2. speakers
  3. 153684-489

A change in efficiency to the final sound

I have a p/p tube amp running a pair of 6Ca7's for about 30 watts per channel .
I have read here that p/p tube amps sound their best when they have to work a bit harder , as opposed to a SET amp that sounds best near idle .
My present speakers are claimed to be 92 db. eff.
If this amp is driving a pair of speakers rated at 85 db. efficiency , should it sound a bit better due to working a little harder or closer to its optimum level ?
Conversely , would the same amp sound a bit worse driving a more efficient speaker of 99 db. due to it working less hard or further away from its optimum level ?


Thank you

saki70

Showing 3 responses by jrwaudio

jrwaudio
331 posts
 
Maybe I can have some input on this as I'll be added a pair of Maganapan 0.7 speakers in a few weeks to my system. Currently I'm using a VAC PA 80 80 set in triode mode with a ARC LS15 pre amp that drive my Definitive technology Mythos ST speakers that are rated at 91 db efficiency 
The speakers do double duty for me as I also use them for HT. The VAC at 35 watts has no problem driving the Mythos ST's  

I'm very sceptical that the VAC with have enough juice in triode Mode for the Maganpan 0.7's but will give it a try and a good listen. More that likely I'll have to convert the VAC to PP and see if that has the power required. It does have 2,4&8 ohm taps and weights a ton! It should be interesting to listen for any changes in sound quality when it's in PP mode
jrwaudio
331 posts
 
As in life, everything is a trade off
Good discussion on PP vs SET

Watch "Single-Ended Vs. Push-Pull Tube Amplifiers 
https://youtu.be/zSJlyTgpsd0

Before I convert my VAC from triode to PP
l will use the same speaker tap ( 4 ohm)
and listen to the speakers with the same volume setting using a sound meter
jrwaudio
331 posts
 
@saki70 it might be awhile before I get my Magnapan 0.7's More than likely another 6 weeks : (   But I will post my findings for what it's worth : )  I found this on my VAC PA 80 80 manual, I had to sent it in and the UPS guy might of been mad at me as it weighs over 70 lbs
They also did an over all upgrade caps etc
It still has the original KT 88 Golden Dragon Tubes

Ultra-linear or Triode?
The input amplifier, phase splitter, and driver stages are triode tubes operated in ClassA with no cut-off or grid current. The output stage is connected for partial-triode, well known for low distortion, good damping factor, and high efficiency. This technique was invented by Alan Blumlein of EMI in England, and was popularized in the US as "ultra-linear." VAC can convert amplifiers to triode connection for a small charge.

More to discover