I'm going to replace some of the input/output Op-Amps inside the Yamaha 03D.

NJM2068D's are whats currently installed so i'm looking for advice on replacement Op-Amp chips with the same pin-outs of higher quality. What IC's do they use in the hi-end stuff?

And i'm hoping I can change just the IC's.

5532s are in lots of gear, including plenty of expensive stuff, 2134 is also possible, National make some specialist 'audio' parts that I mistrust on principle (Audio is not different to any other small signal instrumentation application), plenty of good parts for the right application out there.

However, one question, what exactly is wrong with the 2068D?
Sure it the slew rate is not huge (but it really doesn't need to be), and they are a jellybean part but what is the actual problem you are trying to fix?

What exactly is the surrounding circuit, what are the impedances at the input pins (Current Vs Voltage noise trade off), what is it loaded by (ADC drivers often have to swing capacitive loads for example), will the power supply cope with something that needs more current?

Is the supply decoupling up to snuff, how about the layout, if these are not right you can forget about using anything really fast, it will just oscillate (Not that you need anything really fast for audio).

The 'replace the opamp' thing while sometimes justified has a large element of cargo cult about it IMHO.

Regards, Dan.

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Audiophiles use phono leads because they are unbalanced people!

Nothing wrong with it I was thinking of upgrading the Op-Amps on a 13 year old product.

Here's part of the schematic...

All run of a 15V split supply. What you see is the amp stages directly after D/A conversion to the main outputs.

I think Dan's pretty well covered it
However... if you do decide to replace them, put dil sockets in. Don't solder the replacements direct to the board. Also, don't try to desolder them in one go. Chop all the legs of from the body, then lift the legs out one at a time with tweezers while heating the joint - that way you won't pull out the vias.

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It wasn't me!
(Well, actually, it probably was)

The DIL sockets seems like a brilliant idea!

I'm just thinking if I can improve on the sound the 03D will give. Being a digital mixer the only thing that can affect the sound mainly is the Op-Amps going in and and out.

don't be fooled by if it has higher specs it must sound better either. i remember reading a Douglas Self article comparing 5532's with some fast burr brown op amps that the easily fooled audiophiles were raving about. the conclusion fell in favor of the 5532's. I can't remember the details of the article, it might have compared more but just pointing out that higher specs are not always better. it is a long time since reading the article so could be wrong, in which case

I "upgraded" some spare channel modules & a master out module on a soundcraft delta 200dlx to see what impact on sound it would have from factory spec. the "upgraded" sound just wasn't as detailed, didn't sound so open & dynamic, dull if you like. it was a bit like a direct plugged guitar with no life sort of sound. swapped back & happy day's. the best improvement i got was from the re-cap, new alps faders/buttons & a quality pot for the monitor volume.

Thats an interesting response.

Well checking the caps is something I plan to do anyways when I open it up to check an intermittent channel - I suspect it's a bad connection from the connector board to the AD board. This is why I got it cheap.

And i'm hoping the faders are ok but if need be brand new ones ain't expensive at all.

I wouldn't waste your time and effort. The line output op-amps aren't the weakest link by a long way. The converters are very long in the tooth now and pretty poor by modern standards, and the mic amps are likewise.

I often get very frustrated by those who brandish this notion that you can swap out op-amps like lego bricks, and that some hugely expensive magical new device that the hifi nerds rave about will make some twenty-year old product sound fabulous.

It just ain't true, and there's so much more to it than finding something with an identical pin out. As Dan has said, and Folderol has confirmed, to replace the op-amps you need to thoroughly investigate the power supply capability (voltage and current) and the local decoupling, you need to consider the gain bandwidth and the decoupling/stabilisation conmponents as well as the physical circuit board layout, and you need to consider the input and output impedances. The performance of any given op-amp needs all these parameters and more besides to be properly optimised. Failure to do so will simply squander the performance of a new op-amp if you're lucky, offering no practical advantage but take a lot of time effort and money. And if your choice of replacement op-amp is unlucky (or unsuited to the rest of the circuitry), you'll end up with instability and HF oscillations that may well cause all manner of nasties ina digital environment, destroy the op-amp or your tweeters, or all three!

The guys that designed the 03D knew what they were doing and chose those op-amps for a good reason...

Hugh

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Technical Editor, Sound On Sound

exquisite response from Hugh Robjohns.

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.. is this thing on?

Edited by Stan (22/05/10 11:47 PM)

I hear you loud and clear Hugh Robjohns.

Thanks.

I agree with all Hugh, Dan et al have said, just not worth the agro and might be worse!

Then too you must know your op amps! The TL0XX series are quite ok "cooking" amps for a lot of audio applications and one might be tempted to replace really old codgers like the 741's with such.
Don't. The TL0 bifet amps latchup on switch on momentarily to one rail or t'other and will also do this if overdriven. Designers know this and take suitable precautions or avoid T's where appropriate.

Dave.

Interesting, I didn't know that. I have an old Phonic PMC-1202B that I used a lot in the mid 90s. A couple of years ago I dug it out and replaced the 4558s with 072s. A comparison with some old and some replaced channels seemed to show a clearer top end, as it always seemed a bit 'soft' - I'd always considered the 07x my 'go to' opamp for general duties.

"I'd always considered the 07x my 'go to' opamp for general duties."

Yes, for most jobs theye are fine. Another drawback is an inability to drive less than about 10k with low distortion but as a lot of them are found in guitar pedals nobody cares!

The previously mentioned NE5534/32 is an excellent all round chip but be aware that it draws more juice, might need 33puff or so across the feedback R and although they will give very good results with a 1MOhm input R the output offset volts will be all over the shop.
Dave.

Likely to be a bit high noise at 1M input surely, they are bipolar (so lowish voltage noise but high current noise), maybe a jfet input part would do better if that is the source impedance?

You begin to see the issues inherent in just swapping opamps?

Regards, Dan.

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Audiophiles use phono leads because they are unbalanced people!

The chip "sees" about 7k, a guitar, for the application I had in mind. Yes, oc it would be noisy I think but you always use shorting jacks.

The big problem, as I say is that with such a high input R you get a big input offset voltage and if you want any kind of gain you need to ponce about with servos.

So, you say Dan, "Why use an NEE?" Because it was there!

Dave.

It was there, it was good enough for the job, it came in within budget, and other things mattered more, sounds like good engineering to me.

Regards, Dan.

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Audiophiles use phono leads because they are unbalanced people!

Funny "updating" a 13-year old product with some NE5532's. That chip must be older than I am.

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Expert in non-working solutions

Quote Havoc:

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Funny "updating" a 13-year old product with some NE5532's. That chip must be older than I am.

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Yeah, but it's still a decent chip, IMO. It's not uncommon in high-end audio gear. Many a studio console is stuffed with them and whilst some AD or BB chips might be more 'audiophile', the ole' 5532 parred with some decent circuitry and ditto power supply can sound pretty good enough.

Cheers,
Frank

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Imagination is more important than knowledge - A. Einstein

BC214l's are older and BC109C's practically prehistoric but audiophools still drool over discrete "op amps" using them (or similar, s'all jus Silicon!).

Dave.

Well judging by most of the posts here it seems its not worth tinkering with the 03D even though I was prepared to upgrade PSU components and other relevant circuits to work with new Op-Amp chips.

Quote ef37a:

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BC214l's are older and BC109C's practically prehistoric but audiophools still drool over discrete "op amps" using them (or similar, s'all jus Silicon!).

Dave.

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1964 for BC109, amazingly still in production

... and what a lovely little thing it is

Beste tre jambus

P.S.
You learn such useful things on here

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It wasn't me!
(Well, actually, it probably was)

Edited by Folderol (25/05/10 09:44 PM)

Ah, but the BC109C had a guaranteed higher gain than the bog standard BC109

As far as I remember there was also a D version with even higher gain


Martin

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YewTreeMagic

Dont lump all hifi companies/people/engineers as fools. :-{{{{ You will have seen 5532s in Meridian products for example until very recently. Just plucking a quote from this thread with no malice meant......

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Being a digital mixer the only thing that can affect the sound mainly is the Op-Amps going in and and out.

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Quote fay spook:

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Dont lump all hifi companies/people/engineers as fools.

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I think that has been the consistent response throughout this thread.

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You will have seen 5532s in Meridian products for example until very recently.

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No quite sure where Meriidan come into this, but it has already been said that 5532s are very good little audio op-amps when used appropriately.

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Just plucking a quote from this thread with no malice meant...

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I think Ramirez has already learned why his earlier statement is a little wide of the mark.

Hugh

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Technical Editor, Sound On Sound

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remember reading a Douglas Self article comparing 5532's with some fast burr brown op amps that the easily fooled audiophiles were raving about.
the conclusion fell in favor of the 5532's.

whilst some AD or BB chips might be more 'audiophile',
the ole' 5532 parred with some decent circuitry

but audiophools still drool over discrete "op amps" using them (or similar, s'all jus Silicon!).

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I was explaining that "audiophile" companies do understand that 5532s are good and gave an example. I know you know but others do too!!

Fair enough -- I don't think the suggestion was that the manufacturers were the problem though. I think the argument was against 'audiophiles' themselves who may have thought that more exotic (and expensive) op-amps would necessarily be better than the venerable 5532 in all applications.

Hugh

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Technical Editor, Sound On Sound

I am sorry I didnt make myself clear enough.

I have a foot in both camps, having working in the hi-fi industry for 15 years and I am still in pro-audio, and I see good and bad practice by end users in both worlds. I have heard many superb domestic hifis, in fantastic rooms (with acoustic treatment and no mixers between speakers and ears!)and with huge collections of music (most audiophiles I know have spent tens of thousands of pounds building their collections and avoid illegal downloads- these people pay your bills!). I have also seen the reverse and all shades in between......

Perhaps I should pen a Sounding off piece about the two side of the same audio coin.

Maybe we could try branding 5532s as vintage? That usually works.

Quote fay spook:

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Maybe we could try branding 5532s as vintage?

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Check out some of the mid 70's Neve circuits when the 5534 had a TBA number (it could have been the TBA1034).

James.

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JRP Music - Audio Mastering and Restoration.
http://www.jrpmusic.net

Quote fay spook:

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Maybe we could try branding 5532s as vintage? That usually works.

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Brilliant idea!

I was thinking of painting them gold too...

hugh

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Technical Editor, Sound On Sound

Is there a prize for whoever comes up with the most plausible 'explanation' as to how the gold paint improves the sound?

My starter...
Gold powder is often used in chemical filtering and purifying hardware, so it stands to reason that a carefully applied even coating on the chips will allow the delicate nuances of the purest audio though, whilst effectively blocking the coarse distortion products.

The gold lacquer is formulated to have an atomic lattice such that audio waves will glide though effortlessly but harsh distortion waves have a configuration that cannot pass. These are then absorbed into the substrate where they are converted into harmless free electrons.

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It wasn't me!
(Well, actually, it probably was)

Don't, just don't. I have no problem with [s]idiots[/s]audiophiles paying x times more for other opamps then I have to pay for an NE5532A that works just as well if not better. I do admit that I (we?) are in the wrong line of business to fleece the [s]gullible[s]easily impressed non-technical audience but let it go. Please....

Mea culpa, mea culpa, mea maxima cupla: I have made some JE990's.

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Expert in non-working solutions

Edited by Havoc (05/06/10 08:29 PM)

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I have no problem with [s]idiots[/s]audiophiles paying x times more

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I am happy to report again that hifi manufacturers use 5532s. I am a little unsure who the "fools" are who pay over the odds for replacement op amps. There is an after market tweak section but this is relatively small. I didnt see any hot rodded amps in my time. Can you give some examples where someone has seen the mods and heard them? Was the sound better/worse or different? The other side is the active DIY community rather than the tweakers. Look at what they are doing, want a good monitor amp? Try a gainclone over a Samson. Want some speakers without any cabinet colouration then try an open baffle speaker. Thats just a couple of examples where there is discussion and research.

How much is a 5532, 20p, an exotic from Analog Devices, £2.50. Overall cost of an "audiophile" system, £5,000. Number of op amps for a hifi, 4. Number of op amps in a 32 channel mixer, I dont know but I would expect 64 upwards. So its no real cost for a hifi system to try some chip rolling but a lot more for a mixer to be swapped out.

There are plenty of posts in these forums that suggest that a complete technical knowledge isnt universal here much as it isnt in hifi. Ultimately no technical knowledge is required to make or to listen to music but dont use it as an off pat remark for ALL audiophiles. And dont forget most audiophiles will be jealous of the music talent amongst us and that is the focus rather than "poor" amps and speakers.

For every myth in hifi there is one in pro audio. A good example of myths for pro sound would be the NS10s. For years the quote for them was "if it sounds good on NS10s it will sound good on anything". Now we are told they sound good because they arent reflex loaded and the time domain response is great. Oh and you dont need any tissue on the tweeter. Which description is right? For everyone who knows that for a great vocal sound you need a great singer there is someone who thinks you just need the same mic!

As I have said before get out and hear a good hifi before you say all audiophiles are fools. No rant intended.........honest.........

"No rant intended.........honest......... "

No rant percieved Mr Spook.......honest! I have used the catchall term "audiophool" but perhaps I can explain what I mean by that?

I have been interested in sound reproduction for over 50years. My first "heros" were G.A.Briggs, Peter Walker, G,King, Lindsley Hood and most of the writers at Wireless World, Hi Fi News and Tape Recorder(Oh! Wither Hugh Ford?). These people held to sound engineering principles. They readily admitted that you could not tell EVERYTHING about how a sound "system" behaved from measurement but they were convinced, as am I, that if someone claims to hear some effect that effect must be reproducable and fit with the known laws of physics. I.e . it is up to the CLAIMENT to prove his case.

An example is high priced cables. There is no science that suggests one metal or "grade" of metal makes any difference to the quality of the signal running thru' it and I am not aware in the 20yrs or so that this Big Lie has been promoted that such has ever been proved.

I have the greatest respect (and some envy!) for those that can devine subtle differences in systems but these differences ARE subtle! For us mere mortals the "world" is never quiet enough, the signal never "pure" enough and speakers never of the analytical quality of the audioPHILES!

It is the arrogant and well heeled phools that I mean to berate when they claim that unless you spend £100 a mtr on wires and have a £1000 per channel mic pre amp you are doing little better than Edison.

Dave.

Thanks Dave. I am glad I was able to pitch the message the right way!


Why am I filling my open baffle speakers with sand? Gilbert Briggs of course!!

Angus McKenzie, Mac Hellyer, David Robinson (yes, that David Robinson - he went on to great things at Dolby), John Crabbe - all save Robinson now gone, but not forgotten.

Rants are often good for the soul and entertaining for the reader... but I fear you are trying to defend the hifi industry when there is no need...

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I am happy to report again that hifi manufacturers use 5532s. I am a little unsure who the "fools" are who pay over the odds for replacement op amps.

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Individual hifi tweakers who think magic chips will render their average hifis into something spectacular. They do exist -- you can read about all over the internet and in a good many 'hifi' magazines.

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Number of op amps in a 32 channel mixer, I dont know but I would expect 64 upwards.

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Er... more like 200 in total, with probably around 8-10 in any complete signal path. But even so, the additional cost of using exotic opamps wouldn't dent the budget much for a £250,000 SSL or Neve console ... yet they still don't tend to use exotica because, as we all know, the venerable 5534 / 5532 does the job perfectly well when used appropriately.

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A good example of myths for pro sound would be the NS10s. For years the quote for them was "if it sounds good on NS10s it will sound good on anything".

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That is generally true, in my experience -- although perhaps it requires a definition of the term 'good'. Replace that with 'well balanced' and it's definitely true.

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Now we are told they sound good because they arent reflex loaded and the time domain response is great.

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Definitely true... but again, it's the definition of 'good' that's important. In this case, it's the absence of time-domain smearing which makes it much easier to hear the true balance between bass instruments.

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Oh and you dont need any tissue on the tweeter.
Which description is right?

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never been convinced about the tissue paper thing... but the rest is right as explained above.

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For everyone who knows that for a great vocal sound you need a great singer there is someone who thinks you just need the same mic!

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Yes... and they're all noted in my black book and will be the first ones against the wall to be shot when the revolution comes

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As I have said before get out and hear a good hifi before you say all audiophiles are fools.

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Presumably you count yourself as an 'audiophile' but I don't think there's a need to get too defensive about it... or even join audiophiles anonymous!

Audiophiles aren't necessarily fools. Those who indulge in random chip swappage might be...

Hugh

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Technical Editor, Sound On Sound

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I'm going to replace some of the input/output Op-Amps inside the Yamaha 03D.

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Audiophiles aren't necessarily fools. Those who indulge in random chip swappage might be...

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Guess that makes me a fool then.

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Guess that makes me a fool then.

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I did say ~might be~ rather than 'are'...

But I also said much earlier that the op-amps in the analogue I/O of the 03D aren't the quality-limiting weak point of the mixer, and so changing op-amps won't deliver significant quality improvements in that specific case.

Hugh

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Technical Editor, Sound On Sound

Quote Hugh Robjohns:

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But I also said much earlier that the op-amps in the analogue I/O of the 03D aren't the quality-limiting weak point of the mixer, and so changing op-amps won't deliver significant quality improvements in that specific case.

Hugh

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Agreed. Having used it for a week or so i'm liking the sound and the processing ain't bad either.

But then again, what do I know....

Someone barking up the wrong tree here. Anyway, I just designed the NE5532 into some communication gear. There great for driving telephone lines. Another few thousand used each year.

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Expert in non-working solutions