MI 330 ics,LOW impedience?MEDIUM impedience?

I take interest in older MIT 330 interconnects.

There seem to be those marked as LOW impedience,others as MEDIUM impedience.How to choose ?( matching power amps or preamps ?or other principles as guidelines in deciding whether LOW or MEDIUM impedience?)

Besides,are there those with HIGH impedience?

*** My preamps,1.Audio research ReferenceII,Mk II
2.Krell HTS 7.1
My power amps,1.Krell FPB 650MC mono,mono
2.Krell FPB 300 stereo *************

Need your help.
Thank you in advance!

Most likely you would need high impedance from source to preamp and low impedance from pre to amp. You can also buy the newer version called Oracle, which has high medium and low imnpedance all together. You just need to pick one of them on the network box.
Sorry, TYPO in topic of this item.It should be "MIT" 330 interconnects.
Wish get your advise of experience.
Thank you!
The impedance of MIT cable should match the input impedance of “down stream” component. For example; the impedance of the cable between your Pre. & Amp. Should match the input impedance of the amp. I believe that most Krell & ARC components are “medium” for their single ended inputs. But you could also email them or MIT for information on specific units.
The idea of having impedance-matched interconnects is to get optimum matching between components. The rating of the cable should match the INPUT IMPEDANCE of the DOWNSTREAM component. So, in going from CD to Preamp, only the input impedance of the Preamp counts. In going from Preamp to Amp, only the input impedance of the amp counts. Values follow:
Low -- under 40 K ohm
Medium -- 40 K to 90 K ohm
High -- over 90 K ohm
Hope this helps.
Are you referring to the MIT 330 with the network boxes, or just the original (plain) MIT 330 ICs without boxes?
Thank you for your advise!
Very helpful!
Thank you!