Seriously considering tube preamp…opinions?

@tvad Thanks. I did consider that perhaps since my Salk order is standard veneer and not delivered yet, I might just change my order with Jim and go with a more sensitive speaker. Not sure if he’d allow that but IF the speaker I ordered was of higher quality and price, I’d still come out the same in overall costs and Jim would sell a more expensive product. (I don’t want to make assumptions about what he considers reasonable, so I’m ready to be rebuffed if he balks at such a proposal.)

The key issue is that the other models I might now consider that are more sensitive than the 84 db speakers I order are: 87db, 88db, or 90db. The 90db speakers are more than double the Wow1’s ($3800 vs. $1500). QUESTION: a jump of 3 or 4 db in sensitivity doesn't really buy me enough, does it? It should be 6db? 

@almarg Thanks for reminding me of the dynamic jumps. That’s key part of music realism in the genres I enjoy. Good to have 90db as a starting point. That may rule out some makes of speaker if I try to broaden out my amp choices. Daedalus is nice, perhaps a bit much for me right now. I’ll keep an eye open.

@mesch Part of it was increase, part was just thinking out the wider parameters. "I wandered into a bar, looking for love," kind of captures my state of mind at the start.
I will reconsider the speaker budget. Part of that might come from a higher sensitivity speaker choice. The output stage (tubes or not) is still open. I have heard both sides. But I also am aware that matching tubes/ss is a dangerous game, and I’m a bit shy on this front. That leads back either to integrated tube/ss, all tubes, or all ss.
I will check for used and visit dealers.
Thanks for posting and enjoy your family time!

@tvad 90db. Ok. (I guess 88db isn't better enough.)

Bookshelves: I began with bookshelves because I wanted new desktop monitors. Then, I opened up to the idea of a larger room/space. In the meantime I bought a sub. As I got deeper in, I realized that I really wanted a listening space. So, I guess bookshelves are a remnant of the earlier parameters — and I think they do offer flexibility for future placement. But if I was to be pushed, well, I guess I'm now at the point where I'd entertain floorstanders. Here come the Maggies! (Just kidding. I think.)

@hilde45  The thing you have going for you with the Salk speakers is they have a moderate 8 ohm impedance with no nasty phase angles or dips. This makes the job of the amplifier easier. Jim is pretty conservative about his ratings- I suspect what passes for 83 dB or so for him is 86 or 87dB with some other brands- it depends where on the curve of the speaker you measure its sensitivity!

If I can make a suggestion: When working with **any** amplifier (tube, solid state, class D), its distortion will be lower if it is not asked to work hard! To this end, your amplifier investment dollar will be better served by a loudspeaker that is higher impedance (8 ohms as opposed to 4, and 16 as opposed to 8) because the amplifier will make less distortion. This is both easy to hear (as the distortion is higher ordered harmonics and addition IMD) and easy to see in the specs. When you can hear it and measure it, its real :)  In the case of tube amplifiers with output transformers, the higher impedance will allow the output transformer to operate more efficiently. When the OPT (OutPut Transformer) heats up, its converting amplifier power into heat :(  When driving lower impedances, not only does the OPT operate less efficiently, it can also lose bandwidth. On the bottom end this can be up to an octave of bandwidth loss between 4 ohms and 8!


On top of this loudspeaker efficiency is also important, particularly in the case of tubes, as tube amplifier power is more expensive (the industry went solid state not due to performance but cost reasons decades ago). This also helps the amp to make less distortion since it doesn't have to make as much power. A 3dB change in efficiency doesn't sound like much to the ear, but that is a difference of twice the power in the amp! So when you go from 83dB to 89dB, to make the same sound pressure the amp need only be 1/4 the power. The $$$$ implications should be obvious.


The less distortion, the more the presentation will sound like real music.


One other thing: lower efficiency loudspeakers are inherently less dynamic. This is due to heating of the voice coil- which in turn reduces its sensitivity. The more power you give it, the worse this becomes. There tends to be less thermal compression in higher efficiency loudspeakers.

I'm in a similar situation (looking for a tube pre / SS amp combo.) and I was wondering if there are tube pre's that are more suited to SS amp matching in terms of impedance matching.  Do I just go by the 1/10 rule (output impedance for the pre)?  This would narrow my search down considerably if I could find a tube pre that is SS amp friendly.