Anyone know what's the flavour of the month
for op amps?

It's just for some buffers and equalizers to
go before a power amp so tbh, a 741 would
probably be as good as is required but
there's nothing wrong with being trendy. :-)

--
Roger.

In message , Old Fart at Play
writes
Anyone know what's the flavour of the month
for op amps?

It's just for some buffers and equalizers to
go before a power amp so tbh, a 741 would
probably be as good as is required but
there's nothing wrong with being trendy. :-)


Reasonably priced and good, (though not in the AD897 class) is the
OPA604 or OPA2604 (dual version).

Mind you, if you aren't too concerned about dc precision, the venerable
NE5534 and 5532 are still widely used and respected.

Oh Oh, wait for the screams :-)
--
Chris Morriss

"Chris Morriss" wrote in message
...
In message , Old Fart at Play
writes
Anyone know what's the flavour of the month
for op amps?

It's just for some buffers and equalizers to
go before a power amp so tbh, a 741 would
probably be as good as is required but
there's nothing wrong with being trendy. :-)


Reasonably priced and good, (though not in the AD897 class) is the
OPA604 or OPA2604 (dual version).

Mind you, if you aren't too concerned about dc precision, the venerable
NE5534 and 5532 are still widely used and respected.

Oh Oh, wait for the screams :-)
--
Chris Morriss

I wouldn't use anything other than the OPA637 or the 627 for gains of less
than 5.

Graham Holloway.

In article , Graham Holloway
wrote:

I wouldn't use anything other than the OPA637 or the 627 for gains of
less than 5.

In order to put the cat amongst the pidgeon I will admit that I ended up
preferring to use HA12017's as general purpose op-amps for audio purposes.

These were originally developed by Hitachi for use in RIAA preamps, but I
found they have a nice balance of low-noise, reasonable bandwidth, etc.
Their main drawback was that I had to experiment to determine the optimum
compensation and output bias networks as Hitachi gave no data for anything
other than RIAA purposes! :-)

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

On Fri, 23 Jan 2004 09:07:46 +0000 (GMT), Jim Lesurf
wrote:

In article , Graham Holloway
wrote:

I wouldn't use anything other than the OPA637 or the 627 for gains of
less than 5.

In order to put the cat amongst the pidgeon I will admit that I ended up
preferring to use HA12017's as general purpose op-amps for audio purposes.

These were originally developed by Hitachi for use in RIAA preamps, but I
found they have a nice balance of low-noise, reasonable bandwidth, etc.
Their main drawback was that I had to experiment to determine the optimum
compensation and output bias networks as Hitachi gave no data for anything
other than RIAA purposes! :-)

As noted on the UKRA website, I used the superb SSM 2017 and SSM2131
for critical audio duties, but I've also used the LT1028 and AD 845
wirth considerable success. OTOH, the venerable NE5534 is still good
enough for most audio purposes.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

Jim Lesurf wrote:


In order to put the cat amongst the pidgeon I will admit that I ended up
preferring to use HA12017's as general purpose op-amps for audio purposes.

These were originally developed by Hitachi for use in RIAA preamps, but I
found they have a nice balance of low-noise, reasonable bandwidth, etc.
Their main drawback was that I had to experiment to determine the optimum
compensation and output bias networks as Hitachi gave no data for anything
other than RIAA purposes! :-)


I still have a couple of HA12017s and an RS datasheet from 1982.
(Photocopies on request).

What values did you come up with for compensation for line-level
low-gain circuits?

--
Roger.

In article , Old Fart at Play
wrote:
Jim Lesurf wrote:


In order to put the cat amongst the pidgeon I will admit that I ended
up preferring to use HA12017's as general purpose op-amps for audio
purposes.


I still have a couple of HA12017s and an RS datasheet from 1982.
(Photocopies on request).

I have the Hitachi databook for them.

Are the 12017's still avalable, or are they now obsolete and deleted from
all stocks?

What values did you come up with for compensation for line-level
low-gain circuits?

This has reminded me that the diagram really should be on the Armstrong
site as I used them for the 700 preamp...

10pF from pin 5. 100pF from pin 1.

Join the other ends of the above caps together and to a 1k resistor to
ground.

I also tended to have a 10pF or 20pF across the feedback resistor.

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

I tryed in my DAC some opamps - NE532, NE5532, NE5535, TL074, AD513, BA4560,
BA4580, OPA4134, OPA627, AD825 and AD8065 - the most natural sounding was
AD825 (it is in SMD case only).
Uzytkownik "Old Fart at Play" napisal w
wiadomosci ...
Anyone know what's the flavour of the month
for op amps?

It's just for some buffers and equalizers to
go before a power amp so tbh, a 741 would
probably be as good as is required but
there's nothing wrong with being trendy. :-)

--
Roger.

AD846 is a great sounding chip but expensive.

Regards
Ralph

Old Fart at Play wrote:

Anyone know what's the flavour of the month
for op amps?

It's just for some buffers and equalizers to
go before a power amp so tbh, a 741 would
probably be as good as is required but
there's nothing wrong with being trendy. :-)


NE5532 is still top of my list for this type of application. See Dougla
Self's excellent web page.

Ian