The Opamp thread

[Themilkman46290]

What other opamps did you compare those with?

Ad8066,ad825,opa2134,opa2132,ad823,muses8920,lt1364,opa827,lme6172, the ad825 and 823 would be my favorites aftar the v5i and lme49710ha

 

[HeyManslowdown97]

One pair of SS V6 duals costs about 130 USD, a pair of dual Sparkos costs 160 USD and a pair of Sonic Imagery 994Enh-Ticha Dual 188 USD! So, quite expensive, although the Burson still provides the "cheapest" high-end solid-state opamps, after all.

BTW, I asked once NJR/JRC why the MUSES01/02 are so expensive? They nicely told me that it's not just a simple marketing gimmick, but more related to the production costs, because MUSES01/02 (and newer 03) are manufactured on their own dedicated production line, apart from regular opamps, and using a different Q&A process. All of the above are delaying a lot the time to manufacture each of these products, hence the much increased price.

A well-designed DAC or amplifier, with a very good ground plane and a low-noise power supply should perform admirable with most audio , starting from NE5532/5534 (also, I recommend JRC5532DD/JRC5534DD, which outperforms the NE5532/NE5534 in all aspects) to OPA1622, OPA627, AD797 or similar.

Great stuff and good to know about a well designed DAC and how op amps performances and with very good ground plane and power supply. I know the importance of this!!! Great Basic electrical principles go a long way!

Will try the JRC5532DD/JRC5534DD but like I said I’m cheap. Haha

 

[raoultrifan]

like I said I’m cheap

Let's call this...frugality, OK?

AD8599, AD797 should fit the bill. Also, might worth testing MUSES8920 if you don;t find it very expensive; it should work fine in I/V and LPF and VoltAmpStage.

 

[scruffy1]

raoul, may i jump in and pick your brains ?

i run a xonar hdav1.3 in the htpc, to a nad d3020 driving a 2.1 wharfedale setup (diamond 10.1 + 10dx)

the xonar had a dual opa627 in the primary, and then a dual v5i, which was even better (replacing the supplied LM4562NA)



the burson v5 sounds "wrong" as a component, whereas the v5i is the pinnacle of my available combinations - hard to describe, but the stage is great, but the music sounds like it has compression artefacts ("breathing" levels) - running mostly flac files

why is it so ?

and it has (2x) JRC 2114D in the secondary slots (IV); i tried a pair of ad823anz (of questionable parentage) which i thought had "better" specs than the 2114d in the situation, but the distorion was horrible - is this a reflection of my ignorant choice, or rather a confirmation that they are fake ?

is there an iv choice for the hdav that might enhance the rca out quality, or have a better synergy with the v5


as it stands i reckon the burson play is beckoning, but i am happy for the frugal alternative if such a beast is available

cheers

 

[HeyManslowdown97]

“the burson v5 sounds "wrong" as a component, whereas the v5i is the pinnacle of my available combinations - hard to describe, but the stage is great, but the music sounds like it has compression artefacts ("breathing" levels) - running mostly flac files.”

I actually think this makes a lot of sense and am curious as to why this is as well. I’ve experienced this “phenomena” when you mix up combinations of op amps and always wanted to know why that is??!

@raoltrifan

Slightly off topic but I couldn’t help notice your Grados in your aviator. They make them in Brooklyn, New York (where I am from) I’ve heard nothing but great things from guys who make them.

Not really that “frugal” just new at this so I like to discover as many op amps as I can to get an overall arch of sound. My sound isn’t “fixed” per se. I’ve heard nothing but great things about Bursons. I’ve seen them on their eBay store that they offer pretty nice DACs from Gustard, etc with their op amps for a reasonable price as well!

 

[raoultrifan]

Hi @scruffy1, just found your post: https://www.head-fi.org/threads/the-opamp-thread.432749/page-346#post-12642543.
I can't find pics with your card; instead, I found the slim version, but this has no I/V stage and is using https://www.cirrus.com/products/wm8776/.
You need to do RMAA or ARTA tests to see what opamps are getting the lowest THD+N. After that, do listening tests.

 

[scruffy1]

hi raoul

thanks for your reply

the thread you are seeking is this :
https://www.head-fi.org/threads/the...ressions-thread.421890/page-354#post-12644745

to my limited comprehension, the hdav is essentially the stx - full specs and review here :
https://www.pcper.com/reviews/Gener...V-13-Deluxe-Review-Penultimate-HTPC-Soundcard

- but with provision for a 7.1 output daughter card for home theatre (which also features swappable dip sockets for all the channels), and no discrete headphone connection, which is where i thought the iv slots may have actually come into play

from my experimentation it is clear they influence the rear rca outs (to the nad)

apologies for my ignorance, rmaa and arta are acronyms with no prior meaning to me, but google is my friend and i will have a look
are they essentially equivalent ?

my problem is not being educated enough in electronics to interpret the spec sheets for opamps; the best i can do is see the voltage ranges at which they are rated, and then rely on reports from other users as to their virtues - that's why i am keen for practical recommendations for which choices


add to that the recent acquisition of a pam an headphone amp (with vostok and rtc "new old stock" tubes to try out), and i am overwhelmed with lovely acoustic toys to figure out; i must say tubes are another great experience but not sure better, just different and really good

 

[raoultrifan]

@scruffy1, based on http://nihtila.com/2017/01/08/pcm1794a-output-stage-opamp-measurements-lm4562-ne5532-and-opa2134/ I would use 5532 chips in I/V or the original JRC2114D; as per LPF, LM4562 is just fine.

Without measurements, just based on listening tests, I can't recommend you any upgrades, sorry. Reasons would be:
- lack to identify if oscillations or post-ringing occurs
- THD could increase if incompatible opmaps are used

It's all in the PCB layout and power supply rails quality, so sometimes very good and expensive opamps might work worse in some situations.

 

[HeyManslowdown97]

“It's all in the PCB layout and power supply rails quality, so sometimes very good and expensive opamps might work worse in some situations.”

Man this is sooo true. I’ve come up with the same conclusion!

 

[HeyManslowdown97]

@raoultrifan

Hey- I really like your approach to fundamentals especially when it comes to testing for op amp performance! I had a hunch that better op amps with crappy electrical input and output actually sounds worse and I’m glad that you have confirmed it for me with your knowledge. (Save me time- hypothesizing).

When it comes to “well built” Dacs and op amps some even really great manufacturers cut corners on the smallest things like LDOs, Supply Relays, diodes, etc because adding them with licensing can add up. So a part that’s slightly cheaper like < cents adds up when mass market. Ultimately if you can gain the skill to make your own evaluation boards that’s best course of action.

(Some of the DIY Audio post and threads have amazing ideas and concept by DIYers which pretty rad in the age of the internet of things. However, some information should be taken with the a grain of salt).

I bought a multimeter but don’t know how to use it. Is there one you can recommend that checks everything (that’s preferably “frugal” ).

I think it’s fun to learn more about this stuff but there are definitely a lot of fits and triumphs along the way.

Honestly, in this thread I really can’t make an accurate evaluation of op amps since to-date I really don’t have top-notch gear to make an accurate assessing to what op amps to recommend to anyone only my ears to go by but I DO enjoy learning from others’. In my very limited Modding experience I’ve learned that it really humbles you (more so than what people say in threads!)

 

[raoultrifan]

I bought a multimeter but don’t know how to use it. Is there one you can recommend that checks everything (that’s preferably “frugal” ).

I think it’s fun to learn more about this stuff but there are definitely a lot of fits and triumphs along the way.

If it's a RMS-multimeter, then you could measure the AC output voltage when feeding the DAC or amp with 0dB (or -1dB) 1KHz sinewave. Usually around 2V RMS for DACs and more voltage for headamps, of course.

Also, DC-output voltage could get measured as well, no music connected, no cables connected to RCA/XLR/jack inputs. Usually if lower than 3mV of DC voltage should be fine for most 16-32 cans; for 300-600 Ohms cans it could be higher, but not more than 10-20mV.

You could get a cheap ADC like the one built-into ASUS U7, but also a cheap Behringer UMC204 or Focusrite have a good ADC inside too. Then you can start doing some RMAA and ARTA test too.

Basically, with the above simple tools you could identify some flaws in the audio equipment and, why not, some differences between opamps (when swapping them). For more in-depth analysis you need something else, at least QA401 from Quantasylum.

 

[HeyManslowdown97]

If it's a RMS-multimeter, then you could measure the AC output voltage when feeding the DAC or amp with 0dB (or -1dB) 1KHz sinewave. Usually around 2V RMS for DACs and more voltage for headamps, of course.

Also, DC-output voltage could get measured as well, no music connected, no cables connected to RCA/XLR/jack inputs. Usually if lower than 3mV of DC voltage should be fine for most 16-32 cans; for 300-600 Ohms cans it could be higher, but not more than 10-20mV.

You could get a cheap ADC like the one built-into ASUS U7, but also a cheap Behringer UMC204 or Focusrite have a good ADC inside too. Then you can start doing some RMAA and ARTA test too.

Basically, with the above simple tools you could identify some flaws in the audio equipment and, why not, some differences between opamps (when swapping them). For more in-depth analysis you need something else, at least QA401 from Quantasylum.

Thanks and also for recommendations as well! Just cut and paste your info to thoughts in review it later in my NOTES.

How about measure resistors, diodes. Is it the same. Im gonna have to watch some videos on how to read the multimeter. It’s such an essential tell to keep in the tool box rather than “winging it” every desoldering and soldering of components!

What your thoughts about on the AD8620??? Is it a good idea to put it in lpf??? or can you recommend a sop8 Dual channel op amp for limited spacing?!

Don’t laugh but got a “electronics for dummies” book to read later as well. Lol.

 

[raoultrifan]

What your thoughts about on the AD8620??? Is it a good idea to put it in lpf???

Yes, why not? As long as it's not oscillating I don't see any issue.

Worth mentioning that AD797 (single) and the newer OPA1612 (dual) are extremely low-noise opamps and for high-gain stages (like voltage amplification) might really worth a try. Also, the I/V stage could be tested as well.

 

[HeyManslowdown97]

Yes, why not? As long as it's not oscillating I don't see any issue.

Worth mentioning that AD797 (single) and the newer OPA1612 (dual) are extremely low-noise opamps and for high-gain stages (like voltage amplification) might really worth a try. Also, the I/V stage could be tested as well.

I have heard nothing but good things about Opa1612 and I didn’t know they upgraded it.

Really like the Opa2192. It’s just a nice overall op amp for the price (IMO).

So what you are saying is oscillating as that’s what the clock is for?? So it isn’t a good idea for the lpf to have any CMOS op amp in the the early stages?

I’d love to put the AD797 in the lpf if I could figure out a way!!!

 

[raoultrifan]

By newer I meant...newer, because OPA1612 is a newer design then let's say NE5532 or even LM4562. OPA1612 is one the most low-noise opamps ever built, so totally recommended for unity-gain stages (LPF or output stage of a DAC, but also I/V stage too).

You should be able to find single-to-dual DIP8 adapters for mounting 2xAD797 on a DIP8 socket.