Voltage presence in phono preamp inputs? Is it right?

[wrankin]

@Mooly,

I will try the OP2134 then

@Mark,
cannot really comment on that, my knowledge about electronics is
really poor and very basic although I like (and try) to learn

Actually, on Rod Elliott's construction page for the P06, more specifically the op amp section of the "Guide to Components" page, he specifically mentions the use of the OPA2134 (versus the NE5532) because of the very low input current in case you are concerned about reducing the DC offset.

Question - does anyone have measurements of the input currents / offsets for other well-regarded phono preamp designs (commercial or DIY)? I think it would be an interesting comparison.

Thanks,

-bill

 

[Ian Finch]

With the help of tutorials such as https://www.analog.com/media/en/training-seminars/tutorials/MT-038.pdf , datasheets are the easiest way to select the best opamp for the application, be it for noise, offset current, voltage etc. However, there is also the price and availability factor. You simply can't buy the best genuine, current products for just 50c through an online selling platform, as I've seen OPA2134 offered recently.

Also visit TI's site for the masses of multiple references, docs, tables and performance comparisons they keep there in the public domain.

 

[guentir]

The EP06 is a good one.
Use the "right" values to get a flat response with little noise:

 

[safe1]

Hi again and many thanks @Mooly
I have finished my P06 build and i tried both
Opa2134 and AD823.

AD823 is the clear winner in my system, definitely
much more detailed with better soundstage than
OPA2134.

Well AD823 chips are more than double the price
of 2134, makes sense.

I'd say P06 sounds really good, very good...
My old creek obh-8 with nichicon muse capacitors
has really a very hard time to keep up with P06 (with the AD823 chips)
in terms of musicality and detail...

Money well spent for the P06.
I'm expecting the muffsy kit to arrive too though so the winner
of all three will be permanently connected to my TT and i'm done with it,
I hope

 

[Mooly]

Thanks for the update and I'm pleased to hear its all working well.