DL-103 + A23 SUT + Pro-Ject Tube Box DS = ?

The A23 designed for the DL-103 is a hard combination to beat. If I had the money I'd have one myself but I'm pretty satisfied with my Denon AU-320. It to was designed to work well with the DL-103 cart. The other thing about SUT's that I found is they are dead silent if setup properly. If you get hum or other noise, there are problems going on.I have to agree with Chakster about the tonearm, those Denons really like a heavy arm. It will work on your arm but you are giving a lot up. Do some reading on this.
It's why my TT project has a Audio Technica ATP-12T arm mounted in the back position. Effective mass of 21 grams and I plan to use a 18 gram headshell on it as well. Those carts were built for heavy broadcast arms.

BillWojo

@billwojo So, simply increasing the downforce will not acheive same effect?  I was planning on researching and using Nasotec Swing headshell, which weighs 11.5 grams.  18 grams is a lot!  Thoughts?  Link below:
https://highend-electronics.com/products/nasotec-swing-headshell-202a1
https://hifipig.com/nasotec-swing-headshell-202a1/

Not at all. I don't think I'd waste my money on that Nasotec. Not every gram of mass added to the headshell adds to the effective mass either, it's not as simple as EF mass = 12 Grams and a 10 Gram headshell = 22 grams of EF.
I would use as heavy a headshell as you can find and add some weight to the counter balance. It will help some.I'm using a Audio Technica AT-LH18H for my headshell on the ATP-12T tonearm.
There have been some lengthy discussions on this board about EM.

BillWojo

I don’t care about Stereophile recommended componets and their reviews at all, but I know very well that low compliance cartridges from the late 60’s designed for high mass tonearms. Also I know that DL-103 designed for broadcast radio stations with its conical tip.

I like Zu Audio speakers and cables, but their MOD of the stock DL-103 will not make this cartridge any better, because the problem if this cartridge is its Conical Tip (rolled-off sound, very short life span).

Those guys at Stereophile can’t recommend Pioneer PC-1000 mkII cartridge, because they know nothing about it, but it was the best Pioneer MM cartridge in the 70’s and far better than Denon DL-103 from the 60’s.

In fact ZU recommended you exactly what they are selling.
And Stereophile do not recommend anything that not available for sale in the stores today, but all those modern MM cartridges are junk compared to vintage MM from the 70s/80s. If in Stereophile expert’s opinion a DL-103 is better than modern MM cartridges it is nothing but a confirmation how bad those modern MM really are. Because DL-103 is nothing special, just a cheap LOMC.