bmcevers said:
Hi Bmcevers,
I saw that my Musical Fidelity X-24k Dac uses the NE5532.
Do you think an upgrade is apropriate here?
What opamp would you suggest instead of the NE5532?
I have some BB 627's and AD826's that I recieved as samples.
Can I use one of these? Are they 100% pin compatible?
Any suggestion very much welcomed!
Regards,
Lucas.
I concur to the findings of bmcevers. But OPA2604/OP249/OP275 win it from NE5532 in subjective terms. Not all parameters are better than NE5532 though ( it is very hard to beat a NE5532 specwise ! ). They are more or less drop in replacements whereas LM6172/AD826 and others need some more consideration/testing/datasheet reading/measuring. Some of the newer high-speed opamps cannot be fed with higher supplies than +/- 12 V which can be dangerous if the supplies in your DAC are +/- 15 V or higher
There are quite some threads about the pros and cons of using NE5532 and some threads nearly started wars
After all sound quality is most important to me. OPA2604 is the one that gives least problems/unexpected results and it sounds fine. Make sure whatever opamp you use that it is adequately decoupled. Change the caps in the DAC too for good types like Panasonic FC.
If you're not sure and want to try further I advise you to use good quality IC sockets, try some opamps and after you've made your choice you can remove the sockets and solder in the best opamp you've found. Work tidy and clean the PCB afterwards to remove debri from the flux. The question whether to coat the PCB with polyurethane or not is a controversial one so I won't go into that.
jean-paul said:
I concur to the findings of bmcevers. But OPA2604/OP249/OP275 win it from NE5532 in subjective terms. Not all parameters are better than NE5532 though ( it is very hard to beat a NE5532 specwise ! ). They are more or less drop in replacements whereas LM6172/AD826 and others need some more consideration/testing/datasheet reading/measuring. Some of the newer high-speed opamps cannot be fed with higher supplies than +/- 12 V which can be dangerous if the supplies in your DAC are +/- 15 V or higher
There are quite some threads about the pros and cons of using NE5532 and some threads nearly started wars
After all sound quality is most important to me. OPA2604 is the one that gives least problems/unexpected results and it sounds fine. Make sure whatever opamp you use that it is adequately decoupled. Change the caps in the DAC too for good types like Panasonic FC.
If you're not sure and want to try further I advise you to use good quality IC sockets, try some opamps and after you've made your choice you can remove the sockets and solder in the best opamp you've found. Work tidy and clean the PCB afterwards to remove debri from the flux. The question whether to coat the PCB with polyurethane or not is a controversial one so I won't go into that.
Thanks Jean-Paul, your answer is really helpful!
The MF does already have IC sockets, so trying various opamps is not a dificult task.
I will order some OPA2604 then.
Do you think the OPA627 might work too?
I I decide to try the AD826, what could happen? Could only the opamp itself get damaged, or could other components suffer?
Thanks again!
Lucas
Lucas_G said:
OPA627 is one of the best but they are singles so you need adapters. You need dual opamps when the originals are NE5532. OPA627 beats OPA2604 hands down. I don't like adapters so I would choose dual opamps.
AD826 is a fine opamp, give it a try. Nothing will get damaged. I thought AD826 to be a current feedback RF amp but I mixed it up with AD844. Liked the sound of AD844 a lot but it gets very noisy by the years.
Noise of AD826 is higher than with other opamps but we shouldn't exxagerate that. Used them only once after advise from a forum member. What I haven't done is comparing AD826 with AD8620 and LM6172 which is the dual opamp that I used recently. Still want to do that when time permits. AD826 is way better than NE5532 too soundwise.
I am curious what the outcome of your experiments will be.
The AD-8620 is a dual version of ADI's Fine AD8610. http://www.analog.com/UploadedFiles/Data_Sheets/734705833AD8610_20_c.pdf
The AD797 and OPA2134
I'm also thinking of building an equaliser for the low frequencies (20-120Hz) using a good Randy Slone circuit. It uses state variable filters, four opamps per band, and 11 bands in all. I'll need 46 opamps per channel for that one. I guess I can stick to the NE5532 for that one?
Thanks,
Tarun
Can you please comment on AD797 and OPA2134? I was wondering how good these are; I have the opportunity of getting one or two of each. I am not intending to build MM/MC pre-preamps, where the ultra-low noise requirements would make the AD797 a good choice. I was thinking of applications like active xo, line-level preamps, etc. For active xo, the NE5532 becomes attractive simply because of its low price; I'll need dozens of op-amps.jean-paul said:
I'm also thinking of building an equaliser for the low frequencies (20-120Hz) using a good Randy Slone circuit. It uses state variable filters, four opamps per band, and 11 bands in all. I'll need 46 opamps per channel for that one. I guess I can stick to the NE5532 for that one? Thanks,
Tarun
IMHo the OPA-132 and 134 series are amoung the worst sounding Op amps made selling for over $2.00 USD not much if any better than an LM-356. The AD-8610/20 and OPA-627/637 are amoung the best again YMMV these all have enought open loop gain for high Bitrate DA convertor use and fet inputs to acomidate a wide range of input impedeances. The Dielectric isolation process Keeps the bad effects of input capacitence down to a minimum. Moreover these Op amps have cascoded input stages to futher reduce input capcitence effects.
Really, not my opinion. OPAx134 är quite OK as long as it fits. This is depedant of how sensitive your hearing is. I have tested a few opamps in my headphone amps and often I have had different opamps for left/right. Noone, including myself have for sure picked a difference or pointed out which channel is the best. But personally I have most feelings for OPA627 and AD8610 in low gain applications. I can say at least that OPA124 won't get you really disappointed, like the LM324 or 741! Those are really bad for audio!ppl said:
cdl said:
Sorry, fmak, I didn't really mean that they sounded the same - just that both played music fine
You are right that the characteristic of the sound is quite different; 627 is impressive, and maybe on the bright side for my setup. Until now, my impression of 825 is that it is softer, and a little bit more leaned back, which is comfy especially for orchestral music.
Will keep posting - cheers, cdl
I have been listening to AD825 for some time now, and found it quite comfy. But the other day I had the soldering iron going for other purposes, so I thought I'd just change the output resistor back to 100ohm (i had put 470 ohm there while playing around with OP37). It changed the sound dramatically! So I will have to test opa627 again, I think... a quick "plop in" of the opa627 did sound very different to AD825.
I have noticed that a slight hum is audible with AD825, while there is nothing with opa627, so I guess the latter has better PS noise suppression.
/cdl
opamps
I would like to post a "general reply" to the people asking questions on this thread, and people that are supplying answers.
I realize a lot of the people on this forum like to give their "subjective" opinions of their personal favorite $12 esoteric opamp. Although I believe the opa627 is an excellent amp, I don't believe it's price tag (or performance for that matter)justifies it's worth in an audio circuit. I can tell from the questions posted on this thread that these people are inexperienced, don't try to confuse them so early on in their "audio education".
Start them off with "tried and true upgrades" and then let them decide if they want to experiment with the very real possibility of oscillations and other types of circuit failure from trying to use an IC that was never designed to work in an audio circuit in the first place (AD825/6, the description says for use in video cameras and portable instrumentation).
This is what I call "Setting someone up for failure". when people are set up for failure, they get discouraged and lose interest. Lets all please stick to the facts. I'm not trying trying to start an
" I know everything about opamps " war, all I'm saying is that if you start new people off in this hobby with conventional wisdom and solid facts (NE5532 costs 75 cents in the US and for audio is objectively a better than the $12 OPA627) they have a better chance of succeeding and staying interested, and this is a hobby I believe needs more members.
Enough said, back to the facts!
1. OPA627 is not a drop in replacement for the NE5532. The NE5532 is a dual opamp, the OPA627 is a single. NOT the Same PINOUT (Read: not a drop in replacement). It is illadvised, but you could probably alter the board with some jumpers and sockets that would allow you to use the OPA627. Although after you do, you might find some noise or oscillation may creep into the signal path and spoil your fun. In 99% of all cases, replacement of a NE5532 WILL result in LOWER OVERALL MEASURABLE PERFORMANCE. That is a fact, not my subjective opinion. You can argue all day about this or that opamp having some unmeasurable "mystic sound quality" but the facts are it WON'T measure up. What I hear with my ears, and what you hear with your ears may be completely different, but until they come up with a way to measure this, I'll trust a $10K distortion analyzer over human hearing any day.
2. If you wanted to design an amp stage from scratch, the OPA627 would be a viable (albeit costly) candidate. You could then take into account the characteristics of the OPA627 and design the stage accordingly.
3. Two direct replacements right off the top of my head would be the National LM833 (dual) of LM837 (quad), although they don't quite measure up (distortion and load driving capabilities) they seem to posess low offset voltages for all you "direct coupled, no caps in the signal path" fans. The other is the only other opamp that I know equals the NE5532 in noise and distortion specs: the NJR2114 from New Japan Radio. It is a little harder to find but is excellent in every respect (maybe even slightly better than the ne5532) and may cost slightly more, you could contact NJR.com to find a distributor that handles them.
I hope I didn't offend anybody, as it is never my intention. I just felt it had to be said.
Sincerely,
Brannon
I would like to post a "general reply" to the people asking questions on this thread, and people that are supplying answers.
I realize a lot of the people on this forum like to give their "subjective" opinions of their personal favorite $12 esoteric opamp. Although I believe the opa627 is an excellent amp, I don't believe it's price tag (or performance for that matter)justifies it's worth in an audio circuit. I can tell from the questions posted on this thread that these people are inexperienced, don't try to confuse them so early on in their "audio education".
Start them off with "tried and true upgrades" and then let them decide if they want to experiment with the very real possibility of oscillations and other types of circuit failure from trying to use an IC that was never designed to work in an audio circuit in the first place (AD825/6, the description says for use in video cameras and portable instrumentation).
This is what I call "Setting someone up for failure". when people are set up for failure, they get discouraged and lose interest. Lets all please stick to the facts. I'm not trying trying to start an
" I know everything about opamps " war, all I'm saying is that if you start new people off in this hobby with conventional wisdom and solid facts (NE5532 costs 75 cents in the US and for audio is objectively a better than the $12 OPA627) they have a better chance of succeeding and staying interested, and this is a hobby I believe needs more members.
Enough said, back to the facts!
1. OPA627 is not a drop in replacement for the NE5532. The NE5532 is a dual opamp, the OPA627 is a single. NOT the Same PINOUT (Read: not a drop in replacement). It is illadvised, but you could probably alter the board with some jumpers and sockets that would allow you to use the OPA627. Although after you do, you might find some noise or oscillation may creep into the signal path and spoil your fun. In 99% of all cases, replacement of a NE5532 WILL result in LOWER OVERALL MEASURABLE PERFORMANCE. That is a fact, not my subjective opinion. You can argue all day about this or that opamp having some unmeasurable "mystic sound quality" but the facts are it WON'T measure up. What I hear with my ears, and what you hear with your ears may be completely different, but until they come up with a way to measure this, I'll trust a $10K distortion analyzer over human hearing any day.
2. If you wanted to design an amp stage from scratch, the OPA627 would be a viable (albeit costly) candidate. You could then take into account the characteristics of the OPA627 and design the stage accordingly.
3. Two direct replacements right off the top of my head would be the National LM833 (dual) of LM837 (quad), although they don't quite measure up (distortion and load driving capabilities) they seem to posess low offset voltages for all you "direct coupled, no caps in the signal path" fans. The other is the only other opamp that I know equals the NE5532 in noise and distortion specs: the NJR2114 from New Japan Radio. It is a little harder to find but is excellent in every respect (maybe even slightly better than the ne5532) and may cost slightly more, you could contact NJR.com to find a distributor that handles them.
I hope I didn't offend anybody, as it is never my intention. I just felt it had to be said.
Sincerely,
Brannon
The true about op amps...
For some measures and form of the residual distortion look at:
http://fnt-www.ss.titech.ac.jp/~hajime/uec/distortion/opa.html
Regards
For some measures and form of the residual distortion look at:
http://fnt-www.ss.titech.ac.jp/~hajime/uec/distortion/opa.html
Regards
analysis results
That's an interesting comparison except that at 1kHZ the distortion from all those opamps will be extremely low. At 1kHZ the negative feedback (NFB) loop has a fierce grip on the signal . The upper octave (10kHZ-20kHZ) is where it really becomes evident which amps are superior because the NFB starts to taper off.
Brannon
That's an interesting comparison except that at 1kHZ the distortion from all those opamps will be extremely low. At 1kHZ the negative feedback (NFB) loop has a fierce grip on the signal . The upper octave (10kHZ-20kHZ) is where it really becomes evident which amps are superior because the NFB starts to taper off.
Brannon
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