Best replacment for NE5532 in Phono preamp

[corbato]

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.

[jean-paul]

As above, I have searched this forum without reaching a conclusion.

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.

[corbato]

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.

[mlloyd1]

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

Originally posted by corbato
... 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....

[corbato]

Originally posted by mlloyd1
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 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.