Tube preamps, basic design parameters


I am looking to add a tube pre to my HT system. It’s been in the works a while, but time to get serious. Not being technical by nature, I’m finding myself lost in the choices. Asking for advise on what to buy in any given budget results in individual preferences from other uses that I can’t compare to my own preferences. 
My basic thinking on adding a tube pre is to add that nebulous concept of ‘more involving’ to my listening. I don’t feel my system is lacking much, but may be slightly top heavy (more highs than lows?), but only very slightly. My only exposure to a tube component thus far is a PrimaLuna at a dealer, and it did sound wonderful....although no component or the room, obviously, was mine, so how much was the pre amp is anyone’s guess. I do value accuracy and definition, but from my reading, most tube preamps now have moved far away from the old days where you had to choose that over ‘involving’.

Is there a way to predict, based on design philosophy of any given manufacturer, what ‘flavor’ I can expect? LTA has a design they champion in their MicroZOTL line, there are many small outfits with owners/designers of no doubt very creditable knowledge who all claim the best value, bang-for-buck designs, and bigger operations with larger R&D and yes, marketing budgets who make great claims. 
I get it, there is no ‘best’, but is there a way to translate design philosophy into expected sound flavor? Is an 8 tube pre amp by its nature going to produce a different flavor than a 2 or 4 tube one? Is a separate Power Supply a deal breaker? Those kinds of things? I will say I’m not particularly interested in buying something I will need to send back for upgrades every year (another thing I read about in some manufacturers, being able to order the build almost a la carte, as if I have a clue what I’d want the build to be, when I’m still green as grass).
english210
My Oppo is hooked up HDMI out to a Marantz AV8802a for movies, and balanced analog out to the AVP’s CD input for 2 channel. My plan (I think) is to have the Pre’s only source as the balanced input, and then the AVP’s main outs to the HT input of the pre, with the pre passing the signal when it is off. That way the wife is doing nothing different when watching TV/movies, and I can leave the AVP off when listening to music, and just turn on the pre and the Oppo. The Odyssey stays on 24/7. The critical listening for 2-channel will be Oppo-Pre-Power with the AVP not in the loop.
Do the materials dictate the ‘flavor or quality or reliability?
Yes.
A capacitor stores current for when the audio signal needs it, correct?
Not in the case of a coupling capacitor. Its used to block DC from one gain stage to the succeeding stage of gain while passing the audio signal at the same time.


We use the Teflon copper foil capacitors as they are simultaneously reliable and musical. Paper and oil parts are very musical, but they can develop a slight electrical leakage over time which can lead to reliability problems in the gear in which they are installed. That is why we don't use them.


The Stratos has balanced inputs and so can benefit from a balanced preamp. The trick here is that the HT stuff would be an input to the preamp, but you might also have other sources like a CDP, tuner or even a turntable that you use with the television turned off. In that case a preamp will be useful; if you only plan to use the HT as your only source there's not much point in getting an additional preamp as it will be an extra block in the signal chain that you don't need.


Now there are HT processors that are designed to work as a signal source rather than as the preamp itself; if that is what you get then the preamp makes sense. In such a situation you wouldn't need an HT bypass.



So I read Atmasphere’s ‘blurb’ on the MP-3, and it does highlight my question. It mentions upgraded capacitors (copper foil?), and I’ve read about other kinds of capacitors, is there a ‘best’? Do the materials dictate the ‘flavor or quality or reliability? A capacitor stores current for when the audio signal needs it, correct? Like buffering while streaming?
Yes, the mains (Aerial 7T’s) are driven by an Odssey Stratos + SS amp. Oppo UCD205 being fed Tidal through Roon from a Mac Mini. HT bypass needs to pass the signal when turned off. Mick at Supratek says that’s doable, as do some other brands. Prima Luna and others say the pre must be on, which seems to be the default for most.
Implementation matters, and that's hard to tell from any of the parameters you've used.

I would say you need a pre with a HT bypass first of all, so that eliminates a lot of old school and inexpensive contenders.
@OP, 
Well, you post got the attention of one of the best/nicest designers of stereo equipment.
And, though he is too classy to boast his products, I will. In fact, I was in the same situation as you are, a few years ago. From the advice of Ralph (Atmasphere) and other Audiogon members, I found his experience, and products to be first class. As a result I own a pair of MA-1 amps as well as a MP-1 preamp (upgraded from a MP-3).
You won't go wrong with his either his advice or equipment.
Bob