NE5534 replacement - National LME 49710?

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dickiefunk

Member
Joined
Jul 10, 2007
Messages
19
Hi,

I'm looking to swap out the socketed NE5534 opamps in my Presonus Eureka preamp and from doing quite a bit of research read that the LT1357, OPA 627BP and AD 797 have been the most popular options.
I was recently recommended I check out the National LME 49710 and am wondering if anyone on here has tried this opamp?

http://www.national.com/pf/LM/LME49710.html#Overview

Has anyone compared this opamp to either the LT1357, OPA 627BP or AD797 in the Presonus Eureka, MP20 or MP80?
 
pucho812 said:
why the 5534 is a perfectly good op amp

Agreed. I would recommend looking elsewhere for upgrading sound. Not saying that putting in a new SUPER Duper opamp won't change the sound, just that it may or may not be better, and 5534 definitely have a pleasing, natural character about their sound. (WHAT!?!?! DISTORTION CAN SOUND GOOD SOMETIMES???)

Have you considered replacing electrolytic coupling capacitors?
 
dickiefunk said:
Hi,

I'm looking to swap out the socketed NE5534 opamps in my Presonus Eureka preamp and from doing quite a bit of research read that the LT1357, OPA 627BP and AD 797 have been the most popular options.
I was recently recommended I check out the National LME 49710 and am wondering if anyone on here has tried this opamp?

http://www.national.com/pf/LM/LME49710.html#Overview

Has anyone compared this opamp to either the LT1357, OPA 627BP or AD797 in the Presonus Eureka, MP20 or MP80?

What matters is how they work in the context of that circuit..

If it has a socket, I think you need to try them and let us know...

Try to be scientific...

JR
 
Yes the 5534's are socketed.

It will be hard to do a decent A/B of this preamp with the different opamps because I only have one and doing identical performances with the various sources I would like to record would be almost impossible.
It would be easier to do if I had two units side by side and split the signal but unfortunately I don't.
One of the Presonus techs has used the LT1357, AD797ANZ and OPA627BP as alternatives and he found the LT1357 to be clean and extremely quiet. The AD797ANZ was also as quiet but sounded a little more musical. The OPA627BP had a little more lowend.

 
You could make a line level to Mic level pad / cable then connect a soundcard output to the preamp input and play a sample of music, which means you can make 100% repeatable comparisons, assuming you set leave the gain set the same each time.
 
While not the most scientific, i think recording different sources and trying to make them "close enuff" with let you be able to decern changes in the quality of sound.

Hey better yet, make a line to mic pad and put some pre-recorded stuff through it. perfectly the same every-time.
 
abechap024 said:
pucho812 said:
why the 5534 is a perfectly good op amp

Agreed. I would recommend looking elsewhere for upgrading sound. Not saying that putting in a new SUPER Duper opamp won't change the sound, just that it may or may not be better, and 5534 definitely have a pleasing, natural character about their sound. (WHAT!?!?! DISTORTION CAN SOUND GOOD SOMETIMES???)

+1

I tried OP2604 instead of 5532 in my new comp design (sidechain and audio path) thinking "ohh these opamps are waaay better, it'll sound unreal now".  Dead wrong.  It was sterile, and so clean and transparent I had to do a double take to make sure it was really compressing.  Threw the 5532's back in and it was business as usual.
 
OPA2604 is far from sterile, clean and transparent. That's the first time I've heard anyone say that. In many popular swapping cases it will be more distorted than NE5532. Think aphex aural exciter, just more subtle.

Most of the time when people upgrade their mixers etc standard parametric EQ circuits with OPA2604 the sound becomes a bit too hyped, and then it's back to NE5532 with, "ok that was pointless"

But there really are better sounding opamps than either of these for just about any swapping scenario.

Also, a "super duper opamp" will change the sound of just about any unit. You can re-voice gear this way. Stop kidding yourself with the ancient "NE5532 is adequate" bullsh*t". It's more than 30 years old, and that exactly how much semiconductor and material design has advanced since.

Besides, opamp swapping is fun when things are socketed and you have various options available. It's a real ear opener.

PS. I would jump right away in the NASA/deep/sonar end with something like ADA4898-2 or AD8599 (or their single package versions).

PPS. forget the dated and very expensive OPA627. There's OPA827 already.
 
Ne5534 can be plenty adequate, but it depends on what you want out of your gear. It took many blind tests before I convinced myself that, shesh. yea it does sound good.

Always depends on circuit and implementation. So take everything with a grain of salt.

I don't think saying its "30 years old" is a valid argument. They were doing amazing things back then, just like today.

I'm sure if we asked the OP if he would want to trade in his preamp for a nice ALL TUBE phatty, he would do it in a heartbeat, and shoot that technology is ...ancient?

But then again maybe not, depends on what you want. CLEAN and PRISTINE is just a few clicks away from COLD and STERILE depending on circuit and other factors.  WARM and 3D is just clicks away form MUSHY and UNDEFINED.

thank goodness though. Experiment get some opamps and try them all out. You might be surprised what you find, and what blind listening tests over the course of a couple days will show.
 
abechap024 said:
Always depends on circuit and implementation. So take everything with a grain of salt.
+1
I don't think saying its "30 years old" is a valid argument. They were doing amazing things back then, just like today.
Having lived through that period, yes there were other ways to get decent performance but not easily with cost effective off the shelf parts.

The introduction of NE553x and TL07x opamp families ushered in an age of off the shelf, better than audio speed and low noise, for general purpose audio path designs. The details still matter (they always do) but these parts when properly used will get you respectable sound quality.

JR
 
The LT1357/1358 might be worth testing if you want to get rid of (some) dc-coupling-elco's.
Due to their low bias-loading characteristics, their output-dc levels can be very low. (this is superior to the 553x)
In a number of applications I found the LT135x a better replacement for the TL07x's.
It feels happy in high-impedance input-circuits while being able to drive relative low-impedance loads.

Again, it depends on your circuit, those 553x's still sound very good to me in low-impedance applications.

Theo
 
abechap024 said:
I don't think saying its "30 years old" is a valid argument. They were doing amazing things back then, just like today.

Not with semiconductors they weren't. That tech was in preteens at the time. And we are talking about cheap mass production mentality after all, with accountants - rather than engineers - selecting parts.

But then, this is mainly a cloners forum. I tend to overstate the meaning DIY as "looking for new better options through experimentation".

abechap024 said:
I'm sure if we asked the OP if he would want to trade in his preamp for a nice ALL TUBE phatty, he would do it in a heartbeat, and shoot that technology is ...ancient?

Not valid comparison at all. opamps aren't used for distortion. Except with perhaps guitar stomps but they have been happy with TL07x from day one. Tubes really did have their golden age, and it's far past. New remakes don't sound as good as the golden age types. But semiconductor tech is moving forward and it would be plain stupid not to follow that progress in audio gear as well.
 
The 49710 is a good sounding amp..I swapped the 5534s in the mix buss of my DDA console and it opened up nicely.!..I tried the LT-1357 and it was good, a little " clean" for my taste..The 627 was a dissapointment... :eek:..I actually preferred the 5534s over them..!..The 627 didn't sound bad, but definately wasn't worth the cost..I have the 49710 driving the outputs of a Simon -Kloi DI  ( ADB-400 )box..Very good..!..Good luck..
 
I will help to add to this thread as I go.  I have an old busted up MP20 that due to being dropped and then repaired will not be worth anything if sold.  Therefore I am going to "upgrade" it, and try to get it to be as clean and accurate as possible to complement my down and dirty NYD one bottle 6SN7.

Each channel has a 5532 output, two "dual servo" 5534 input, and another quad surface mount for an insert that's hard wired into the circuit.  Here are the replacements I've ordered to play around with:

5534:
OPA827, OPA211, AD797, AD4627, AD8597.  Mind you I haven't paid for these parts, free samples are available through the websites.

I've ordered a whole list of 5532's, but that's outside of the scope of this thread.

I will leave channel 2 alone, and just mess with the 5534 on channel 1, and then record some results.  I'm the kind of person who can't hear the difference between subtle component changes, so I will be doing as much as possible to measure the difference.  I'll send the same pre-recorded track through each channel at the same time and record that back

I've already created SOIC to DIP adapters to stick in the sockets and tried out the AD797.  I couldn't tell the difference at all.  I wish I could tell you "it sounded more natural, more 3D, blah blah blah" but I'm going to be honest, I think all that stuff is malarky. 

Give me a week or two for shipping.
 
I have my own test rig for opamp swaps that I consider very trustworthy. It's a studiomaster trilogy mixer channel strip vs. another one. Audio goes through five stages of opamps doing different tasks: preamp, mid/high/low semi parametric EQ and several buffers for pan and fader.

A channel strip of course then goes to either group or master sum, again with several buffers and finally a line driver.

This isn't a perfectly scientific set up, but instead represents a common scenario where the choice of opamp voices a whole unit. You never have just one opamp stage in real life, like in the also trustworthy but unrealistic scenarios in Samuel Groners book. Instead you have 10!

I have learned that just swapping all opamps of a single channel strip paints a pretty accurate picture when voicing a unit. Let's say I browse to some opamp in SG's book that has obvious THD issues across all measurements, like OPA2604. I put five stages of this opamp in the channel strip. What do you think will happen? Yes, of course THD meters really light up. Soundwise we are in grain city and stereo sound stage becomes flat. "and wtf just happened to the treble?"

Not exactly subtle.

Browse to another page in Groners book where some opamp performs great across most tests. Now test rig THD meters will display nearly no distortion even when going through all stages. And then you find out sound is still lacking, or "why do I hear 2dB of more bass between these channels when they measure the same, but only have different opamps"?

Again, not subtle. But quite baffling! Maybe a better test rig would shed more light, but at this point I don't care and just pick the one that sounds best.

Testing single summing stages, or differential driver stages is more difficult in this mixers +10 opamps in series scenario, but one can make quite educated choices just by changing half of that chain.

The bottom line is, the choice of opamp will make a remarkable difference in sound.
 
Kingston said:
Not exactly subtle.

======

. And then you find out sound is still lacking, or "why do I hear 2dB of more bass between these channels when they measure the same, but only have different opamps"?
=====

The bottom line is, the choice of opamp will make a remarkable difference in sound.

Sam's opamp testing reveals how they work under ideal conditions and I would advise caution about trying to impute too much from how they measure in his tests to how they will behave in a given circuit. While an experienced designer will extrapolate and make predictions based on several different opamp parameters. 

The transfer function of 99.9% of opamps used in consoles is defined by negative feedback networks. There will also be secondary effects related to power supply quality, and even integrity of PCB layouts (crosstalk, ground corruption, etc).

There can be measurable deviation from the transfer function commanded by the NF networks if opamps are used with inadequate open loop gain for the NF closed loop gain commanded. The widely used TL07x can be marginal for OL gain at 20kHz if used at higher closed loop gains... The nominal benchmark measurements in Sam's overview does not reveal the whole story, of how they act in every circuit. Hypothetically substituting an opamp with more OL gain for a TL07x in a marginal design could improve compliance to the original NF network, but if the original designer tweaked that NF for flat with the TL07x, the new better opamp will now deliver too much gain at HF.

The vast majority of audible differences that are "not exactly subtle" are not exactly hard to measure either. Hook up a simple sound card with signal generator and metering to measure basic frequency response.. More often than not, "remarkable" sonic differences are very apparent in basic bench testing.  I have measured many differences that I couldn't hear, but never heard a difference that I couldn't measure, while back in the day I did dabble some in DIY test equipment, to refine my bench measurements well beyond what I could hear. 

Swapping out just the opamps without consideration for the components and other contributory factors around them can deliver variable results. A more scientific approach, should lead to more reliable forward progress. 

JR

PS; While not a perfect analogy swapping out opamps is a little like bolting better carburetors on a car motor. It may work better, it may not... Even a significantly better carburetor, without adequate fuel flow, increased intake valve lift, optimal ignition timing (a denser charge burns faster), manifold flow, etc. will not magically live up to it's capability.
 
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