My take on a heater supply...

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Dave the bass
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#31 Re: My take on a heater supply...

Post by Dave the bass »

...agreed, in comparison to AndrewL's clever supplies. We spent a day ABC-ing them, it was good.
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#32 Re: My take on a heater supply...

Post by jack »

I know others here have beaten me up about this, but I really really like to understand the how and why of audio - that does not mean for an instant that the sound isn't the deciding factor - after all, that's why most of us do this - but I do find that a detailed understanding allows me to be more precise in refining a design. I can rationalise the tangible items - the intangibles are more tricky - the psychology, personal taste, subjectivism...

Of course, anyone can do a whole bunch of AOT to improve what they have, but it doesn't help that much if you want to change your design - you are back to square one - AOT - and it's very time consuming.

My approach, partly because I'm stuck over 4,000 miles away from my normal listening environment and they really don't believe in soft furnishings here, is that I do a lot of up-front theory and design, then modelling, then prototyping & unit testing, then refine a few times so that the technical requirements are met.

At this point I should start with something with deterministic behavior - if is cr*p, then I've made a mistake in either the initial specification or one of the processes up to this point.

Now the listening tests can begin - the AOT phase - this is hugely iterative and can revert back to any point on path. However, I am normally in a position of strength as, if something needs to be changed, the consequences are well understood.

So, if it doesn't sound right but it measures right, then it's down to a mistake I've made, and should be able to be rectified.

It takes time, but there is (for me) great satisfaction in really and truly understanding both the how and the why.
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#33 Re: My take on a heater supply...

Post by simon »

Wow. I don't recognise this dullness or shut in sound of Rod's regs at all. Guess I need to compare them directly against Andrew's.
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#34 Re: My take on a heater supply...

Post by pre65 »

The only Rod supply I used was for a 26 pre-amp project.

I tried it up against an Andrew I battery powered 26 pre and there were differences, but we put that down to the actual valves used.

The project is no more, Andrew I has the Rod's and Simon has the 26s.
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Nick
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#35 Re: My take on a heater supply...

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I know others here have beaten me up about this, but I really really like to understand the how and why of audio - that does not mean for an instant that the sound isn't the deciding factor - after all, that's why most of us do this - but I do find that a detailed understanding allows me to be more precise in refining a design. I can rationalise the tangible items - the intangibles are more tricky - the psychology, personal taste, subjectivism...
One of the joys of DIY is that we can pick the problem we want to solve, and I look forward to your take on the heater problem. But having watched the process Andrew and Mark went through, I think I need to stand up a little and declare that it wasn't one of AOT tweekyness. What I saw going on (and it was fun watching without having to do any work) was not a process of tweaking the design and using what sounded best, it was a process of iteratively understanding the problem, that understanding then dragged the solution. A very different thing that AOT would infer.

The danger I have seen with DIY is part of its advantage, we can do whatever we want, so we pick to do what we want to do, but sometimes that leads us to a disconnect between the problem we are solving, and the solution that other people want to use. (Help I think I am describing Agile, someone stop me).

I have spent the last 18 months or so, getting to understand a small fraction of where we are with solid state analog design. I have realised there is a entire sub culture in amp design now where designs are invented, topologies thought of, tweeked and measured entirely within the realm of spice simulation, and the merits for or against the solution is judged by a group of peers without it seems the design ever being actually built and tested. Now dont get me wrong, I can entirely see the appeal of that, and maybe I am wrong, maybe they do get built, and go on to live long and happy life’s in the real world playing music, but I suspect not.

As I said I look forward to what Nick (Jack) comes up with, I think it should be great, but I just wanted to point out what might be a disservice to the work Andrew and Mark did and my belief in understanding the problem before trying to produce a solution.
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#36 Re: My take on a heater supply...

Post by shane »

AOT?
The world looks so different after learning science. For example, trees are made of air, primarily. When they are burned, they go back to air, and in their flaming heat is released the flaming heat of the Sun which was bound in to convert air into tree.
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#37 Re: My take on a heater supply...

Post by pre65 »

shane wrote: Mon Apr 17, 2017 10:36 amAOT?
Adjust On Test.
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#38 Re: My take on a heater supply...

Post by jack »

Nick wrote: Mon Apr 17, 2017 10:18 am ....But having watched the process Andrew and Mark went through, I think I need to stand up a little and declare that it wasn't one of AOT tweekyness. What I saw going on (and it was fun watching without having to do any work) was not a process of tweaking the design and using what sounded best, it was a process of iteratively understanding the problem, that understanding then dragged the solution. A very different thing that AOT would infer...
That certainly was not what I was intending to infer - Andrew & Mark have not had a go in the past about the numbers game - that's elsewhere... and I really admire what they've achieved.

I have tried Andrew's supply in the past as well as Rod's and many others... and liked most of them, but, as you say, that's the joy of not doing this as a job - you can pick and choose the areas you want to investigate.

At the end of the day, I'm not that bothered if no-one else likes what I end up with, so long as I and the family are happy - not that my family care that much - they're more than happy with the Vortexbox and digital stuff flying around the house, especially SWMBO as she's a linguist (many languages) and it means she can get the Arabic/Greek/Italian/whatever internet stations she wants. They do like the difference the little uFonkens make though...

Audio is a small part of my "extra-curricular" activities , however when I start in a new area, like many I take the modular approach - buy in those bits you don't understand/can't (at that time) design as well yourself. Of course, there are many areas where no matter hard I try, I'll never get to where I want to be, but at least you can try.

There's something immensely satisfying (for me) in listing to some great music and knowing that you designed and fabricated each part of the signal chain that it is reasonable to do, i.e. the pre-ams, amps, speakers, cases whatever.
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shane
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#39 Re: My take on a heater supply...

Post by shane »

pre65 wrote: Mon Apr 17, 2017 10:37 am
shane wrote: Mon Apr 17, 2017 10:36 amAOT?
Adjust On Test.
Ta!
The world looks so different after learning science. For example, trees are made of air, primarily. When they are burned, they go back to air, and in their flaming heat is released the flaming heat of the Sun which was bound in to convert air into tree.
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#40 Re: My take on a heater supply...

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pre65 wrote: Sat Apr 15, 2017 2:27 pm In that case, well done Mark. :D
Aww, shucks :oops:
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#41 Re: My take on a heater supply...

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simon wrote: Mon Apr 17, 2017 9:11 am Wow. I don't recognise this dullness or shut in sound of Rod's regs at all. Guess I need to compare them directly against Andrew's.
Yes - but it's only the top octave that doesn't quite work. The midrange is fine, and the bass extension and timing were our reference point for what we had to do with the Lehane ones. They are also very quiet.
The key to getting the top end to work on Andrews was getting stray inductance out of the feedback loop for the current source. We ended up using a high quality ceramic cap in there, not something you'd normally choose for audio, but it was the right solution here. You could probably do something to fix Rod's in this area if you looked at the circuit a bit and did some experiments. Again , it was a phase thing coming in. The inductive caps were causing a drop in Zout above 10kHz, which in turn must have caused a small phase rotation in the signal circuit above 10kHz.
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#42 Re: My take on a heater supply...

Post by simon »

Interesting Mark, particularly the ceramic cap. I have some of Andrew's boards so I need to try them as I'm intending to box up 26-10Y-300B this year. Maybe.
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#43 Re: My take on a heater supply...

Post by ed »

IslandPink wrote: Mon Apr 17, 2017 4:14 pm
simon wrote: Mon Apr 17, 2017 9:11 am Wow. I don't recognise this dullness or shut in sound of Rod's regs at all. Guess I need to compare them directly against Andrew's.
Yes - but it's only the top octave that doesn't quite work. The midrange is fine, and the bass extension and timing were our reference point for what we had to do with the Lehane ones. They are also very quiet.
I must have been away when all this occurred but I would ask the same question as Simon at first. I too had no visibility of the top octave not working......so, two questions
1. are the Mark/Andrew solutions readily available and can they cope with high currents, and
2. How does this all compare with Guido's solution?

yes, I know, that makes three questions really
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#44 Re: My take on a heater supply...

Post by ed »

I forgot.....

it occurred to me that I was a tad superficial about this heater thing because I was taking the line that if the thing really got tedious and complicated I would just go back to a 2A3 solution......for me the difference in sq was minimal between the 2A3 and the SV572 and the only real difference was about half a watt in measured power.....

which leads to my favourite get out clause....life is too short!

ho hum
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#45 Re: My take on a heater supply...

Post by andrew Ivimey »

I remember this Eduard, I remember. You really put a lot into this.

Me, I still thoroughly enjoyed the a.c. alternative. At the other end of the scale just getting 833s working is enough and smps computer supplies light things up a treat.

It's just occurred- loads of distortions and or artifact when using computer power supplies. My GM70s are still just using raw computer power supplies- they just work.

These valves go LOUD. Loudness is a function of distortion- rocknroll - gotitt .

Now I really will shut up.
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