It can be a tougher call if the unit has some kind of history to it. My tough call right now is whether or not a lot of my projects need to go away or at least move a bit forward. Now I see why some people can pile up a bunch of stuff and leave it forever.
That is an entire different subject but a valid one. The piling up of stuff is a disease not a hobby. When the pattern is to mainly gather and not no actually repair and use it one could ask himself what the benefit exactly is. Often listening to music is then last on the priority list.
Listening to music? There you go again.... I thought the idea was to use as many boxes, switches, lights, cables and what not.... listening to music? Seriously?
🙂
I do wonder though, seriously, at what point do we cross the line between rebuilding and redesigning? I've been reading this thread for day one and I see two trains of thought. Rebuilding will preserve the qualities of the amp.... redesigning opens up a whole can of worms.
Nothing is stopping a person from taking both roads at the same time and choosing what is best as they achieve results down the line. I prefer that approach to keep my options open.
I think copying a stupid design is itself stupid.
And there are ways in software and alternate designs to build or eliminate the pre-amp section entirely.
However, there are Class A fans out there, so then convincing the owner that the new one is better will be difficult.
I would not have bought a unit for that price in any case.
Best way is to find an old amp with phono pre amp built in, or make one from the many chip amps available, power consumption is less than 2 Watts in those...5532, TL072, AD797, OPA2134, and others are all well regarded.
And there are ways in software and alternate designs to build or eliminate the pre-amp section entirely.
However, there are Class A fans out there, so then convincing the owner that the new one is better will be difficult.
I would not have bought a unit for that price in any case.
Best way is to find an old amp with phono pre amp built in, or make one from the many chip amps available, power consumption is less than 2 Watts in those...5532, TL072, AD797, OPA2134, and others are all well regarded.
But, But ,it is Class A though...
Wonder what the specs are, seems to be balanced so that doubled the Class A madness.
For a 40 to 60 watt preamp it was still working after 30 or so years.
Not to bad. Poor little crispy critter.
Discussing a " redesign" for a Class A pre power supply to be more efficient is almost comical.
Switch mode wont last more than 5 to 7 years. This one went 30 plus.
So admire the efforts to just build a new board, not to difficult design.
Just a little time.
Would say the thermal madness and runaway temp of the actual pre needs a look too.
From the pics one side looks hotter than the other. Little DC offset and runaway temps after 30 years.
Wonder what the specs are, seems to be balanced so that doubled the Class A madness.
For a 40 to 60 watt preamp it was still working after 30 or so years.
Not to bad. Poor little crispy critter.
Discussing a " redesign" for a Class A pre power supply to be more efficient is almost comical.
Switch mode wont last more than 5 to 7 years. This one went 30 plus.
So admire the efforts to just build a new board, not to difficult design.
Just a little time.
Would say the thermal madness and runaway temp of the actual pre needs a look too.
From the pics one side looks hotter than the other. Little DC offset and runaway temps after 30 years.
25 years and very EOL. Not just EOL, it needs a new PCB no it needs a complete new PSU. We don’t know how many hours it was used in those years. Maybe this was the lone survivor and were the others already recycled to electric tooth brushes 10 years ago. Hot electronics have shorter lifetime. In some countries it is silly habit to buy so much stuff that storage space needs to be rented, maybe it spent 15 years in storage.
If it is a good idea to copy the clear imperfections and again have a very hot and mediocre performing PSU then do so. The PSU is today nothing special. Just one that gets too warm without any added benefit from energy waste. Technology then could not be made more efficient. Making a new one just as inefficient as the old one would be comical.
In any case a power on/off switch should be added. It is crazy to have this heat 24/7 unattended in a home. The lack of a PE connection while having a 3 prong IEC inlet should also be examined.
If it is a good idea to copy the clear imperfections and again have a very hot and mediocre performing PSU then do so. The PSU is today nothing special. Just one that gets too warm without any added benefit from energy waste. Technology then could not be made more efficient. Making a new one just as inefficient as the old one would be comical.
In any case a power on/off switch should be added. It is crazy to have this heat 24/7 unattended in a home. The lack of a PE connection while having a 3 prong IEC inlet should also be examined.
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Borderline political...
So, in your opinion, either junk it or redesign it?
It is not unusual to have components that stay on all the time... for best sound performance. My own devices, most of them sound better after being on for at least one hour. Some of them, like the DAC in my main stereo, stay on all the time. Some people keep their P3 on all the time too....
Is that an issue?
I mean, this device has lasted 25 years, state of the art design perhaps. Maybe it has lived its life?
Anyhow, that's my take:
State Of The Art is not necessarily designed to last a lifetime nor is it designed to be efficient... it is designed to sound the best without compromise.
Or perhaps you want to make it better.... that I can understand.
So, in your opinion, either junk it or redesign it?
It is not unusual to have components that stay on all the time... for best sound performance. My own devices, most of them sound better after being on for at least one hour. Some of them, like the DAC in my main stereo, stay on all the time. Some people keep their P3 on all the time too....
Is that an issue?
I mean, this device has lasted 25 years, state of the art design perhaps. Maybe it has lived its life?
Anyhow, that's my take:
State Of The Art is not necessarily designed to last a lifetime nor is it designed to be efficient... it is designed to sound the best without compromise.
Or perhaps you want to make it better.... that I can understand.
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Borderline political? Where?
It is up to the owner but rebuilding just the PSU is easy. It is also not that expensive and makes the device ready for testing its merites. Making the PSU 100% the same is pathetic. It needs ventilation/convection which the designer forgot. Why not make it better/cooler!?
You assume it has been powered on its complete lifetime. Maybe it belonged to a hoarder that kept it in storage with all his other hoarded junk and was that junk sold after his death.
Even if stuff sounds best when being powered on continuously (a myth as it sounds the same as yesterday in an hour), it usually does not win from a wire. Don’t focus to much on brand and reputation, time went on. I had a 100 Euro DIY DAC outperforming a Krell 32X DAC.
It is up to the owner but rebuilding just the PSU is easy. It is also not that expensive and makes the device ready for testing its merites. Making the PSU 100% the same is pathetic. It needs ventilation/convection which the designer forgot. Why not make it better/cooler!?
You assume it has been powered on its complete lifetime. Maybe it belonged to a hoarder that kept it in storage with all his other hoarded junk and was that junk sold after his death.
Even if stuff sounds best when being powered on continuously (a myth as it sounds the same as yesterday in an hour), it usually does not win from a wire. Don’t focus to much on brand and reputation, time went on. I had a 100 Euro DIY DAC outperforming a Krell 32X DAC.
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In some countries it is silly habit to buy so much stuff that storage space needs to be rented
OK, so you advocate making it better. That sounds fine to me.
OK, so you advocate making it better. That sounds fine to me.
Having so much stuff that it does not fit in your home anymore is not political, it is material boulimia.
Of course make stuff better, always challenge yourself to do it better than it was done. When doing something better do it best as possible. It is really not top design but stuff with created reputation and always similar features. I know 100% for sure it can be replaced for something new way cheaper with similar performance (except phono). And: who, except turntable enthusiasts, needs a preamp with gain today!?
I had a similar device also with external PSU (a nuisance) but sold it as it had no purpose anymore with digital sources driving amplifiers directly. Same with good FM tuners here. Things in time, you got the picture.
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No, only similar with voltages and losses. There is no opamp in the KSP-7B PSU.
Today one should also consider to add CLC filtering with 2 x 4700 µF per rail for less ripple voltage and against RF/mains pollution.
Not a nighmare at all, an evening relaxed designing.
Today one should also consider to add CLC filtering with 2 x 4700 µF per rail for less ripple voltage and against RF/mains pollution.
Not a nighmare at all, an evening relaxed designing.
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Also no transformer. It has no similarity to that of KSP-7B except that it also converts AC to DC in a (through the eyes of 2025) crude way.
What is less practical/ergonomical than a preamp with external PSU ? Yes a preamp with external PSU and external transformer. Suppose you decide to use it with Topping B200's with each its external PSU. That is 7 devices, a storage persons wild dream 😀
What is less practical/ergonomical than a preamp with external PSU ? Yes a preamp with external PSU and external transformer. Suppose you decide to use it with Topping B200's with each its external PSU. That is 7 devices, a storage persons wild dream 😀
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