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Vintage Audio (record players, hi-fi etc) Amplifiers, speakers, gramophones and other audio equipment. |
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22nd Jun 2020, 5:59 pm | #41 |
Moderator
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,784
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Re: Pye 1004 (Transistor Black Box) amp faults, help wanted please
Adding tone controls may be tricky if you do that though - obviously it's possible, but it means adding another op-amp to the new amp module, and makes the changes more difficult to reverse in the future.
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22nd Jun 2020, 7:33 pm | #42 |
Dekatron
Join Date: Nov 2003
Location: Heckmondwike, West Yorkshire, UK.
Posts: 9,637
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Re: Pye 1004 (Transistor Black Box) amp faults, help wanted please
We usually aim to make any changes reversible. To be honest though, once the player is in use is it likely to be reversed? An older or rarer item perhaps, although then that is less likely to be modified.
Whilst muddying waters, I quite believe members' experiences that transistor substitutions are not successful, but I wonder just why with this player and not others? |
22nd Jun 2020, 7:44 pm | #43 |
Moderator
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,784
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Re: Pye 1004 (Transistor Black Box) amp faults, help wanted please
It would be possible to add envelope shaping in the TD2030 NFB circuit, which would avoid the need for an additional op-amp. It's not normally done that way though, and would still involve hacking around the tone control wiring. It's Nick's decision though - it's his record player, probably already rescued from a future in a skip. It's not the Elgin Marbles.
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