Don't? As in never? Or didn't in this case (although you were not present, and are merely presuming...)?
A little grammatical uncertainty there... but I was hoping that Jan would give it a shot. And report back.
The basis? Having done it? Having been present when others were trying to do it so that there was no difference? Having been friends with a recording engineer for a (now defunct) highly regarded classical label... stuff like that.
_-_-
I don't think I have any of those. Lots of EE's I have worked with talked them up. They were touted as a lower cost alt. to AD712.
Jan, SY, and I did the op-amp mic thing before and all was fine and yes I was there.
There is so much talk by industry professionals on both sides of this, who do you believe?
The main selling point is LCR RIAA at an earthly cost. Always has been. I just happen to know the sound of my phono pre since I have been building the same basic circuit since 2010. So it is easy for me to hear the op-amp sonics.
As far as the slew rate kick, I learned it from Jim Williams of Audio Upgrades. You can find posts of his all over the place in the recording forums.
Do you want me to list what I have been called before this? They are all posts that the mods have let stand. I'm just serving it back this time.
Hey credit where credit is due, that was National's work long before we acquired them (we would have done 11 pages of THD graphs 🙄 )
You are actually touching on one of my big complaints with the LME parts though: lots of THD graphs, but none of the more basic information that would make actually using the part easier.
Ah, ok, so you went to ETF then?
I have no comment on the opamp mic thing, haven't yet either.
Believe about what?
SY takes 6 not 5 buffers to hear them, Jan I have no data points on, and you and I have had private electronic correspondence, which I will keep private. So, I'm not sure what the significance of your comment is?
Btw, not sure you want it that way, but ur PM box is apparently filled...
_-_-
This comment belies a false dichotomy, you might be interested to know that I have worked with several self taught/drop out engineers that have designed IC's at the highest level. There have even been CTO's of large companies that are not degreed engineers.
Let me spell it out, we made some recordings with op-amp based mics (same op-amp) at an earlier time and they came out fine. Apparently I have to pay up or clear out the mail box, my grace period is over.
There seems to be a divide between parts marketed for audio and general purpose parts. For some audio parts, the general purpose or higher frequency data can be missing. The opposite is true for the "fast" parts where you can sometimes get plots that don't start until 100 kHz or higher. Yeah, you can assume the performance below that is going to be good, but sometimes it would be nice to see it anyway.
The TI datasheets are much better than the LME ones in any case, though.
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So have I.
All I said was I didn't have any and I remember EE's talking about them.
Got a dual opamp suggestion for me to try?
If it matters I apologize publicly. Bob Pease and (the other) Jim Williams were friends of mine for 40 or so years. Jim died tragically from a sudden brain aneurysm and Bob had a heart attack at the funeral. I lost my temper at the soulless comment, not being a trained qualified listener or not caring enough would have been sufficient.
If I have to have a dual opamp, I'll have HA5222. But the 25V/uS might be a turn-off for you. Long out of production of course.
Agree on both counts. The audio parts coming out of our team in Tucson (OPA16xx) should have all of the usual op amp curves that are present in a general purpose op amp datasheet. If there's a curve in particular you are referring to feel free to post it here or shoot me a PM and I'll make sure we get it into the datasheet on future parts, or when we periodically update the datasheets I can try to add it.
As for high speed parts not showing low frequency data I also completely agree. And while the assumption is made that everything is fine at audio frequency that's not always the case. A good example of this is the THS6012 which is a high speed amplifier also sold as a headphone amplifier under the part number TPA6120A2. The THS datasheet doesn't show any distortion information below 100kHz. However, notice in the TPA datasheet that at high output power levels, the distortion below 1kHz begins to rise due to thermal effects.
Come on guys, slew rate is just a an indication of how an IC will behave with complex high frequency signals. Associated with slew rate is open loop bandwidth, gain bandwidth, and phase modulation or PM distortion. Slew rate is important, but not just for what it is, except that it should be higher than 5V/us in preamps, if at all possible. I tend to prefer 100V/us for my best stuff.
I just got done with a build that I used BA4560's.
I am trying to broaden my horizons and try different opamps, I usually use NJM4850 or OPA2134.
They all sound great to me.
I am trying to broaden my horizons and try different opamps, I usually use NJM4850 or OPA2134.
They all sound great to me.
Sure it matters. Apology accepted! I'm still an a****. A PITA too. I don't do it for no reason. I want people to get the best sound out of their gear at earthly prices. I was frustrated doing multi-track recording in the 80's not getting the sound I wanted and listening to my stuff get mangled form tracking to mixdown. It never left me.
What exactly would it "prove"? That a copy to a different medium / format can be different than the original? That we already knew.
A more lucrative experiment would be to compare copies of the same generation. Since there's no way to go back in time and install a digital recorder at the venue..... you're left to copying Jan's tape to a second Nagra and to a digital recorder then compare the results.
In 40+ years of working in Hollywood studios, THE smartest engineer I ever worked with had NO college education. He didn't need it.
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