Wavac 805

as an example i had my Verity driven with NAF 845SE 28watt stereoamp and although 95Db at 8 ohms nominal it was a j*ke i'm sorry to say.
it not only has to do with impedance, electrical phase behavior is way more important.
the volume behind the woofers and the size woofers in itself are all depending too.
30 watts may be all you need, but i have experienced too many amplifiers to look at watts only.
there may be 50 watts which are the most authoritive watts ever, there may be 600 watts as the most tiresome watts ever. it is all about topology and design -read powersupply- which makes or breaks any amp.
the Wavac 833v1.3 is one of the very best amps i ever heard, and at the same time one of the most authorative amps too. that comes at a price my friends.. after the 833v1.3 SET life will never be the same.
Wavac has reputation to really drive with authority opposed to many other SET amps.

I own the MD-805m and I say that it won't be able to drive 85db/ 4Ω speakers PROPERLY. Of course if you listen at very low volumes and music with one voice and a guitar maybe it will. :) Impedance curve is also very important as stated above.

Teddy Bear my wavac with the Verity Sarastro has great low end and pure and sliky highs! Maybe you had a problem with tubes?

I have MD 805's and it can't drive low end has grainy highs and liquid midrange. Had over EUR 50k worth of cables trying to get it sound right. Speakers are 90db/4 ohm.

I think you are asking too much from the 805 amps for your speakers with sensitive as low as 85db/4 ohms. 87db or above would match this beautiful amp. I have tried both 87db and 90db, the MD805s really give its full potential with 90db or above , used with 87db speakers sometimes it shows small hint of strain.

A gentleman I know used the 805s running into speakers rated at 90db/4 ohm(speakers w/ a somewhat flat curve) and they sounded wonderful..IMO the 805s are doubtful with your speakers.I would look into SS with some muscle

You also need to look at the impedance curve of the speakers. Most speakers have a dip around the bass region, which means that the amp will have to supply a lot of current. If your amp can't do it, not only will you get less bass - your midrange and top end will clip.

Look for speakers which have a benign impedance load. As flat as possible, and 8 Ohms.

I agree, my 22 watt 845 SET drives 89db speakers perfectly. In general it depends on volume you listen at, room size, musical tastes, a solo singer is different from a Symphony orchestra with all the stops out. I have heard the Wavac and it is very special, mind you , it should be at the price.

Some people will listen to this combo and say YES the amp can drive this speaker.Others listening to the same combo will say the opposite.I have no experience with the Wavac but I can say that my 30 watt SET drives my 88dB/4 ohm speakers
perfectly.Of course this is to my ears.
Sorry I cant give a better reply I hope others are able to.