Look at the LTC1250 or the MAX4238 op-amps. These have high input impedance, like a tube, huge gain (> 1 million V/V), and noise that is flat down to 1Hz and then DROPS as frequency goes lower, whereas the noise of a JFet may skyrocket below 1Hz.
Linear Tech will sample the LTC1250 in the PDIP package.
If you want to start a revolution in sound, try heating the circuitry to a constant temperature. This eliminates 99% of extraneous noise, clicks, pops etc etc etc. WD40 all connector pins to exclude air and corrosion.
Never conduct low-level signals in a cable. The latest EEG equipment has local preamps at the electrodes and this eliminates the need for wet electrodes.
Joke redux
This is another joke, right? Did you look at the Maxim datasheet carefully? These parts achieve their incredibly low noise down to DC by commutating the input stage at a frequency of 10-15kHz. Do you think audiophiles will enjoy listening to a pseudorandom high frequency tone? The clock component shows up clearly as a glitch on many of the plots.
This is another joke, right? Did you look at the Maxim datasheet carefully? These parts achieve their incredibly low noise down to DC by commutating the input stage at a frequency of 10-15kHz. Do you think audiophiles will enjoy listening to a pseudorandom high frequency tone? The clock component shows up clearly as a glitch on many of the plots.
I hope this post resulted in testing the OPA1641 and OPA827, both excellent opamps. I do tend to prefer JFET or bipolar input stage chips
IMO its all about application, as i'm sure has been discussed here. some jobs I prefer discrete but in general I prefer a mix of opamps and discrete. opamp input stage and discrete output stage; sometimes ended with an opamp to servo the output for DC coupling.
cant say i'm much of a tube guy, but then I havent spent much time or money on experimentation.
but yes we cant argue about taste, theres no accounting for it. certainly makes for interesting reading (for a few pages at least)
I dont know if it was resolved, but there is absolutely feedback naturally occuring. just look at DNA
IMO its all about application, as i'm sure has been discussed here. some jobs I prefer discrete but in general I prefer a mix of opamps and discrete. opamp input stage and discrete output stage; sometimes ended with an opamp to servo the output for DC coupling.
cant say i'm much of a tube guy, but then I havent spent much time or money on experimentation.
but yes we cant argue about taste, theres no accounting for it. certainly makes for interesting reading (for a few pages at least)
I dont know if it was resolved, but there is absolutely feedback naturally occuring. just look at DNA
Scientifically seen power amps do not behave different from 'pre-amps'. With NFB always stability is an issue (e.g. Bode diagrams). Of course the load of an amp (pre-amps also could be loaded differently if they have been built into a separate box!) should be involved with the stability calculations and or simulations.
To get an idea of what I mean, look at my website (pa0su.nl) under chapter: 'Artikelen over audio', paragraph: 6. Another 35 watt Solid State Amplifier.
Herb.
opamps vs tubes
At overload, tubes squish and transistors crunch ---
There are pluses and minuses for both :
Tubes - bigger , larger xformers, cost more, more fragile, circuits are generally less safe ( than solid state) , and HEAT. BUT , they tend to sound better - because unlike a transistor , they are not dirty like transistors when they switch on and off.
OPamps - Economy, smaller circuits and supplies, can beat the crap out of them and they will work ( vibration), noisy due to the numbers of transistors involved to make one opamp ( anywhere fro 5 - 50+ each making its own noise) ... SIMPLE to use and create with.
Honestly , Most people listening to cd's cant tell the difference between class A and AB --- Especially if you are entering your 50's ( sniff ! ) Listen to analogue , the difference is more noticeable in the "quiet moments" of a tune. When its all said and done, What class/power to use?, How much to spend?, How fast to build?. Here's hoping you next creation sounds "clean" !)
At overload, tubes squish and transistors crunch ---
There are pluses and minuses for both :
Tubes - bigger , larger xformers, cost more, more fragile, circuits are generally less safe ( than solid state) , and HEAT. BUT , they tend to sound better - because unlike a transistor , they are not dirty like transistors when they switch on and off.
OPamps - Economy, smaller circuits and supplies, can beat the crap out of them and they will work ( vibration), noisy due to the numbers of transistors involved to make one opamp ( anywhere fro 5 - 50+ each making its own noise) ... SIMPLE to use and create with.
Honestly , Most people listening to cd's cant tell the difference between class A and AB --- Especially if you are entering your 50's ( sniff ! ) Listen to analogue , the difference is more noticeable in the "quiet moments" of a tune. When its all said and done, What class/power to use?, How much to spend?, How fast to build?. Here's hoping you next creation sounds "clean" !)
As a generalization this is wrong - designers use MORE tansistors in low moise pre- and head amps to get the noise down. Double the number of transistors and the noise gets 3 dB less.
jan didden
WD40 is very corrosive. I use it only to loose bolts of car, bike....
I will deal with Laura later 😉
Perhaps she will grow to a Lara....
A couple of months ago i had to use the emergency key to open the car, couldn't get the da.n key in.
Took an entire WD40 bottle before it hit that the door key hole has a removable plastic cover with an opening. 🙁
(hail to sensor operated automatico car lights, a dead battery everytime you switch them on oldfashioned by hand)
Let's hope you mean Alison Caroll. (aka what a relief)
Lara CrAft is more likely.
Took an entire WD40 bottle before it hit that the door key hole has a removable plastic cover with an opening. 🙁
(hail to sensor operated automatico car lights, a dead battery everytime you switch them on oldfashioned by hand)
Let's hope you mean Alison Caroll. (aka what a relief)
Lara CrAft is more likely.
Well, now I can say I've heard something better. Analog Devices' single AD8597 and dual AD8599 now rule the roost. Then there are also the modular Burson's and Dexa's which blow away everything.
Mean you the discrete OP-Amp modules discuss by this thread?
http://www.diyaudio.com/forums/solid-state/207233-burson-single-audio-opamps-one-greatest.html
and this URL?
http://www.newclassd.com/index.php?page=55
Where are the simplified schematics ?
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>single AD8597 and dual AD8599 now rule the roost...
Huh? Totally unsuitable for serious audio.
Please have a look at the LME49990. In every respect far better.
Huh? Totally unsuitable for serious audio.
Please have a look at the LME49990. In every respect far better.
By starting post #234 I mistook the AD8597 with the ADA4627/ADA4637, discuss about
http://www.diyaudio.com/forums/soli...-1-outperform-burr-browns-opa-627-opa627.html
Thus the actually question is follow:
Does the discrete solutions, discuss about
http://www.diyaudio.com/forums/solid-state/207233-burson-single-audio-opamps-one-greatest.html
and about
http://www.newclassd.com/index.php?page=55
outperform the integrated solutions from the top class models like AD797, OPA827/837, ADA4627 and that one from the LME series, which allegedly now rule the roost (at least according the diagrams from the manufacturers) ?
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best op amp......
Discrete op amp's are nonsence!
With integrated circuits all transistors do have equal properties which are very important in long tail pairs, current mirrors etc. The designer could and will use thiss features in his design to get a better amplifier.
With discrete components you should contort yourself with each individual implemetation to reach the same quality.
Discrete op amp's are nonsence!
With integrated circuits all transistors do have equal properties which are very important in long tail pairs, current mirrors etc. The designer could and will use thiss features in his design to get a better amplifier.
With discrete components you should contort yourself with each individual implemetation to reach the same quality.
I dont like getting into these debates as instead of looking for facts a lot of members just present voodoo claims.
That said I honestly get better results with discretes but Ill make no voodoo claims but there are some facts I can think of making a difference. In short I feel passives play a role. Inside opamps there are also resistors and caps etc and while these have become much better there is much room for improvement. In modern opamps caps are usually fabricated by using a mosfets gate drain channel, these are far less linear and have many other undesirable properties whereas in the discretes one usually opts for very good quality caps especially the vital compensation caps using Npo ceramics, polestyrene etc.
Use x7r or worse caps in a discrete and see what happens with the sound, it degrades.
Before these mosfet caps other methods were used, when you look at there properties, its quite scary.
That said I honestly get better results with discretes but Ill make no voodoo claims but there are some facts I can think of making a difference. In short I feel passives play a role. Inside opamps there are also resistors and caps etc and while these have become much better there is much room for improvement. In modern opamps caps are usually fabricated by using a mosfets gate drain channel, these are far less linear and have many other undesirable properties whereas in the discretes one usually opts for very good quality caps especially the vital compensation caps using Npo ceramics, polestyrene etc.
Use x7r or worse caps in a discrete and see what happens with the sound, it degrades.
Before these mosfet caps other methods were used, when you look at there properties, its quite scary.
Cap's in op amps???
No idea what you try to say about capacitors in op amps. Every solid state transistor does have parasitic capacitors which should be compensated in critical applications, but in general? Capacitors?? With integrated op amp's you get the possibility to bootstrap (see my web site on microphone pre amp.) the input capacitors....
Herb.
No idea what you try to say about capacitors in op amps. Every solid state transistor does have parasitic capacitors which should be compensated in critical applications, but in general? Capacitors?? With integrated op amp's you get the possibility to bootstrap (see my web site on microphone pre amp.) the input capacitors....
Herb.
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