Those are looking great! I wish I had the room in my house to have a pair of electrostats
properly set up. Unfortunately they would have to be placed within about 18" of the back wall, which would defeat the purpose I believe
That is the nice thing about headphones, it doesn't matter what size my house is!
properly set up. Unfortunately they would have to be placed within about 18" of the back wall, which would defeat the purpose I believe
That is the nice thing about headphones, it doesn't matter what size my house is!
Hi,
the slotted hole pattern allows for a higher degree of openness.
On the other hand the stiffness of the sheets/panel is reduced.
Will You bend the sheets and build a curved stator?
Is there a special reason for the bends at the side rims or will these be cut off?
Just 3 layers of paint won´t be sufficient. Depending on the paint You will get a thickness of the dried layers of typically ~50-75µm. You won´t get this thickness at the hole edge though. Together with the burrs left over from the stancing, the flashover treshold will be too low. Think of min. 300µm, better 500µm of dried layer thickness without deburred metal sheet.
jauu
Calvin
the slotted hole pattern allows for a higher degree of openness.
On the other hand the stiffness of the sheets/panel is reduced.
Will You bend the sheets and build a curved stator?
Is there a special reason for the bends at the side rims or will these be cut off?
Just 3 layers of paint won´t be sufficient. Depending on the paint You will get a thickness of the dried layers of typically ~50-75µm. You won´t get this thickness at the hole edge though. Together with the burrs left over from the stancing, the flashover treshold will be too low. Think of min. 300µm, better 500µm of dried layer thickness without deburred metal sheet.
jauu
Calvin
Hi Calvin,
You are absolutely right about the reduction in stiffness. I fold 2 sides at the edges of the metal sheet to increase their stiffness. Let's see how they would turn out. I wish I knew how to stretch the Mylar to put on a curve panel. The curve panels look so cool to me. Can you teach me please, Calvin?
About the paint coating, I forgot to mention that I put 2 layers of base coating before the top 3 layers of plastic paint. So, in total I have 5 layers of paint. I'm not sure how thick the coating is. With a well coating, can you touch the panels when you play music? Do you still need to put some protective layers on both side of the stators?
Wachara C.
You are absolutely right about the reduction in stiffness. I fold 2 sides at the edges of the metal sheet to increase their stiffness. Let's see how they would turn out. I wish I knew how to stretch the Mylar to put on a curve panel. The curve panels look so cool to me. Can you teach me please, Calvin?
About the paint coating, I forgot to mention that I put 2 layers of base coating before the top 3 layers of plastic paint. So, in total I have 5 layers of paint. I'm not sure how thick the coating is. With a well coating, can you touch the panels when you play music? Do you still need to put some protective layers on both side of the stators?
Wachara C.
Hi,
the bending as in Your pics increases the stiffness in vertical direction.
Since You normally clamp these edges into a supporting/stiffening frame there´s no real advantage to do so, because the weak part of the panel is its middle. When glued together the complete panel is of course stiffer than a single metal sheet, but not enough to kill vibrations. Curving the sheets increases the stiffness much more and it lessens the demand of the fixed listening position a bit.
It´s no secret that for a curved panel You have to stretch the diaphragm only in the straight direction. This rules out thermal treatment of the diaphragm. A just mechanically stretched membrane needs many hours to break in and settle to the intended operating point. Apart from this temporary disadvantage, or if You can heat treat the membrane as I do, the curving is advantageous.
jauu
Calvin
the bending as in Your pics increases the stiffness in vertical direction.
Since You normally clamp these edges into a supporting/stiffening frame there´s no real advantage to do so, because the weak part of the panel is its middle. When glued together the complete panel is of course stiffer than a single metal sheet, but not enough to kill vibrations. Curving the sheets increases the stiffness much more and it lessens the demand of the fixed listening position a bit.
It´s no secret that for a curved panel You have to stretch the diaphragm only in the straight direction. This rules out thermal treatment of the diaphragm. A just mechanically stretched membrane needs many hours to break in and settle to the intended operating point. Apart from this temporary disadvantage, or if You can heat treat the membrane as I do, the curving is advantageous.
jauu
Calvin
Hi Wachara!
I am still alive and working on this project when I am able. Unfortunately my computer crashed and I am having it repaired so posting pictures right now is very difficult. I have almost completed the energizer and have a couple of questions about the circuit. In the power supply there are three resistors, two of which are unmarked. The third is marked as 1K, are the other two the same value? What wattage rating do these need to be? Also, the diode on V1 that is connected to the grid of the second half of the tube, would a 1n4007 be ok in this position(I hope so I already soldered one in place!). I need to research the pin configuration for Stax headphones as I would like to be able to use this with them as well as the home-made versions I have yet to complete. I should be getting my computer back in a couple of days and I will show what I have done.
Thanks,
Matt
I am still alive and working on this project when I am able. Unfortunately my computer crashed and I am having it repaired so posting pictures right now is very difficult. I have almost completed the energizer and have a couple of questions about the circuit. In the power supply there are three resistors, two of which are unmarked. The third is marked as 1K, are the other two the same value? What wattage rating do these need to be? Also, the diode on V1 that is connected to the grid of the second half of the tube, would a 1n4007 be ok in this position(I hope so I already soldered one in place!). I need to research the pin configuration for Stax headphones as I would like to be able to use this with them as well as the home-made versions I have yet to complete. I should be getting my computer back in a couple of days and I will show what I have done.
Thanks,
Matt
Hello Matt
Where is Wachara ? Lying on the sand, under the palm trees ?
Apply the Ohm's Law. The current for one amplifier is around 12 mA then 24 mA for 2 amplifiers. For 10 volts (310-300 v) and 12 or 24 mA current for one or two amplifier you can use 820 or 390 ohms resistors. Each resistor dissipates approximately 0,3 watt, then use 1 watt minimum resistor. Each of the six 10k resistors in the output stage dissipates 0.25 W, also use 1 watt minimum resistors. http://en.wikipedia.org/wiki/Ohm's_law
1N4007 is OK
The pin configuration of the Stax "Pro-Bias" (580 volts) connector is on the Andrea Ciuffoli's site: http://www.audiodesignguide.com/my/stax_transf.html
Best regards !
Philippe
Where is Wachara ? Lying on the sand, under the palm trees ?
Apply the Ohm's Law. The current for one amplifier is around 12 mA then 24 mA for 2 amplifiers. For 10 volts (310-300 v) and 12 or 24 mA current for one or two amplifier you can use 820 or 390 ohms resistors. Each resistor dissipates approximately 0,3 watt, then use 1 watt minimum resistor. Each of the six 10k resistors in the output stage dissipates 0.25 W, also use 1 watt minimum resistors. http://en.wikipedia.org/wiki/Ohm's_law
1N4007 is OK
The pin configuration of the Stax "Pro-Bias" (580 volts) connector is on the Andrea Ciuffoli's site: http://www.audiodesignguide.com/my/stax_transf.html
Best regards !
Philippe
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Hi Philippe and Matt,
I am here. I didn't want to give Matt to much pressure. I just keep quiet and wait to see his progress. I'm glad that Matt has almost finish with his headphones.
Matt, let's see a lot of your photos, please.
Oh, thanks philippe for your answers to Matt's questions.
Wachara C.
I am here. I didn't want to give Matt to much pressure. I just keep quiet and wait to see his progress. I'm glad that Matt has almost finish with his headphones.
Matt, let's see a lot of your photos, please.
Oh, thanks philippe for your answers to Matt's questions.
Wachara C.
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