Topic: Opinions on UA5 A/D Converter?

[Brian Skalinder]

Brian, they go through a gain stage, or just an attenuator?  I never tested it, but I didn't think you could actually amplify the line-in signal.  Pretty cool, actually.

Good question.  I remember a note from Doug mentioning the specific op amps used through the RCA inputs, but I don't think I have the email any longer so I can't relay the specific op amp number.

Had to do a bit of research, but apparently op amps are used to amplify the differential between two input voltages and are thereby able to provide an increase in gain (positive voltage differential) or decrease in gain (negative voltage differential).

So...the answer to whether the RCAs go through a gain stage is:  yes, an op amp gain stage (wish I had the part # from Doug's email).  And I believe the op amp gain stage may be positive or negative.

but I think part of these mods actually improves the analog input and may actually improve the sound when bypassing the mic in and usind the rca inputs.

Nope, the Oade mods only upgrade the op amps through the XLR mic inputs, not the RCA inputs.

[Terps]

most of the op-amps in the ua-5 are the same p/n.

[Brian Skalinder]

My previous post was incorrect.  Wouldn't be the first time.    Specifically, about whether the Oade warm/presence mods improve the RCA inputs as well as the XLR mic inputs.  Saw this over on Oade, thanks to Lyle for posting over there and Doug for getting back to him:

The RCA inputs do benefit from the MOD, but there is still one stock Op Amp in circuit with the RCA path, still the most critical ones have been replaced. It should be easy to hear , still the best way to know !
peace...Doug

[drumminj]

Great, Lyle.  Way to ruin our fun by introducing facts rather than let us argue with each other based on speculation.  D'oh.

That is good to know, though.