65amps Apollo

The Ampeg B-15 is arguably the most celebrated amp in bass history.
By Jonathan Herrera ,

The Ampeg B-15 is arguably themost celebrated amp in bass history. In its mid-’60s heyday, it offered rich and warm tone at a decent volume, and was particularly well suited for studios, like Hitsville U.S.A., the original home of Motown records and house bass player James Jamerson. While Jamerson’s tone and playing were undoubtedly in part responsible for the B-15’s legendary status, it’s also just a great sounding amp. With the Apollo, boutique tube-amp builders 65amps wanted to make an idealized B-15-esque all-tube low-watt amp. I’ve long wondered why more tubeamp builders don’t jump on the opportunity that the dearth of contemporary B-15-style amps presents, so I was especially pleased when the Apollo rig arrived at the office.

In important ways, the Apollo is similar to the B-15, but it’s also substantially different. Among the important similarities are the inclusion of a few key features of the B-15 tone recipe, namely its quartet of octalbase tubes, two 6SL7’s in the preamp (handling initial gain stages and phase inversion) and two 6L6’s tubes in a Class AB configuration in the power amp. Good 6SL7’s can be tough to find, and major kudos to 65 for providing killer NOS National Union and Sylvania tubes in our tester. Another important B-15-like characteristic of the Apollo is its simple Baxandall-style tone stack. The passive network is a more hi-fi alternative to the Fender-style tone stack, with a somewhat flat response at the knobs’ center position. The Apollo also uses a tube rectifier (5AR4), a feature not common to all classic ’60 B-15’s (the B-15N utilized a solid-state rectifier until the tube’s return in the ’64 B-15NC). The sag of a tube rectifier is a big component of a tube amp’s unique sound, although the Apollo’s stout power supply minimizes its influence somewhat.

After the similarities above, the Apollo diverges from its inspiration. Most obviously, it’s not a combo, nor does it have that alltime- cool underlit plexiglass screen of the old B-15. Still, it’s exceptionally handsome and quite light and portable for an all-tube rig. The Apollo also offers a frequencyresponse- limiting switch with FULL and NORMAL positions. The NORMAL setting is designed to replicate a vintage-spec circuit, with its narrower bandwidth. Conversely, FULL expands the amp’s bass and treble response, resulting in a markedly bigger and broader sound. Additionally, the Apollo boasts a 3-way input pad—an excellent feature that accounts for the increased output of today’s basses. It’s always a drag playing an old tube bass amp and realizing your super-modern high-output active bass is just too hot for the input, resulting in grit and grind no matter what you do.

The Apollo head’s construction was excellent, with clean point-to-point wiring, a hardy chassis, and top-notch components, including two beefy Mercury Magnetics transformers specially designed for the amp. I did miss having an XLR output, which is pretty much standard on bass heads now. I understand that it’ll be mic’d in a studio, no doubt, but it’d be pretty cool to benefit from the groovy 6SL7 preamp as the front end for a console or audio interface. The front panel is dead-simple, although I initially found the labeling of the 3-way input pad switch a bit confusing. The cabinet itself was no less rugged. The 11-ply Baltic birch cab is well braced and uses nice-anddeep dovetail joints for added rigidity. Its grille was well attached and buzz-free.

Played with a handful of vintage basses as well as some more sizzly new stuff, the Apollo was punchy, warm, and thick sounding. I didn’t have a B-15 around to A/B it with, but I have spent a lot of time with them. Though not scientific, my comparison is thus: the Apollo can be made to sound somewhat similar, but it’s really a different animal entirely. It’s no less tuneful, and in many ways it’s a more reliable, stout, and hi-fi design, but it’s not a B-15. What it is, however, is a delicious-sounding portable means of getting syrupy and mojo-laced tube tone from a relatively portable rig.

The FULL/NORMAL switch had a profound impact on tone, with the NORMAL setting yielding a notably smaller-sounding, pokey vintage sound. The EQ is functional and effective, though don’t expect lasersharp precision. The PAD switch is also an essential determinant of the Apollo’s sonic personality, since high-output basses easily clip the front end (not an entirely bad thing, if that’s what you’re after) without the pad engaged. Its dual padded settings make it even more flexible than a single switch.

I dug the Apollo greatly. It’s expensive—a lot more than even a well-sorted vintage B-15 might be—but it’s got loads of tone and vibe. It’d work on low- to mediumvolume gigs without incident, but I expect it will really shine in the studio, just like its inspiration. Regardless, if you’ve got the dough and that unshakable tube lust, it’s pretty darn sweet.

Street Head, $2,195; cabinet, $645
Pros Warm and gooey tone with loads of vibe and a solid sonic footprint
Cons No XLR output


Power output 50 watts @ 8Ω minimum
Tone controls BASS, TREBLE, Baxandall tone stack; FULL/NORMAL switch narrows frequency spectrum
Power amp topology Class AB
Tube complement 6SL7 (2); 6L6 (2); 5AR4 rectifier
Weight 29 lbs

Configuration 1x15
Speaker Custom-designed Celestion 400-watt
Cabinetry 11-ply Baltic birch
Weight 50 lbs

Made in U.S.A.
Warranty Lifetime limited
Contact www.65amps.com