Megatron Electrostatic Headphone Amplifier

[nopants]

Just to double-check...these are the same diodes found in the old PSU (STTH1210D), you're saying we can't use these anymore? A quick google search doesn't yield anything meaningful for stth512fb

 

While we're at it, can we still use the KBU* part for the new psu's LV bridge (vs RS402L)?

[spritzer]

Those are not isolated diodes so it will explode quite spectacularly. 

 

Same bridge is used. 

[GeorgeP]

^{Those are not isolated diodes so it will explode quite spectacularly.} 

 

^{Same bridge is used.} 

 

^{Yes, I think that was already covered somewhere in this thread or the KGSSHV thread.}

^{But could he not go about isolating them with some Kapton? Would not be pretty and would need to ensure it stayed in place from a mechanical perspective. Obviously the correct parts would be the best approach.}

[insanity]

Thats because its a typo and should be stth512fp

 

Just to double-check...these are the same diodes found in the old PSU (STTH1210D), you're saying we can't use these anymore? A quick google search doesn't yield anything meaningful for stth512fb

 

While we're at it, can we still use the KBU* part for the new psu's LV bridge (vs RS402L)?

Edited September 26, 2013 by insanity

[spritzer]

We are dealing with a lot of raw DC voltage here so the only option is to use the isolated diodes.  Any other route may work but it probably won't. 

[eggil]

Well, I will change them before they explode

The 1210 is TO220

The 1512 at mouser is DO247

Edited September 26, 2013 by eggil

[spritzer]

This is it. 

Edited September 26, 2013 by spritzer

[GeorgeP]

Alternatively, he may only need to replace two rather than all four (in each grouping) - two insulated beside two uninsulated. Just a thought.

Edited September 26, 2013 by GeorgeP

[spritzer]

You don't mess around with 600VDC and it's tendency to arc. 

[eggil]

Devils for not paying attention when I play with fire!

Thanks for helping me avert a stupid disaster.

[Emooze]

Mis-post

Edited September 27, 2013 by Emooze

[RiStaR]

Wondering how everyone else is coming along with their Megatron build?

 

I'm getting jittery waiting for the call that the rest of my items have arrived. This is my first tube project so was hoping for more info before I plonk everything in and power it all up

[nopants]

power and filament transformer arriving from sumr this weekend, should be able to finish (finally). Going to try the input stage with AC first, but I have a Millet Regulator lying around as well.

 

Mundorf supreme leads are too thick for the wima spots, for anyone that was curious

[RiStaR]

Just did a power-on test with everything on the floor. It powers up nicely!

 

Left it running for about 10 mins... no sparks and all... pretty stoked! Late over here now... will do the sound test tomorrow - going to have trouble focusing tomorrow!

 

Offset/bias didn't go above 3.5V for the time I had it up running.

 

Some night pictures:

 

 

Edited October 3, 2013 by RiStaR

[nopants]

congratulations, that offset is better than what I can adjust to in my kgsshv

[RiStaR]

congratulations, that offset is better than what I can adjust to in my kgsshv

 

Cheers! Good luck to you when you power yours on over the weekend, too!

[palchiu]

Congrats! RiStaR

 

It's looks awesome.

 

BTW, should we make offical BOM for Megatron's PSU?

[RiStaR]

Congrats! RiStaR

 

It's looks awesome.

 

BTW, should we make offical BOM for Megatron's PSU?

 

Have you looked at Lil Knight's site? http://tee8tee4388.blogspot.sg/

 

I didn't follow all of them but it's a good starting base?

[chinsettawong]

The glowing tubes look super nice, RiStaR!  Congratulations.

[eggil]

[Just did a power-on test with everything on the floor. It powers up nicely!

Left it running for about 10 mins... no sparks and all... pretty stoked! Late over here now... will do the sound test tomorrow - going to have trouble focusing tomorrow!

Offset/bias didn't go above 3.5V for the time I had it up running.]

Mama Mia ! :0

Edited October 4, 2013 by eggil

[RiStaR]

Cheers Wachara and Eggil

 

I can't wait to go back and hook it up to a source and it's only mid-day here

 

Hopefully everything works fine then I can focus on all the other parts (so much more to go!)

[JoaMat]

Beautiful pictures, RiStaR. Congratulations.

[palchiu]

Have you looked at Lil Knight's site? http://tee8tee4388.blogspot.sg/

 

I didn't follow all of them but it's a good starting base?

 

Tran only post BOM for AMP board. 

[RiStaR]

Thanks Joamat

 

You're still the first to build it! Really looking forward to heading home and testing it tonight.

 

palchiu: It's the KGSSHV PS board... the BOM for that is also on that site.

[spritzer]

There are at least three of these already built...