I have a power amp that uses NE5534N op amps for the electronic balanced inputs, it is in a unity gain configuration. It looks as though these are dead and I would like to replace them with the best quality modern op amps having the same pin out. Can anyone tell me which would be the best new device in terms of sound quality? Since there are only two of them I am not too concerned about the price, quality of sound is most important.
The 5534s use a local +/-15V which is very simply derived from +/-90VDC main rails by 4W 1K5 resistors supplying 15V/1W Zeners. The resistors run quite hot. It seems quite a rudimentary regulation system. The rails seem quite stable but I could imagine they might move a bit if the amp was being used to anything like its full extent. I hope this helps?
Op amps in small-signal audio design - Part 3: Selecting the right op amp
Hi, worth a read, from a big fan of the 5534, should know what is better, rgds, sreten.
Add the supply decoupling caps as described above if they are not there.
Hi, worth a read, from a big fan of the 5534, should know what is better, rgds, sreten.
Add the supply decoupling caps as described above if they are not there.
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Hi,
Am no expert on Op-Amp or such,but the 5532 is a Dual Op-Amp where as the 5534 is a single, so they are not same (as in plug in replacement) !
If you are looking for the best,cost no bar then I can suggest you to look at Burson Audio's Discrete Op-Amp which most claim is the last word in Op-Amps !!
Hope this helps !
Regards.
Am no expert on Op-Amp or such,but the 5532 is a Dual Op-Amp where as the 5534 is a single, so they are not same (as in plug in replacement) !
If you are looking for the best,cost no bar then I can suggest you to look at Burson Audio's Discrete Op-Amp which most claim is the last word in Op-Amps !!
Hope this helps !
Regards.
There are number of ultra-super-low distortion opamps now... you'd have to check to see which are unity gain stable, AND to look at ur schematic to see if the 600ohm drive capability is needed. If it is, then you have to select from those that have the same drive capability.
Perhaps if you can post the schematic and model?
Afaik the 5532 is a dual of the 5534...
What I wonder is if they use the same die topology as they did when it first came out or if it has been internally changed over time.
Oh, I'd put sockets in the holes and plug in different opamps and see which sound best, if any...
_-_-bear
PS. using an opamp as a unity gain stage (buffer) in the front end of a power amp is somewhat unusual, I'd expect some gain there. Are you sure that is what it is, and it's not a servo??
Perhaps if you can post the schematic and model?
Afaik the 5532 is a dual of the 5534...
What I wonder is if they use the same die topology as they did when it first came out or if it has been internally changed over time.
Oh, I'd put sockets in the holes and plug in different opamps and see which sound best, if any...
_-_-bear
PS. using an opamp as a unity gain stage (buffer) in the front end of a power amp is somewhat unusual, I'd expect some gain there. Are you sure that is what it is, and it's not a servo??
The NE5534 is still a great device. Be aware that more modern faster opamps may well oscillate in an old circuit - this is more of a factor with the 5534 because it requires external compensation components.
Dropping 90V to 15V by simple zener shunt regs is, to be quite honest, an extremely poor way to do it. Expect those resistors to fail at some point.
Dropping 90V to 15V by simple zener shunt regs is, to be quite honest, an extremely poor way to do it. Expect those resistors to fail at some point.
Not if you use properly rated resistors. And as for the supply design, it's a simple version of shunt reg....i would prefer it by length over those standard regulators. You just have to carefully filter it with a good elcap.
Hi,
I'm always getting the single and dual versions confused, but :
(Surely you'll need four of them not two, for stereo balanced inputs ...)
LME49710 - High Performance, High Fidelity Audio Operational Amplifier
D. Self is a champion of the 5532/5534 so if he says its better it probably is.
The 5534 is better than than the 5532 bandwidth and slew rate wise
as its compensated for gains > 3 rather than unity. The LME49710
is unity gain stable. It depends on the gain used in your application
as to whether a less compensated op-amp might work better.
Short version for audio is its very difficult to improve on the 5534,
but very easy to spend a lot more for no real quality gains.
rgds, sreten.
5534 also has less noise than than the 5532, I understand it
parrallels the the input sets of transistors of the dual version.
I'm always getting the single and dual versions confused, but :
(Surely you'll need four of them not two, for stereo balanced inputs ...)
LME49710 - High Performance, High Fidelity Audio Operational Amplifier
D. Self is a champion of the 5532/5534 so if he says its better it probably is.
The 5534 is better than than the 5532 bandwidth and slew rate wise
as its compensated for gains > 3 rather than unity. The LME49710
is unity gain stable. It depends on the gain used in your application
as to whether a less compensated op-amp might work better.
Short version for audio is its very difficult to improve on the 5534,
but very easy to spend a lot more for no real quality gains.
rgds, sreten.
5534 also has less noise than than the 5532, I understand it
parrallels the the input sets of transistors of the dual version.
Thanks for the suggestion but I on't think I will be going in for non-IC circuits.
Thanks for the input. The amp is an 80s HH VX-1200 studio/broadcast/HiFi amp, I could post the schematic but is there a limit on file sizes? It doesn't need 600 ohm drive I don't think. This op-amp is being used as a differential amp to receive the +ve and -ve signals from an XLR input. Feedback and input values are the same (22K) with a CMRR pot on one input. Gain is performed further on by discrete components.
It is a simple way of regulating and the resistors are mounted up in the air and obviously get hot. They haven't failed after 25 years but I think their demise might be imminent. I could imagine that noise from the 90V rails might get back into the inputs. Is the 33pF attached likely to be the ext compensation component you describe?
Hi,
the schematic is here : http://www.soundservicesni.co.uk/downloads/schematics/VX1200.pdf
The 33pF is the compensation capacitor, usual value is 22pF.
rgds, sreten.
the schematic is here : http://www.soundservicesni.co.uk/downloads/schematics/VX1200.pdf
The 33pF is the compensation capacitor, usual value is 22pF.
rgds, sreten.
I bet that most of the recordings we know from the last 30+ years went through at least one 5534 during production - I mean mixdown and mastering. Some of the really high-end sonic parts in the production line like the Neumann, bfe or Lawo summing units use the NE5534AN, the one with the better noise specs, together with hi-Q transformers.
The NE5534N and the less noisy brother are definitely better sounding than the NE 5532 dual versions, which you will find in true professional circuits quite rarely.
The NE5534N and the less noisy brother are definitely better sounding than the NE 5532 dual versions, which you will find in true professional circuits quite rarely.
the circuit topology, values are less than optimum - common mode input Z not balanced, cm frequency response not balanced
impedance too high for decent noise performance, esp with bjt input op amp
don't replace with "low noise" 1 nV bjt op amp - the current noise will be too high with 22 KOhm, the R give >20 nV/rt Hz noise by themselves
impedance too high for decent noise performance, esp with bjt input op amp
don't replace with "low noise" 1 nV bjt op amp - the current noise will be too high with 22 KOhm, the R give >20 nV/rt Hz noise by themselves