Op Amp Rolling

[NTTY]

12 years ago I tested some op-amps I had lying around in a C'Moy (including rail splitter)

Portable op-amp headphone amplifier test

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Very interesting! Thank you for sharing

 

[Bartez2000]

I'm very glad to have discovered that page with all that software on it.
I can already see how much fun I'm gonna have with that harmonics VST lol.

That Audient (it's the older model from 4-5 years back) has 1-line level input.
Here is a picture of said input:

Can't wait to nerd out with DeltaWave and Multitone.
Thanks @pkane for making such software available for us poor audio techs.

However, we did not get any measurements with and without the op amp.

 

[quocheiser]

Hey @Bartez2000 still planned for 2025. I've been overseas due to a family bereavement, 2024 was a crazy year.

 

[quocheiser]

You didn't really think @quocheiser already had measurements, did you? That was an EQ to compensate for "veils lifted".

@quocheiser:
IF there were a significant difference that would be a strong hint for bad things (like oscillations) going on.

Btw, the sardonic tone on this forum surely puts off lots of people who are here to educate themselves and also enjoy the hobby.
I must have let this "veils lifted" comment slide as I tend to turn the other cheek, but now you're just putting words in my mouth which is really uncool.

 

[quocheiser]

An addendum to this thread that I posted rather on the Fosi Community forum that sums up why I won't be bothering to measure differences in op-amps in my system https://community.fosiaudio.com/threads/op-amp-roll-zd3-or-za3.5450/post-6133

Thanks to everyone kind or helpful when responding to my original post in this thread. I've saved a lot of time and energy due to your knowledge.

 

[I’mthedudeman]

Ah yes, the Sparkos SS3602 ended up being my preferred op amp in my VTV Purify Stereo amp with VTV I/O buffer board after trying several different op amps. BTW, those I tried included the Burson V6 Vivid which I found a tad warm and slightly lacking in detail.

Did you try the Sparkos 2590?, just curious

 

[Gorgonzola]

Did you try the Sparkos 2590?, just curious

No, only the SS3602. But I note the VTV I/O I used will accommodate the "professional" form op amps.

 

[olds1959special]

What the MUSE02 does for music is exquisite! I tried the Sparkos again and found that it has a bright edge and bass boom, while the MUSE02 has an incredible musicality to it. The sound is smooth and silky!

 

[JSmith]

What the MUSE02 does for music is exquisite! I tried the Sparkos again and found that it has a bright edge and bass boom, while the MUSE02 has an incredible musicality to it. The sound is smooth and silky!

JSmith

 

[olds1959special]

View attachment 464605


JSmith

I admit my perception changes all the time. I have been going back and forth between the Sparkos SS3602 and MUSE02 op-amps in my Fosi P4's in both my systems and I prefer the warmer sound of the MUSE02 (today.)

But I think it is a silkier, warmer sound that has a specialness to it that the Sparkos doesn't have. There is a little bit less dynamics (slightly compressed sound) and detail is presented in more diffuse way.

Sorry for being subjective. Here's a more technical explanation of the specifications of the op-amp. Note the low crosstalk and high bandwidth.

 

[solderdude]

op-amp rolling.... it keeps on giving ... because ...

I admit my perception changes all the time

 

[JSmith]

my perception changes all the time

Yes it does and you're brain is reaching to find this difference you seek that doesn't really exist.


JSmith

 

[solderdude]

And his brain seems to be doing a very good job at this too
It appears @olds1959special is as human as humans can be.

 

[antcollinet]

What the MUSE02 does for music is exquisite! I tried the Sparkos again and found that it has a bright edge and bass boom, while the MUSE02 has an incredible musicality to it. The sound is smooth and silky!

I admit my perception changes all the time.

You should check your underwear. I'm pretty certain that is what is changing the sound for you. Try correllating what you are wearing with your sound perceptions. Cross check underwear choice combined with currently selected op amp. I think you'll find the results revealing.

 

[Schlippwhip68]

In the review of the Fosi V3 (Fosi Audio V3 Amplifier Review), Amir wrote “There are replaceable op-amps for those of you who have nothing better to do than mess with the design.” For those who want to do just that, it is difficult selecting which op amps to “roll with”.

Both the Fosi V3 and the Aiyima 07Max (and now Fosi ZA3) use NE5532 chips. Perhaps the first move is to drop in a chip from the same series but with a higher specification, and, as suggested in other threads elsewhere, purchased from Mouser or Digi-Key.

Moving on, there are many DIP-8 op amps to choose from, although many from Texas Instruments in this particular packaging are now marked as “End of Life”. As ASR thrives on numbers, what are the most suitable op amps to drop in as replacements for the NE5532, based purely on the specification sheets?

Texas Instruments identifies op amps considered suitable for audio applications: see https://www.ti.com/amplifier-circuit/op-amps/audio/products.html#. This list shows 71 products, with 14 chips in the DIP-8 package. Other forums provide additional suggestions, and the Mouser database provides yet more possibilities.

File 1 (attached) provides a list of possible drop in replacements for the NE5532, where the pin-out and supply voltages are compatible. Measurements such as THD + Noise and CMRR are high on the list and other measurements such as overshoot and settling time may be important for audio applications.

It is also important not to use an op amp that has high gain and/or classified as high speed, as this may lead to ringing and possibly the overall amplifier itself becoming unstable.

File 2 (attached) provides a rough “order of merit” under each of the parameter headings from File 1. The figures suggest the chips to start with would be the LM4562NA/NOPB and LME49720NA/NOPB.

One surprise from this list is the lack of entries for the MUSES01 and MUSES02 chips; MUSES03 is not included as it is a single channel chip and not a drop in replacement for the NE5532.

Finding “the right op amp” is not easy. Any advice on what to look for in the specification sheets will be much appreciated.

It’s not easy finding the right op amp and in my experience not particularly cheap either at least sometimes measurements may give a more solid lead than curiosity.

I am currently waiting for an amp/preamp to arrive which I will roll. I already have the sound I want in my head and have an idea which op amp is going to provide the result I am looking for. The sound I want is not provided by the stock NE5532 chips although they have been well implemented.

 

[Down South]

Surprising that Fosi will supply the Muse chip????

 

[solderdude]

Where there is a demand there will be supply.
Where there is demand and supply money will exchange hands and profits (usually) are made.
Money makes the world go round.

 

[pma]

I already have the sound I want in my head and have an idea which op amp is going to provide the result I am looking for.

Sounds like a plan.

 

[Joe Smith]

I'm happy to have put all this behind me...

 

[LTig]

It’s not easy finding the right op amp and in my experience not particularly cheap either at least sometimes measurements may give a more solid lead than curiosity.

I am currently waiting for an amp/preamp to arrive which I will roll. I already have the sound I want in my head and have an idea which op amp is going to provide the result I am looking for. The sound I want is not provided by the stock NE5532 chips although they have been well implemented.

Uh huh.