audio-talk

Ive just walked to Eastfield with my new top plate. R & R engineering kindly guillotined it for me. Fukc diving into the GM70 project. Ive change tack again, consudering Mikes fears and considering my past experience. Im makling the four Mullard EL822’s as push pull output on a ccs tail with a b...

Great to hear, I can do 6 watt with a 630 volt power supply. But I dont really think its worth building at all for just that. So I’ll wait until Ive built it for proper voltages. As I have a 6 watt amp.

On the bright side Ive found out where you get youre 500x500 sheet of stainless guillotined in Scarborough. I’ll go there on the bus when theyre next open; Monday. But a word to the wise, just buy another Hammond Chassis next time, it will be cheaper in the long run, and as you should be downsizing ...

It may be already too late, but before going wild camping I’ll be found trying to sell my valuanle audio stuff at whatever the National Vintage Radio Fair has become by then. I’ll have to give it all up when Im wild camping. Or I may be found on a canal in a 72ft converted barge, or a boat in the ha...

Good idea. I have no vehicle on the rd a scrap van outside the house and a car born 2005 sorn at covid as covid crippled me financially the lovely conservatives didnt support people who hadnt been self employed for a year infront of the covid outbreak. As I dont have a crystal ball I wasnt able to k...

Just IMO, I don't like the idea of 2 x EL84 in parallel, seems like a step too complicated. Also getting them biased the same with fixed bias couild be a headache. So then what, separate bias circuits with trimmers? I assume the issue is must drive a 2.5k primary? Why can't the secondary load be al...

Just IMO, I don't like the idea of 2 x EL84 in parallel, seems like a step too complicated. Also getting them biased the same with fixed bias couild be a headache. So then what, separate bias circuits with trimmers? I assume the issue is must drive a 2.5k primary? Why can't the secondary load be al...

PS I still listening to a real nice el34 amp and its 6 watts is all required to be honest. Quad 57’s need that as a bare minimum Im saying. Though the greater power of the 6550 shone out, the emotion wasnt thrre, its a cold sound. I never liked any versions of the wad kt88 I heard and the last itera...

Why 4 watts? because on the speakers 2 watts would be a waste of project.Wad did a pse 2a3, I did a pse 801a. I didn’t find it a problem, but I think you are saying fixed bias makes valve balancing is then likely to drift. I could just build the driver amp only and go back to IT coupling focus on th...

Its more about getting 4 watts instead of 2 watts. The fixed bias is to avoid requirement for autobias bypass cap. Thanks for the warning.I could check the bias with the clamp meter though so it will show if bias balance is an issue. The 4 watts would be fine at home, but 2 watts not. I wound the op...

It has to be said some Mullard valves not unrelated to EL84 are available at Langrex for £14. In this amplifier they require less bias but should be worth trying same power out, but a Mullard. My EL84’s if British are not nos but well worn. I do have Russian equivalents which Ive always liked. But t...

Just spotted can do 275v triode mode probably get 2 watts.

Screen is ok at 250v so at 250v 3k5 opt (same as el84) bias -7 50mA gives 1.97 watts.

Sorry, not EL82, it’s EL822. This is a 13 watt dissipation pentode and Vade Mecum gives triode curves. Hasn’t enough in common with EL84 but it would be a lot cheaper, has similar gm 13ma/volt mu 23 the data on triode connected isnt provided but the curves are given showing 13 watt dissipation. http...

simon wrote: ↑Sat Jan 06, 2024 8:38 pm Hmmm, I've lost my Sound Practices CD so don't have a copy of that 45 CCS circuit, well that's probably a good thing.

I lost mine, its greating.