What Are You Building Today

[swt61]

That sounds like it would be excellent with halibut!

[luvdunhill]

Got my new power supply ready for my KG amp collection

 

[G600]

What is it for?

I have seen a similar but smaller stup a while ago, it was a local power backup for wired home telephone.

[kevin gilmore]

totally 100% safe.  looks like about 100kva.  proper personal protective equipment required.  typically 600v if its to generate 3 phase.  makes the stuff birgir is doing to e-cars look tame.

[swt61]

I've seen a similar setup in the dungeon of a leather bar back in the early 80s. Most likely for a different purpose though.

[MASantos]

X-altra MM/MC phono stage.

A project published on audioexpress a few years ago and a different design approach compared to my Simplistic phono designed by Salas over at diyaudio.com

 

Will be fun to compare both. 

 

Edited September 18 by MASantos

[JoaMat]

Aerial picture of a balanced amplifier for dynamic headphones. Only light from LEDs and tubes. ISO-25600, F4, 1/13 sek.

And in day light. 4 x 2A3, 4 x 12BH7, 8 x switch mode filament supplies, 2 x GRHV and 4 x transformers.

DIY is still fun. 

 

[wink]

5 minutes ago, JoaMat said:

Aerial picture of a balanced amplifier for dynamic headphones. Only light from LEDs and tubes. ISO-25600, F4, 1/13 sek.

And in day light. 4 x 2A3, 4 x 12BH7, 8 x switch mode filament supplies, 2 x GRHV and 4 x transformers.

DIY is still fun. 

 

All it needs is an Unobtanium case...😁

[jokerman777]

10 hours ago, JoaMat said:

Aerial picture of a balanced amplifier for dynamic headphones. Only light from LEDs and tubes. ISO-25600, F4, 1/13 sek.

And in day light. 4 x 2A3, 4 x 12BH7, 8 x switch mode filament supplies, 2 x GRHV and 4 x transformers.

DIY is still fun. 

 

Very cool! How do you couple output stage to headphones, doesn't look like output transformers are used?

[JoaMat]

No output transformer. There are output electrolytics to headphone.

Schematically it looks something like this.

Reason for three KSC2690A in CCS is to distribute the heat, so no heat sink needed. At the moment I only use two transistors in CCS due to insufficient transformers.

I don’t know how to optimize the circuit, but I’m happy with the result.

[JoaMat]

A few words regarding filament supplies I’m using with 2A3 and 300B tubes.

9 VAC => unregulated 11 VDC => XL4015 DCtoDC step down converter...

... with trimmers for output voltage and current limiter. It’s easy to set voltage to correct voltage depending of tube and also to trim current to achieve a sort of soft start. So far it works ok.