2. amps-preamps
  3. 1249244359

Can you lower gain requirements on tube amp?

I have a Cary Rocket 88R tube amp (30w tri/60w UL) that requires more gain then I'm used to to get to 'realistic' (ie louder) listening levels (90db+). I have a Promitheus Ref4 TVC passive that I love, but volume knobs at full throttle sometimes still isn't loud enough. I literally need it go to 11.

Specs on the TVC state -48db to 0. I'm curious if I can do something to the amp, ie roll different driver tubes or??.... to decrease the gain requirements? I've also contacted Nicholas at Promitheus to see if he can modify the gain, haven't heard back yet.

I will also state that my speakers are Usher 6381 rated at 87db/8 ohm. The Cary drives them well, but wondering if the speakers sensitivity relates to loudness (ie more sensitive speakers would generate more loudness at the same volume settings?)

I don't want to introduce a tubed buffer into the mix -- tried it and didn't like the sound. Want to work with what I have if possible. Thanks

FYI tubes in the Cary are:
kt-88 output
12BZ7 / 12AX7 / 12AY7 drivers (currently using 12BZ7)
EL-84 / 6BQ5 current source
tholt

Showing 2 responses by tholt

tholt OP
545 posts
 
2 other things -- I like to run in triode over UL, though UL gives me a 2db boost. Also, does voltage into the TVC affect volume? ie if I had a source with higher output would it increase volume? My current cd player is rated at 2V, +/-3dB output.
tholt OP
545 posts
 
Thanks so far.

Newbee/Rodman -- are you suggesting that a source with higher voltage will produce more gain at the amp end? My cdp is rated at 2V, +/-3dB output. To answer your question: yes, much of my recorded material does provide adequate SPL's, albeit at close to or at the volume knobs wide open.

The Cary's input sensitivity is 1.2V for full output.

Sounds like some of you are suggesting that the speaker load is also contributing to the lack of loudness, I would concur with that. However, the sound is very full, not missing anything and this coming from after using 160w class D amps. I prefer the Cary. My listening space is roughly 10' x 15' x 12' -- an area within a larger open space but still I would consider small/med size, which helps. And with other preamps with either more gain or active, I am able to achieve all the volume I need. I just prefer the TVC, hence the thread.
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