On Wed, 20 Oct 2004 22:39:33 +0100, Ian Bell
wrote:

Pooh Bear wrote:

Wally wrote:

As some of you may be aware, I have an on-going speaker rebuild fantasy
bubbling away in the background. The plan is to bi-amp, and part of this
involves a second line output on the pre-amp, to send a signal to the
bass amp. The bass/midrange driver will have no high-pass components in
the crossover - I intend to let the bass roll off naturally, and try to
match the low-pass filter feeding the subs to this roll-off. I'm edging
towards trying to make a prototype filter and would welcome comments...

The pre-amp is a Cambridge A75. The chips it uses are NE5534N op-amps,
evidently low-noise and suitable for high quality audio. My intention was
to use the same chips for my active filter / output stage, on the
assumption that the pre-amp's PSU will be delivering the right
voltage(s). However, it looks like these chips are no longer made - what
would be a suitable alternative?

5534s are most certainly still made. What made you think they aren't ?

Available from many places. Best audio op amp ever made IMHO. Try Maplins
for starters.

If it's good enough for Meridian output stages, then it's good enough
for me! :-)
--

Stewart Pinkerton | Music is Art - Audio is Engineering

Stewart Pinkerton wrote:

If it's good enough for Meridian output stages, then it's good enough
for me! :-)

They're in the 203? That means that my audio signal goes through nothing but
5534s before hitting the valves (which are soaked in swamp water to give 'em
soul...).


--
Wally
www.artbywally.com
www.wally.myby.co.uk

On Thu, 21 Oct 2004 19:33:58 +0100, "Wally"
wrote:

Stewart Pinkerton wrote:

If it's good enough for Meridian output stages, then it's good enough
for me! :-)

They're in the 203? That means that my audio signal goes through nothing but
5534s before hitting the valves (which are soaked in swamp water to give 'em
soul...).

They are indeed in the 203. Ditch the valves and you'll have some
chance of hearing what the performer intended (it's not all soul
music, y'know!)........................
--

Stewart Pinkerton | Music is Art - Audio is Engineering

In article , Stewart Pinkerton
wrote:
On Thu, 21 Oct 2004 19:33:58 +0100, "Wally"
wrote:

Stewart Pinkerton wrote:

If it's good enough for Meridian output stages, then it's good enough
for me! :-)

They're in the 203? That means that my audio signal goes through
nothing but 5534s before hitting the valves (which are soaked in swamp
water to give 'em soul...).

They are indeed in the 203. Ditch the valves and you'll have some chance
of hearing what the performer intended (it's not all soul music,
y'know!)........................

If you/anyone has available circuit diagrams for the 200/203/263 I would
love to have a copy. :-)

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html