impact of op amps on preamp design

any cdp from the 80's would have a R2R or ladder dac, which is arguably a superior dac, compared to a modern delta-sigma one bit type. some of your impression of quality may come from that side of the equation.

Dunno about generalities but I've had poor experiences with companies on the discrete only crusade (reliability & sound) and I opened up an old CD player from the 80s which had impressed me with it's headphone out to find a single JRC opamp clinging to the back of the jack.

I've also noticed many discrete component companies simply mimic the circuit of the opamp with larger components. If that's the route you're going may as well just buy a component with an op-amp to begin with. There are mini discrete boards you can drop into their slots to compare such as the Sparkos Labs product.

I prefer tubes but I've heard opamp based circuits sound quite good. Execution is pretty important regardless of the devices used.

Give it a listen- if you can live with it and love it is what is important.

I know almost nothing about electronics, but I do know what sounds good to me. I own a Morrison Elad pre based on op amps and it sounds very good. I since bought a Lamm, which is better, but the Morrison still sounds good. I think op amps were just one of those popular whipping boys because they weren't handmade, exotic or tubes.

opamps tend to have one defining characteristic to their sound and that is a slight thinning of dynamic envelope. It has to do with their origins all being in a single bit of sand or silicon. And that all internals are of a silicon nature, capacitors, resistors, transistors, all that is internal to the chip is of a silicate nature. The dielectric effects, and so on, all related to the single mini slab of silicon that is in the given chip.

Discrete is much the same, but that the substrates of some may be different than another in the same circuit. Plus the size of the given transistor junctions are different, thus thermal effects upon dynamic expression of signal is different, as well the self noise is different than the chip.

Then the ancillary devices of outboard capacitors, outboard resistors, trace sizes and lengths, how they interact with their given environments be it bare wire, enameled wire, and skinned wire and traces on boards and the boards interacting with the traces..and the components and their distances from one another having their given electromagnetic interactions. As well as mechanical motion causing an injection of motor noise.

All that being said, discrete can sound very rich and vibrant and opamps can sound very sterile. Just the two wildest swings of the given spectrum of expected  and mentally projected sonic signatures.

Those stereotypes still hold true today as a broad reality of potential differences in opamps vs discrete circuitry.

Surface mount technology in discrete is making surface mount technology sound more and more like that of the given best opamps, so one has to be careful in their comparisons.

Suffice it to say there are good examples of each type, ie, full size (to-92 and to-220 size devices, etc) discrete transistor... vs that of surface mount smaller discrete... vs single chip opamps and their supporting circuitry (power supplies, coupling caps, etc)..which is generally fully discrete in sizing.

What I’m trying to say is that there is overlap in perceived qualities of each type, and any given one may be perceived as being ahead in quality, of any other.

IMO and IME, when to comes to pinnacles of quality in each type, full sized discrete still wins..when everything is optimized.

Personal results will vary due to individual tastes, individually created hearing experiences and physical design of the given ears/experience/training..and individual emotional leanings in perception and desires....and so on.