JBL L212 Amplifier - Low Output?

[GT777]

Hi all

I have had some refurbished L212 for about 8 months, I think it is a great speaker system.

Up until now, I have used a Unison Research Unico SE 140 watt Hybrid Amplifier and it could drive the speakers to VERY loud levels.

It was reasonably dynamic and a good sound.

The amplifier is a good thing but I felt the L212 could do with more.

I purchased a Valve Pre Power - Mystere PA21 and Ca21 that had a retail value of about $8k AUD when new some 5 years ago.

The PA21 power amplifier is about 50 watts with the original KT88 and about 80 with the KT150.

My issue now is this.

I can hear the quality of the amps and I really like it. It gives me a whole new respect for the speakers however the volume control needs to go to 3 o'clock for a reasonable volume.

There does not seem to be a lot of distortion that I can tell which suggests the amp is not struggling at this point but I have never in 25 years had to play a system at 3 oclock.

I can push it up to 5 oclock and it hardens a little.

The volume is not enough by any standards.

Now I do not play music very loud all the time.

I have tinnitus and need to protect myself from further damage but I know these speakers have done great things on other amps and this just does not seem right.

There is no channel imbalance, no issues I can find with the amps.

I wanted to know what the opinions are here as I am a little lost.

I have read a couple of people's reviews where they say they have listened to long term with 30 EL84 watts or even a 5 watts flea powered amp and If this is true then the 80 watts from the KT150 should be perfect for these.

I would be really appreciative of any advice on what could be going on here.

Thanks
Gareth

[speakerdave]

The towers' sensitivity is rated at 90 dB 1w 1m, not super efficient, but a pair of big pentodes should be enough. Maybe it would be worthwhile to have a tech check your new electronics. For a field test, you could try them with another set of speakers you know well.

[GT777]

The towers' sensitivity is rated at 90 dB 1w 1m, not super efficient, but a pair of big pentodes should be enough. Maybe it would be worthwhile to have a tech check your new electronics. For a field test, you could try them with another set of speakers you know well.


Thanks Dave

I am trying to find the output voltage of the source and impedance of the pre/pwr to see if there is an issue here also.

I will try some different speakers, I have some Leak Sandwich here I can try,

Cheers

[hjames]

I run my L212 towers with a Jolida JD-502CRC - about 65w/ch with KT88, 85w peaks ...
Depending on the source, the volume can vary somewhat - digital streaming from my Mac Airport express-> DAC,
CDs and SACDs from an Oppo disc player, and output from a TT with Stanton 68EEE.
I would like a bit more output from some sources - King Crimson just needs to be louder, as does most Who albums -
other stuff is fine as is ...

[rusty jefferson]

Agree with Dave about having the equipment checked. Obviously, be sure all the specified tubes are installed, and measure well. Previous owners sometimes do crazy things, and sometimes a circuit will work with a similar tube that has reduced gain. Say, replacing a 12at7 with a 12au7 in a driver/gain stage.

The published gain for your preamp is 19db, and the amplifier is 26db. You should not have the volume control turned up to 3:00 with 90db efficient speakers in a "normal" sized room. It would be very loud, and you should notice the distortion. As an example, I have a friend who is using a PP kt-88 amp that has 26db of gain (40 watts per channel) and a passive preamp (0db of gain) with 90db speakers to normal realistic levels (not concert) with the preamp at 2-3:00. His room is 24'x16'x10'