Looks good! The tube can handle 50w maybe but you want to use this power for the fundamental frequency and not waste it for other harmonics the tube can produce.
Hey guys,
I am interested in making a plasma tweeter. I am gonna read through this thread fairly closely and absorb what it says... I look forward to making a pair of these. I have a pair of AMT's and these look like they would be something else cool to DIY because conventional tweeters are boring haha... I will be gathering materials to build and follow your lead to see what works and proven well. Any tips for a first try? I am very serious about the project and would love some input. Thanks!
Chris
I am interested in making a plasma tweeter. I am gonna read through this thread fairly closely and absorb what it says... I look forward to making a pair of these. I have a pair of AMT's and these look like they would be something else cool to DIY because conventional tweeters are boring haha... I will be gathering materials to build and follow your lead to see what works and proven well. Any tips for a first try? I am very serious about the project and would love some input. Thanks!
Chris
Hello Chriss,
Welcome.
Have a look at :
Nymeria
Excuse my poor english level,but what do you mean by AMT ? Transistors ?
If yes you can find the Magnat tweeters schematic on the web.
I think it's easier to build your own units with tubes
(For example Gu50:good and cheap)
For the moment I have some troubles with my voltage doubler, 890ufcapacitors are too strong,400uf should be better.
Regards
Welcome.
Have a look at :
Nymeria
Excuse my poor english level,but what do you mean by AMT ? Transistors ?
If yes you can find the Magnat tweeters schematic on the web.
I think it's easier to build your own units with tubes
(For example Gu50:good and cheap)
For the moment I have some troubles with my voltage doubler, 890ufcapacitors are too strong,400uf should be better.
Regards
Hi Chris, tubes are forgiving when pushing too hard during experimenting. So it is easier to start a project with them. The additional heater power supply is no fun but now we can get cheap switched mode psu’s. The high voltage should not scare you of but arrange some fuses or current limiters in case something goes wrong. Best you start with a proven circuit like the one i provided in a previous entry. Good luck !
Best regards, Frank
Best regards, Frank
I have found some documents on this topic that i collected over the years. When ever i find more i will place it.
Attachments
http://ds.agavaceae.ru/su/6s20s.gif
Lampie 519 ,i know that your project use high voltage.Perhaps this will be usefull
Lampie 519 ,i know that your project use high voltage.Perhaps this will be usefull
Thanks, Marco! I have already a bunch of these tubes but until now i have not used them. My guess is that these are no good for audio but i can try anyway.
Attachments
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Now power supply is OK.
The 6V 5A switching power supply for filaments does the job (6,2v) for less than 10€ with shiping fées.
I gotta some difficulties with The full wave voltage doublers:capacitors are strong 890uf and the start current killed 3 interruptors and a lot of fuses.
So i mounted a 3 Ohms 10w wirewound resistor at the entrance.Now it works. I think that 400uf should bé enought and better.
Empty voltages are 680V and 340V for middle point.
It's more than i hopped. So i have no idea of loaded voltages.
The 6V 5A switching power supply for filaments does the job (6,2v) for less than 10€ with shiping fées.
I gotta some difficulties with The full wave voltage doublers:capacitors are strong 890uf and the start current killed 3 interruptors and a lot of fuses.
So i mounted a 3 Ohms 10w wirewound resistor at the entrance.Now it works. I think that 400uf should bé enought and better.
Empty voltages are 680V and 340V for middle point.
It's more than i hopped. So i have no idea of loaded voltages.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
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You can see here:
.the 6v 5A switching led power supply.
.the Latour voltage doubler with a black 3,9 ohms10w resistor at the entrance and à 300K 5W discharge resistor.
Fuse and EMI filter.
.Red light is on switching power supply wired (voltage is 6,2v).
To test my system,i must ad a 47k 5W potentiometer in front of the 2nd grid and wire it on the middle point of the voltage doubler.
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I must now test my voltage doubler loaded.
I want to do that first with resistors.
807 tube's 2nd grid work around 7ma at 250v.
I will use a 39k resistor to simulateur it.
I have a rought idea of impédance value of the system,i think it's nearly 4,5 K.
So i need a 50w resistor.
What do you think about that ?
I want to do that first with resistors.
807 tube's 2nd grid work around 7ma at 250v.
I will use a 39k resistor to simulateur it.
I have a rought idea of impédance value of the system,i think it's nearly 4,5 K.
So i need a 50w resistor.
What do you think about that ?
The resistor will get hot! Not sure what will happen if you use the tube as it needs warming up time. Then the voltage will be too high. I would use 47uf capacitors instead of the big values you use. Then the voltage is lower and does not draw too much power at start up.
Hello,
PSU ? You mind power supply? I waiting for 12 Ohm 20W 10 Ohm 10w resistors ordered on ibê.
I will provide a schematic if you want.
Otherwise I have some difficulties with my pictures hoster.
Regards
PSU ? You mind power supply? I waiting for 12 Ohm 20W 10 Ohm 10w resistors ordered on ibê.
I will provide a schematic if you want.
Otherwise I have some difficulties with my pictures hoster.
Regards
You said that the fuses blow, so i guess there is some issues with the power supply (PSU). Is there a ground leak? Do you have a schematic of the PSU?
Hello,
At first,there is no possibility for a ground leak.The tweeter is full insulated :it stands on a wood table with insulating carpet.Rubber bands are bellow the frame.
2nd,i have no idea of PIO K41-1a 0,1uf esr capacitor.
Voltage doubler is directly wirered on 240 ac voltage tought a fuse , EMI filter,switch and a 3,9 Ohm resistor.
But even with this resistor and voltage doubler alone ,i saw a flash inside the switch.
At first,there is no possibility for a ground leak.The tweeter is full insulated :it stands on a wood table with insulating carpet.Rubber bands are bellow the frame.
2nd,i have no idea of PIO K41-1a 0,1uf esr capacitor.
Voltage doubler is directly wirered on 240 ac voltage tought a fuse , EMI filter,switch and a 3,9 Ohm resistor.
But even with this resistor and voltage doubler alone ,i saw a flash inside the switch.