1. Home
  2. amps-preamps
  3. 1252463792

Next step: tube pre or tube power amp?

I own a Rotel pre/pro RSP-985 SS preamp and a matching Rotel 120 watt power amp. If I wanted to move into tubes, would I get better mileage out of a tube pre or tube power amp?

I love the convenience of the rotel preamp (remote, built in DACS etc) but I understand that a tube pre will have more impact than just a tube power amp. Is this correct?

Also, my speakers are 91db efficient. What wattage tube power amp would I need to drive them to medium/loud levels?

thanks

Steve
stevecuss
tvad
9,467 posts
 
09-09-09: Stevecuss
My speakers are GR Research AV3s in an AV2 cabinet. They are 8ohm nominal/6ohm minimal and 91db sensitive.

You should have no problem with a tube amp. Depending on the size of your room and the volumes at which you listen, you could probably get away with less than 75 wpc, but I'd still suggest 75 wpc minimum.
tbromgard
787 posts
 
I would opt for a tubed pre amp. It will give you a hint of tube magic, and a ss amp will give you slam speed and bass impact.
buconero117
2,311 posts
 
Tube pre is the way to go. The load to the speakers you have is better if it comes from a SS amp.
tvad
9,467 posts
 
The load to the speakers you have is better if it comes
from a SS amp.
Buconero117 (Threads | Answers)

I disagree. 8 ohm nominal impedance with a 6 ohm minimum is a reasonably
flat impedance curve which can be handled without any problem by a push
pull tube amplifier.

91dB sensitivity is a non-issue. It can be driven by either a SS or tube amp.

Frankly, IMO, the OP has his choice of SS or tube amp (provided the tube amp
is a push pull design). He may even have the opportunity to use an OTL tube
amp.
stanwal's avatar
stanwal
3,147 posts
 
You can figure out your minimum power needs by remembering that you double the power for each 3db gain in loudness. So the 91db sensitivity at one watt needs 2 watts for 94, 4 for 97db and so fourth. This gives the MINIMUM required, which is not necessarily the ideal power but is a rough guide. I doubt if you would need 75 with your current speakers but if you intend to change it can't hurt to get a larger amp as long as it is of the same quality.
More to discover