I'm exactly the opposite. No musically trained but Electronic Engineer and I consider myself as a laboratory rat. What I say is always from what I learned in the university, from old good text books of the apogee of tubes era and my own experience. But in fact I'm unable to distinghish between LA440 and LA432 in an instrument, i do in an oscillator.
But when you design an electronic device, usually the PSU is the last. Because you know what load it will have, line regulation, choke or capacitor input filter, transformer voltages and currents, if a SMPS, its frequency and topology, et cetera. Unless you are strictly limited but foreign reasons: for example if your device only has available 12VDC, 24V, and so on. So, the audio characteristic is adjusted in the audio forward path. I never saw a guy adjusting the audio characteristic manipulating PSU parameters. This doesn't mean is bad, it means it is weird way.
But when you design an electronic device, usually the PSU is the last. Because you know what load it will have, line regulation, choke or capacitor input filter, transformer voltages and currents, if a SMPS, its frequency and topology, et cetera. Unless you are strictly limited but foreign reasons: for example if your device only has available 12VDC, 24V, and so on. So, the audio characteristic is adjusted in the audio forward path. I never saw a guy adjusting the audio characteristic manipulating PSU parameters. This doesn't mean is bad, it means it is weird way.
Attached the circuit that the PSU is feeding. A laboratory rat is a great activity - I'd enjoy it!
A tube stage is no good to me if it doesn't sound right, so I do a lot of building and listening. What I'm hearing is that the smaller the capacitor value above a respectable size, the more lively and realistic the sound. This seems to go against the theory that big capacitors are better. So why could that be? Can you find any theoretical reasons?
What are the values of the plate loading and decoupling resistors and capacitors in the sketch at post #22?
They are not active - I should have deleted them. The PSU in post 18 feeds the anode resistor directly.
That link doesn't work. I am a member of Groups IO but when I go to that page I can't see a download link. Not a very helpful site unless I'm missing something obvious....
Update.... I did download PSUD77 which is for Mac. Haven't opened it yet - checking what OS versions it works with
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In any case, no one software will tell you how it will sound for your taste. Its a waste of time imo.
I'm exactly in the same direction.
Let's imagine that you will find the version you like. Since this option is based on the integral behavior of the power supply that includes all cables and consumers starting from the voltage-lowering transformer and up to the tube anode, the sound will be influenced by any change that occurs on this power supply chain. If there is any change on this supply chain, a change that will certainly appear because many consumers are connected to these supply lines, you will start all over again in search of the optimal power supply configuration.
The correct solution is to make the sound independent of the power supply and then you can modify the amplifier to get the desired sound and, more than that, it will sound the same regardless of any modification on the power line until your power source.
I'm struggling to understand you here. If I understand you correctly you are talking about:
1. The "power supply chain" - meaning everything the comes before the wall socket with 230V on it
2. The actual PSU of the tube stage, which is what I've been discussing here
Do you really think that the "power supply chain" has a significant contribution to the sound aside from being a few volts over or under a nominal 230V?
And exactly how can the sound (PSU+tube stage) be independent of the "power supply chain"?
Osvaldo:
The purpose of the software would be to try to explain what I'm hearing, as much as possible
1. The "power supply chain" - meaning everything the comes before the wall socket with 230V on it
2. The actual PSU of the tube stage, which is what I've been discussing here
Do you really think that the "power supply chain" has a significant contribution to the sound aside from being a few volts over or under a nominal 230V?
And exactly how can the sound (PSU+tube stage) be independent of the "power supply chain"?
Osvaldo:
The purpose of the software would be to try to explain what I'm hearing, as much as possible
It depends on the circuit topology. There is a parameter called Power Supply Rejection Ratio. It gives you an idea of how much a variation in supply voltage affects the amplifier's output. The larger the value, the better. Generally speaking, single ended amplifiers tend to be more dependent because audio signals path includes power lines.
In the other hand, symmetrical amplifiers (push pull, differential amplifiers) are more immune to such variations because, or affect to both channels in the same way making the net result negligible, or they are ex-profeso made immune. In the 40's and 50's had been developed some circuits to counteract this phenomena. See for example, the differential amplifier theory and the SRPP topology.
Theoretically the PSU must be transparent but not always it happen.
If it satisfies you, nothing to say about.
How much will you love to drive a car that, in order to function, will only need fuel from one specific place?
That's far too mystical for me, I'm afraid. What does that actually mean in terms of a tube PSU?
There you go... I thought you set the record (post 22), but someone out there always proves you wrong.
If you move the power socket from let wall to right wall you will not like the sound. An this because the power supply is not transparent.
The tests and improvements in post 22 are not well designed and made.
I'm not completely against this way of working, even I did the same when adjusting the speakers, but I relied more on the measurements and less on the ears.
In order for the improvements to be made correctly, all the changes had to be made by someone else without you seeing anything and you just having to listen.
The tests and improvements in post 22 are not well designed and made.
I'm not completely against this way of working, even I did the same when adjusting the speakers, but I relied more on the measurements and less on the ears.
In order for the improvements to be made correctly, all the changes had to be made by someone else without you seeing anything and you just having to listen.
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I personally find no audible difference in where I plug my equipment in. Others might vary. I always take suggestions seriously and try them out whenever I can. I'll look at mains cables at a future point. My system might have as many as 8 power cables at any time.
What is very audible is the kind of capacitors and their values. I'm very satisfied with the 2 days work I did playing around with capacitors. And many thanks to all on this thread who have contributed. The system sounds a lot better - more clarity and improved treble. Just what I wanted to achieve. I build and build, listen and listen. I'll modify a component 10 times in a day, and listen each time for the changes. It has always worked for me and brought me, through steady long-term improvement, to a point where it's just a joy to listen to music on my amplifiers.
The end sound quality is always what matters. Clearly I do a lot of maths in putting stuff together and my big Excel file is full of formulae of all kinds. I'm totally into the theory - self taught but spend endless hours with tutorials of all kinds. You have to.
What is very audible is the kind of capacitors and their values. I'm very satisfied with the 2 days work I did playing around with capacitors. And many thanks to all on this thread who have contributed. The system sounds a lot better - more clarity and improved treble. Just what I wanted to achieve. I build and build, listen and listen. I'll modify a component 10 times in a day, and listen each time for the changes. It has always worked for me and brought me, through steady long-term improvement, to a point where it's just a joy to listen to music on my amplifiers.
The end sound quality is always what matters. Clearly I do a lot of maths in putting stuff together and my big Excel file is full of formulae of all kinds. I'm totally into the theory - self taught but spend endless hours with tutorials of all kinds. You have to.
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