I need help selecting a tube amp


OK Tube-heads. You win.

Can anyone recommend a suitable tube amp to drive some old JBL horns? (for 4435 Studio monitors, compression driver model 2425H). Nominal efficiency of 25% (500Hz to 2.5kHz)

With the advice from a friend I recently hooked up an old tube amp to my JBL studio monitor horns and was totally blown away. Those old large format studio monitors finally reached out and touched me. I felt like I was wrapped by a warm blanket after years of being in the cold. Norah Jones, Allison Krauss, Fleetwood Mac, Dire Straits and other vocal-and string oriented SACDS were amazing. I couldn't stop listening.

So into by the sound I've decided to begin educating myself about tubes with the hopes that in the end I'll be able to narrow my search, and ultimately purchase five amplifiers for my surround system (highs).

My system consists in part of five two-way JBL 4430-series studio monitors (vintage the 80's). I've been driving them with Crown's wonderful solid state Reference amps. I've always loved the lows, but the highs always seemed edgy and sterile - that is, until the other night when I tried tubes on them for the first time. What a wonderful surprise! I use active crossovers set at 1k for the bi-amping.

My head end is all Emm Labs: CDSD transport, DAC6e and 6-ch. pre.

My friend (who recommended I try the tube amp) says my horns are a good candidate for tube amplification due to the their efficiency. So I looked up the driver model 2425H online under JBLs vintage page and found that they are "25% nominal efficiency (500Hz to 2.5kHz)"

Help. What does this mean to someone who is looking for a suitable tube amp to drive them?

There are also sensitivity specs like: 117dB SPL, 1W @1m. The specs also say the recommended wattage is 100W. How do I make sense of these specs when choosing a tube amp, correct wattage or trying to get a good match? I need a starting point!

I look forward to being enlightened by all of you tube-masters interested based on your knowledge and experience, and who really know your stuff.

Signed truly tube-happy,

Dean
quantumavman

Showing 1 response by jalanc42069

Hello QAVman, wow, that soumds cool. 117db!, what that means is your speakers will put out 117decibels, measured with a 1 watt signal, measured at a distance of 1 meter from the speaker. That's freakin' loud! I don't know how large your listening room is but basically, any tube amp will do it, so start auditioning to find something that sounds good to you. Personally, I would look at the single ended triode amps first, they have a sweetness and presence in the midrange that is hard to beat, my favorite is the 2A3 sound, but 300B, 45,845, etc also sound great. SETs are usually noted for being a little soft in the bass(unless you spend the bigbucks, although i recently heard the Almarro 205 SET amp - 5 watts/$800., and the bass was great), but i assume you have subs. I've also heard some great push pull and OTL amps, which usually are stronger at the bottom. Although i havn't heard it yet, Transendent Sound makes a hybrid single ended/OTL amp called the SE OTL that appeals to me(best of both), they can be used in stereo or mono. Five of those would be a cool set up! I've heard they work excellent with the Klipshhorns, so they might sound great with your JBLs.( i have no affiliation with TS, i'm just a fan, and hopefully future buyer. These are loose generalizations on the different topology styles and by no means are they universal, so see(hear) what your ears say. Good luck and have fun. Thanks for reading this (too) long post. Regard, Alan