Op Amps

[dBincognito]

Is there any benefit upgrading the NE5532P op amp to a SA5532AP op amp ?

Other than the higher temperature rating.

http://pdf1.alldatasheet.com/datasheet- ... 532AP.html

[Eric D]

In all reality there is no benefit to upgrading any op-amps in PG amps.

In these circuits the op-amps are ran with high feedback. Feedback helps keep the output clean and helps compensate for deficiencies in the op-amps.

If the op-amps were ran with no feedback, where the circuit relied totally on the quality of the op-amp, then upgrading them would improve the sound quality significantly. This is the case in a lot of DIY or premade esoteric headphone amplifiers on the market. Many of these headphone amps have no feedback, so the op-amp chosen is critical to the quality of the sound. There is actually much talk in the high end audio community about how feedback reduces the quality of the output. Some high end home amps are advertized as feedback free for this reason. So, putting a nice BB op-amp in a circuit with feedback may reduce the quality of the op-amp down to the original part.

Using feedback lets PG (any every other manufacturer) pick cheaper parts and have the same performance as more expensive items. Upgrading the op-amps is really more for bragging rights than anything else. It lets someone set their amp apart from the rest, while providing no sonic improvement.

[dBincognito]

Eric D
What are your views on using Black Gate caps...or Elna...something of that nature for the rail caps

[Eric D]

Eric D
What are your views on using Black Gate caps...or Elna...something of that nature for the rail caps

I have no views on that. Never used them, or heard the results of using them. I have no knowledge in this area.

I do know I like WIMA caps in PG amps (signal path stuff), because they look nicer, and stand up straight instead of getting mashed over.

[dBincognito]

There is 21 BA4560 op amps inside of a ZX450v.2

[1moreamp]

There is 21 BA4560 op amps inside of a ZX450v.2

Ask Dedlyjedly both of his Ti-500'4's have a complete BB compliment in them. Not a single JRC 45XX was left inside them.
I have A B'ed exact same amps before and after to my fellow tech's and blind tested and "every time" they picked the BB amps as sounding better in the mids and highs In there opinions. And every time they never knew which amp was which till after the sonic listening test.
I even know of another board member here that has redone his Xenon 200.4 with all BB op-amps, and as controversial as it may be I must say it did sound really smoother and cleaner on the highs. < and I own three Xenon 200.4's

I am not professing its is something everyone should do or even consider. But for those that were brave and in some cases financially well endowed I have never seen or had anyone ask me to reverse the change.
When you have 26 op-amps in the circuit path there is a bunch of room for improvement. Using the very best parts is never a mistake.

My personal feelings are that any company that can and does individually serialize there op-amps then guarantees them to meet or exceed spec's, well that sounds good to me.
Just ask PG or SoundStream or any other maker about how much incoming parts testing they do just to get a part qualified for use in production. Bumm parts exist everywhere. And rather then rework the final product its always smarter to part QC prior to build up. Its dome everywhere, even my best buddy that works for Agilent has to over see incoming parts QC. And they build the top of the line best of the best test equipment.

The use of Feedback corrects for nonlinear distortion issues, and ALL op-amps were designed by their makers taking into account for negative feedback usage. Its part of the CAD CAM design tools used to design this stuff < or did you guys think there are still using slide rules and what not
General Op-amp CAD design parameters include negative feedback. If your circuit does not need a high gain factor sure no negative feedback will work, and without negative feedback the Op-amp can and usually will introduce a tonality all of its on. Just like it would if it had negative feedback.
As for black gate caps and such all capacitors can influence SQ. There have been extensive blind test also for these mods but bear in mind almost any apple to orange change will cause a huge Sonic shift. Just because the different device acted differently in the circuitry. Electronics is not a cookie cutter type industry were as long as the part physically fits it will work correctly. And jumping from part A to part B without real world testing can create monster nightmares or circuitry instability and all sorts of other strange things.
Its sort of like saying let me put my chevy 350 in place of a dodge hemi. One it does not fit very well but even if made to fit how will it work together with the rest of the vehicle. Maybe great, and maybe 'oh Shit". Nothing should be done that can not be tested and approved to me proper operation...just my 2 cents worth.

Its expensive and if your hearing ability is not up to par you will never hear the difference, and as we all get older every bodies hearing drops off especially on the high end. Its all about the individual, especially when it comes to sonic perfection or imperfections. Whats good for some is useless for others....Have a great day...

[vin78]

Damn, C thanks for the monster response Awesome!

[GX3]

Its expensive and if your hearing ability is not up to par you will never hear the difference, and as we all get older every bodies hearing drops off especially on the high end. Its all about the individual, especially when it comes to sonic perfection or imperfections. Whats good for some is useless for others....Have a great day...

what did you say ......... i didn't hear you can you repeat that guess "they" were right


I guess BB wont make a difference for me .... I liked this CD way too much back in the day

[1moreamp]

Damn, C thanks for the monster response Awesome!

THX Vin ...

[Eric D]

I would love to see someone perform a double blind test to prove op-amp improvements are audible.

Until then it makes perfect sense for them to sound better, as no one would ever admit the additional money spent did not improve anything. We humans have a bad habit of justifying any of our purchases, even when nothing is gained. I will keep putting them in amps so long as people request them.

Great op-amps are just as much smoke and mirrors as silver speaker wire, and gold electrical outlets in home audio. And to think we then take these modified amps and put them in our cars, quite possibly the worst and most un-revealing acoustic environment known to modern man…

[BigBrent]

So, I want to put BB's in my M50. I can see that there are three op amps, hence the trilinear designation? Or are there two? I have three chips that have 8 pins, one I can't find any info on. 2 have the spec of RH5532N and RH412, and one has the designation of 2903D, JRC and 3091A. Can't find any info on the third. Are all three of these op amps? If so, what BB will drop in? Or are there only two op amps, the RHXXXXN chips? I am assuming too, that the smaller package chips (6pins) are not replacable or op amps? Thanks.

[Eric D]

So, I want to put BB's in my M50. I can see that there are three op amps, hence the trilinear designation? Or are there two? I have three chips that have 8 pins, one I can't find any info on. 2 have the spec of RH5532N and RH412, and one has the designation of 2903D, JRC and 3091A. Can't find any info on the third. Are all three of these op amps? If so, what BB will drop in? Or are there only two op amps, the RHXXXXN chips? I am assuming too, that the smaller package chips (6pins) are not replacable or op amps? Thanks.

There look to be three op-amps on the M50. The 6 pin devices are optio-isolators (maybe I spelled that right) which you should leave be.

All the op-amps are two channel or two circuits. The first is an input buffer for what ever drives your amp (headunit, EQ, line driver, etc). It also is likely the unit which handles phase inversion for one channel, so you can bridge the amps outputs. The next op-amp is either the bass boost or gain. It would work with one of the knobs on the amp (bass or gain) to adjust these features. The last is what ever the second is not, bass or gain, and it works with the remaining knob.

I use the op-amp below for all my upgrades. It is cheap but still has the BB name on it. If I were really serious about op-amp upgrades and money was no object, there are better units to pick from.

[Eric D]

Ok, I was wrong, there are only two op-amps in the signal path on a M50. On the board they are U101, and U201. I would believe these to be the JRC… parts.

[1moreamp]

PM me if you need options on BB replacements. I will share what I have found to work, and since there are ONLY two op-amps used by PG its really not a big deal, just don't get them mixed up or you can cause circuit instability, and a nice fuzz will appear on all your audio that pass's thru the amp....Sort of like a Linear Power amp does without BB op-amps....lol lol lol

[Eric D]

Cecil, I am going to go out on a limb here and try something. Now I know you and I have our differences, but I also know you have a lot more experience than I do or ever will, and you have an excellent understanding of these topics, probably more so than anyone.

Now recently there was a huge and heated discussion regarding capacitors on the forum. It remained civil and resulted in some insightful knowledge, especially for those reading to learn more about topics such as these. Maybe it turned out so well because I was not involved.

Now, based on your above posts you are a believer in op-amp upgrades. Based on my posts, I am sure you have guessed, I am not. I would like to have a discussion about this, and hopefully come to some conclusion.

The reason I am interested in this is that two or three years ago I would have been 100% on your side concerning this topic. I argued the point on this forum and others. Eventually I was bitch slapped by Thoraudio about the realities of electronics, and I have changed my perspective. He pushed the point that anything you can hear a difference in must be measurable in some way and that is now the idea I like to stick to.

By the way, welcome back to the forum.

[1moreamp]

Somebody "Bitch-slapped you" well it didn't work

Eric all differences aside, There is a huge upgrade urge out there in the real world. I was hesitant myself in the long ago past But I have seen ton's of rework done in 100's of different forums and the demand is there from the public.
I still refuse upgrades if I feel it is not in both my or the clients best interests.
But since a BB MS-275 with new caps can sell for $285.00 plus shipping I think even you will agree that is more money then a stock re-cap'ed MS-275

Now yes I would normally also want a O-scoped and distortion measured FFT analysis myself, if I was deaf and could not perceive subtle differences in tonality < Oh I was a music student most of my school life before I entered electronics, so I have the ability to carry a tune in a bucket >

I consider myself very lucky that even with my advancing years my ears still work pretty OK. I also look at the signal source available to the gear we are discussing here and I can't see some reasons for worrying about amplifier quality as all the sources especially MP-3 just "SUCK"

BUT, as I stated before the requests I have performed for others have all been A B ed by other people, just as a double blind against my OWN internal thoughts, and as I stated before I have NEVER had anyone ever ask me to undo any upgrade.
As I stated above this is a HIGHLY subjective issue, and my only desire is to share the INFO I have gained and to hopefully keep people from turning there high dollar amplifiers into AM/FM radio's.
Cause that what the audio signal looks like when you put the WRONG op-amp in circuit and it oscillates and whistles and whines and fuzz's up the audio signal < and its a bitch to find after its hidden with 25 other op-amps that got swapped all at the same time, think about that one cause I been there and got the TEE shirt, and it was not fun at all...

I have done several PG products successfully and YOU are aware of these in our past. You have also seen me post warnings about such things if you don't have the correct info and are doing something that someone else has not gone before you and debugged fully.. I am just trying to protect folks from themselves.. I am not passing any judgment on there decision to try and increase their product satisfaction nor am I trying to influence them and tell them that they can't hear the difference.

People are all different, some hear like cats and dogs and some can't at all. Just ask anyone that has asked me in our past and they will tell you exactly what I am saying here.

May I suggest you join me over on the DIY audio forum. There you will finds ton's of more info about this matter and meet some very smart and kind people like Steve Mantz and Nelson Pass, and loads of other audio people just like you and me.
TRU BB's there amps at request, That company that bought up Linear power BB's junky old LP products, and Eric you are a EE once you look at LP you have to agree that its about the junkiest car amp with only TO-3's being it salvation, and all their amps have 20 kilo-hertz and above fuzz all over the output < and people wonder how voice coils overheat

I started using BB op-amps back in the early 90's. I used OPA-2604's as D2A after filters along with some AD chips. We also modded Alpine HU's with BB D2A converters back then cause they sounded better then the junky stuff Japan was using.
Everybody built a add on D2A converter back then, even home gear and pro gear people did it, and it sold for top dollar...hum... sometimes you just gotta go with the flow Eric. plus back then the difference in the D2A's could be scope easily and also heard just as easily. Plus what was a extra $600.00 bucks when you just spent $20K in a car Stereo...

Its been a very long road for me Eric, but the client is always right... Peace.....

[dBincognito]

1moreamp

especially MP-3 just "SUCK"

I also would like to add to that statement.....it kills me to no end to have someone show me their SQ system while listening to a MP3 formatted song....that is just a giant oxy-moron......the quality you lose just going from WAV format to MP3 is huge......also, if you can find a HU that is capable of playing at a sample rate higher than 41000bps it is possible to render songs out at a higher sample rate.....the SQ gain from doing this is more than nominal......and I'm sure it would be measurable

[vin78]

I also would like to add to that statement.....it kills me to no end to have someone show me their SQ system while listening to a MP3 formatted song....

+1, convenience does not always = better quality.

Having +1000 songs are good for long road trips though.

[dBincognito]

Not a big fan of CD changers either.....but yes having MP3's are good for the long haul....I liked Kenwood's Music Keg they had

[Eric D]

I would never guess a customer would ask to have their BB op-amps removed because they were not happy with them. That we can agree on. I feel new op-amps is at least as good as stock, but not necessarily better.

I have personally upgraded many things with BB op-amps, most of which I have documented on this forum and others. Never once did I notice any sonic improvement at all. Now, that was my ears, and I have no measurement if they are good or not.

So I guess I want to see some numbers. I want to see before and after measurements showing improvements in something. To say something sounds better no longer holds any water for me, I need some sort of proof.

Also, if they were so great, why would the manufacturer not be putting them in initially? These parts are cheap, $2.50 each. In bulk much less. The additional $7.50 cost added to a MS275 for example could easily pay for itself and then some with some marketing.

Also, maybe I am missing something, but I get the impression you do more to the amp than just drop in some op-amps? If the circuit is properly designed, any pin compatible and spec compatible op-amp will simply drop in (well, solder in). There is not any real magic here.

I personally would be fearful of doing a full BB replacement on an amp such as a ZX450. There are so many op-amps onboard, and since these BB op-amps draw much more current than stock, I would guess that many of them would lower the reliability of the amp over time from additional stress on the 15V rails. In the case of a MS amp, the 15V rails are all ready stressed from the factory, and their zanier regulation circuit is prone to failure.

Lastly, this is more personally directed at you, but I am curious why you are "into" BB so much? It is somewhat widely known Analog Devices makes a superior op-amp at a similar price point, but AD has no where near the reputation BB does. To further this, BB has actually gone down hill in the last few years, and really is not what it once was. So, today BB op-amps are more marketing related than performance.

[Eric D]

On a somewhat related side note, Nelson Pass is my hero, my home amps are one of his designs, but as for Steve Mantz I have no respect for him or his work. Some of his amps are the most unreliable in history (we had countless problems with them back when I worked at Sound Buggy), and his latest complete disregard for the shipping of Vin's amps took any personal respect I had for him and flushed it down the drain…

[dedlyjedly]

I believe I heard a marginal improvement after Cecil got the op-amps swapped out and everything dialed in. Of course I also concede that psycho-acoustics can play a role in any listening tests that aren't performed in a double-blind manner. One must also consider the limitations of auditory memory when making comparisons back-to-back like I did. But that doesn't negate the fact it sounded better to me. In fact maybe it could even be used to support my belief that enjoying the music we love truly is an emotional and subjective experience!

I would definitely be interested in hearing and seeing the results of more quantified measurements and tests though. Also I would like to hear more about overcoming the additional current requirements of new BB chips as I know it was something Cecil had to deal with. I admit that a lot of his previous explanation of this subject escaped me and I'm always looking for more info to absorb concerning this hobby!

And I must say, thanks to both Cecil and Eric for recently returning to share your wealth of information and experience with the Phorum. Interesting technical threads have definitely been proportional to your amount of activity here. Gracias. That's quite enough of my layman interjection so......PROCEED...

[fuzzysnuggleduck]

Just wanted to agree with dedly's last statement.

Thanks for the good discussion guys, lots of things that I don't know a whole lot about but it's all very interesting and reading your opinions is helpful.

I commend the tone of this discussion considering the history here.

I too like measurements when I want proof. But I totally concede the emotional and subjectiveness when it comes to enjoying music.

[easy]

I even know of another board member here that has redone his Xenon 200.4 with all BB op-amps, and as controversial as it may be I must say it did sound really smoother and cleaner on the highs. < and I own three Xenon 200.4's

I can hear the difference of op-amps. As Cecil said, the high and the low are smoother and caught your attention first. Then the mid is cleaner and more definition.

I started using BB op-amps back in the early 90's. I used OPA-2604's as D2A after filters along with some AD chips.

One of the better op-amp IMHO. Very stable (from oscillation) and tonally correct to my ear. OPA2134 is good but not as good as OPA2604.
Pay close attention to V+ and V-.

I am curious why you are "into" BB so much? It is somewhat widely known Analog Devices makes a superior op-amp at a similar price point, but AD has no where near the reputation BB does. To further this, BB has actually gone down hill in the last few years, and really is not what it once was. So, today BB op-amps are more marketing related than performance.

Doc .... every op-amp manufactures or types have "Signature" sound (for lacking a better word). I used both (AD825 & AD826) long ago; they are laid back. BB is more lively and upfront (not in negative way i.e. harsh). LM6172 is also very very nice if you can prevent it from oscillating. I guess as long as your op-amp G = 1, then it is a bit harder to oscillate.
Many better op-amps are counterfeited. Maybe that is one of many answers that you do not hear the difference.

[neverman]

The obvious answer is to just buy amplifiers without op-amps. Discreet components for the win!

I'd argue the point that upconverting a song that was recorded in 41k to anything higher will buy you anything/nothing. It's not like video where you can fill in the holes and questimate the picture details.

You're actually introducing distortion to the original track if you encode it in any way, be it up or down.