +0000 http://chrisgammell.com/?p=120#comment-1002 [...] and change the world. And every resistor value of a circuit board they encounter. And mess with the capacitors. And change the model of the op amps. Oh, and don’t forget to swap out transistors. [...] [...] and change the world. And every resistor value of a circuit board they encounter. And mess with the capacitors. And change the model of the op amps. Oh, and don’t forget to swap out transistors. [...]

]]> http://chrisgammell.com/2008/08/06/replacing-capacitors-on-my-wurlitzer-200a-electric-piano/comment-page-1/#comment-529 Update: Wurlitzer 200A–Still in pieces | Chris Gammell's Analog Life Thu, 11 Dec 2008 03:45:00 +0000 http://chrisgammell.com/?p=120#comment-529 [...] being able to get it working since. When I messed up last time I was actually trying to replace the capacitors and transistors that had dried up and what I had thought was causing considerable hum in the circuit. However, [...] [...] being able to get it working since. When I messed up last time I was actually trying to replace the capacitors and transistors that had dried up and what I had thought was causing considerable hum in the circuit. However, [...]

]]> http://chrisgammell.com/2008/08/06/replacing-capacitors-on-my-wurlitzer-200a-electric-piano/comment-page-1/#comment-507 Best Free SPICE Program | Chris Gammell's Analog Life Fri, 05 Dec 2008 12:03:13 +0000 http://chrisgammell.com/?p=120#comment-507 [...] is that their program is well suited to handle rapidly changing inputs. I plan to re-construct my Wurlitzer 200A schematic in LTSpice in order to better understand some of the parameters affecting the sound and maybe even [...] [...] is that their program is well suited to handle rapidly changing inputs. I plan to re-construct my Wurlitzer 200A schematic in LTSpice in order to better understand some of the parameters affecting the sound and maybe even [...]

]]> http://chrisgammell.com/2008/08/06/replacing-capacitors-on-my-wurlitzer-200a-electric-piano/comment-page-1/#comment-292 How to get job as a new electrical engineer grad | Chris Gammell's Analog Life Fri, 10 Oct 2008 10:09:11 +0000 http://chrisgammell.com/?p=120#comment-292 [...] Capacitors — At DC, a capacitor is essentially an open circuit (think a broken wire). If you apply charge long enough (depending on the capacitance), it can consume some of that charge; after it is charged it will once again act like an open circuit. When considering AC (varying) signals, the best way to think about a capacitor is like a variable resistor. The thing controlling how much the capacitor will resist the circuit is the frequency of the signal trying to get through the capacitor. As the frequency of the signal goes up, the resistance (here it is called “impedance”) will go down. So in the extreme case, if the frequency is super high, the capacitor will appear as though it is not there to the signal (and it will “pass right through”). Taking the opposite approach helps explain the DC case. If the signal is varying so slowly that it appears to be constant (DC), then the impedance of the capacitor will be very high (so high it appears to be a broken wire to the signal). [...] [...] Capacitors — At DC, a capacitor is essentially an open circuit (think a broken wire). If you apply charge long enough (depending on the capacitance), it can consume some of that charge; after it is charged it will once again act like an open circuit. When considering AC (varying) signals, the best way to think about a capacitor is like a variable resistor. The thing controlling how much the capacitor will resist the circuit is the frequency of the signal trying to get through the capacitor. As the frequency of the signal goes up, the resistance (here it is called “impedance”) will go down. So in the extreme case, if the frequency is super high, the capacitor will appear as though it is not there to the signal (and it will “pass right through”). Taking the opposite approach helps explain the DC case. If the signal is varying so slowly that it appears to be constant (DC), then the impedance of the capacitor will be very high (so high it appears to be a broken wire to the signal). [...]

]]> http://chrisgammell.com/2008/08/06/replacing-capacitors-on-my-wurlitzer-200a-electric-piano/comment-page-1/#comment-191 Breaking my Wurlitzer 200A | Chris Gammell's Analog Life Mon, 15 Sep 2008 11:44:13 +0000 http://chrisgammell.com/?p=120#comment-191 [...] it seems that I may have broken the amplifier on my Wurlitzer 200A. This after I took my sweet ol’ time getting all the replacement parts in from Mouser. After [...] [...] it seems that I may have broken the amplifier on my Wurlitzer 200A. This after I took my sweet ol’ time getting all the replacement parts in from Mouser. After [...]

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