Cambridge Audio axa35 integrated amplifier ?

Well, you want some 'warmth' and don't need a phonostage or a DAC. Maybe find a used NAD 326BEE.  I've been a fan of NAD class A/B integrateds. Have owned the 326 and 356 BEEs in recent years.

I must say the Cambridge AXA35 seems a strong contender at that budget. I have not heard it however.  The Schiit DAC is likely superior to the one in the Yamaha 301 which I've heard and have recommended at that budget. A great option for budget system serving both vinyl and digital. Again, you need amplification only, owning a disc player and DAC.

I am not familiar with the Onkyo. 

As an after thought, it is best to keep digital components separate from amplification when possible. Each having their own power supply. Given you have a DAC I would choose between the Cambridge or the Onkyo. They have similar feature sets. The Onkyo does have  tone controls that can be bypassed, a nice feature. I believe the fit and finish of the Cambridge to be better. 

Several on line dealers offer 60 day returns. 

OK, my final answer, I would give the Cambridge a try. Will likely play well with your Tektons.  

According to write up on Cambridge AXA35 the balance and time controls are buried in menu but usable

Oops meant to say tone controls

So for giggles I’m trying an Onkyo TX-NR809 AV receiver I had sitting around that I paid $150 for.  This retailed for $1100 years back.   I have it set to Pure Audio mode which limits to 2 channel and bypasses all the DTS And tone control processing.  Well, it sounds pretty good actually.   The $500 I spent on the used Tektons is just about the best money I’ve spent in audio over the years.  Also no need for a subwoofer either.   May still go the integrated route but thinking I’ll have go up the food chain and up my budget so to speak to make a notable improvement in sound quality