LM741 opamp substitute?

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Greetings,

I am hoping to replace the somewhat dated LM741 opamps in an old 1970s
PKE phono preamp. There are 3 in each channel (6 total). I can post a
close-up pic of the circuit board to anyone who may be happy to comment
specifically. I am hoping to apply a drop-in solution if possible, but
understand that this may not be preferable.

Many thanks,

Stephen


Re: LM741 opamp substitute?



"langleycello"
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** The nearest * readily available *  op-amp to replace the venerable LM741
in most audio applications is the TL071.

 It is indeed pin for pin and a drop in replacement  -  much more bandwidth
& slew rate but very similar noise level to the 741.

Need to see a schematic to exclude any ( not very likely ) issues with the
substitution.





.......   Phil








Re: LM741 opamp substitute?



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PKE are still active, why not ask them ?
Rheilly P



Re: LM741 opamp substitute?



Rheilly Phoull wrote:
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Yes, I have, but they no longer have the available info.

Thanks Phil for your suggestion.

For the sake of it, I include some photobucket URLs of one phono card
(back and front) which may cast some extra light on things, in the
absence of a schematic.

http://i16.photobucket.com/albums/b17/langleycello/IMG_2144-1.jpg

http://i16.photobucket.com/albums/b17/langleycello/IMG_2145-1.jpg

Cheers,

Stephen


Re: LM741 opamp substitute?



"langleycello"


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**   " Lament of the 741 "


 Why substitute me for another type  ?

 Have you all fallen for a load of hype ?

 I look pretty small but my pins are high

 The simple specs you see are all complicated

 I may be pretty old but I'm not outdated   -   yeah  ...



Note:

The uA741 first appeared in May of 1968 -  it was very expensive.

The TL071 first appeared in July of 1977  -  it was dirt cheap.




.......   Phil




Re: LM741 opamp substitute?



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The circuit is easily traced in order to create a schematic.  From there you
should be able to update the circuit.




Re: LM741 opamp substitute?



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**Assuming no oddball circuit highlights, the OPA604 will do nicely. If you
want to take it further, the AD825 (a carrier PBC will be required) will be
(slightly) better again.


--
Trevor Wilson
www.rageaudio.com.au



--

Re: LM741 opamp substitute?



Thanks everyone for your thoughts,

I'll get some 8-pin sockets and opt for a flexible arrangement. Maybe
I'll first experiment with some TL071s, which hopefully should be OK as
an immediate drop in, and then perhaps the OPA604 down the track.

Cheers,

Stephen


Re: LM741 opamp substitute?



"langleycello"
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**  Another low cost & readily available op-amp type that ought not be
ignored is the very famous NE5534P  - available from DSE and many others.

It will likely require a 33pF capacitor between pins 5 and 8  to be " unity
gain stable "  -   as the 741 is inherently.

According to my ( not inconsiderable) experience and also that of renound
pommy audio expert Doug Self, the NE5534 is the lowest noise, best
performing MM phono stage op-amp available.


( MM  =  moving magnet  =  high impedance =  47 kohms)




........  Phil








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**Just a point: With the OPA604 and most other replacement chips (the 5534
is notorious in this regard), you need to ensure that the supply rails are
up to the task. Most other chips consume considerably more current than the
741, although, in absolute terms, we're not talking about a great deal of
current.


--
Trevor Wilson
www.rageaudio.com.au



--

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Whats wrong with the 741? If it aint broke, dont fix it!




Re: LM741 opamp substitute?



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**Let's see:
* It's noisy
* It has a crappy slew rate.
* There are other, audibly superior devices available.

741s should be removed from almost ANY product which uses them. They work
fine at or near DC, however.

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**The 741 is already broke.


--
Trevor Wilson
www.rageaudio.com.au



--

Re: LM741 opamp substitute?



"Trevor Wilson"
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**  Big mistake asking Australia's most notorious audiophool plus hi-fi
dealer vampire.


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** EIN  =  3 uV  ( in  20 kHz bandwidth )

  Signal to noise  = 110 dB ( unweighted) relative to 1 volt at unity gain.



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** An ignorant audiophool opinion TW gets to keep.


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** Another ignorant audiophool opinion TW gets to keep.


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**  An ignorant audiophool opinion TW gets to keep.


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**  Yawn -  all totally irrelevant.



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**  An ignorant audiophool opinion TW gets to keep.



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**  Do look at the vampire's lair.




.......   Phil





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    Geez - now I understand why the ACS demodulator kit (EA 1993)
doesn't sound so crash hot. I shouldn't have used a 741 to do the
de-emphasis! ;-)

Bob

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