audio-talk

I ran a few tests with different loads yesterday and it is definitely better with speakers etc over 2k. The secondary resistance of the O/P transformer is just under 1K. Setting up the regen to howl the Audio output V peaks at around a 3.5K load so I reckon 2k is probably where the most power is tra...

Thanks Steve, Here the Z is 2K plus, there is not a lot of power to play with. The DC resistance of the O/P transformer appears to step up towards the speaker. Running the phones 2K and touching the terminals you get quite a tingle. I will read up on Philips 800 ohm speakers and see what the resista...

Just been looking at Audio exciters, If the coil no longer moves because it is attached to the sound surface and is the magnet assy that is moving then this opens up a whole load of possibilities.

I have a Philips 2514 radio Which has finally been brought to life. I have a 1925 BTH horn Speaker which apart from its size sounds pretty bad. The radio on Hi Z phones is OK, well it's just acceptable I was wondering how I might make a Hi Z speaker. The Present O/P transformer is High in High out. ...

Probably is an early Xray tube, Is that a sort of mirror on the RH side, inside the envelope. Otherwise Does it have mercury in it?

This is an old picture from years ago when I built the first iteration, but it shows what the GU48 looks like lit up. :) https://encrypted-tbn0.gstatic.com/images?q=tbn%3AANd9GcQvjoxIcZul2K_CpUSwM6OklcJ8mySa7OYiGA&usqp=CAU Mine mounted on a Teflon Base with movable solid brass sections to allow...

If it sounds OK and YOU are happy who cares. There are many things you can do with Tubes apart from water and liquids although some tubes correctly treated and modified could become a small acquarium! From illumination and heating to miniature amps and Tesla Megavolt generators the imagination is th...

Hi pre65, I am Near Alicante in Spain. I have an old EL84 class A amp with an HT of 250V. Just for a few tests about 5 years ago, I connected An 813 (RCA) Emission a bit down but OK in place of of one of the EL84s Obviously with a 10V DC filament supply, no other changes apart from the long wires go...

A big Hi to everyone, I have been playing with valves off and on for 60 odd years, and often go OTT with my bottles. Present amp is an all mains toroid job, with EL34s in triode and Antitriode, Long tailed pairs with individual CCSs to balance I in the 350W mains toroids. Presently restoring a Phili...