Responses from allanblissett

Not sure what to think
If you can stretch the funds,  go for the C2700,  tubes, better dac, and lots of McIntosh bling.  Then later upgrade the speakers and the OPPO.   
NAD M23 and a Stereo Pair of REL Subs
Just feed the subs from regular rca line out from your preamp. I have a REL and found no improvement in using the high level outputs of the amp, and it's much simpler.   
What High End AC Cables should Offer
I stated that it was a knock off, I am under no illusion,  but who cares. It works great, that's all that matters. Do you think the high prices you pay makes things anymore real.  
What High End AC Cables should Offer
Just found this amazing item on AliExpress. Check it out!  $29.70  34%OFF | Furutech FI12ML-R L Type Rhodium 24K gold Plated Power Plug hifi  
What High End AC Cables should Offer
That Furutech on parts connexion is identical to the Aliexpress ones I bought for $20 each.   
What High End AC Cables should Offer
The ones I bought from Aliexpress is supposedly a Furutech knock of. At least it says Furutech on it, rhodium plated copper.  They will take any size cable.  The only issue I had with them, is that the ground blade is about 1/8 inch too long,  an... 
Topping D90 bass bloat?
Try the different filter settings that the topping provides.  One might help. I have a few topping dacs, and they do tend to have a deep bass response. Also try some different cables between the dac and the preamp.   
What High End AC Cables should Offer
This is one of the main reasons I built my own cables. I use 90 degree plugs on most. I have been using those cheap ones for years and always wondered why there wasn’t a better quality 90 degree plug made. Well, I discovered some audiophile grade... 
Are you sure its the sp6 that's providing your warmth. Audio Research preamps are not known for warmth.   
Recommended RCA sub-woofer cable? Thank you.
Meadiabridge Ultra subwoofer cable,  on Amazon. Highly recommended for the cost and performance.   
Flexible Power Cords
Learn to build them yourself.  It's great fun choosing the components and building them just the lengths you want.  I have been doing it for years,  DHLABS Encore and Power Plus are both very flexible and available in bulk, they make excellent pow... 
Speaker Cables : Moderate priced
Mogami  3103 or 3104 for speaker cables,  and 2549 for interconnects. Excellent quality and performance.   
Why it is so difficult to find a hifi power cables from IEC-C14 to IEC-C13 terminal?
If you use good quality connectors and solder, it will probably be better than the so called high end stuff.  
Just compared Monster M2.2 and ZU Mission speaker cables
My first jaw dropping moment was back in the nineties when I bought my first pair of Monster Interlink Reference 2 interconnects,  and replaced a pair of Straitwire.  That's when I proved that cables do make a difference. I have had many other hi... 
Better DAC then DA1 module in McIntosh C49 without braking the bank.
If you want to keep it Mac, then you could go for the MDA200 with the DA2 module as I did. It was a nice improvement over the C47 I had.  However with so much more good, more affordable dacs available,  I soon realized my mistake and tried the new...