Tube amp, size and power info........

I am geting a new pair of speakers wich are 99db efficient with a plate amp for the woofer, I have a tube pre but now I can entertain tube power but I want a reasonable price to try and also it needs to fit in a standard rack space (6.5 inches) I would say that anything above 25 watts will do, my pre-amp is a Sonic Frontiers and my usual volume is low to moderate, never obnoxiuosly loud, what are some options that wont break the bank, I know it isnt much but I am talking around $500 new or used.
Thank you as always Chad
It is not designed for a standard rack mount space but for 500 bucks take a look at the Decware Zen amp; it has the right power for your 99db speakers.
Chad, with 99dB-sensitive speakers, you're ready for flea-powered SETs. An affordable one is the ASL Tulip, here , and here is one for $600!!!!!!!!!!
Hey Chad what are you getting for speakers?
Something to consider is with 99db efficiency and a powered woofer you could really get away with a fantastic low powered SET amp. I don't have a specific recommendation in your price range but I'm sure others will. Good luck!
With low to moderate volume listening and 99dB, I definately wouldn't limit myself to amps over 25W of power! You can try some really cool 3W - 10W power amps like 2A3, 45 or 300B and not have to worry. I hope to do that one day myself.
Aball is right. 99dB sensitivity is quite high, especially when your sub is powered, so you don't need to look at 25-watters. 3-10 watts will simply blow you away ... for all of the right reasons. Just do some crit research. I wouldn't spend mega-dollars at first, and I don't think I'd even consider 300Bs at this point, at least not before you know that tubes are where you intend to stay.
You mentioned rack space. Tubes get hot and need to breathe , do not crowd them in a tiggt rack withiout 5 inches of space above .
Name the speaker and this will help.
I've had 97db speakers with a 16 ohm impedance that sounded best with 100watts of SS...this is the what the designer voiced them with.

My experience is that things are not always as they seem.
Agree with Brainwater. Put tubes in a rack and you can bake cookies just like EZ-Bake Ovens. Plus most tube gear is not rack-mountable.

Used AR amps come to mind if you are using the DB99's from Von Schwiekert.

Good luck!
It occurred to me that Ty may be building you a 4 ohm loudspeaker. If the dual 10" midwoofers are run in parallel, then it will likely be a 4 ohm (or below) load. In that case, 99 dB efficient at 4 ohms is equivalent to 96 dB efficient at 8 ohms. An 8 wpc 300B SET amp may not be enough in this situation.

For something cheaper than $500, you might consider a Dynaco ST70 (lots of them on the market, lots of tweaks/mods).
Heck, there's an AR ST-70 C3 listed for $425 at Audio Asylum's Classifieds right now (it ain't my ad, 'goners). That was the first Audio Research amplifier: a modified Dynaco ST-70. Ahh, if I only kept my Paoli monoblocks...those were the days.
Hey everyone thanks for the info, the speakers are going to be built by Tyler Accoustics, though a model is not yet nameable.
I also can put it next to my rack for common sense ventilation, I was hoping to see an amp that had a profile of a normal rack mount, I dont need to see tubes glow to be happy.