Amplifier to power JBL Voice of Theater Speakers

Do you have JBL or Altec both were made with horn drivers but the "Voice Of The Theater" were made by Altec. It doesn't matter all that much with regard to amplification as both were very highly efficient.
These speakers do best IMO with tube amplification. That said I would stay with your pre but not recommend ARC amps. I would choose a more lush amp to work in synergy with the speakers. There are numerous possibilities with these as they don't require a lot of power.
If you go SS find amps that are "musical" or warmish. One of the SS possibilities is an older McIntosh amp, which I have used with some success.
There is one thing that I have not done with my own vintage gear (JBL and Klipsch) which is to ensure that the (Alnico) speaker magnets are working at full capacity. I would have to ask others how that is done.

Could you provide the full model number of your JBL's?
I have a pair of JBL 4676-A rated at 106db.

Mechans is spot-on. Altec Lansing made the VOTT (woofers and the large horns only). Either way, tube power would be best. I'd suggest McIntosh MC275 or perhaps a pair of MC40 or MC60 mono units. Both are extremely efficient, so caution with maximum power is appropriate.

Good luck & happy listening!

I had 4343's for years. I had crossovers made with new parts according to the original specs and put in new solid core wiring and connections (lost the vintage value, but wow..what a difference) I used Pass Labs aleph 2 and then 1.2 and actually like the 2's better. tubes are a great option, but if you are solid state I would go for some used class a low powered amps with lots of capacitance. Easy to overshoot the sweet spot with those. People see big speakers and think big power. Have fun

Voice Of The Theater is what I was told when I bought them 37 years ago. I have photo of the JBL's, I got this from someone else, but this is what they look like. I would get the model number, but they are in another state right now.

Pre-Amp
http://i217.photobucket.com/albums/cc237/rpkoran/Chinchilla/Stereo/Audio%20Reaserch%20Pre%20Amplifier%20Model%20SP-3A-1%20Front_zpsugjsq77l.jpg

Speakers
http://i217.photobucket.com/albums/cc237/rpkoran/Chinchilla/Stereo/JBL%20Voice%20Of%20The%20Theater%20Speakers_zpsv0skmv39.jpg

Vac 200 PHI wonderful amp or Pass 250.8.

This kind of loudspeaker really will not sound right with transistors unless that transistor amp does not employ loop negative feedback (and most do).

Such amps tend to cause a speaker like this to sound quite shrill (and is part of the reason horns were often not taken seriously from about 1970 until about 1995). In addition, if the speaker is old enough (1960s or earlier; hard to tell from the photos) the crossovers might not work as designed if the amplifier has a low output impedance.

So the easy way to get them to sound right is with tubes. This speaker is likely no more than about 99db 1 watt/1 meter, so having a bit of power is nice. I have speakers of similar efficiency and so I use a set of our M-60 amplifiers which are triode and make about 60 watts.

The pictures look a lot like Altec Voice Of The Theatre. JBL speakers made early on (I own two pairs) offered cabinet styles and speaker crossover package to fill the cabinets with. So my C36s have the 030 If I recall correctly, using the 15 inch 16 ohm D-130 extended range woofer/mids speaker and the 075 titanium/aluminum Bullet horns also 16 ohm, and the N2400 crossovers.
Your speakers are from a later period, but make use of the JBL Lansing Heritage pages. In particular look at the product brochures in the "libray" section of the website.

I would also recommend a top notch tube amp.Atma-Sphere would be a first choice along with possibly Graaf,hot-rodded Mac 30-40 monos.......but start with AS,Ralph is a guy who will do the right things on all levels.......thanks,Bob

I dated a neurosurgeon's daughter in 1975, carded his ampitheater door, and checked out his stereo system. Voice of the Theater speakers. Massive beasts standing well over 6' high and ~3' wide. His Amp/preamp system was MacIntosh, a tubed system. He ran a reel to reel tape machine with classical music to unwind after a long day of brain surgery. I never had the cajones to fire up his system but I can still see it in my minds eye today. His budget was limitless so I would look for some older, high quality, MacIntosh equipment.