[Akku]

Maybe it is not exactly the right place but I have seen a lot a discussion here about op-amps and I guess there are people willing to give me an advice.
I want to try to change the NE5534’s in my phono pre-amp. Apart from minor changes in the power supply, is exactly the Trigon you can see here http://www.tnt-audio.com/ampli/trigon_e.html
It has a dual stage, the first is an LT1028CN8 and the second the NE5534AP. The RIAA also is split in two: a LP passive filter and the rest in the feedback loop of the 5534.
I wonder why the designer used such an expensive op-amp in the first stage to end with the 5534 but I guess it was noise voltage he had in mind and in fact the 5534 is said to work very well in phono stages.
At the moment I am thinking about:
1) Another 1028
2) AD797
3) AD843
4) OPA627 or 637
5) OPA134 (I have tried it yet, not bad)
Any suggestion, minding that: a) I cannot use SOT chips (no room for an adaptor); b) I cannot change rails (+/- 12v).
Thank you

 

[guzzler]

the choice that stands out is the AD797: it's a bi-polar chip like the 5534, it's got ridiculously good noise figures, and a phono stage is one of the places an AD797 makes sense. However, it is an exceptionally fast opamp, so you may want to carefully assess feedback, compensation, and decoupling so it might not be a drop in replacement. Without seeing the schematic, it's hard to tell. The article mentions DC offset, and with a fast chip like the AD797, oscillation could occur and potentially make it even worse

g

 

[Akku]

Thank you, Guzzler.
This is what i guessed of the circuit around the 5534.
DC offset: the claim of 200mv offset in the article seems very strange to me. Mine has only +6/+2,7mV at the 5534's output. The offset is null after the 10ohm resistor in series just before rca output.
Is it worth a try?
Maybe I would be safer with a fet imput op-amp?

I forgot to say: I am an absolute beginner, please forgive me if I draw something absurd.

 

[Akku]

I tried the 797 as a substitute for the 5534. It works but I was not satisfied. The bass is weaker and the tonale balance is a bit harsh. I don't know if it is caused by the 797 oscillating in that configuration but I was a bit disappointed. So I tried the 797 in the first stage and the 1028 in the second instead of the 5534: wonderful!I got even less offset than in the original circuit (LT1028 in the first gain stage and NE5534 in the second) that in comparison seams veiled and laid-back.
This was just the last tweak to the phono stage. I changed all electrolitics for BG an Elna Duorex II (FC's in the separate PS), replaced the diodes with epitaxials, changed the poliester films for polipropilene film and foil and polystirene.
I was thinking about bulding a Pearl (Nelson Pass) but for the moment I am really satisfied.