JBL is most known for their massive array and presence in home and pro audio. Especially their home and pro audio from the 1960’s and 70’s. We are talking some of the most renowned and well-known studio monitors and home speakers, including the before-covered JBL L-100 Century (read more here: JBL L-100 Speakers – An overview and guide to to the 70’s icon)
Having had a multitude of different JBL speakers and using the JBL 4343 studio monitors at home, I’ve always been interested in their very small endeavour into electrical equipment.
In their 1964 catalogue they showcased their SE-400 power amplifier, the SG-520 preamplifier and and the JBL SE-401 energizer. Followed by the SA-600 integrated amplifiers and the SE-408 energizer in 1966 and lastly the SA-660 in 1969. this little handful of electronics where short-lived, and the 1970 advertised accompanying tuner never saw production. Some of these power amplifiers, the “Energizers” where designed to be built into a speaker, and the SE-401 and SE-400 is actually exactly the same, whereas the SE-400 came with a case and illumination (so you could see they where turned on).
Catalogs and timeline
First introduced in their 1964 catalog, was the SG520 preamp or “Graphic Controller” and the SE-401 “Energizer” or power amp.
In the next catalog from 1966, was suddenly a fully fledged integrated amplifier in a brushed aluminum finish, and a boxed energizer called the SE-400.
From their 1969 catalog, the JBL SA-660 featuring a black face, SE-400S, SG520 and SE-408S amplifiers are introduced
And then the last sighting for the application range, is in the 1970 with suddenly a Tuner introduced. and this is the only mention of the product, it probably never saw mass production. If the pictured unit is more than an empty shell is a giant question.
And thus the end of the JBL application
For some reason it wasn’t a product-range JBL wanted to continue, maybe they wanted to focus their energy on their booming speaker market and range, battling for being the industry-standard in recording studios (and succeeding!) during the 70’s. I’ve always had a keen eye for these units, but they collect a hefty price on the used market. Primarily because of scarcity and not necessarily because of their quality or performance. I’ve thought they where cool but a bit niche and out of my immediate scope of ownership.
Or so I thought. A couple of months ago I was lucky enought to grab myself a JBL SE-408S Energizer. This is a funny little thing. Extremely simple and built for being robust and easy to use. It is completely ripped of features, not even having an ON-indicator or a power button. Input, gain pot and output is all.
JBL SE-408S
Mine had been sitting idle in the back of a speaker, unused for 20-30 years, and was All-original. Produced in 1966, this was an almost 60 year old device – So I brought it to a good friend and technician for initial startup. The last thing i wanted was to kill the output transistors in this baby, knowing that a recap would most likely be needed to ensure safe operation for the next many years.
The amp was hooked up, started slowly on a variac and then through a simple frequency response and THD test. Below is the results. from a un-restored amplifier those numbers are quite extraordinary!
But, since old electrolytic capacitors IS a known issue and I aim for longevity and ease of use in my gear, i still chose to restuff the Sangamo capacitor, while exchanging all electrolytic capacitors throughout the amplifier. Now, this amp is greatly and smartly built, but not with service in mind.
The overall build quality is pretty, but also draws more from the methods used and known from tube amplifiers than more new transistor based equipment. Point to point wiring, as for example in the power supply.
Simple and effective. but a PITA to maintain. As seen below from replacing electrolytic capacitors.
The Output transistors uses the metal body of the amplifier as a heat-distributor. neat and smart as this was meant to be built into a speaker, with it driving that speaker and the other in a stereo-pair to be wired to the “Active” speaker. Like daisy-chaining your speakers together. Because of that it doesn’t come with a cabinet and heat needs to be vented to the outside of the enclosure.
Sound Impressions
Hooked up it sounds really good – warm yet precise. It drives my JBL 4343 with a great deal of authority but there is a warmth I can only attribute to it’s close proximity of the tube amplifiers and their sound of the time.
Really impressive from 2X40 watts. It’s a lovely and capable machine overall.
Living with it
The amp is a beautiful little feat of engineering and as one would suspect it just works. Although it doesn’t have a relay, and as such you need to ensure you turn on your preamp, before turning on the power amp. The absence of a power switch and indicator showing that the amp is turned on makes this a bit of a chore.
Adding to this, i found that I couldn’t really make it something that would fit into my living-space. Even though i ended up repurposing a Citation Twelve Deluxe cabinet as a cabinet for it – great match visually. But again – the amp has power, input and speaker terminals.. on the front!
I ended up sending it off for a more loving home elsewhere. Glad that I had a chance to make it acquaintance.
