Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Analog Line Level Preamplifiers , Passive Pre-amps, Crossovers, etc.

Drop in replacement for NE5532?
Drop in replacement for NE5532?
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 25th June 2019, 12:57 AM   #201
BigE is offline BigE  Canada
diyAudio Member
 
BigE's Avatar
 
Join Date: Aug 2008
Location: Toronto
Fwiw, the benchmark dac went from the 5532 to the 4562.
  Reply With Quote
Old 25th June 2019, 12:58 AM   #202
anatech is offline anatech  Canada
diyAudio Moderator
 
anatech's Avatar
 
Join Date: Jun 2004
Location: Georgetown, On
Drop in replacement for NE5532?
Hi BigE,
That may be, but was there actually a performance increase, or was it a case of feel good?

-Chris
__________________
"Just because you can, doesn't mean you should" my Wife
  Reply With Quote
Old 25th June 2019, 02:03 AM   #203
mlloyd1 is offline mlloyd1  United States
diyAudio Member
 
mlloyd1's Avatar
 
Join Date: Feb 2001
Location: Northern Iliinois
Drop in replacement for NE5532?
From what I've seen of Benchmark, I'd "guess" (I know, I know ) it was performance increase.
Unless they actually advertise that they made this op amp change.

mlloyd1
  Reply With Quote
Old 25th June 2019, 02:16 AM   #204
anatech is offline anatech  Canada
diyAudio Moderator
 
anatech's Avatar
 
Join Date: Jun 2004
Location: Georgetown, On
Drop in replacement for NE5532?
Well, if the op amp change was early on, like the DAC I/V or first couple filters, I can see there being a performance increase. As the output buffer, I highly doubt there would even be a measurable difference. It's all a matter of application.

-Chris
__________________
"Just because you can, doesn't mean you should" my Wife
  Reply With Quote
Old 25th June 2019, 02:21 PM   #205
Mark Tillotson is offline Mark Tillotson
diyAudio Member
 
Join Date: May 2018
Location: Cambridge UK
Quote:
Originally Posted by mlloyd1 View Post
From what I've seen of Benchmark, I'd "guess" (I know, I know ) it was performance increase.
Unless they actually advertise that they made this op amp change.

mlloyd1

So you haven't measured it. The 4562 has more current noise, which might be an issue, or not, depending on the circuit details and whether noise or distortion dominate. Apart from this its slightly better than 5532, but more expensive - however its getting cheaper and is only about 3 times the cost of the 5532.


For many DACs the choice of opamp is more convenient if 5V-capable and rail-to-rail, saving the need for extra power supplies. There are some excellent performers out there, not normally on the audio radar (since not +/-18V), I've played with the AD8656 dual which is genuinely rail to rail, can easily drive 16ohm headphones directly (+/-220mA), 2.7nV voltage noise, CMOS input (negligable current noise), typical offset 50V and 0.0007% SiNaD. Great match for a headphone DAC. One downside is relatively high flicker noise knee though, but it looks promising for future CMOS input opamps.
  Reply With Quote
Old 25th June 2019, 06:31 PM   #206
Mark Tillotson is offline Mark Tillotson
diyAudio Member
 
Join Date: May 2018
Location: Cambridge UK
This inspired me to knock up some Python and plot combined noise plots for various opamps, total theoretical voltage noise due to opamp and a single resistance R (Johnson plus current noise).
Click the image to open in full size.

Clearly, if 5V devices are ignored, NE5534A still wins from 2k to 40k impedance, basically the range of almost all active filters and general signal processing... The 5532 isn't as quiet but cheaper, dual and no compensation caps needed, still good for most of this range.
This is MM cartridge territory.

Going to lower impedances the LM4562 comes into its own, and for even lower the AD797 (MC cartridge territory, dynamic microphones)

But if you are prepared to limit to 5V operation the AD8656 totally trashes all comers above 1k.


I've randomly assigned JFET and CMOS input current noise density as 10fA, which is probably an over-estimate - its effectively zero at any practical impedance.



Code:
from math import pi, sqrt
 import numpy as np
import matplotlib.pyplot as plt
from matplotlib.ticker import FormatStrFormatter

# data for opamps, name, current noise density, voltage noise density, plot colour
opamps = [ ('NE5534A', 0.4e-12, 3.5e-9, 'r'),
           ('NE5532',  0.7e-12, 5.0e-9, 'g'),
           ('LM4562',  1.6e-12, 2.7e-9, 'y'),
           ('TL072',   1e-14,   18e-9,  'b'),
           ('AD8656 (5V)', 1e-14,   2.7e-9, 'k'),
           ('AD797',   2e-12,   0.9e-9, 'c'),
           ('uA741',   8e-12,  80e-9,   'm') ]

# Boltzmann's constant and Johnson noise factor
k = 1.38e-23
T = 300
factor = 4*k*T

# setup plot
fig = plt.figure()
plt.title ("noise")
ax = fig.add_subplot (111)
ax.set_xlabel ('R')
ax.set_ylabel ('nV')

# vector of resistances
Rvec = np.logspace (1.3, 6, 100)
# Johnson noise in nV
Rnoise = 1e9 * np.sqrt (factor * Rvec)
ax.loglog (Rvec, Rnoise, 'k', label='Johnson noise')

for device, CN, VN, colour in opamps:
    Vnoise = 1e9 * np.ones ([Rvec.size], float)*VN  # voltage noise of opamp in nV
    Inoise = 1e9 * CN * Rvec                        # voltage noise due to current noise into R
    ax.loglog (Rvec, Vnoise, colour)
    ax.loglog (Rvec, Inoise, colour)
    total_noise = np.sqrt (np.square(Rnoise) + np.square(Vnoise) + np.square (Inoise))
    # plot total noise with circle
    ax.loglog (Rvec, total_noise, colour+'o', label=device)

# Make axes tidy and set limits
ax.grid(which = 'both')
ax.set_ylim (1, 200)
for tick in ax.get_xticklabels(which = 'both'):
    tick.set_rotation(90)
ax.xaxis.set_minor_formatter(FormatStrFormatter("%i"))
ax.xaxis.set_major_formatter(FormatStrFormatter("%i"))
ax.legend(loc='upper left', shadow=True, fontsize='x-large')

plt.show()
  Reply With Quote
Old 25th June 2019, 06:38 PM   #207
anatech is offline anatech  Canada
diyAudio Moderator
 
anatech's Avatar
 
Join Date: Jun 2004
Location: Georgetown, On
Drop in replacement for NE5532?
Hi Mark,
Limit this to dual devices. The NE5534A is a single op amp. You can't put it in the same place as a dual. Also, TL072 isn't a particularly great sounding op amp. Looking at your information I can see why someone would try it and leave disappointed. It is a Fet input op amp as well.

Try modeling an OPA2134 (another FET) and the OPA2132 for giggles.

-Chris
__________________
"Just because you can, doesn't mean you should" my Wife
  Reply With Quote
Old 25th June 2019, 07:02 PM   #208
Mark Tillotson is offline Mark Tillotson
diyAudio Member
 
Join Date: May 2018
Location: Cambridge UK
Noise levels only matter for low level parts of the signal chain, otherwise all opamps will sound the same (under double-blind conditions). TL072s were/are commonly used in tone controls and EQs to avoid DC offsets causing potentiometer noise - for this application lack of potentiometer noise is what constitutes sounding good!


This isn't modelling, its calculating from the published noise specifications. Device variation is not allowed for, variations between different manufacturers isn't allowed for, flicker noise knee frequency isn't allowed for.


But it shows that choice of opamp for noise performance is completely dependent on the circuit impedances involved. At 10k for instance changing a 5532 for anything but two NE5534A's (on an adapter!) makes no sense. At 600 ohms changing to an AD797 makes sense. Of course if distortion is also important these priorities will change somewhat.



The OP2134's sweet spot seems to be 20k to 100k, probably a good TL072 replacement for those tone controls or active filter use.
  Reply With Quote
Old 25th June 2019, 10:21 PM   #209
BigE is offline BigE  Canada
diyAudio Member
 
BigE's Avatar
 
Join Date: Aug 2008
Location: Toronto
Have a look at the op37ez.
  Reply With Quote
Old 26th June 2019, 02:08 PM   #210
Mark Tillotson is offline Mark Tillotson
diyAudio Member
 
Join Date: May 2018
Location: Cambridge UK
OP37 only stable for gains >= 5, so rarely useful. The figures are good apart from the input bias cancellation, which means the current noise in the datasheet can only be trusted for equal impedance on both inputs, rarely the case (except for a differential amp circuit).


Probably a good choice for balanced microphone preamp, unknown noise performance in follower, filter, and similar circuits at high impedance due to the unknown current noise in asymmetric configurations.


Figure 7 in the datasheet https://www.analog.com/media/en/tech...heets/OP37.pdf does show curves for both matched and unmatched input resistors from which one can infer the common mode and differential mode current noises if you want. Its the same type of plot as mine so can be compared.
  Reply With Quote

Reply


Drop in replacement for NE5532?Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Replacement for NE5532 bmoraru Solid State 189 6th December 2017 05:55 PM
Replacement of NE5532 op amps in Meridian speakers azl Chip Amps 11 25th June 2016 08:07 PM
input NE5532 replacement T-Dot Digital Source 9 8th October 2009 04:39 PM
Is there a drop in replacement for D260 Mats J Multi-Way 1 21st March 2009 02:27 PM


New To Site? Need Help?

All times are GMT. The time now is 12:47 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©1999-2019 diyAudio
Wiki