801a amplifier

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Nick
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#46 Re: 801a amplifier

Post by Nick »

Not sure I would bother regulating the -ve rail it's just the tail of the cathode follower.
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Paul Barker
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#47 Re: 801a amplifier

Post by Paul Barker »

That makes it easier and I can use the plus side to adjust bias.
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Nick
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#48 Re: 801a amplifier

Post by Nick »

If the output valve b+ and bias setting are unregulated they will track mains variation better.
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#49 Re: 801a amplifier

Post by Paul Barker »

I planned to 572b shunt regulate the main b+. At home my voltage is consistently 243v.

I know that wasteful heavy type of b+ sounds great. I’d find it hard to try without but I suppose I should.
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#50 Re: 801a amplifier

Post by IslandPink »

Good to see someone else going for shunt-reg B+. I've been keeping the faith on that for several years.
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andrew Ivimey
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#51 Re: 801a amplifier

Post by andrew Ivimey »

Even I think that's a good way to go because it's a rock that is solid. Other things can happen down the line ...
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#52 Re: 801a amplifier

Post by Paul Barker »

Just turned up someone with a parallel vt62 amp.

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#53 Re: 801a amplifier

Post by Cressy Snr »

He makes some good stuff that guy. :)
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#54 Re: 801a amplifier

Post by Paul Barker »

OK, so Ive backtracked probably until I retire in two years. Life is different for me these days and I like Steve mentioned his anxiety. I have it too, as my wife’s carer I get first class attention from the GP, but he just wants to pop pills in me. Im not have pills, thank you? He gestured, “the door is always open”.

So un treated, in pigeon holes of my life, anxiety takes over and I get a full head of ideas but dont complete anything. Fortunately my full time job is actually beneficial, when Im working Im in my comfort zone.

So, Ive decided not to go A2 for now. Ive had 4 ST type 46 valves which I never did actually listen to, and I came across someone whe said he 46’s bring out more depths of midrange detail than his 45’s. He was using globes of both. I dont have any 46 globes. Bartaluci writing about the 46, alludes that the 2nd grid which is tied to anode for class A1 use, may bring some characteristics of the mesh plate into play.

So I’ll be in the low wattage camp. On paper 1.25 watts. But hitting that target unlikely in the real world, so I could bank on 1 watt I recon.

Ill have to try it on my most efficient working speakers.

I supose Id better start a new thread. “It’s about time I tried my 46’s”.
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#55 Re: 801a amplifier

Post by RhythMick »

I look forward to reading that.

My view, it's perfectly fine to have a head full of ideas and not act on them. Problems occur when you try to act on them all...
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#56 Re: 801a amplifier

Post by andrew Ivimey »

Nicely put!
Philosophers have only interpreted the world - the point, however, is to change it. No it isn't ... maybe we should leave it alone for a while.
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#57 Re: 801a amplifier

Post by Cressy Snr »

The major and sometimes insurmountable problem for anxiety sufferers is something that I would term as thought crowding. When thought crowding occurs it becomes difficult to function properly. The sufferer has tremendous difficulty sorting through what is important and what is not, as everything in your head is demanding your attention and that you do something about it ‘right now.’ These intrusive thoughts that we have to concede we cannot deal with right now, get packed up into a bundle that gets projected into the future with an arbitrary deadline attached and sits there like some malevolent spectre, reminding you that it still needs dealing with and you can’t relax for one minute. Cue vicious circle.
The anxiety sufferer or the depressive can’t live in the present. They are either in the past regretting, or in the future worrying.
This is why projects like the ones we as a group do are often difficult to stay focussed on for more than five minutes. There are simply too many intrusions.

Intrusions for a normal person might be work related or something comes up that we have to deal with and put our project to one side for a while: and indeed the anxious or depressive person will get these too. Nothing wrong with that and both anxious and depressive people will happily accept that some things are more important than your hobby, just like anyone else would.

However 99.9% of distractions that interfere with anxious or depressed people are not real, they are thoughts: events in the mind, which pile in one after another until the person becomes paralysed mentally and can deal with neither project nor everyday life.

In the early days of my own depressive/anxious behaviours I embarked on a feverish amp building programme. No sooner had I finished one than I tore it down and started another one. Looking back (oops! regret stoppit!) all it did was cost me a packet. It certainly didn’t advance my knowledge, because basically it was build, dismantle, build, dismantle, build, dismantle ad infinitum: not much learning. But build, dismantle, build, dismantle was I learned later, a coping mechanism, a means of pushing the world, as I perceived it, away. Not the best strategy, but I didn’t know any better at the time.

Anyway, enough of the psychology lessons. It’s just good to try to expand people’s understanding of the of the anxiety issue. Anxiety disorders manifest themselves differently in different people, so it is difficult to generalise about how to cope with it. This makes it a complete pain in the arse to talk about.
Paul will have started a new thread by now so this one shouldn’t get any further off topic.
Sgt. Baker started talkin’ with a Bullhorn in his hand.
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andrew Ivimey
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#58 Re: 801a amplifier

Post by andrew Ivimey »

Again, nicely put. But as the cooling ashes get even cooler, vt62s/ 801 are a very very nice 2 Watts max in class A so would be in the same league as 46.

I once saw a 47 transformers coupled to pp 46s - nice idea!
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#59 Re: 801a amplifier

Post by RhythMick »

Cressy Snr wrote: Sun Aug 29, 2021 9:48 am The major and sometimes insurmountable problem for anxiety sufferers is something that I would term as thought crowding. When thought crowding occurs it becomes difficult to function properly. The sufferer has tremendous difficulty sorting through what is important and what is not, as everything in your head is demanding your attention and that you do something about it ‘right now.’ These intrusive thoughts that we have to concede we cannot deal with right now, get packed up into a bundle that gets projected into the future with an arbitrary deadline attached and sits there like some malevolent spectre, reminding you that it still needs dealing with and you can’t relax for one minute. Cue vicious circle.
The anxiety sufferer or the depressive can’t live in the present. They are either in the past regretting, or in the future worrying.
This is why projects like the ones we as a group do are often difficult to stay focussed on for more than five minutes. There are simply too many intrusions.

Intrusions for a normal person might be work related or something comes up that we have to deal with and put our project to one side for a while: and indeed the anxious or depressive person will get these too. Nothing wrong with that and both anxious and depressive people will happily accept that some things are more important than your hobby, just like anyone else would.

However 99.9% of distractions that interfere with anxious or depressed people are not real, they are thoughts: events in the mind, which pile in one after another until the person becomes paralysed mentally and can deal with neither project nor everyday life.

In the early days of my own depressive/anxious behaviours I embarked on a feverish amp building programme. No sooner had I finished one than I tore it down and started another one. Looking back (oops! regret stoppit!) all it did was cost me a packet. It certainly didn’t advance my knowledge, because basically it was build, dismantle, build, dismantle, build, dismantle ad infinitum: not much learning. But build, dismantle, build, dismantle was I learned later, a coping mechanism, a means of pushing the world, as I perceived it, away. Not the best strategy, but I didn’t know any better at the time.

Anyway, enough of the psychology lessons. It’s just good to try to expand people’s understanding of the of the anxiety issue. Anxiety disorders manifest themselves differently in different people, so it is difficult to generalise about how to cope with it. This makes it a complete pain in the arse to talk about.
Paul will have started a new thread by now so this one shouldn’t get any further off topic.
Thanks for sharing Steve. Impossible for a non sufferer like me to properly understand, not even close I'll bet. I hope you didn't take my post as trivialising the issue, if so I apologise.
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Paul Barker
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#60 Re: 801a amplifier

Post by Paul Barker »

Cressy Snr wrote: Sun Aug 29, 2021 9:48 am Paul will have started a new thread by now so this one shouldn’t get any further off topic.
Not an issue as it is extremely pertinent to the thread, which one day I will return to and build the 801a amp, but realistically: long time.
"Two things are infinite, the universe and human stupidity, and I am not yet completely sure about the universe." – Albert Einstein
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