Preamps

my experience with a 625/aeris/corus set up a few years ago was that in comparison to aeris direct the corus was softer and frankly boring. on the other hand the aeris was too hot. end result is i sold it all for better or worse. things change so it’s hard to compare a few years later but i now have a luxman c-900u plus m-900u and boring w current setup has never crossed my mind. but.. different speakers cables etc. i do i know enough to say that i’m pretty sure that the corus is not a special piece except perhaps with the optional upgraded 9k power supply. fwiw

Virtually all tube preamps are ‘not’ designed to drive a main and secondary amp(subwoofer). ARC addresses this on their website. I have a friend that has looked far and wide for for a duo amp driving tube pre and i believe vtl turned up as satisfactory but at a price. of course

Ricred1:  I know something about the corus and 625 amp as I owned them and should have kept them.  If I had just ponied up and bought the uber power supply I think I’d be miles ahead of trading and selling to TRY to find something better. I would beg borrow or steal to get to try that power supply in my home. I bet jeff would help if you call him directly. It’s absolutely worth the effort imho. you’d then have something very special.

ARC has a fact sheet on their website expressing concern about the tube preamps driving a main amp plus sub. it’s in black and white unless they pulled it. it killed a ref 6 deal for me.,

just looked at arc site. article called the thorny issue of impedance. it’s located in a ‘tips’ section.

i’m told that vtl tube pres can handle the situation. i fixed it by buying an awesome tube amp to be used w a great SS preamp. IMHO this more than gets you to full tube sound. the tube amp is the last thing the speaker sees. and what a choice of great SS preamps out there. what a great hobby!

ozzy... luxman c900u but would have been happy w ML 523. Amp ARC 75se. great match but then i bought the lux m900u amp. have both but going to have to give up Ref 75se. what a great amp. a plethora of riches

the 523 is an awesome unit. i don’t want to denigrate JRDG because he’s a great designer and fine fellow. but in my system the ml 523 was considerably more satisfying to me than the corus BUT the systems were different. my sense however was that the ml was more finely detailed, transparent and very musical. and being a ml unit a true joy to operate and so beautifully built.  the only better ss pre that i’ve personally owned that might exceed the ml is the luxman c-900u but either one would satisfy almost anyone in my humble opinion. 
if you’ve owned a corus i don’t think you’ll be happy with good sound but lousy package. you’re going to want both.