Search found 8835 matches

by Paul Barker
Sun Mar 17, 2024 9:01 am
Forum: Everyones Projects
Topic: 6550 SE Amplifier
Replies: 104
Views: 8470

Re: 6550 SE Amplifier

https://i.postimg.cc/JztSR81n/IMG-1154.jpg At the moment single ended one valve has a 4k6 load, but I drew the above to see what PSE looks like but the opt’s are 2k ohm. This graph represents 4k because two EL34’s achieve double the power. So power out becomes 16 watts. Don’t ask me where the disto...
by Paul Barker
Sun Mar 17, 2024 7:07 am
Forum: Everyones Projects
Topic: OK…so I’m on wi’ summat
Replies: 135
Views: 23657

Re: OK…so I’m on wi’ summat

Agree.
by Paul Barker
Fri Mar 15, 2024 9:04 pm
Forum: Everyones Projects
Topic: 6550 SE Amplifier
Replies: 104
Views: 8470

Re: 6550 SE Amplifier

I found the electro harmonix EL34’s sound much better. But thats a bonus because a single New Boxed GE 6550 /KT88 £195 on Ebay. So Ive got 8 and 6 used but work like new 4 sovtec and two Tungsol made in Britain. 🇬🇧 so I can sell those, since EL34 much better sounding.
by Paul Barker
Fri Mar 15, 2024 6:41 pm
Forum: Everyones Projects
Topic: OK…so I’m on wi’ summat
Replies: 135
Views: 23657

Re: OK…so I’m on wi’ summat

Oh pooh, really sorry to have to tell you this, honest I wasn’t copying you. I adjusted b+ in my amp to get g2A 425v the bias on the cathode 39v 48 mA. 21 watts dissipation. Totally better by a mile than the 6550.Diana just nuck up on me, I nearly jumped out my skin. “Gosh its sounds really……signifi...
by Paul Barker
Fri Mar 15, 2024 5:26 pm
Forum: Everyones Projects
Topic: OK…so I’m on wi’ summat
Replies: 135
Views: 23657

Re: OK…so I’m on wi’ summat

Envious
by Paul Barker
Fri Mar 15, 2024 5:18 pm
Forum: Everyones Projects
Topic: 6550 SE Amplifier
Replies: 104
Views: 8470

Re: 6550 SE Amplifier

The good news is non of the output valves are sounding any different but a couple GE’s are 5v down in bias. The 4 Sovtec’ all ST62 are 5v down including the fourth which was never used. The GE’s sound better and drawer more current. But the Sovtec’s are all the same as the new one of the four. So no...
by Paul Barker
Wed Mar 13, 2024 10:07 am
Forum: Everyones Projects
Topic: GM70 Monoblocks’
Replies: 4
Views: 270

Re: GM70 Monoblocks’

https://i.postimg.cc/6Q6frQ9X/IMG-1152.jpg So Ive drawn a 4k resistive load. +150v anode and g2 -6v bias. Not having enquired anywhere as of yet. But 2v peak seems to convert to 150v peak. GM70 needs 120 volts peak. Assuming the 10y mu of 8 I can get gain of 6 from. Not having calculated the circui...
by Paul Barker
Wed Mar 13, 2024 9:08 am
Forum: Everyones Projects
Topic: GM70 Monoblocks’
Replies: 4
Views: 270

Re: GM70 Monoblocks’

Nick wrote: Wed Mar 13, 2024 9:03 am Image

38W @ 0.03% THD, £5 + Heatsink and power supply.

Just saying :-)
Brilliant and a lot cheaper to build I guess.
by Paul Barker
Wed Mar 13, 2024 9:07 am
Forum: Everyones Projects
Topic: GM70 Monoblocks’
Replies: 4
Views: 270

Re: GM70 Monoblocks’

The first difficulty is a matched pair of power chokes capable of choke input. If anyone has bought such a pair and regrets it. paulv1505@ insert the applemail ending here. I have a pair of cores in a double C core transformer. One core of that monster per channel would make said pair of chokes. But...
by Paul Barker
Wed Mar 13, 2024 8:28 am
Forum: Everyones Projects
Topic: GM70 Monoblocks’
Replies: 4
Views: 270

GM70 Monoblocks’

https://i.postimg.cc/JzQ7GJ9h/IMG-1149.jpg https://i.postimg.cc/ZKp5zXHp/IMG-9131.jpg quick image upload So discovering how much power is available in A1 SE and how low 2nd harmonic at the Maximum Power. The project worth the effort. Many years ago I bought the power transformers pictured, likewise...
by Paul Barker
Tue Mar 12, 2024 2:44 pm
Forum: Everyones Projects
Topic: 6550 SE Amplifier
Replies: 104
Views: 8470

Re: 6550 SE Amplifier

Image
by Paul Barker
Tue Mar 12, 2024 9:11 am
Forum: Everyones Projects
Topic: 6550 SE Amplifier
Replies: 104
Views: 8470

Re: 6550 SE Amplifier

Thanks for pointing out the risk.

Now that this amp is bedded down on the top floor I’ll have to build something for ground floor.
by Paul Barker
Tue Mar 12, 2024 9:09 am
Forum: Everyones Projects
Topic: 6550 SE Amplifier
Replies: 104
Views: 8470

Re: 6550 SE Amplifier

Yes, and probably the 6550’s are slow. Its just I’d not thought of the power out condition, but I suppose it is going to occur sooner or later. Call me a Luddite but Ive just ordered a dls10, even though I know I spotted one lately. At £17 on ebay delivered, not a huge cost, meanwhile I’ll hope ther...
by Paul Barker
Tue Mar 12, 2024 6:34 am
Forum: Everyones Projects
Topic: 6550 SE Amplifier
Replies: 104
Views: 8470

Re: 6550 SE Amplifier

I see, so if there is an outage, the power supply would come straight on without enough current demand for critical inductance and momentarily reach 1.414. So I need a slow start for the valve diodes.. there was a slaw start idea in a Glass Audio letter. I think it was to pass the ground connection ...
by Paul Barker
Mon Mar 11, 2024 12:04 pm
Forum: Everyones Projects
Topic: 6550 SE Amplifier
Replies: 104
Views: 8470

Re: 6550 SE Amplifier



The Quads seem as efficient as the kEF’s. This 8/9 watt amp drives them good.