Yes, and I've spat most of them out. I think I could live wtih OPA627 and AD797 and maybe LME49720, but I haven't heard them all. There are some new ones I haven't heard that might be even better like OPA211, OPA827 and ADA4627.Nelson,
a bitter, acrid flavor...
I've found that by blending opamps I can almost get the sound I want.
Borat, a word of warning: the world of opamp rolling is addictive.
The "gain set to zero" part is rather amusing.
Back in the early NE5534 and OP27 days, DIY folks even easily managed to distinguish between Signetics/Philips, TI, or Burr Brown manufacture for the same part number.
high end op amp is one that has best performance.
ultra-high-end implies out of reach. no op-amp is out of reach so it doesn't really apply there.
are you trying to say that its harder to build an amp using an IC than without one ?
how so ?
You're asking the wrong guy
Just keep looking at the datasheets, the popular OPA134 for example has 120dB gain (open loop gain=OLG).
Simply gain of amp+NFB=OLG
How much NFB is good for you, is up to you to decide. About 20dB counts as low-NFB design...
Have fun, Hannes
In the end, any work should be judged by it's results, not what was used to get there.
There are a lot of bigots in audio though. People judge things by the parts used without an open mind and people make all kinds of claims for the audibility of various parts without any real science to back their claims.
That is why it has become like talking about religion......because it is one.
There are a lot of bigots in audio though. People judge things by the parts used without an open mind and people make all kinds of claims for the audibility of various parts without any real science to back their claims.
That is why it has become like talking about religion......because it is one.
ok how does that help me ?
i believe in the potential of science. that is different from thinking that science is always right. i know that is not the case.
but just because science fails from time to time doesn't mean i am going to give up on it.
science has to be dynamic. when science becomes static it becomes a religion.
thats why i started by building speakers 11 years ago. but i have speakers now figured out to a large extent ( with the exception of linear phase crossovers perhaps, which i do not fully understand ). its time to round myself out by gaining more knowledge about amplifiers.
...or it may be miss-applied, when for example in order to compare tuning of grand pianos scientists thoroughly measure how well their strings are aligned according to magnetic fields of the Earth.
I use opamps because they are often the best tool for the job. In terms of explaining why other people don't, you would have to ask them. I think you will find a number of answers, some valid and some not.
As a speaker designer you must know that subtle changes in the crossover design can have a significant impact on the perceived sound. Rather than chasing my tail swapping active circuits, I'd rather focus on voicing something in the crossover. If a given active device sounds too forward, or too relaxed, that is easily adjusted for in the crossover. Why chase your tail trying to find the "perfect" opamp or circuit when it doesn't exist? Use high quality parts and adjust for any of their "sonic signatures" in the crossover designs. Let other people chase their tales looking for the "perfect" circuit knowing that the transducer and the room are going to be the biggest obstacle in final performance.
Sorry for the delay in replying.
No, it is not necessarily harder, which is a relative measurement, but it is simply different. If you try to build an op-amp based amplifier using a tube / valve design (e.g. single-ended triode) you will most likely be disappointed.
What I had in mind when I said this was a comparison of the CMoy headphone amplifier and using Warren Young's suggested ~$9 op-amp[1] with Walt Jung's cheap components but quality headphone amplifier design[2] that has a higher parts count from Walt Jung's book Audio IC Op Amp Applications. The CMoy circuit makes compromises to obtain maximum simplicity, whereas Jung's design lacks high-end components[3] but excels due to good design.
1] Burr-Brown (TI) OPA2132P in DIP package
2] Section 4.3.1 Headphone Drivers, pg. 118 (3rd ed.)
3] (MC)34081 is cross-reference to either OPA132(A) for single op-amp or OPA2132(A) for the dual version
0.00005% thd+n
The LME Series of opamps are the "King of the Hill" right now and that is coming from someone who was laid off from the audio group at National 10 months ago. (We had multiple audiophiles listen to these parts in our proto designs and "all of them" were impressed and several were Tube Guys!)
The LME49710HA VFB or LME49713HA CFB in the metal cans are the best opamps you can buy right now in terms of specs and sound quality. (Digi-key is out of the metal cans now though!) I still like the old metal can hybrid AD9610's but they have been out of production for a very long time and were mil spec only... and way to expensive! ($300 each 20 years ago!) The AD811 CFB's were the monolithic versions of the 9610's and are very good (I used them for years in all my designs) but I am selling off the last of my stock of 300 of those ($4 each in DIPS if anyone wants them) because the specs and sound quality of the LME49713 are better. In fact we designed the 49713 to beat the 811 for audiophile designs. Also in our testing we discovered that the metal cans beat the plastic packages for identical die every time!
Also since these opamps can actually be run at very high rails (+/-22VDC or more!) the higher gains are easier to achieve especially since these are also very low noise parts. (1.9nV/√Hz for the 49713!)
Hope some of these "very biased" comments help.
Mark / Audioman54
The LME Series of opamps are the "King of the Hill" right now and that is coming from someone who was laid off from the audio group at National 10 months ago. (We had multiple audiophiles listen to these parts in our proto designs and "all of them" were impressed and several were Tube Guys!)
The LME49710HA VFB or LME49713HA CFB in the metal cans are the best opamps you can buy right now in terms of specs and sound quality. (Digi-key is out of the metal cans now though!) I still like the old metal can hybrid AD9610's but they have been out of production for a very long time and were mil spec only... and way to expensive! ($300 each 20 years ago!) The AD811 CFB's were the monolithic versions of the 9610's and are very good (I used them for years in all my designs) but I am selling off the last of my stock of 300 of those ($4 each in DIPS if anyone wants them) because the specs and sound quality of the LME49713 are better. In fact we designed the 49713 to beat the 811 for audiophile designs. Also in our testing we discovered that the metal cans beat the plastic packages for identical die every time!
Also since these opamps can actually be run at very high rails (+/-22VDC or more!) the higher gains are easier to achieve especially since these are also very low noise parts. (1.9nV/√Hz for the 49713!)
Hope some of these "very biased" comments help.
Mark / Audioman54
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.