Rather that sit there at the PC, criticising the pedigree of the design, let's just accept that its a generic one, using a common range of generic parts, chosen for low price and wide availability which I guess for the primary market of India, is particularly important, since the cost of imported components would be many times that of local manufactures and few have the cash to waste on airfreight/postal charges.
For a first-time builder, it makes good sense to go as cheap as possible on parts, keeping in mind your expectations for acceptable sound quality. There's no need to shoot for the stars of technical excellence and mindblowing sound on the first iteration because it's already there and you learn very little from the exercise. However, the more expensive semis such as the output transistors, would best be a modern, audio-specific type and the cheapest are genuine Toshiba 2SC5200/2SA1943. Don't waste time and money on unsuitable general purpose type power transistors here in what is obviously intended to be a very low distortion amp.
For a first-time builder, it makes good sense to go as cheap as possible on parts, keeping in mind your expectations for acceptable sound quality. There's no need to shoot for the stars of technical excellence and mindblowing sound on the first iteration because it's already there and you learn very little from the exercise. However, the more expensive semis such as the output transistors, would best be a modern, audio-specific type and the cheapest are genuine Toshiba 2SC5200/2SA1943. Don't waste time and money on unsuitable general purpose type power transistors here in what is obviously intended to be a very low distortion amp.
Ian, please read my post #40.
Delhi is the biggest source market here in India, particularly this type of populated PCB, and those traders buy in large quantities. the price advantage is passed on.
Most semiconductors, caps, diodes, pots and resistors are imported here, local is expensive, and lacking variety.
Genuine Toshiba are expensive, equivalent types are also sold.
And like I mentioned, many sellers are there, with Chinese or the more expensive Keltron capacitors used, those are with technology from Sprague, better than most Chinese. So same board is sold in two versions, Chinese or Keltron caps.
To build a set like this with parts from assorted sellers, and risk of failure, for 6 quid?
I would buy the ready boards, and build the cabinet etc.
40 odd quid would bet me a ready amp, the 4440 based amps are only 8 GBP, and enough for most users at 20 WRMS/ch or so.
Delhi is the biggest source market here in India, particularly this type of populated PCB, and those traders buy in large quantities. the price advantage is passed on.
Most semiconductors, caps, diodes, pots and resistors are imported here, local is expensive, and lacking variety.
Genuine Toshiba are expensive, equivalent types are also sold.
And like I mentioned, many sellers are there, with Chinese or the more expensive Keltron capacitors used, those are with technology from Sprague, better than most Chinese. So same board is sold in two versions, Chinese or Keltron caps.
To build a set like this with parts from assorted sellers, and risk of failure, for 6 quid?
I would buy the ready boards, and build the cabinet etc.
40 odd quid would bet me a ready amp, the 4440 based amps are only 8 GBP, and enough for most users at 20 WRMS/ch or so.
I am just following the instructions of my mentor. Who has advised me to start with an old designs. Step one learn how it works. See if you can improve it by just changing parts. Understand the concepts and the schematics. Then take a modern design. And see how things have evolved.
Am very happy with this purchase. It was good value for money. It came with a schematic. And its a great way to learn.
My personal quest is to replicate the sound of my dads music system which he owned in the 70s. (Which as kids we were never allowed to touch). Now 50+ years latter Im trying to recreate that sound. While at the same time trying to understand why none of the modern audio sounds the same.
This is purely a hobby. I run a business that has nothing to do with audio. And lead a pretty comfortable semi retired life that allows me to have hobbies.
Once I gain some confidence I may eventually try to create an exact replica of the amp he owned. Circuits for it are floating around. Its just a regular transistor Akai amp from the 70s. Pre STK. Nothing special about it either.
Im not into Audio Snobbery. Where people love to brag about how much they blew and whats the latest greatest thing on the market. I have enough friends and family on that trip.
The power is overestimated. There are no conventional output short circuit protection. There is no speaker protection\turn-on delay.
Replacing transistors will not give an improvement without selection.
Replacing transistors will not give an improvement without selection.
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Replicating his speakers will get you closer to your goal than replicating his amplifier.