Not our typical DIY thread....

[Alaric]

I was wondering about op amps. Specifically, compatible with the Burr Brown OPA2134. My motherboard allows the option of op amp rolling and I'd like to see what's up. The current op amp sounds great, for computer audio. It's the best motherboard audio I've ever heard, and was a primary reason for choosing it. Gigabyte used to offer a "Premium upgrade kit" that contained 3 op amps for this purpose but they're no longer available. The three were Analog Devices AD827JNZ, Linear Technology LT1358CN8 and Texas Instruments OPA2111KP. I can find these individually but I wanted to see if anyone here could add some experience, insight, or both to the situation before I start buying op amps. The pin out for the current op amp is below. Since some new Schiit isn't in the budget right now I thought this would be a relatively inexpensive upgrade path and fun besides. Thanks in advance for looking.

[BobEllis]

Data sheets are your friends. That's a standard dual op amp pin out so the connections are the same. The AD and LT have bipolar inputs, while the BB are jfet. Normally you'd design the input circuit with a bit lower resistance with bipolar than jfet to minimize offsets. Also, the AD and LT are faster chips, so more care must be taken to avoid oscillation. Since Gigabyte offered the chips as options it is probably safe to assume that they are properly bypassed for the higher speed chips. The question then becomes how did they handle input biasing and output offsets. I suspect there is a nondescript electrolytic capacitor in series with the output to block any DC. That could have more impact on sound quality than the output buffer chips.

That said, for a few bucks it's worth a shot to see if you can hear a difference (hopefully for the better). All you need to do is pull the old chip and drop in the new. There's also a National Semiconductor dual that people like at DIY Audio. It's really fast and may be too fast for your board layout, though.

Audibility will depend on the rest of your system. I used to use an active crossover that had TL082s and putting that in line noticeably degraded the top end. When I built the same circuit with OPA2134s I didn't notice a loss of quality with the filter in the circuit. That was before my Ardents, though. Back then I wasn't sure if I could hear the difference between power amps and now it's very clear.

Have fun and let us know what you hear, if anything.

[JonMarsh]

Bob is right on the money with his comments.

It's VERY important that the board layout and bypass can safely support "upgraded" op amps with their wider bandwidths- otherwise, oscillations and ringing on transients can result.

One issue to be aware of is that many of the newest high performance op amps may not be available DIP8 anymore, if that is the package type used on your MB. SMD types of course require adapters or soldering to replace.

The LM4562 is my current favorite in moderate/low cost dual op amps; the 44V rail version, the LME49860 is similar, but handles rails up to +/-22V, but they may be going end of life due to low demand. I have some stock just for future projects.

Another one to check out is the OPA1612, if you need really low input noise (1.1nV/rootHz). Of course, that's of no value a conventional buffer where the noise performance of the resistors may dominate. It also has a lot of output drive. Only available in a small SMD package.

[Alaric]

My motherboard actually has some nice looking gold Nichicon caps in the audio section, but I couldn't tell you about the resistors. The op amps Gigabyte used to offer go from 8 MHz to 50 MHz bandwidth, so I'm hoping I can sneak the LM4562 in for a listen. For $30 I can try the LM4562, OPA2111 and the LT1358 from Amazon. I'm not expecting any huge differences, and from what I gleaned from researching this I'm going uphill to improve the op amp in the board now. While the mobo has a better than average audio section, it is still a mobo audio section. But, it's low budget fun and maybe I'll learn even more than I have already. Thank you both for the input!

[BobEllis]

Take a look at Mouser and Digikey - they may have better pricing than Amazon.

[Alaric]

I went with Digikey. I have a LT1358, OPA2111, and a LM4562 coming. Should be interesting!

[5th element]

All of these opamps should be sonically transparent, but ignoring that for a moment, it's interesting to note that the LM4562 (and the entire range that it's from) were designed from the ground up for audio reproduction.

[Zvu]

EDIT: wrong op amp

AD797 looks quite nice (although not dual). AD8599 also.

[5th element]

AD797 requires quite specific attention, in terms of layout and surrounding components to work without oscillating.

It's usually not suitable for opamp rolling unless your circuit happens to work with it.

[Alaric]

And the AD8599 is SOIC, and I'm not sure if that will work with my mobo. All the op amps Gigabyte deems "compatible" are PDIP.

[Zvu]

I threw few op amps that are low noise and might be well suited for audio aplication. Jon mentioned OPA1612 with input noise of 1.1nV/rootHz, in AD797 it is 0.9nV/rootHz so it might be interesting. My comment wasn't ment to offer a replacement for your op amp on your mother board - sorry for not making that clear in my post.

There are adapters soic to dip though, if that's the only obstacle for trying it.

@Matt:
Have you worked with AD797? My friend will try something quite simple with it (his words) as a preamp.

[Alaric]

I threw few op amps that are low noise and might be well suited for audio aplication. Jon mentioned OPA1612 with input noise of 1.1nV/rootHz, in AD797 it is 0.9nV/rootHz so it might be interesting. My comment wasn't ment to offer a replacement for your op amp on your mother board - sorry for not making that clear in my post.

There are adapters soic to dip though, if that's the only obstacle for trying it.

@Matt:
Have you worked with AD797? My friend will try something quite simple (his words) as a preamp.

I didn't take it that way, so no worries. I wasn't aware of the adapters you mentioned, I'll definitely look in to them. I don't expect huge differences between op amps, but so much is dependent on the supporting circuitry and outboard gear, as well as circuit design, that I'm keeping an open mind. I have a rather small listening area and (large) 91db sensitivity speakers that are quite detailed and sometimes border on forward. They're fed by 25 watts of decent Class A amplification, and the combination seems to be pretty good at reproducing what goes in to it, warts and all. I have been quite impressed by the sound quality of this motherboard (for a motherboard, anyway) so far. I will still end up with a Schiit Modi Uber but I'm hoping this adventure with op amps will at least entertain me until then, if not make the wait a little more pleasant. I still want to get a Analog Devices AD827JNZ if finances allow this month, too. It may be too "in your face" with my speakers, from the description, but it's supposed to be one of the more noticeable differences.

[BobEllis]

A suggestion that you might consider saving up for bigger step up than the Modi Uber. I've got a Schiit Modi Multibit, it was a big improvement over the DAC in my Oppo BDP-103 and computer. Even my girlfriend noticed the improved clarity. Jon put it on the bench, for the price it did quite well but has some zero crossing glitching. It seems to be a Schiit Multibit thing, even Yggy has it to a lesser extent than Modi MB but still there. On Jon's recommendation I got a Cambridge 851D which is another significant step up. Probably not as big a step per dollar as the Schiit is, but that's the diminishing returns curve. The Modi MB now resides in my desktop system.

[Wayne1]

If you are willing to invest a little bit more money in op-amps, you may want to take a look at the discrete op-amps from Sparkos Labs

I have used them as replacements in a couple of DAC output sections and I have been very pleased with the results.

[Alaric]

A suggestion that you might consider saving up for bigger step up than the Modi Uber. I've got a Schiit Modi Multibit, it was a big improvement over the DAC in my Oppo BDP-103 and computer. Even my girlfriend noticed the improved clarity. Jon put it on the bench, for the price it did quite well but has some zero crossing glitching. It seems to be a Schiit Multibit thing, even Yggy has it to a lesser extent than Modi MB but still there. On Jon's recommendation I got a Cambridge 851D which is another significant step up. Probably not as big a step per dollar as the Schiit is, but that's the diminishing returns curve. The Modi MB now resides in my desktop system.

I looked at the multibit, but wasn't sure how much better it would be. The Cambridge is nice (cost/budget ratio aside) but we're getting towards the high end for my rig there. LOL.

If you are willing to invest a little bit more money in op-amps, you may want to take a look at the discrete op-amps from Sparkos Labs

I have used them as replacements in a couple of DAC output sections and I have been very pleased with the results.

I'm intrigued, but an $80 op amp!? Which op amps did you replace, and can you tell me what changes you noticed with the Sparkos Labs units?

[BobEllis]

Renron did a comparison between my Modi MB and his inexpensive DAC that uses the same chip and Jon benched it http://www.htguide.com/forum/showthr...eeze-Audio-DAC Of course it is the implementation as much as the chip, but after rolling the buffer op amps and thinking his sounded quite good, he said the Modi MB was a healthy step up. He ended up going about the same level as the Cambridge, Ardents resolve so well everything in the system matters. Of course YMMV, but I think the step from Uber to MB is likely still in the big returns part of the curve.

Given Wayne's experience I assume the Sparkos discrete op amps are unity gain stable, but they don't specifically say that on the product page. That causes some concern in an output stage buffer, which is typically a unity gain position. EDIT: The data sheet shows a unity gain case in the typical applications.

[Alaric]

Ardents resolve so well everything in the system matters.

I haven't heard the Ardents, but I assume they're a step or two up from my Paradigms. LOL. My speakers aren't too shabby at revealing what's fed them, good, bad or indifferent, though. I would say my amp is the least strong link in the chain. I'll have to think over $80 op amps, however. After researching further I discovered Dexa, Burson, Muses, and NewClassD as well. By the time I got done rolling the big boys in the field I could have bought a Multibit. I was just looking for a little fun and if lucky a slight bump up until the Schitt is in the budget. I'll definitely report back when they get here and I get a chance to try them out.

[Wayne1]

I have tried out many flavors of op-amps. It usually depends on the circuit. LT1364 is a nice smooth sounding unit. I have used AD-797 with adaptors as well as LME49990. I have tried out Burson and Dexa discreet op-amps. For what I like to hear, the Sparkos sounds the best with the rest of my system. For me the price was worth it.

[5th element]

Discrete opamps are just a joke as far as I'm concerned and it's as if to say the process of making/using an IC is somehow going to 'ruin' the sound. Of course what passes most by is that the processes used to make discrete transistors, and the like, are the same ones used to fabricate the ICs themselves. Silicon substrate with a wire bonded frame.

Going IC brings about many inherent linearity gains in that you significantly reduce parasitics, end up with excellent matching between the internal transistors and because the entire amplifier is contained within a tiny space, you reduce its susceptibility towards picking up any airborne interference.

It's the fact that the entire amplifier is compact and self contained that allow for the ludicrous technical performance that modern opamps can provide. It's a benefit, not a detriment.

Yes I have used the AD797 and it's a lovely device. All precautions necessary for using it in correctly are detailed in the datasheet. It's not difficult to use, as per say, it's just not suited to opamp rolling because it needs attention paying to its application (unlike lots of others that are unconditionally stable, in most circuits, in their stock form and can drive capacitive loads till the cows come home).

[Wayne1]

Here is a picture of the current output section of my DAC



It was designed for LME49710. I prefer the sound of the Sparkos.

[Alaric]

it's as if to say the process of making/using an IC is somehow going to 'ruin' the sound

The Devil is in the details. So is sound quality.

It was designed for LME49710. I prefer the sound of the Sparkos.

What DAC are you using? I haven't found out what DAC chip my mobo uses yet, but I imagine there are some synergy issues at work in every system that just "works".

[Wayne1]

It is a DIY effort. JL Sounds I2SoverUSB feeding JL Sound AK4490 DAC board into the analog section.
USB and DAC boards powered by separate Salas Reflektor shunt regulators. Analog board fed by Salas BIB shunts powered by separate toroidal transformer.
The digital regulators are fed by separate R core transformers.

I will try to post some photos of the whole thing later.

[Alaric]

It is a DIY effort. JL Sounds I2SoverUSB feeding JL Sound AK4490 DAC board into the analog section.
USB and DAC boards powered by separate Salas Reflektor shunt regulators. Analog board fed by Salas BIB shunts powered by separate toroidal transformer.
The digital regulators are fed by separate R core transformers.

I will try to post some photos of the whole thing later.

Nice! I've never gotten in to DIY speakers because I lack equipment and ability in woodworking. I'm definitely able to solder, though, so I'd love to see your build. Jon claims to be more of a "sparks and wires" DIY guy, but looking at his photos of the cabinets for the Ardents makes me believe there is a lot of modesty there. Those things are gorgeous.
I may have to do some DIY on my SACD/CD player soon. The disc read error problem is getting out of hand lately. The laser is out of production and I need to see if the resistor mod was done at the factory. It may have been, since I have a late production model of the SA8260.

[Alaric]

Got my op amps in! Sort of. After almost wrecking my 2134 taking it out I won't be changing the 4562 out until my IC puller arrives Sunday from Amazon. I do have some observations on the 4562, though. After spending the day with it I know the 2134 won't be going back in. I think the noise floor is a tad higher than the 2134's but the trade offs are well worth it. More detail without it sounding busy or disjointed, a little more laid back, and just plain more accurate sounding-in my set up. I have no idea how things would play out in any other set up. The Realtek chips in all my other motherboards were just awful. Flat, one dimensional, like a poor drawing of music. The combination of the Creative Labs chip and I assume (uh oh) the decent op amp made this mobo a huge improvement. A real soundstage, etc..

The big step up allowed me to overlook what the 4562 brought to the forefront-the 2134 was too forward, bordering on harsh at times, and a mite "shouty". Even my girlfriend heard the difference between the two, and she's happy listening to Pandora on her phone. The backing vocal track on Sheryl Crow's "I Shall Believe" was suddenly much easier to discern but no louder than before or more pronounced, but now easily distinguished as a separate voice. Sheryl Crow's voice is smoother, louder passages don't sound like she's straining anymore. Cymbal decay is much better and bass is cleaner and more detailed. Queen's "Fat Bottomed Girls" isn't nearly as well done as my Sheryl Crow album (Tuesday Night Music Club) but the improvements are just as easy to hear. The pronounced bass lines on the track are detailed and crisp, and the chorus sounds like voices singing instead of a clump of voice. Finally, Lou Reed's "Walk On The Wild Side" from the Transformers album is once again a masterpiece. Herbie Flower's bass strings can be clearly heard vibrating, but again it isn't an intrusive distraction, just a natural part of the performance. The wonderful saxophone on the track is unfortunately still a little punishing through my computer. My amp and speakers are very good to horns on CD and SACD, but the DAC in my motherboard just isn't there. It has the same problem with the horns on Natalie Merchant's "Break Your Heart", but handles the percussion and Natalie's voice on "Jealousy" with ease and manages to keep the track from sounding congested, while keeping the plethora of instruments right there in the mix.

I am aware my post makes it look like I can stop saving for that Krell and Von Schweikert gear because I bought an op amp. Not quite. The differences are mostly subtle, with the exception of the improved coherence and placement of the instruments on the soundstage. The fact that those things were noticed by someone who wouldn't spend more than $20 on speakers, ever, was surprising to both of us. I'm listening to The Hollies "Long Cool Woman" as I type this and this is why it's one of my reference songs. I'll have more when my tool arrives and check out the rest of my toys.
Cheers!

[BobEllis]

Welcome to the Dark Side. You'll now be seeking the next level of improvement for the rest of your life, often at the expense of things that make more sense.

It always amazes me when people who don't pay much attention to sound quality notice, especially without prompting. A friend with a nice HT video setup kept telling me he wouldn't be able to hear the difference if he upgraded his sound. Then he heard my Ardents and now he gets it. He still hasn't cracked open his wallet, but he knows what he's missing.

[Alaric]

It seems I won't be getting to the rest of them until Tuesday at the earliest. My IC puller has apparently run in to a snag with Amazon. My Sunday delivery is now Tuesday. *sigh*

Welcome to the Dark Side. You'll now be seeking the next level of improvement for the rest of your life, often at the expense of things that make more sense.

Oh, I've been an Audio Sith my whole life, going back to my Tandberg/Nakamichi/ADS rig in the mid 80s. Budget is definitely my only impediment. I still have a 17 year old daughter and a fondness for food and living indoors, all three of which have to come ahead of toys and obsessions. If I should find myself the a PowerBall winner I will spend millions in search of aural nirvana. I always wanted to hear some Goldmund amps in a home environment....and a pair of Luxman bf1000 would be nice for the bedroom!

[Wayne1]

So as not to hijack this thread any longer,
I started a thread about my DAC build over on Digital.

DIY Modular DAC Build

[Alaric]

I don't mind the hijack, but after seeing your DAC it definitely deserves its own thread.

[Alaric]

And Amazon screwed up yet again. Still waiting for my IC puller. I should have taken a bus to Fry's and gotten one. :M

[BobEllis]

I use needle nose pliers.

[Alaric]

I tried that, and almost destroyed the thing. It was a tad snug, to say the least. It should be here tomorrow. And after more reading, I'm probably going to go ahead and get a AD827JNZ. After that I'm looking at a big price increase I can't justify when I can get a half decent DAC for under $300.

[5th element]

Usually ICs aren't that difficult to remove from sockets, but this is when you've installed the IC yourself. I'm guessing that you may have had difficulty because the IC was factory installed and probably pushed in to an extreme that made is very difficult to remove.

Needle-nose pliers or a good pair of tweezers usually work. Often I'll take a very small flat head screwdriver and place it under the IC and lever it out, that's if there's space.

I'm surprised that you found the 4562 noisier than the 2134. I can't see any reason for this, except for the input current differences as the 4562 is a BJT device and the 2134 a Jfet. The 4562 therefore has much higher input bias currents and this would increase noise if large resistors were used in the opamp circuit, but using large resistors isn't customary as it usually increases overall noise and susceptibility to noise pickup.

[Alaric]

I'm guessing that you may have had difficulty because the IC was factory installed and probably pushed in to an extreme that made is very difficult to remove.

I'd say you're spot on with that.

I'm surprised that you found the 4562 noisier than the 2134. I can't see any reason for this, except for the input current differences as the 4562 is a BJT device and the 2134 a Jfet. The 4562 therefore has much higher input bias currents and this would increase noise if large resistors were used in the opamp circuit, but using large resistors isn't customary as it usually increases overall noise and susceptibility to noise pickup.

Or it makes the motherboards noise more audible? Or, more likely, I can hear the noise in the recordings that wasn't as discernible before. I can't see most of the audio section of the board because it has a plastic shroud over it, and removing that requires pulling the motherboard, water pump, etc.. The 4562 is more laid back, which I seem to prefer over the 2134's presentation. That would be an evolution in my preferred listening style. I originally got (and still love) my Paradigms for their forward and detailed sound. But, I picked my amp to temper that somewhat so I would get the detail without the harshness. The 4562 seems to fit better with my gear/preferences. I'll try the other two tomorrow and see how they sound. I'm interested in the OPA2111. I'm curious as to whether or not it shares anything with the 2134 besides the manufacturer. I still want to try an AD827, but I'll have to order one first. After that I'll be saving up for some Schiit. Maybe all these op amps can be re used for some fun with a Modi!

Update: I'll have to go back and listen to the 2134 again. After getting the Creative software program completely off, several things have changed. Horns once again sound very good, bass extension is much lower and more pronounced, and cymbals are much cleaner with a more natural decay. Tomorrow I'll finally have time to roll some op amps and see what's what.