What am I missing? Pre/power gain and input sensitivity.

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I've been reading some of these discussions, and had to chime in here, as I've been trying to get to the bottom of what constitutes a good match preamp to amp as well.
I am finding it comes down to gain, output impedence of preamp to input impedence of amp, voltage output of preamp, and input sensitivity of amplifier. Transconductance apparently comes into play with tube preamps as well.

Here is a link from Steve Deckert at Decware that describes these factors: https://www.decware.com/paper55.htm

I currently have a Decware Torii Junior, 20 watt tube amp, and Canary Audio C630 tube preamp. Looking to replace with a Rogue Audio RP-7.

 Cannot get above 86dB spl at 10’ without pushing both units above 70% full throttle on some recordings. But at these sound levels, the music is liquid velvet, gorgeous. Just want a little more headroom, and volume.

Canary output impedence: 1600 ohms; Torii Jr Input impedence 100k ohms

Also, Decware amps are set to 2 volt input sensitivity, compared to industry standard of 1 volt or less.

These two specs reveal this is probably not a good match. Lower output impedence (50-100 ohms) matched with a high input impedence (100k+) is a happier balance. Higher max output voltage on preamp and higher gain helps as well.

Of course for those of you who have 100 watt+ amplifiers, this is all a moot point.

Enjoy hearing good sound! Like a gourmet meal!

@switlikbob I recently got Omen DW (97dB, 12 ohm), too! Pretty impressed so far. It’ll be interesting to see what I think after a few months acclimating when I finally get around to switching back to my Dynaudio Audience 82 (87dB, 4 ohm) again to compare. I’m using a Primaluna DP HP (26dB, 1.2V max in) so my pre needs no gain from my ~2V sources - Oppo BDP-105, Bluesound Node 2i. I’ve been lusting after a First Watt F7 (14.5dB, 2.7V max in) but was running the numbers first. At my listening position I rarely hit 90dB and most of the time am <80dB. So both of these amps would probably be at ok with any of the speakers I’m interested in.

I’ve been making too many changes all at once lately - cables, speakers, amp, streamer. So I’ll probably leave upgrading my pre until later. I still haven’t even played with tube rolling the Saga+ yet. I’ve been making a list of preamps to look at eventually. There’s a recent thread that has a bunch of 6SN7 based options.

My main objection to vinyl is the ticks, pops, and noise.

@cat_doorman A lot of ticks and pops that people react to when playing vinyl are caused by the phono preamp itself (due to high frequency overload) and aren't actually on the LP itself. Its a bit technically complex to describe quickly, but has a lot to do with the fact that the phono cartridge has an inductance and the tonearm cable has a capacitance- together they can create Radio Frequency energy that can overload the phono section's input stage for very brief periods- the ticks and pops. So if the designer didn't take this into account, you get more ticks and pops. And yes, most of the phono sections out there have this problem!

I’m a prime example of what Ralph has stated above. For about 6 years I owned a well thought of phono pre and just thought the tics and pops were part of the vinyl. Couldn’t believe the difference and improvement when changing phono preamp. If playing a clean copy can’t hear anything but the music.
As to the gain/voltage equation, the purchase of an amp with only 18db of gain negated the use of my preamp, which had only 12db of gain. To add to the imbalance, the amp requires 2.5 volt input to reach full power. Purchased a preamp with 20 db gain that definitely pushed the amp to full power. The preamp manufacturer actually mentioned that the amp’s lower gain would be a plus in combo with his preamp. All in all things are matched up very well. And I’m done for the foreseeable future.
Posters like Ralph (AtmaSphere) and Almarg are very valuable to this forum. The technical info they provide can guide you to make sound purchases.

Upnorthsound: Thanks for the link to Steve’s ramblings, I’ve spent a valuable hour perusing his musings. I especially liked his discourse on ‘the weakest link.’

dentdog: +1 on the value of some of the contributors to this space. I have been surprised at how much some of them are willing to give to the community.