dynaco st-70 (35 rms) is small for jbl l4333A ?

[mati1979]

hi, i want a buy pair l4333A.
I have a st-70 (35+35 rms)
this tube amp is small for l4333A ? http://www.audiokarma.org/forums/images/smilies/scratch2.gif

[MikeBrewster77]

hi, i want a buy pair l4333A.
I have a st-70 (35+35 rms)
this tube amp is small for l4333A ? http://www.audiokarma.org/forums/images/smilies/scratch2.gif

They're bi-amp capable. Maybe use the ST-70 on the high end and a more robust SS on the low end?

[Audiobeer]

It would work but you would never realize the full potential of the 4333a with the Dynaco.

[speakerdave]

It would work but you would never realize the full potential of the 4333a with the Dynaco.

Yeah, it's a little small, but you can get hours and ours of musical enjoyment with the combination.



They're bi-amp capable. Maybe use the ST-70 on the high end and a more robust SS on the low end?

When you throw the switch for external crossover on the back of the 4333a the high pass and compensation elements for the horn and slot will stay in the circuit. You will need to provide external low pass prior to the power amp for the woofers, though. In off-the-shelf electronic crossovers JBL recommends 12 dB per octave as being closest to the built-in low-pass, but they note that the voltage drive for the built-in low pass also has some compensation engineered in. I do not know if a card load for the 5234/5 family of JBL crossovers has ever been worked out for this speaker. If it has, that would be ideal.

I used that model speaker with a 60 wpc tube amp and found it quite adequate for most of my listening, which is done at quite reasonable loudness levels. If you often have the desire to crank up the volume you will easily want 200 wpc or more. I found that my Audio Research VT60 made listening to compression drivers and slot tweeters much more pleasant than the solid state electronics I had around, and I was willing to forego high volume levels as a trade-off. However, there is a huge number of solid state amps I have never tried, so it's very possible your mileage may vary.

In my judgement, in the not-so-long run, you will want a larger amp, but until you can arrange that, the ST70 will play music for you. Like most high quality speakers, and this is one, the 4333a becomes a different animal when fed the big watts. It plays very sweetly at low volume, but also can make a party.

[mati1979]

Thank you !!
i have a room 17mt2 (5x3.5) :o:

[spkrman57]

It would work but you would never realize the full potential of the 4333a with the Dynaco.


You would not get everything that JBL is famous for with that small a amp.

But with a D130 and 075 would be overkill!!! LOL

Regards, Ron

[robertbartsch]

..get a big SS amp w/150WPS or so and never look back

[mati1979]

..get a big SS amp w/150WPS or so and never look back

i have a SAE series X-15A (150*2 w)
but a Dynaco is better than SAE. :o:

[Fred Sanford]

i have a SAE series X-15A (150*2 w)
but a Dynaco is better than SAE. :o:

OK, so you're almost there, then...get yourself an active crossover that can give you an 800Hz low pass, and use the Dynaco for highs/mids and the SAE for lows.

je

[Regis]

You may want to consider a MOSFET amp. They are different than regular transistor (Bipolar Junction) amplifiers. They have often been described as 'tube like' in their sound. Perreaux has made a line of MOSFET amps for many years and they pack plenty of power, but sound smooth and sweet.

[Beowulf57]

I wouldn't worry about it at this point: give your ST-70 a run and see what you think. Your room is relatively small and you will get a pretty good volume level before distortion sets in. As well, tubes are fairly forgiving of clipping and rather than becoming harsh, tend to sound a bit muddy in the bass region where most of the power lies.

The 4333A has the following specs:

Maximum Power Input’
75 watts continuous sine wave
(Bi-amplification
configuration)
Below 800 Hz
75 watts continuous sine wave
Above 800 Hz
30 watts continuous sine wave
Nomrnal Impedance 8 ohms
Power output*
4333A
101 dB SPL
Measured at 3.0 m (10 ft) in a room
volume of 57 m3 (2000 cu ft) with
1/2 rated power input

So in your room you should be able to get up around 104-105 dB SPL with two speakers: plenty loud. The main thing you are likely to notice (as others have pointed out) is limitations in bass control. The ST-70 does not have a well-regulated power supply, so as the bass demands go up the B+ will sag and power output will drop= loss of bass dynamic range and control.