Amp/Preamps vs. High end AV Receivers


Hi,
I am sure this topic had been discussed exhaustively. I am new to this arena looking for some help to upgrade my Onkyo AV Receiver (135 w/channel). I am debating whether to the AV route or the AMP/Preamp combo. Naturally, I understand that I get what I pay for.

Would appreciate some inputs and suggestions regarding:
1. AMP/PREAMP combo route - 
2. AV route

I am not looking at a huge budget but a decent one. 

Thanks in advance
terrancej
I can't afford really high-end expensive gear but that being said I have my "analog" system which consists of Emotiva separates which cost about the same as my Denon w/atmos and neural x for home theatre. About the only difference my aging ears can tell is that Emotiva separates seem to have better low end or more precisely go lower.
I've not found that inexpensive speakers mean that there isn't a benefit from better electronics. They seem to benefit quite a lot.
Regardless of what is being played- HT, music videos or 2 channel, my prior comments apply regardless. In a nutshell, **all** single-box audio systems are compromised in order to get everything in one box. The more the separate aspects of a HT system are broken out to separate components, the more **potential** exists for vast improvement.

Back in 1999, Stereophile, at a Stereophile Show in NYC, set up two Home Theater rooms side by side. The two rooms were identical (being in a hotel) and the video equipment was identical as well. One used a regular home theater receiver/processor, the other used separates. A poll that they took showed that 90% of people visiting both rooms thought that the room with the high end audio system had a better picture!

@jdub071 What speakers do you have? Your experience depends on the speakers. The op here has speakers that are quite a value for money and need good amount power to get them singing.

These days one can get excellent 2 or 3 channel amp with great measurements, one must consider their speaker before getting an amp however.
I have B&W 600 S3, 602 S2, 605 S2 and LCR6 S2's that I bought new about 17 years ago. These I run in my bedroom with a Denon AVR-X2400H receiver w/55 inch 4K Samsung TV. For my audio I have emotiva Bas-x 150 amp w/pt-100 preamp with either ELAC B6's or B&W 685 S2's w/polk 10 inch subwoofer. Terrencej said he was not looking at a huge budget so I guess all that is in the eye of the beholder or rather ears.
@jdub071 Denon AVR-X2400H is not even rated for 4 Ohm. As long as it works for you that is good. What levels do you listen to normally?.