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BBC AM8/16 PCB circuit diagram..
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tony sayer
Aug 16, 2012, 6:26:33 PM8/16/12
to
Bit of a long shot but anyone here got a circuit diagram for one of
these units at all they wouldn't mind me having a copy of at all?..
Thanks in advance...
--
Tony Sayer
Dave Liquorice
Aug 16, 2012, 6:50:04 PM8/16/12
to
On Thu, 16 Aug 2012 23:26:33 +0100, tony sayer wrote:
AM8/16 is a Quad 405 with bolt on cards, remove the cards and you have a
standard Quad 405. That may help?
http://www.harbeth.co.uk/usergroup/archive/index.php/t-1226.html
--
Cheers
Dave.
AM8/16 is a Quad 405 with bolt on cards, remove the cards and you have a
standard Quad 405. That may help?
http://www.harbeth.co.uk/usergroup/archive/index.php/t-1226.html
--
Cheers
Dave.
tony sayer
Aug 16, 2012, 7:20:58 PM8/16/12
to
In article <nyyfbegfubjuvyypb...@srv1.howhill.co.uk>, Dave
Liquorice <allsortsn...@howhill.com> scribeth thus
No, it was the filter PCB in that unit Dave..
--
Tony Sayer
Liquorice <allsortsn...@howhill.com> scribeth thus
--
Tony Sayer
Dave Liquorice
Aug 16, 2012, 7:49:02 PM8/16/12
to
On Fri, 17 Aug 2012 00:20:58 +0100, tony sayer wrote:
> No, it was the filter PCB in that unit Dave..
Ah so you want the filter card information, not clear the AM8/16 sort of
> No, it was the filter PCB in that unit Dave..
refers to the whole box. B-) I probably still have the power amp board
layout and circuit diagrams from the "405" I built back in the mid 80's.
--
Cheers
Dave.
Brian
Aug 17, 2012, 5:32:58 AM8/17/12
to
On Thu, 16 Aug 2012 23:26:33 +0100, tony sayer <to...@bancom.co.uk>
wrote:
>
>Bit of a long shot but anyone here got a circuit diagram for one of
>these units at all they wouldn't mind me having a copy of at all?..
>
>Thanks in advance...
Assuming you're interested in the filter board, I don't recall there
being anything very complicated about them.
It's been a while, you understand, but memory suggests a triplet input
buffer followed by a series of Sallen-Key filters. Apart from the
buffer, all the silicon is configured as npn/pnp compound emitter
followers.
This might give you a start:
http://downloads.bbc.co.uk/rd/pubs/reports/1979-22.pdf
The +30V power is derived from +50V (from the parent 405) using a very
simple emitter follower. These would go o/c occasionally, resulting,
clearly, in loss of output.
HTH,
Brian
Brian
Remove 2001. to reply by email.
wrote:
>
>Bit of a long shot but anyone here got a circuit diagram for one of
>these units at all they wouldn't mind me having a copy of at all?..
>
>Thanks in advance...
being anything very complicated about them.
It's been a while, you understand, but memory suggests a triplet input
buffer followed by a series of Sallen-Key filters. Apart from the
buffer, all the silicon is configured as npn/pnp compound emitter
followers.
This might give you a start:
http://downloads.bbc.co.uk/rd/pubs/reports/1979-22.pdf
The +30V power is derived from +50V (from the parent 405) using a very
simple emitter follower. These would go o/c occasionally, resulting,
clearly, in loss of output.
HTH,
Brian
Brian
Remove 2001. to reply by email.
Dave Plowman (News)
Aug 17, 2012, 6:03:03 AM8/17/12
to
In article <843s28te3tojdbgsj...@4ax.com>,
pic I have of the actual board component side shows there's rather more to
it. For example, the filter circuits show a total of 6 transistors - the
actual board some 14. Rather more than could be accounted for by a PS and
input buffer.
--
*White with a hint of M42*
Dave Plowman da...@davenoise.co.uk London SW
To e-mail, change noise into sound.
Brian <Br...@2001.bjforster.force9.co.uk> wrote:
> Assuming you're interested in the filter board, I don't recall there
> being anything very complicated about them.
> It's been a while, you understand, but memory suggests a triplet input
> buffer followed by a series of Sallen-Key filters. Apart from the
> buffer, all the silicon is configured as npn/pnp compound emitter
> followers.
> This might give you a start:
> http://downloads.bbc.co.uk/rd/pubs/reports/1979-22.pdf
> The +30V power is derived from +50V (from the parent 405) using a very
> simple emitter follower. These would go o/c occasionally, resulting,
> clearly, in loss of output.
The BBC publication does give the basic filter circuits, but a (low res)
> Assuming you're interested in the filter board, I don't recall there
> being anything very complicated about them.
> It's been a while, you understand, but memory suggests a triplet input
> buffer followed by a series of Sallen-Key filters. Apart from the
> buffer, all the silicon is configured as npn/pnp compound emitter
> followers.
> This might give you a start:
> http://downloads.bbc.co.uk/rd/pubs/reports/1979-22.pdf
> The +30V power is derived from +50V (from the parent 405) using a very
> simple emitter follower. These would go o/c occasionally, resulting,
> clearly, in loss of output.
pic I have of the actual board component side shows there's rather more to
it. For example, the filter circuits show a total of 6 transistors - the
actual board some 14. Rather more than could be accounted for by a PS and
input buffer.
--
*White with a hint of M42*
Dave Plowman da...@davenoise.co.uk London SW
To e-mail, change noise into sound.
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