I have built the old version of his plasmatweeter, I used the circuit found at http://www.ece.villanova.edu/~cdanjo/plasma.html
So far just one is built, but the second one should be done soon. It sounds good, and is decently loud, i have to use a seperate amp set @ a much higher volume to get an acceptable volume level out of it. Even just using 1 tweeter makes a difference in the sound, my stereo sounds much better with it.
However it is a little bit trickey to get the bugs out of it. The coil is crytical. If you use a wire guage too small it will overheat and melt the coil form, or glue. For testing purposes im using black 35mm film canisters as coil forms. the wire i believe is #22awg, it is black enameled and came from the primary of a car ignition coil.
If the coil is wound wrong and does not resonate @ the correct frequency your tube will overheat and can get ruined. If the gain is set too high the tube will fry.
To set the gain, warm up the tube filliments for ~1.5 - 2 min but leave the high voltafge off. Turn the gain all the way down. Play music into the tweeter at normal listening level. Turn on the high voltage, and turn up the gain just untill the tweeter ignites by itself. Then turn the gain down just a tiny bit.
Turn off HV and let it sit for a minute. Then turn on the hv again and the tweeter should ignite by itself. it it dosent raise the gain a tiny bit. Keep an eye on the tube to make sure that the plates dont start to glow orange. If it runs for a few min without the plates getting too hot then its all set, and you shouldnt need to play around with the gain anymore.
So far just one is built, but the second one should be done soon. It sounds good, and is decently loud, i have to use a seperate amp set @ a much higher volume to get an acceptable volume level out of it. Even just using 1 tweeter makes a difference in the sound, my stereo sounds much better with it.
However it is a little bit trickey to get the bugs out of it. The coil is crytical. If you use a wire guage too small it will overheat and melt the coil form, or glue. For testing purposes im using black 35mm film canisters as coil forms. the wire i believe is #22awg, it is black enameled and came from the primary of a car ignition coil.
If the coil is wound wrong and does not resonate @ the correct frequency your tube will overheat and can get ruined. If the gain is set too high the tube will fry.
To set the gain, warm up the tube filliments for ~1.5 - 2 min but leave the high voltafge off. Turn the gain all the way down. Play music into the tweeter at normal listening level. Turn on the high voltage, and turn up the gain just untill the tweeter ignites by itself. Then turn the gain down just a tiny bit.
Turn off HV and let it sit for a minute. Then turn on the hv again and the tweeter should ignite by itself. it it dosent raise the gain a tiny bit. Keep an eye on the tube to make sure that the plates dont start to glow orange. If it runs for a few min without the plates getting too hot then its all set, and you shouldnt need to play around with the gain anymore.
Dont think i'll have a problem weith the coil. I have some ceramic bar i am planing to lathe down to the right size and drill out. i have had problems however with finding the right components from uk suppliers, this may be because i am not an expert and am simply looking for parts as they are listed on the schemtic from the site above. if anybody has a simple list of parts required etc.... a friend made a pair with me about a year ago and the sound was fantastic but he brought most of the stuff back from hols in the states and we had to run them on a 110volt stepdown transformer. They also genarate a massive amount of interferance to a plasma screen tv making it unwatchable whilst they ran. the hi-fi was fine however so i suspect this may be solved by a better case as ours lived in plastic boxes to insulate some of that nasty high voltage.
Check out this thread and watch out for the ozone.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=1841&highlight=
http://www.diyaudio.com/forums/showthread.php?s=&threadid=1841&highlight=
Any part numbers etc would be fantastic.. The tweeters will sit either side of the chimminy in my lounge. I plan to put 2 holes in the wall and run 2 lengths of ducting up the chimmily with 2 small pc case fans to provide some suction, the outlet of these holes will be about 8" from the discharge and i'm hoping this will be enough to remove some of the ozone. I remember hearing that ozone harshley attacks rubber! Imagin this means the rubber on my bass/mid drivers aswell as my credit cards and my gimp suit!
Just to point out, the plasma cutter in my workshop seems to be the same thing. you get an monster arc discharge then you blow compressed air through it and burn of the o2, this makes a flame up to about an inch thick and 3 inch long. i'd think this would make a huge amount of ozone but looking through the handbook only tells you to 'use in a ventilated area'! Intrestingly if it's runing and the big compressor or something starts up the power surge makes the flame change breifly and you get sound! (not music, but a noise none the less). Now if i made a pair could i just run them from the pre out on my amp and just remove the jumper bars to kill my speakers tweeter? does the design on the web allow you to ajust gain and xover?
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.