Audio Research I/50 vs Decware (int.amp) La Scala- has anyone compared in 2-Channel Home Audio Posted August 23, 2022 1 hour ago, RealMarkDeneen said: The devil is in the details: "properly designed and executed tone control circuit does not degrade the signal quality ...." That's the challenge. Engineers would spend a lot of time arguing first over, "just what should a useful tone control DO?" Is 20dB boost at 30 Hz, necessary? Is 3dB cut at 1kHz enough? What's the value of 10dB cut at 20kHz? Maybe a 10-band parametric EQ should be embedded into a preamp? In fact, is "tone control" a different entity from "equalization?" The number and quality of parts involved surely is an issue for cost and SQ. Scratchy pots, cheap capacitors, additional stages, certainly are parts of the decision. Extra stages absolutely 100% WILL alter the SQ. I doubt any audio engineer would argue against that. The system also presents issues. If bookshelf speakers are in use, isn't SOME bass-boost useful? In certain glassy rooms, or if using some peaky phono cartridges, isn't some treble cut useful? Also, no two producers agree on how to EQ and master recordings, so there is no consistency there to rely upon. The last statement about the reasons TC were eliminated is a dubious opinion. A more likely reason is that engineers could not imagine a TC system that would be meaningful for "most" of their buyers. If you look at the older circuits, from say a PAS 3, I doubt many contemporary users would find it useful as all the cuts and boosts are centered at 1kHz. Possibly useful in 1968, but today? I think a good reason to leave them off might be that parametric equalizers are a better answer for people who like to fiddle the tone. Just guessing about what tone adjustments would be useful sounds like a deadly waste of time. I don’t think “guessing what tone adjustments would be useful“ is any more of a “deadly (?) waste of time” than, say, decisions that go into a speakers crossover points, frequency cut-off, etc…. Besides, all McIntosh, Luxman, and Accuphase integrated amps that feature tone controls also have defeat switches. This makes it easy for the listener - when they encounter an imperfectly recorded song - to decide for themselves if adjusting bass and/or treble improves the sound or makes it worse. If the latter, then leave them zeroed or hit the defeat switch. The argument that the additional signal breaks needed for tone controls or even their defeat switches somehow deteriorates the signal is utterly ridiculous in my opinion. Take a look at a mixing board. Pretty much every audiophile approved recording from Steely Dan to Diana Krall to Norah Jones was produced using a mixing board with literally hundreds and hundreds of signal breaks required by the various pots, sliders, and switches. Yet the music that comes out the other end of these things is thoroughly enjoyable. …If every signal break deteriorated the sound then what would come out the other end of a mixing board would be unrecognizable. Btw, I’ve had my McIntosh integrated for nearly 8 years and there is not one iota of scratchiness or noise in any of the switches.