Success Rolling Opamps in EE Minimax DAC

Thanks for all you time and effort. Cant wait to hear the news considering I just placed an order for one (very first DAC for my new jolida tube int. amp). For the meantime, I will be enjoying it when I do get it.

Doug, what tube are you using with you DAC?

At the moment I'm not using anything exotic, just the stock 12AU7 tube. The reason is that for testing Opamps I felt it would be far more beneficial to use the stock unit's tube as opposed to an alternative. If I use the stock unit in testing Opamps the results are applicable universally, versus for a subset of those who roll tubes.

I've got a couple others but no time now to work with them post-Opamp rolling.

i own the minimax dac. i have several nos tubes. i believe that if you use the tube gain stage, you bypass the opamp. is this correct ?

if this is correct, it may be more productive of your time to tunr the dac with a tube rather than try to find a suitable opamp.

also, if i am correct isn't the absence of an opamp preferable to the presence of an op amp ??

Mrtennis, to my ear the influence of the Opamps supercedes that of the tube rolling.

I'm checking on the SS/tube output question.

Doug, As you know there are two pairs of opamps in the EE DAC: Two NE5532 dual opamps for I/V (current to voltage) for tube and solid state; and two NE5534 single opamps for solid state output only.

Operating the EE DAC with the tube stage engaged bypasses the single opamps' circuit.

I generally prefer operating the DAC in solid state mode and found that rolling a variety of quality (read "expensive") tubes didn't have nearly the beneficial effect as did switching to your LME497X0 opamps.