looking for a quality integrated that allows for bypassing of the preamp section

Perhaps the simplest solution would be an integrated that has the inputs that allow one to bypass the preamp and use the integrated solely as an amplifier (what's the term for this input?). What feature would I be looking for and could I get some recommendations up to $1500 used?

The most common term is HT Bypass. 

Here is a link to a comprehensive list of integrateds having this feature.  As your looking to buy used you should be able to find one that addresses your needs with your budget.
http://www.audiophile.no/en/articles-tests-reviews/item/426-amplifiers-with-processor-input

paraneer----thank you very much for both the term I was missing and a comprehensive list .  Much appreciated!

paraneer----might there be a list of integrateds that allow you to disconnect the preamp from the amp section via jumpers?  Thanks again.

might there be a list of integrateds that allow you to disconnect the preamp from the amp section via jumpers?

There may be but that feature isn't really HT Bypass. 

The purpose of HT Bypass is to turn an integrated amp into a power amp with the push of just one button and controls its volume from the a remote surround processor.  Bypassing the integrated's preamp section.  And then go back to the integrated's preamp by pushing the same button again when playing a source connected to the integrated.

No changing cables each time you need to use a different preamp but want to use the integrated's power amp section full time.

"The purpose of HT Bypass is to turn an integrated amp into a power amp with the push of just one button and controls its volume from the a remote surround processor. Bypassing the integrated's preamp section. And then go back to the integrated's preamp by pushing the same button again when playing a source connected to the integrated."

Not all on the list function that way. Many just have a direct amp input and the only way to change is disconnect cables. If you can't find an integrated with enough power that has HT bypass via button push or menu selection, then you might try looking for a preamp that switches between active and passive.

I don't mind switching the one pair of interconnects from an input to the direct input to the amp (I've seen this on some of the bigger Chinese muscle integrateds).  The big Shengya and Xindak come to mind but these just never seem to be available on the used market and going through Cattylink means getting them in 220, 230, or 240 v thus the need for a step up/down converter.  That's not a deal breaker necessarily.   Even using the HT bypass, I'd be switching that 1 pair of interconnects between that input and an active one as I'm going direct from the Oppo to the amp with the 2 channel outputs and I use the FRONT outputs from the Oppo to drive stereo subwoofers.  I would prefer not to ad a preamp though as that would require 2 cables swaps each time I went from preamp-less to using the preamp.  Thanks.

Vintage Accuphase 202 would be my choice.

czarivey-----that's an odd choice for the circumstances.  What's your thinking on that recommendation?  I love vintage tuners but never have considered vintage amps.  My thinking is the parts available today are far superior to the old stuff.  Am I mistaken?

lcherepkai
looking for a quality integrated that allows for bypassing of the preamp section

Looks like the Pass Labs Int (integrated) series have preamp inputs, so you can use it as a poweramp.
http://hometheaterhifi.com/wp-content/uploads/2010/08/pass-labs-3.jpg

Cheers George

The more I deal with rebuilding the vintage equipment, the more I'm sure that it's the BEST bang for the buck. The parts used in these units do get old, but replacements are available and they could be serviced to the original specs or better. 

Yeah, there's certainly an avid group of vintage fans.  I had a buddy with an old Sansui integrated who played vinyl exclusively on Def Tech BP-8 speakers to very good effect.  Compared to my system, his was lacking detail and focus but it was always warm, and full-bodied, and very holographic and most importantly, satisfying.  So maybe you have something there.  Thanks.

And George, if I could afford the Pass or Gamut integrateds, I'd already have one of them.  They're both at least 2x what I could afford for this second system and I'm quite pleased with the big tube amp I have in the main system.  (Maybe I should just get that second job, upgrade to my heart's content, and then go from there).  Thanks for the good advice.

I indeed found heaven with my electronic repair tools and I pick up that skill every unit I go through. It brings the joy working on these with FULL detailed service manuals of vintage audio components available at hifi-engine that often show details on how properly calibrate stages after repair!
I’m on project now repairing Sansui G-9000 which is extremely complex..
Prior done with Pioneer SX 636 that sounded very close to tube amp after restoration -- extremely musical and clean.
I started from my friend’s Accuphase E202 that had uneven channels in preamp section and than fully restored unit with new and less noisy power transistors and filter caps.
Did lots of side by side comparisons of modern and vintage restored units and more often than not I give my preference to vintage audio and one of the vast reasons that it’s serviceable and service manuals are PUBLIC and not secret. Another reason that these units had been manufactured by far more honest industry than today’s high-end audio that is rather boutique than functional.