IMO, any preamp, especially any phono stage ought to come with return privilege's.
If I could find a way to need this beauty, I'd beat you to it
https://www.ebay.com/itm/Vintage-Luxman-CL35-MKIII-Tube-Preamp/303871182981
Transparent, love it, keep it, or send it back, cost of return shipping is not a lot to risk.
Of course you could write the seller asking about transparency, the tone defeat features ...
a quickie find about it
https://skyfiaudio.com/products/luxman-cl-35-mk-iii
If I could find a way to need this beauty, I'd beat you to it
https://www.ebay.com/itm/Vintage-Luxman-CL35-MKIII-Tube-Preamp/303871182981
Transparent, love it, keep it, or send it back, cost of return shipping is not a lot to risk.
Of course you could write the seller asking about transparency, the tone defeat features ...
a quickie find about it
https://skyfiaudio.com/products/luxman-cl-35-mk-iii