Important Re Opamp Rolling Plus Version of EE DAC


Regarding Opamp rolling the EE Minimax DAC Plus; NOTE: I have been in contact with Morningstar Audio about the opamps used for the Plus version; It is not acceptable to simply use any of the opamps which worked for the original version. Though the circuit board is laid out similarly the opamps are different enough that not all sets of opamps used for the original version will work with the Plus version.

I had mentioned the LME49990 but upon investigation it is not suitable for the Plus version of the Minimax DAC and you could harm the DAC. You opamp roll at your own risk and could damage the unit if you use inappropriate opamps. I am seeking a listing of appropriate Opamps for the Plus version and will post it when it is available.

Opamp rolling is effective and easy, but please wait until a listing of appropriate opamps becomes available.
douglas_schroeder
Doug,

My friend sold his EE Minimax and also the Minimax Plus just a couple of days ago. He just didn't want to mess around and could not dial out a midbass hump or bloated quality. He borrowed a couple of pricey tubes and got nowhere.

He's going to borrow my Rega DAC for a few days and also give the W4S DAC 2 a second try with a better cable.

It seems a lot of people are doing mods that are quite basic to the sound quality of the Minimax and I don't see that as a good thing. I feel a component should start off on the right foot and get better as you dial it in. I'm sure the Minimax is making a lot of people happy, especially folks who like the DIY angle on gear.

Happy holidays!

Rob
Doug, regarding the LME49990 opamps - please make sure that you have the chips properly oriented with single opamps in the U6 and U7 sockets and dual opamps in the U1 and U2 sockets... afaik, neither Morningstar nor EE has issued a warning regarding use of the LME49990 in the EE DAC Plus.
Get the 'specs'.....the Data Sheet on the OEM opamps.....
Any others with same pinout / voltage should work as well.

Am I missing something?

My headphone amp....a DIY, uses OPA2134 family but about a dozen others will also work.