Remember that preamps tend to have fixed gain stages internally.
What am I missing? Pre/power gain and input sensitivity.
I’ve read a few posts about power amps with lower gain needing a pre with additional gain, but no one seems to mention input sensitivity in those conversations. If my source outputs 2V and my power amp input sensitivity is only 1.2V then whether the power amp gain is 16dB or 26dB my pre amp is attenuating the signal and the amount of gain on the pre doesn’t matter at all. With a given set of speakers, to get the same SPL with 2 different amps they should just need to output the same voltage, regardless of how they get there.
Am I missing something?
Am I missing something?
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- 14 posts total
@cat_doorman It sounds like we are roughly the same age based on your walkman story. I am also running all my music digitally, through my Marantz DAC and into a bottlehead tube preamp and then into Bob Latino VS-120, Zu Audio Omen DW speakers. I have been experimenting with different preamps, a lot, even though my amp has an attenuator / preamp section. I just don't find that I get the same "richness" out of my music without the additional preamp. I have also been swapping in different tubes, and that make an enormous difference (12ax7, 12au7, 12at7). I know you were more interested in gain, but I suggest strongly that you experiment with good tube preamps, if you like that sort of sound as much as I do. I was using, and just sold a Rogue Audio 66 preamp, and that thing sounded magical with my setup. |
< 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. 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. |
- 14 posts total