I have a very high tolerance for behaviour that looks trollish, but might just be ignorance.Beginning to? It has for severaldaysweeks already!
That tolerance - in this case - is pretty much consumed.
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Sparkos SS3602 Opamp Rolling In Fosi P4
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That tolerance - in this case - is pretty much consumed.
Hi very interesting thread as always
I have one unit myself and I am impressed by the level of sonic detail i get
I have a question about the circuit
Is the 5532 the only opamp used?
It seems buffering the inputs before the pot
Nothing active after the pot?
I have one unit myself and I am impressed by the level of sonic detail i get
I have a question about the circuit
Is the 5532 the only opamp used?
It seems buffering the inputs before the pot
Nothing active after the pot?
I am curious about you experience with MUSES02. We use it in our buffers for Hypex Class D and they sound and measure quite well and never found the sound to be "congested". The problem with JRC MUSES02 is the market saturated with fakes and the manufacturer advises to buy from either Digikey or Mouser. We use the later.
Nobody talk about the opa2604 I had the opportunity of listening to a line preamp from Hegel using the single version 604 The sound was very clean indeed but not too sterile
audiophile.no
Clearly there are other parts around the opamp contributing to the overall sound
it has fets at the input It should not cost much more I do not know if it can be used without modifications though
Hegel P2A
For en stund tilbake så hadde jeg en Hegel CDP2A på hjemlån for omtale. Den imponerte i en sånn grad at jeg bestemte meg for å ta for meg flere Hegel-produkter. Nå gjenstår det bare å finne ut om forforsterkeren P2A er av samme kaliber... av Stian Gårdsvoll, 8.februar 2004 P2A er en forbedret...
it has fets at the input It should not cost much more I do not know if it can be used without modifications though
I never tried OPA2604. I am curious so I will be ordering a few samples. Too bad they don't have DIP8 version of it anymore and Mouser doesn't even carry it. Only SOIC8 seems to be available from Digikey.Nobody talk about the opa2604 I had the opportunity of listening to a line preamp from Hegel using the single version 604 The sound was very clean indeed but not too sterile
Clearly there are other parts around the opamp contributing to the overall soundHegel P2A
For en stund tilbake så hadde jeg en Hegel CDP2A på hjemlån for omtale. Den imponerte i en sånn grad at jeg bestemte meg for å ta for meg flere Hegel-produkter. Nå gjenstår det bare å finne ut om forforsterkeren P2A er av samme kaliber... av Stian Gårdsvoll, 8.februar 2004 P2A er en forbedret...
it has fets at the input It should not cost much more I do not know if it can be used without modifications though
Hi as i said the actual part used in that preamp is the single version 604AP
I have never understood if two single OAs sound different from a single dual
I guess they decided to use it after some evaluations
Hegel is a very good brand
To be honest i have one P2A now packed away that i listened for a while
I had the feeling of a very high transparency almost shocking
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olds1959special
Major Contributor
My pair came from Mouser. I thought I liked the sound (seemed warm) but preferred the Sparkos SS3602 in the end.
I think it depends on the whole implementation. In my case, the opamp is in the buffer stage driving Class D so it may sound different. We have tested a number of discrete op amps, SS3602 is one of the best and behaves like an IC. Most discrete opamps are Class A and can draw too much current for the existing power supply/voltage regulators.
Mouser carries OPA604 so I will get it instead of 2604. We have a bunch of small PCBs to convert two OPA627 into a dual DIP8 so I will try that with two 604s. BTW, OPA627 is quite impressive too, although still expensive and only available as single channel.
MAB
Major Contributor
Perhaps people could provide measurements of what is actually happening. These impressions and opinions of the sound of an opamp are ignorant of how we hear, and indicate the poster has never read, or is purposely ignoring the content on this forum, and the limitations of human hearing. Since misinformation isn't OK, let's set the record straight.
I have a preamp made from spare parts, I added sockets for OpAmp rolling. The sockets add noise and distortion all by themselves compared to direct soldering of the packages to the PCB. I also have a supply of OPA2604, and other OpAmps:
The preamp is fairly high performance, non-inverting. I built it with two different feedback loops on Left and Right channels to demonstrate that the surrounding passive components are more important in the performance of the Preamp than the choice of OpAmps, you can find that discussion here.
I am starting to get some degradation in the DIP8 sockets of this preamp, after repeated demonstrations of what actually happens when OpAmps are swapped. These sockets typically only rated for 100 insertion cycles, and this assumes the careless user doesn't hack it up after rolling just a few OpAmps.
After carefully seating the OpAmps for each test, here is the performance difference between an OPA2604 and the NE5532:
Superman might hear these measured differences, which are far below human perception, below audibility. Even tightening the screws on the the preamp's chassis cover makes a difference at this level of performance. If we take OpAmp rolling seriously, we also need a thread on midrange warmth vs. chassis screw tightness.
I am sure someone will want to make something out of the difference in 2nd HD, which is a real difference of the two OpAmps, but at -120dB, this is inaudible and of interest only outside of audio.
The gain and frequency response also don't change between OpAmps.
I hope people appreciate how absurd OpAmp rolling is.
It's also absurd to enter a thread, where it's demonstrated that OpAmp rolling is inaudible, and passive-aggressively bend the conversation back to woo woo.
Is it me or is there an uptick in the number of trolls? We have old and new members, and now vendors bringing necro threads back to the surface, ignoring the content and OP of the thread, or actively trying to overwrite the intent. Would be OK if there was evidence, but of course that won't happen.
I have a preamp made from spare parts, I added sockets for OpAmp rolling. The sockets add noise and distortion all by themselves compared to direct soldering of the packages to the PCB. I also have a supply of OPA2604, and other OpAmps:
The preamp is fairly high performance, non-inverting. I built it with two different feedback loops on Left and Right channels to demonstrate that the surrounding passive components are more important in the performance of the Preamp than the choice of OpAmps, you can find that discussion here.
I am starting to get some degradation in the DIP8 sockets of this preamp, after repeated demonstrations of what actually happens when OpAmps are swapped. These sockets typically only rated for 100 insertion cycles, and this assumes the careless user doesn't hack it up after rolling just a few OpAmps.
After carefully seating the OpAmps for each test, here is the performance difference between an OPA2604 and the NE5532:
Superman might hear these measured differences, which are far below human perception, below audibility. Even tightening the screws on the the preamp's chassis cover makes a difference at this level of performance. If we take OpAmp rolling seriously, we also need a thread on midrange warmth vs. chassis screw tightness.
I am sure someone will want to make something out of the difference in 2nd HD, which is a real difference of the two OpAmps, but at -120dB, this is inaudible and of interest only outside of audio.The gain and frequency response also don't change between OpAmps.
I hope people appreciate how absurd OpAmp rolling is.
It's also absurd to enter a thread, where it's demonstrated that OpAmp rolling is inaudible, and passive-aggressively bend the conversation back to woo woo.
Is it me or is there an uptick in the number of trolls? We have old and new members, and now vendors bringing necro threads back to the surface, ignoring the content and OP of the thread, or actively trying to overwrite the intent. Would be OK if there was evidence, but of course that won't happen.
MaxwellsEq
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I think people have aright to try different opamps same as trying Class A vs Class AB vs Class D amps. It is not trolling and being passive aggressive. Whether the difference will be audible is a different question and it will depend on a lot of factors.
The preamp in your measurements only does 6dB gain. If you try it at 12dB gain and higher input voltage the second and third harmonics do eventually get into the audible range.
The preamp in your measurements only does 6dB gain. If you try it at 12dB gain and higher input voltage the second and third harmonics do eventually get into the audible range.
DVDdoug
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Of course you have a right to do whatever you want with your stuff!
But if you make "unlikely claims" here without measurements or controlled blind listening tests we have a right to challenge you.
That would be unlikely... If you are building microphone preamps or phono preamps with gains around 60dB noise can become an issue but with a competent design you're not going to get audible distortion unless you push it into clipping.
12dB is not a lot of gain. From the preamp input to power amp output you would expect 20 to 30dB of gain.Of course you have a right to do whatever you want with your stuff!
But if you make "unlikely claims" here without measurements or controlled blind listening tests we have a right to challenge you.
That would be unlikely... If you are building microphone preamps or phono preamps with gains around 60dB noise can become an issue but with a competent design you're not going to get audible distortion unless you push it into clipping.
Regarding the "unlikely claims" that some opamps sound different it depends a lot on your setup and state of your hearing. Some new woofers like Accutons have way less distortions than the paper based ones and will help hearing the difference. This is hard to measure though. Music is a number of frequencies which constantly vary in volume - not 1KHz or 20Hz measured at constant voltage...
MAB
Major Contributor
I'm not trying to take away from people's right to make stupid claims and say ignorant things, or work on electronics despite having no knowledge of the field, and no experience with electrical safety.
It's a forum on audio science, I am arguing for more integrity in the posts. Thanks for highlighting the need for more integrity in posting here; you got everything wrong.
The preamp has much more gain than 6dB, if you had followed any of the links in my post, you would have found that out. This test was done at +6dB gain since it is a typical application, which is fine for testing the overload margins of the preamp with different OpAmps.
I tested that as well if you had followed the link, which you didn't read. So much for curiosity, which is something we do want people to come here with.
Here is the distortion across four different gain settings, at just below the point where the preamp's output clips.
First with the NE5532:
And the OPA2604:
The rising odd order HD that you hoped/speculated/guessed existed doesn't actually behave the way you anecdotally suggested. The two OpAmps have distortion that is inaudible across these gain, as expected from a preamp.
What you can see is elevated mains noise on the OPA2604, this is a limitation of DIP8 temporary socket contacts, shows up at high gain on the OPA2604 due to the lack of a perfect ground. Soldering the OpAmp to the PCB fixes that
. The only thing high gain demonstrates is the limitations of the DIP8 replaceable socket to make reliable contact after multiple insertions. Regarding your right to swap OpAmps, you also have the right to listen to mains hum, if your ears are that sensitive. Not many of us listen to music on consumer audio equipment with the gain set to 30dB.
Deafening volume, impossible to even listen critically at that level. Or you have a corner-case amp with low sensitivity. Your example is quite absurd, which is common in consumer audio... Audiophiles dream up corner cases they read about in print advertisements, and cluelessly spout them as if they know about electronics. Clearly you haven't ever measured distortion, at low or high gain, and are repeating marketing crap to try to sound informed. Thanks for your speculations and anecdotes though, so common in audio, it's in the audiophile's Bill of Rights.You dramatically overestimate your hearing. It's OK, you overestimate my hearing too, and my ego thanks you.
Also, speaker drivers, including Accuton's most advanced units, have orders of magnitude more distortion than all but the worst performing electronics. How do you not know this? Have you ever looked a driver distortion? Here is what a nice Accuton driver's distortion looks like:
Not that Accuton is lower than other drivers (they are not despite your unsupported claim), it's just odd you think a driver's distortion at -50 dB is comparable to a preamp's distortion at -100dB.
MAB
Major Contributor
You probably don't realize this, but your graph shows speaker distortion on the order of tenths of percent; ~0.1%.
The preamp measurements I made and the differences between OpAmps, are on the order of thousandths to ten-thousandths of a percent; 0.001% to 0.0001%.
You are off by two to three orders of magnitude.
You could have told this from my graph of speaker distortion as well, even easier in fact since it was in dB.
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My point was that paper based woofer are usually above 1% which will mask better amp performance.You probably don't realize this, but your graph shows speaker distortion on the order of tenths of percent; ~0.1%.
The preamp measurements I made and the differences between OpAmps, are on the order of thousandths to ten-thousandths of a percent; 0.001% to 0.0001%.
You are off by two to three orders of magnitude.
You could have told this from my graph of speaker distortion as well, even easier in fact since it was in dB.
Regarding your measurements ( I am not arguing with you). Is it taken using QA403? What load value are you using for your measurements?
MAB
Major Contributor
1% is four orders of magnitude, even less audible. You also need to take the Klippel distortion test to inform yourself how much distortion is actually audible. You can't pass 80dB even with a pure tone. If you can, please post your results. Someone pointed this out to you earlier when you implied you had great hearing and could hear all of these artifacts, did you ever go and take the test?
1 kOhm load.
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