Best replacment for NE5532 in Phono preamp

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corbato

corbato

Member
Joined 2003
#1
As above, I have searched this forum without reaching a conclusion.

The design in question is Rod Elliot Phono (RIAA) Preamp. A simple job, that actually does the job quite well. I use this to transfer LP's to my PC for further processing and burning on CDR.

However, there is a bit of nasty shrillness in the upper middle ranges. This becomes quite evident in loud female vocal material such as Connie Francis etc.

Would changing the opamp make any difference? I have tried OPA2134 with slightly better results in the lower ranges. I have used fairly standard components in my construction and a well laid out homemade PCB. The pre-amp is stuffed into a metal box that sits inside the TT with external power supplies (even for the TT motor). Hum is zero with just a wee bit of noise.
Thanks in advance.
 
#2
As above, I have searched this forum without reaching a conclusion.
Click to expand...

The conclusion which opamp is best can only be made by you yourself. OP275, OPA2134 and OPA2604 are good replacements in general. It is a matter of taste which you like best, try them all for finding out.

If the PCB would tolerate single opamps I would recommend OPA627/627 as they are a lot better than the duals I mentioned. The choice in good single opamps is more diverse than with dual opamps. Maybe something to think about when you design a new board next time ?

Since the preamp is direct coupled I would stick to Fet input opamps as the above mentioned.


BTW Are you sure the nasty shrillness in the upper middle ranges is caused by the preamp ? Level could be too high or the sound card could be the problem etc. etc.
 
#3
Single opamp

Thanks jean-paul,

I am coming around to building a new layout which will take a single opamp. I've requested OPA627's. The only limiting factor is the size - the board should fit into the 3"x2.5" shielded box inside the TT.

I use an M-Audio Audiophile 2496 sound card with quite happy results. That shrillness persists even if I hook up with a SE 6BQ5 amp. Reducing the gain does help some how, but it brings other problems further down the road. The M-Audio likes to see near optimum input level for the processing that I do such as click and pop removal.

Alternatively I will be looking forward to your recommendation on a new design for the phono preamp.

Thanks again and best regards.
 
#4
Hmmm....
Are you sure this shrilliness is not on the original LP? And are you sure that the turntable (arm blance, catridge adjustments, etc.) are correct? These make a difference.

I have the Elliot phono board too. It's nice with OPA2132 at the front and OPA604 in the back. However, I have the Hagerman Bugle which I actually like a little better.

mlloyd1

corbato said:
... However, there is a bit of nasty shrillness in the upper middle ranges. This becomes quite evident in loud female vocal material such as Connie Francis etc....
Click to expand...
 
#5
mlloyd1 said:
Hmmm....
Are you sure this shrilliness is not on the original LP? And are you sure that the turntable (arm blance, catridge adjustments, etc.) are correct? These make a difference.
Click to expand...

I use a 6DJ8 RIAA phono pre-amp for my regular listening without getting that shrillness. The TT has been setup quite satisfactorily after many months of tweaking. I could use the 6DJ8 outfit for my PC transfers, but then this pre-amp has a bit of hum, while the Rod Elliot design is absolutely quite. This means an additional processing at the PC to remove the hum. I prefer to have minimum digital processing.

I must try the Hagerman. I decided not build it earlier 'cause of some real oddball resistor values it calls for. I think it can be squuezed into the small enclosour that I have - a major design parameter.

Could you tell me in which the Haggerman is better than Rod Elliot?

Thanks so much for the info.
 
#6
corbato said:
As above, I have searched this forum without reaching a conclusion.

The design in question is Rod Elliot Phono (RIAA) Preamp. A simple job, that actually does the job quite well. I use this to transfer LP's to my PC for further processing and burning on CDR.

However, there is a bit of nasty shrillness in the upper middle ranges. This becomes quite evident in loud female vocal material such as Connie Francis etc.

Would changing the opamp make any difference? I have tried OPA2134 with slightly better results in the lower ranges. I have used fairly standard components in my construction and a well laid out homemade PCB. The pre-amp is stuffed into a metal box that sits inside the TT with external power supplies (even for the TT motor). Hum is zero with just a wee bit of noise.
Thanks in advance.
Click to expand...
check out this URL's:
http://www.nanovolt.ch/resources/ic_opamps/pdf/opamp_distortion.pdf
https://pdfs.semanticscholar.org/f0b1/73d0f261554b3a7d73c370db303c27240c85.pdf
Amazing opamp measurement shoot-out
 
#7
LT1115 and m5220 (from cassette players).They both allow higher voltage rails.The overload behavior is directly linked to the max supply voltage and the ability to source enough current .These 2 op-amps are way better than many other for riaa pre.
 
#8
> check out [these] URLs

All those papers are obsolete, as none of them mentions the LME497x0 series, which is not only orders of magnitude better than anything mentioned therein but also cheaper, and specifically 40 times cheaper than the OPA627. Check out the LME49720 or the equivalent LM4962, but be quick as they have end of life'd them.
 
#10
For moving-magnet cartridges, their ultra-high current noise makes the LT1115 and LM4562 less suitable - although if you are only interested in the noise with a record playing, the record's surface noise tends to dominate anyway unless you do something really stupid, like choosing ultra-high current noise op-amps and connecting a bunch of them in parallel (like this Elektor design: Supra 2.0 | Elektor Magazine ).
 
#11
Indeed , the lt1115 has twice the current noise of ne5534 and 4 times less voltage noise...but the only problem and BIG one is the input impedance which is too low for mm cart...I had in mind a transimpedance preamp schematic with a transistor front end.If the mm cart is connected straight to the op-amp than there aren't many available choices...OPA2132 is better than opa2134 and OPA1542.On paper opa1642 showed better noise specs while in real life the OPA2132 was significantly better. Njm2068 is really good though while OPA2228 looks best .
 
#12
Doesn't the feedback increase the input impedance to some astronomic value?

The LT1115's current noise is worse than it seems at first sight: you have to reverse-engineer it from the "total noise versus unmatched source resistance" graph, because the spec table value only applies when the impedances driving the positive and negative inputs are equal, which almost never happens in real life. The same holds for the LT1028. In both cases, the noise current is about 3 to 3.25 pA/sqrt(Hz) rather than 1 to 1.2 pA/sqrt(Hz).
 
#13
MarcelvdG said:
Doesn't the feedback increase the input impedance to some astronomic value?
Click to expand...
Not really sure about that at high frequencies with a riaa network and under overload condition when hitting the supply rail...I'd rather go with a transimpedance design with a transistor front end and i actually have a better suggestion to make than the ESP design , a very cheap design too, but usually nobody asks me anything 😉
 
#14
we have a long thread on transimpedance MM on here. I have a balanced transimpedance MM board I really need to get hooked up for testing. With some tricks it has exceedingly good noise performance. Turd polishingly good in fact 🙂
 
#19
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