I'm considering used Vandersteen Quatro

They'll go into a room that is 13 x 21 x 8.5 ft.
Driven by a Prima Luna Classic.
They have a sn about 1900, I don't know what that says about their age.
I'll audition them with my gear on Saturday.

I'd appreciate any tips.
The Quatro's are wonderful speakers, but I'm not familiar with the Prima Luna Classic.  I did a quick search and now assume it is an integrated amp with 35 - 40 WPC (depending on tubes used), correct?  If so it is probably not a good match.  First, the Quattro must use a high pass filter, either between the amp and preamp or built in to the preamp.  As far as I could tell the Prima Luna does not offer preamp out/amp in connections nor does it appear to have a built in high pass crossover.  I could be wrong, but it is important!  Second, 35 - 40 WPC is definitely on the low side for these speakers.  Your room size is on the small to medium size so that is good, but what type of music and how loud you listen to it will be the determinant for power.

pmotz, thanks. Yes it's 35-44 W depending on tubes. The quatro manual says 30-200W into 8 Ohms required. I plan on upgrading the amp before too long.  What's loud? Last night I listened to Edie Brickell & New Bohemians, Buddy Guy, Lenny Kravitz, and Kodo (Japanese Drums) at different volumes I typically play. I measured up to about 90 dB.  Is that loud?

Thanks for pointing out the issue with the crossover, I spoke with John this morning and he talked about setting up the 100 Hz filter. I didn't know what he was talking about at the time and figured I would ask on Saturday. I just looked at the manual though and see what you refer to.  I read on Vandersteen's "Ask Richard" section that he answered a lot of questions on his site about integration with PL.

I sent an email with a link to the quatro manual to PL to see what they say.

Other speakers I'm thinking of are on the "A little help" thread.  Thanks again for your help.

According to PL, you need separates - there is no way to install the HP crossover.

They also said that changing to KT-120 will not help the Arro with the bass; simply too small a woofer.

As noted above there are a few PL users with Quatro so there must be a different way - which Richard Vandersteen noted in his answers.  I'm sure John at Audio Connection already knows and we'll see on Saturday.
I would actually audition the Vandersteen 2Ce Sig II’s before you move up the line to the newer speakers (e.g. Treo). It should be a relatively easy load to drive, much easier than the 3A Sig (which I own). The 2Ce Sig II’s dig fairly deep into the lower octaves and don’t have the need for a crossover. However all Vandersteen speakers are made for biwiring and the barrier strip requires spades less than 0.5 in wide, so you may need to reterminate your current speaker wire for best connection.

One other thing to mention - if you decide to purchase Vandersteen speakers, follow one of the speaker placement methods outlined in the manual. Read it carefully and make sure that measurements are exact. You will be rewarded immensely with your patience.
Jetson, 90 dB is not very loud for peaks, but if that is an average loudness then it is fairly loud.  Given the type of music you mentioned, and assuming 90 dB was the highest level measured, then you don't listen too loud.  That's good for your hearing and requires significantly less power.  Even at those levels, though, more power would be beneficial.  I think the Prima Luna would work initially, power wise, but more power and a separate amp would be better for the Quatro's.  Given that Prima Luna has said the filters won't work then you have many options to consider.  Yage's advice on the 2Ce is good.  Personally, I like Vandersteen speakers.  I started with 2Ci, then 3A Signature, now Model 5.  It all depends on your listening biases.  Choosing speakers is a daunting task, so many options.  If you like the Prima Luna, I'm sure there are many high quality speakers that will work with it.  Good luck!
yage: Thanks for the heads up on the cable terminations if I go that route. I think that’s a good idea. It’s less expensive, leaving room for upgrades, and I see what you mean graphically on the impedance curves.

I have two concern with the signature models. My concern with the Signature Vandersteen models is that they have rear facing subs. The speakers front will be about 30" from the wall.

See the attached picture of my Totem’s with the Micron Carats on top. Aside from the loveseat issue, you’ll note that I have a radiator convector behind the left speaker.

The other concern I have is that they’re 16" wide and 10" deep as compared to 10" wide and 16" or 19" deep. I don't know if they'll fit as well and i expect my wife will be less pleased. Although, after putting up with me since 1988, she still lets me have my way - sometimes.

I like the PL except for the power issue.

I am also going to audition the Rega RS-7.
Vandy 2CE speakers are incredible sounding bargains…seem to always be available used with stands for peanuts. 
I ran the Quatro's for over 4 years in a 15' x 11.25' x 8' room and they worked really well once I spent the considerable time to dial them in for room placement and then adjust the bass equilizer for finishing touches.

They worked very well with an EAR 890 that pushes 70W class A tube power with a lot of oomph.  I liked them even better with a 100W VAC Phi 200 driving them.  I actually used my Primaluna Dialogue One for a short interim fill, and they sounded nice and musical, but were not powerful enough for loud rock, big orchestra, electronica, etc.  It is a EL34 based amp with 35W, and I would bet that KT88 might work a smidge better.  More power was better, though.

I would seriously think of a more powerful amp if you like concert levels of louder music.
@jetson - I think your wife will probably have an issue. The Vandersteens are bigger and will look more physically imposing than the Totems. My wife doesn't care too much because the stereo is down in the basement. Is there no other room you can use? If you've got the land, perhaps you can build a listening shed out back. (I believe Michael Lavorgna of AudioStream has a barn on his property for this purpose.)

In any case, my room is about 22' x 13.6' x 8' and I have the speakers firing down the long wall and about 24.25" from the back wall - measured from 'acoustic center' with the distance calculated using Vandersteen's 'odd dimensions' method. It's what sounds best so far to my ears while also accounting for room layout limitations.

You might get just as good (or better) results with a two-way standmount speaker and subwoofer.
John at Audio Connection, and Richard at Vandersteen.  Both ...the very best. 
the odd dimension placement makes any speaker sound better and you can always use the meter and a test disc to tweak for room nodes at listener position. The Vandy manual is a tour de force for proper setup...

Agree on the VAndy info all are giving.  Glad you went with the 2's.  You'll  love them I'm sure.  I'm running the Ayre AX5 Twenty with my Treo's and am trying to sell the Treo's for the Quatro's.  I will just install the filter on the inputs and manually plug in the balance out from my Rhea or the Balanced output from my Empirical OSDE/SE.  Not the best solution, but it works easily and I'm always up to put on a record so it's easy.

Recently heard the Vandersteen Quatro CT's. Liked 'em. Very much
BTW- John at Audio Connection is a very good guy to deal with- 
Guys, I've sent a few folks to Johnny in the last couple of years and they all have been very very happy.  Jetson is included in this.  He just understands how and why things sound good together.  Yes, he loves Vandersteen, but he also sells Proac, Maggies, B&W, NOLA and many others.  He also understands your listening room and inexpensive ways to improve your sound.  I've never heard a bad word about him.  It's rare to find someone who is more willing to help even if it means nothing in his own pocket.  Yes, I think he's the top dealer in the country to deal with that I personally have met and I've been to a lot of places and met a lot of great dealers.  Just have never found anyone better IMHO.