Hello.
I am set to upgrade my M-Audio Audio Biddy preamp/direct box. Recording guitars through this box does not give satisfactory results.
It uses NJM4560 and NJM4580 opamps in its signal chain for amplification.
I do not need any effects from preamp, just amplify and match the signal to go into sound card.
Question: What kind of op-amps are used in high-end direct boxes/ processors ? I can not find any schematics on the net, just descriptions of how wonderful all these devices sound 🙂
Or may be they don't use opamps - only dicreet transistors. I am not talking about tube devices - too expensive to build and maintain 🙂
Regards, George.
I am set to upgrade my M-Audio Audio Biddy preamp/direct box. Recording guitars through this box does not give satisfactory results.
It uses NJM4560 and NJM4580 opamps in its signal chain for amplification.
I do not need any effects from preamp, just amplify and match the signal to go into sound card.
Question: What kind of op-amps are used in high-end direct boxes/ processors ? I can not find any schematics on the net, just descriptions of how wonderful all these devices sound 🙂
Or may be they don't use opamps - only dicreet transistors. I am not talking about tube devices - too expensive to build and maintain 🙂
Regards, George.
Giora said:
Having worked on lots of pro kit, I have to say that most of it uses dead cheap 074 or similar priced types. There are very, very few companies that use "high end" components. Make of that what you will... 😉
Thanks for your reply.
Well, mass production is what it is. Saving cents, not even dollars is the name of the game.
Given that, what are the "high quality" components in terms of opamps ?
One forum member named OPA2604, another NE5532.
I guess, I would have to sample them and try it myself.
I know one sound engineer who works with professional bands. He says it is all bogus, these opamps are all the same and it does not matter 🙂
I don't know, the hard thing for me is a lack of quantitative analysis that would say - this is what should sound good, and this is what should not 🙂 I may be I am not familiar wih them.
One thing I know for sure - opamps in my device sound terrible 🙂
Well, mass production is what it is. Saving cents, not even dollars is the name of the game.
Given that, what are the "high quality" components in terms of opamps ?
One forum member named OPA2604, another NE5532.
I guess, I would have to sample them and try it myself.
I know one sound engineer who works with professional bands. He says it is all bogus, these opamps are all the same and it does not matter 🙂
I don't know, the hard thing for me is a lack of quantitative analysis that would say - this is what should sound good, and this is what should not 🙂 I may be I am not familiar wih them.
One thing I know for sure - opamps in my device sound terrible 🙂
The NJM parts are used extensively in Mackie mix boards - in particular the NJM2068 and NJM4560 devices. I don't have the specs for any of these but would be very interested in seeing how they compare to some of the AD or BB op-amps that are highly regarded.
I've heard, for example, that the NJM2114 is equivalent to the National 5532 which is used *everywhere*....
If someone knows where the specs can be located, perhaps we could come up with a matrix or cross-reference guide?
I've heard, for example, that the NJM2114 is equivalent to the National 5532 which is used *everywhere*....
If someone knows where the specs can be located, perhaps we could come up with a matrix or cross-reference guide?
To get specs is not a problem - I've got most of them.
Go to Google search engine, type the name of the device - you get a pdf file.
The point is : what constitutes good ?
For instance: high slew rate, low THD, low input noise. All of these parameters contributes to the "good" sound. But looking in the spec sheets, these parameters are more or less the same for all of these devices.
What constitues good ?
Go to Google search engine, type the name of the device - you get a pdf file.
The point is : what constitutes good ?
For instance: high slew rate, low THD, low input noise. All of these parameters contributes to the "good" sound. But looking in the spec sheets, these parameters are more or less the same for all of these devices.
What constitues good ?
i can`t answer your post.i`m just looking at where the big money parts are in the computers in studios.the sound card.it`s big bucks to step up to a studio type card.
the tech you know may be right it`s doesn`t matter about the interface.i haven`t seen any mega buck interfaces.but i have seen some very very very high dollar soundcards.
just something else to think about.
the tech you know may be right it`s doesn`t matter about the interface.i haven`t seen any mega buck interfaces.but i have seen some very very very high dollar soundcards.
just something else to think about.
What constitutes a professional sound card ?
A/D, D/A and opamps at send/receive passways.
Could you name these components that are high level in your mind ? That you saw being used in high level sound cards ?
What are these cards anyway ?
A/D, D/A and opamps at send/receive passways.
Could you name these components that are high level in your mind ? That you saw being used in high level sound cards ?
What are these cards anyway ?
What constitutes "good" ? - This almost entirely depends on the components and circuit topology surrounding the opamp - For audio frequency operation, the demands on the opamp are not great. Noise is probably the most critical specification for high gain stages - but even here, the standard TLO72 was adequate for even high quality mixer input stages some years ago.. however, this was (is)on the edge of acceptability - replace the TLO7x with a TLO8x and one could often hear the noise that the difference in the specification of the two devices made (25nV vs 18nV). the THD on a well configured TLO7x circuit is about 0.01%.
Better specifications are available from the newer replacement parts, and from other more expensive parts - but the inclination to using lower cost parts by manufacturers is fine, provided competent engineers are crafting good circuits with the lowest cost components available. Every extra expense is multiplied by at least 4x extra cost to the end purchaser. One WILL get a better result from a carefully crafted design using the lowest possible cost components which can do the job, than from a 'design' where the highest spec/price parts have been inserted, but care has not been taken over the basics - like matching impedances correctly, or decoupling the opamps adequately.
My first move, when upgrading equipment, is to check the local decoupling.. Capacitors have improved dramatically over the years, and replacing local bypass capacitors with low ESR parts can make a huge difference to performance. Often, I will remove the inadequate bypass capacitors, and replace them with modern ceramic caps soldered directly across the IC supply pins.
The most critical areas where opamp quality can have a dramatic effect, is in filter / tone modification circuits - but care needs to be taken replacing opamps - In particular, the input topology needs to be looked at - JFET, CMOS, BUTLER etc type input stages may not be exchangable if the design has taken care to exploit the particular charactaristics of the input circuit.
Better specifications are available from the newer replacement parts, and from other more expensive parts - but the inclination to using lower cost parts by manufacturers is fine, provided competent engineers are crafting good circuits with the lowest cost components available. Every extra expense is multiplied by at least 4x extra cost to the end purchaser. One WILL get a better result from a carefully crafted design using the lowest possible cost components which can do the job, than from a 'design' where the highest spec/price parts have been inserted, but care has not been taken over the basics - like matching impedances correctly, or decoupling the opamps adequately.
My first move, when upgrading equipment, is to check the local decoupling.. Capacitors have improved dramatically over the years, and replacing local bypass capacitors with low ESR parts can make a huge difference to performance. Often, I will remove the inadequate bypass capacitors, and replace them with modern ceramic caps soldered directly across the IC supply pins.
The most critical areas where opamp quality can have a dramatic effect, is in filter / tone modification circuits - but care needs to be taken replacing opamps - In particular, the input topology needs to be looked at - JFET, CMOS, BUTLER etc type input stages may not be exchangable if the design has taken care to exploit the particular charactaristics of the input circuit.
You might find the following link helpful -
http://headwize2.powerpill.org/projects/showproj.php?file=opamp_prj.htm
http://headwize2.powerpill.org/projects/showproj.php?file=opamp_prj.htm
Fred, thanks very much for your insights.
It's a very good point about good circuit design being of primal importance, one should not over-obsess about highest quality op-amps.
One specific question to you.
I have a sound card that uses NJM 5532 op-amps for input stage before A/D convertor.
Input to the sound card is taken from pre-amp that uses NJM4560 and NJM4580 parts.
I can see from the specs that NJM 5532 is higher quality opamp.
Would it make sence to replace NJM4560 and 4580 with NJM 5532 so to bring all signal path to the same device ?
Taking your point about good circuit design, it might seem irrelevant.
I am recording my guitars this way, SNR and spectral flatness is critical here, later the signal will be compressed, equalizied, and other audio modeling will be introduced. The goal is to bring the signal to the software as undistorbed as possible.
It's a very good point about good circuit design being of primal importance, one should not over-obsess about highest quality op-amps.
One specific question to you.
I have a sound card that uses NJM 5532 op-amps for input stage before A/D convertor.
Input to the sound card is taken from pre-amp that uses NJM4560 and NJM4580 parts.
I can see from the specs that NJM 5532 is higher quality opamp.
Would it make sence to replace NJM4560 and 4580 with NJM 5532 so to bring all signal path to the same device ?
Taking your point about good circuit design, it might seem irrelevant.
I am recording my guitars this way, SNR and spectral flatness is critical here, later the signal will be compressed, equalizied, and other audio modeling will be introduced. The goal is to bring the signal to the software as undistorbed as possible.
"I can see from the specs that NJM 5532 is higher quality opamp.
Would it make sence to replace NJM4560 and 4580 with NJM 5532 so to bring all signal path to the same device ?"
Without seeing the circuit, and probably spending some time doing the sums, I cannot answer this! - But the placing of the 'highest quality' amplifier imediately before the A/D is likely to be good design - this opamp will probably be configured with components to form a lowpass filter, which will roll-off high frequencies which could cause aliasing problems at the A/D - and a 'better' opamp here is apropriate to cater for the demands of this extra function.. I expect that any 'improvement' made to the preceding opamps would have no effect on the performance of the system.
I have not checked the spec of these NJM parts - I personally have found NJM (New Japan Radio I believe is the manufacturer) parts inferior compared to Analogue Devices (my first choice) or Texas Instruments, National Semiconductor or ST. - I did not want to give this opinion without first declaring that I think the circuitry is far more important than the opamps generally - But I have had to change NJM parts probably 30% more than the others.. This MAY be a simple statistical issue - It may just be that more of the equipment I have worked on uses NJM more than other parts, and my 'bias' against NJM is not justified or scientific - they are about 40% cheaper to Japanese manufacturers - and a lot of the gear I modify is Japanese (Sansui, Roland, Yamaha, Akai - only rarely do I get a Moog or Sequential or Mackie to play with!)
One final thing - The A/D converter! The components arround this are absolutely critical to performance, particularly the layout / decoupling etc.. Poor quality capacitors, or anything which causes digital delays on the busses, or anything like a noisy reference voltage, will mess your signals up badly.. Some A/D IC's are just bad anyway - but even good ones will sound bad if utmost care is not taken with selection of peripheral components - If unsure, I would change all the capacitors around the A/D to the highest quality low ESR parts available.
Design of a sound card is not a trivial issue, and (assuming a good design team) a target price is likely to be the starting point - (or, at least, an extremely important factor) - The components would be selected to meet price/spec requirements - It is unlikely that there will be a particular 'weak link' or 'strong link' in the design - more likely is that strengthening any 'link' will simply expose the others as 'weaker' - to get the 'chain' to be 'stronger', all the 'links' are likely to need improving - And if you do this, you are designing / building a new sound card!
But sometimes one gets a bad designer in a team, and incompetent managment who let bad design through, or staff changes etc - and a weak link is created - and finding / strengthening this link gives a huge system improvement -
Good luck!
Would it make sence to replace NJM4560 and 4580 with NJM 5532 so to bring all signal path to the same device ?"
Without seeing the circuit, and probably spending some time doing the sums, I cannot answer this! - But the placing of the 'highest quality' amplifier imediately before the A/D is likely to be good design - this opamp will probably be configured with components to form a lowpass filter, which will roll-off high frequencies which could cause aliasing problems at the A/D - and a 'better' opamp here is apropriate to cater for the demands of this extra function.. I expect that any 'improvement' made to the preceding opamps would have no effect on the performance of the system.
I have not checked the spec of these NJM parts - I personally have found NJM (New Japan Radio I believe is the manufacturer) parts inferior compared to Analogue Devices (my first choice) or Texas Instruments, National Semiconductor or ST. - I did not want to give this opinion without first declaring that I think the circuitry is far more important than the opamps generally - But I have had to change NJM parts probably 30% more than the others.. This MAY be a simple statistical issue - It may just be that more of the equipment I have worked on uses NJM more than other parts, and my 'bias' against NJM is not justified or scientific - they are about 40% cheaper to Japanese manufacturers - and a lot of the gear I modify is Japanese (Sansui, Roland, Yamaha, Akai - only rarely do I get a Moog or Sequential or Mackie to play with!)
One final thing - The A/D converter! The components arround this are absolutely critical to performance, particularly the layout / decoupling etc.. Poor quality capacitors, or anything which causes digital delays on the busses, or anything like a noisy reference voltage, will mess your signals up badly.. Some A/D IC's are just bad anyway - but even good ones will sound bad if utmost care is not taken with selection of peripheral components - If unsure, I would change all the capacitors around the A/D to the highest quality low ESR parts available.
Design of a sound card is not a trivial issue, and (assuming a good design team) a target price is likely to be the starting point - (or, at least, an extremely important factor) - The components would be selected to meet price/spec requirements - It is unlikely that there will be a particular 'weak link' or 'strong link' in the design - more likely is that strengthening any 'link' will simply expose the others as 'weaker' - to get the 'chain' to be 'stronger', all the 'links' are likely to need improving - And if you do this, you are designing / building a new sound card!
But sometimes one gets a bad designer in a team, and incompetent managment who let bad design through, or staff changes etc - and a weak link is created - and finding / strengthening this link gives a huge system improvement -
Good luck!
today i changed them
i just replaced a 4580 i had burnt at the headphones output in my behringer mixer. What i can tell you right now is that placing a 4560 in the now socketed ic place, I can hear bad bass . I bought this cheaper replacement as well as the original 4580( a dollar versus 4). As i am not too knowledgeable in electronics i tried a safe way and placed a cheaper one just in case some s...t happened. All that happened was that in the unmodified circuit the 4560 sound worst than the stock part . Maybe if i put a better opamp it would sound better. I know its just an analogue mixer but.... I left a socket in to try different op amps and see which one pleases me the most . Although i`am just happy now i did it myself for a fifth part of what one pro wanted for it. Plus the involved learning.
i just replaced a 4580 i had burnt at the headphones output in my behringer mixer. What i can tell you right now is that placing a 4560 in the now socketed ic place, I can hear bad bass . I bought this cheaper replacement as well as the original 4580( a dollar versus 4). As i am not too knowledgeable in electronics i tried a safe way and placed a cheaper one just in case some s...t happened. All that happened was that in the unmodified circuit the 4560 sound worst than the stock part . Maybe if i put a better opamp it would sound better. I know its just an analogue mixer but.... I left a socket in to try different op amps and see which one pleases me the most . Although i`am just happy now i did it myself for a fifth part of what one pro wanted for it. Plus the involved learning.
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