> Im looking to an alternative to the Philips-NXP NE5532n > preferrably the Analog divice brand. > Ive tried the NE5532AP *texas intruments( so far but they lack > headroom. Anyone any thoughts_
** Yep - you need to get into rehab ASAP.
Mind altering drugs are a devastating social evil.
> Im looking to an alternative to the Philips-NXP NE5532n > preferrably the Analog divice brand. > Ive tried the NE5532AP *texas intruments( so far but they lack > headroom. Anyone any thoughts_
> Cheers
> Marc
what does like headroom mean? is this for replacement or a from scratch project?
> Im looking to an alternative to the Philips-NXP NE5532n > preferrably the Analog divice brand. > Ive tried the NE5532AP *texas intruments( so far but they > lack headroom. Anyone any thoughts_
Tell us about the application.
In normal audio circuits, the headroom is set by the power supply voltages and gain staging. Neither of those are changed when you change out good op amps. NE5532 are good op amps - a classic and still widely used despite their age.
<relishing the fact that Marc being a good Phildoite probably has me killfiled and/or will grant me no credibilty, and thus will shoot himself in the foot by ignoring this really helpful post>
> the aplication is an XTA DP226 which had its OPamps blown > by some ignorant stupid git. who managed to put RS485 > through a DMX repeater and in the outputs of the XTA. the > NE5532n dont like that.
DMX which is essentially RS 422 is not a good thing for most line level outputs. Neither is mic + phantom.
But you already knew that!
> The xta techdept is sendin some NE5532n over, for the > time being i use the Ti NE5532ap but they do lack > headroom in given application though the specs do not > differ......
Details. please. Which spec do you see as being a problem?
> I was wondering if anyone had experience putting > different brands opamps to use as they all seem to have > the same specs but turn out to be quite different.
I've done a ton of scientific expermentation related to that issue, both listening tests and bench tests, and it doesn't bear out many anecdotes that one hears.
> to validate the question > the NXPphilips ones are becoming a hard to source item > here.
Philips sold off their semiconductor business recently. That may have some impact on availability.
On Fri, 27 Nov 2009 16:26:27 +0100, Marc Amsterdam <re...@newsgroup.only> wrote:
>I was wondering if anyone had experience putting different brands >opamps to use as they all seem to have the same specs but turn out to >be quite different.
I can't tell you about 5532's but I can relate stories about other op amps...
One that comes to mind is the 739, which was used in mic and phono pre amps. One type that I had was quite stable, but replacements from another company were unstable in the same circuit, oscillated like crazy... Since I couldn't find the original types, I scrapped the mixer. (I found out later there were internal end external comp. types available.)
Another slightly different problem I had concerned TI op amps, I forget the number but they were FET input, 8p DIPs... very popular in the late 70s or early 80s, and the ones from TI tended to BREAK into pieces when their leads were flexed to fit into the sockets! I lost a whole bag of them that way! I ended up using non-FET replacements from another company... s' weird...
So my conclusion is, NOT all op amps are the same, even if they have the same part no. Just check out the spec sheet, most parameters have ranges, you hope you get a center spread but you can be unlucky!
As far as your headroom problem, you must have a circuit with very tight specs... you aren't meeting the drive requirements or something... can you get a schematic? Did you check your power supply for any voltage droop? Maybe those ops are drawing power, or even oscillating!
> I can't tell you about 5532's but I can relate stories about other op > amps...
** Here we go off into la la land.
> One that comes to mind is the 739, which was used in mic and phono pre > amps.
** Back in the 1970s.
> One > type that I had was quite stable, but replacements from another company > were > unstable in the same circuit, oscillated like crazy... Since I couldn't > find the > original types, I scrapped the mixer. (I found out later there were > internal end > external comp. types available.)
** Fairchild made the uA739 - which needed external R + C compensation.
Raytheon later made the RC4739 - which, while pin compatible with the uA739, is of quite different design.
Pays to read the numbers and have a glance at the data sheets to.
> Another slightly different problem I had concerned TI op amps, I forget > the > number but they were FET input, 8p DIPs... very popular in the late 70s or > early > 80s, and the ones from TI tended to BREAK into pieces when their leads > were > flexed to fit into the sockets! I lost a whole bag of them that way! I > ended up > using non-FET replacements from another company... s' weird...
** Faulty metal - you should have returned them.
> So my conclusion is, NOT all op amps are the same, even if they have the > same > part no.
> <relishing the fact that Marc being a good Phildoite probably has me > killfiled and/or will grant me no credibilty, and thus will shoot himself > in the foot by ignoring this really helpful post>
Being ignored by the vast majority of people on here, even on the rare occasions you actually have something useful to say, is the price you pay for being such an idiot. You bring it all on yourself but are too much of a coward to accept any sort of responsibility so try to blame everything on other people.
>> One >> type that I had was quite stable, but replacements from another company >> were >> unstable in the same circuit, oscillated like crazy... Since I couldn't >> find the >> original types, I scrapped the mixer. (I found out later there were >> internal end >> external comp. types available.)
>** Fairchild made the uA739 - which needed external R + C compensation.
>Raytheon later made the RC4739 - which, while pin compatible with the >uA739, is of quite different design.
>Pays to read the numbers and have a glance at the data sheets to.
Didn't have spec sheets at the time, was given "739" chips by the boss. I found out later, as I said.
>> Another slightly different problem I had concerned TI op amps, I forget >> the >> number but they were FET input, 8p DIPs... very popular in the late 70s or >> early >> 80s, and the ones from TI tended to BREAK into pieces when their leads >> were >> flexed to fit into the sockets! I lost a whole bag of them that way! I >> ended up >> using non-FET replacements from another company... s' weird...
>** Faulty metal - you should have returned them.
They were DIFFERENT!
>> So my conclusion is, NOT all op amps are the same, even if they have the >> same >> part no.
>** Shame your examples do not even back that up.
Learn to read... but it doesn't matter, op amps have a spread of parameters, you just ignore it.
>> Just check out the spec sheet,
>** Just like you did not.
Not applicable, I checked the data later... perhaps the OP did the same...
>> As far as your headroom problem,
>** Marc has a headroom problem - alright.
> His swollen head to too big for his hat.
HA!!! You talk about swollen heads??!! The Koreans have to wait for you to lie down before they shoot a missle over Oz!!!
> Im looking to an alternative to the Philips-NXP NE5532n > preferrably the Analog divice brand. > Ive tried the NE5532AP *texas intruments( so far but they lack > headroom. Anyone any thoughts_
> As far as your headroom problem, you must have a circuit with very > tight specs... you aren't meeting the drive requirements or > something... can you get a schematic? Did you check your power supply > for any voltage droop? Maybe those ops are drawing power, or even > oscillating!
Yes, the 'headroom' ascertion seems a bit odd to me too.
It would be nice to know exactly how this apparent failing actually manifests.
>>> Yes, the 'headroom' ascertion seems a bit odd to me too.
>>> It would be nice to know exactly how this apparent failing actually >>> manifests.
>> ** The XTA DP226 displays a parameter called "Headroom".
>> Obviously allows one to tell immediately if a new input IC is up to >> scratch or not .....
> Not from what I read.
** What do you think my " ..... " meant ????
> From the descriptions of the various instances of 'headroom' in the > manual, they are simply level indications/warnings wrt max unclipped > output level.
> Phil Allison wrote: >> "geoff" <ge...@nospam-paf.co.nz>
>>> Yes, the 'headroom' ascertion seems a bit odd to me too.
>>> It would be nice to know exactly how this apparent failing actually >>> manifests.
>> ** The XTA DP226 displays a parameter called "Headroom". >> Obviously allows one to tell immediately if a new input IC is up to >> scratch or not .....
Not so much.
> Not from what I read. - it's not some sort of internal self-test of > levels at all. > From the descriptions of the various instances of 'headroom' in the > manual, they are simply level indications/warnings wrt max unclipped > output level. > But I only had time to skim the manual and as usual you are doubtlessly > right.
I found two mentions. They lead me to believe that they relate to unclipped input level, which varies depending on how the built-in limiting is set.
No way do they indicate subtle aspects of op amp performance.
bob u wrote: > On 11/27/2009 7:13 AM, George's Pro Sound Co. wrote: >>> what does like headroom mean?
>> Headroom is the space between the steering wheel and my lap :-0 >> ba da boom >> George > Its room for the female head that's between your lap and the steering > wheel. In some past life, i tried a lab experiment on the subject.
> Luckily, no cars or humans were injured. A few brain cells might have > be a casualty though,,,,, ;)
Just don't slam on the brakes or get in accident ... or something might be lost in the translation ....
