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I am down to 2 choices (PP or SET amp?) to run my JBL L100 (alnico)

Hi! I am down to 2 choices;

   >Bob Latino's VTA ST-120 


Power output . . . . . . … > 60 watts RMS per channel at 1 KHz at less than 1 % THD with both channels driven in ultralinear mode or > 32 watts RMS in triode with both channels driven
Frequency response . . . .. 10 Hz to 30 KHz +/- .1 dB at 1 watt  
Power bandwidth  . . . . …. 17 Hz to 30 KHz +/- .3 dB at 60 watts
Harmonic Distortion   . . . . Less than .15% THD from 20 Hz to 20 KHz at 1 watt, less than 1% THD at 60 watts 20 Hz to 20 KHz
IMD …………………….......… Less than .45% (19 Khz and 20 Khz) at rated power
Hum and noise . . . . . …..  More than 90 dB below 60 watt output
Sensitivity . . . . . . ……….  900 millivolts for 60 watt output
Bias setting …………....…    .550 volts DC per each KT88 or 6550 output tube
Feedback ………………......… 13 dB total loop feedback
Size .................. ...…..…. 13" x 9.5" x 6.5"
Tube complement ............4 X KT88 or 6550 or KT120, 3 X 12AU7 or 12BH7 or 5963 or 5814 or 6189 or CV4003, 1 X 5AR4/GZ34 or Weber WZ68 SS rectifier
Weight …………………......…. 38 pounds (shipping weight = 45 pounds)


   >Audio Note Kit1 300B

S
pecifications:
Power: 8 Watts Class A
Output Tubes: 2 x 300B
1st Stage Gain: 6SN7
Rectifier Tube: 5U4GB
Front Insert Plate:: Solid Copper
Inputs: 1 (option of 3)
Option of Elma 3 input selector at $75
Outputs: 1 x Stereo Pair 4, 8, 16 ohms
Recommended Speakers: min 88dB
Width: 53 cm
Height: 20 cm
Depth: 45 cm
Weight: 18 Kilos
Chassis: 3mm Aluminum with Black Powder Coat



Listening room is 12' x 12'

JBL L100 Century

SpecsFrequency Response:Unknown Sensitivity:91dB (1W input, measured at 1m) Impedance:8ΩPower Capacity:50W (continuous program)High Frequency Driver:LE25 36mm (1.4″) Paper DiaphragmMedium Frequency Driver:LE5-2 130mm (5″) Paper DiaphragmLow Frequency Driver:123A-1 300m (12″) Pressed Paper DiaphragmCrossover Frequencies:1,500Hz and 6,000HzEnclosure Type:Bass ReflexEnclosure Dimensions (HxWxD):600x360x350mm (23.5×14.5×13.75″)Weight:24kg (each speaker)
128x128rodulfo23
rodulfo23's avatar
rodulfo23 OP
6 posts
 
I have the old JBL L100 (alnico) straight array speakers/low serial. I did not mention, I am running either power amp with Hagerman (DIY) Clarinet Tube Preamp.
glennewdick's avatar
glennewdick
1,658 posts
 
you will need more power then 8wpc, I have a SET 300b amp and it having a hard time with louder listening with 94db speakers let alone 91db. 
roberjerman
4,319 posts
 
An 8 watt SET will only work with the L100's at low volume levels. If you want to ROCK OUT with those JBL's you will need a LOT more power! I have JBL 166's and use Dynaco MkIII's and an ARC D75 with them.
elliottbnewcombjr
5,333 posts
 
Well, your speakers high efficiency allow lower powered amps, SS or Tubes, I always like that.
However, a large woofer needs it's own magnet, and an amp working in it's 'easy' range for proper control. A port, reactive to the woofer, also wants that woofer tightly controlled.

based on those speakers, I would go for 60/32 wpc over 8 wpc.

Keep in mind, you will more than likely change your speakers. a higher powered amp will give yoou many more options regarding sensitivity choices.

It is a low powered amp that can destroy speakers, not a powerful one.   

Triode/Ultralinear.

Someting I always have been curious, to hear in my home with my speakers. I just bought Cayin A88T wjhich converts 45wpc ultralinear to 22 wps triode. I got the triode bug out of my system pretty quickly, so far I prefer everything Ultralinear. I keep trying to find something that benefits from Triode, nope. btw, all the Cayin reviewers, and my audiophile friends prefer ultralinear. I can hear why. It is not the reduced power, my speakers, horns, are incredibly efficient.

My friend has 8 wpc 300b mono blocks driving his wonderful speakers. Excellent, superb, with limited bass. He needs to keep the volume down to avoid distortion when those tubes try to do too much. He comes here when he wants to enjoy more bass or more volume.

btw, tube amps, as you know, but for others,

distortion specks up to 1.0 % (original stuff from the 60's, ... and new stuff) sounds just fine, it would be a mistake for anyone to reject the idea of tube sound based on comparison to SS miniature digitally produced percentage specs.
pehare's avatar
pehare
835 posts
 
Great advice above from these guys...8 wpc isn't going to cut it.  While you're looking at Latinos perhaps the ST70 he builds would sound better than the big 120 with your speakers.  I've found that smaller tube amps ie with just enough power to get the job done right sound better than overkill big tube amps.  Have fun!
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