I would like to share my way of connecting to our Meridian 500 series products.

I bought some Ugreen RS232 Female plugs using AliExpress, and hoocked them to a Apple MacMini permanent.

The MacMini is running a Windows XP Virtual machine, using VMware Fusion and the cables are permanently pass through to that virtual XP machine running the Meridian legacy configuration software.

This cable worked fine so far, also for our DSP33 speakers.
I can highly recommend it.

Using a PC with a virtual machine, with tools like free software Vmware player you could achieve the same result.

The cable I am using is a Ugreen USB RS232 Com Port. Make sure you buy the RS232 Female version of course.

I hope this info is usefull.

I have connected all of our Meridian products, permantly to our MacMini, and the MacMini is only needed for configuration nothing else in our setup.

#1 568.2mm, HD621, G91DH, 513, 511, DSP3100 , DSP33C , DSP33, 2x MJ Pro 50 MKI, M1500
#2 G68ADV, HD621, DSP3100, DSP33C, DSP33, 3x MJ Pro 50 MKII, Control 15, Vertex 2
#3 G61rsl, HD621, 596P, DSP7000, DSP5500HC, DSP33, 2x MJ Pro 50 MKII, M1500

Spare: , 2x 568.2mm, 562V.2, DSP33, Director, G55, M60.2, MS200,
Applied mods: NOS-SRx Filter by Mr. Apodizer