If you’ve read Gregg Hopkins and Bill Moore’s new book, Ampeg: The Story Behind The Sound, you know that Jess Oliver played a major role in the success of Ampeg. Oliver Sound Company, Inc. is to Ampeg what MusicMan and Randall are to Fender, and since space for non-Ampeg items was justifiably restrained in Hopkins and Moore’s book, it seems timely for anyone whose interest has been recently piqued to look at the Oliver line in detail here (last month I wrote, “As direct descendents of classic Ampeg and some of the coolest amps of all time, the Oliver line perhaps deserved more space;” this may be true, but since I didn’t even mention the Musicman and Randall amps in Fender Amps, I guess I should retract). So here is about as much as you’ll ever need to know about Oliver amps, short of reprinting catalogs and schematics, with technical support from the man himself.
Shortly after the 1966 NAMM show, Oliver left the Ampeg company and started one of his own, teaming up with Harry Bloom, whose name appears under his on the Baby Bass patent (along with Ampeg founder Everett Hull).
Bloom had a machine shop with serious tools (including a Bridgeport milling machine) that were essential in the design of the pickup, and when Hull wanted his name included on the patent, Oliver added Bloom’s (the men had been introduced by composer Raymond Scott regarding the sale of a high-end Conn Strobe unit and the story goes that Bloom originally purchased the tuner to help develop an inexpensive toy xylophone, but when he discovered he had to pay an excise tax if the thing played in tune – as in no longer a toy, but a musical instrument – he lost interest in the project).
Oliver left Ampeg in September of ’66 and by the end of the year, was able to entice Bloom into converting his shop in Brooklyn into a musical instrument amplifier factory, offering him half of the new company. Both invested $5,000 to get started and it wasn’t long before a line of “Patented” amps was coming out of the small building at 49-01 Farragut Road (the patent was actually not granted until May 26, 1970, but was applied for February 28, 1967). Showing up at the NAMM show in the Summer of ’67 with a line designed by Oliver, Gene Andre, and Alex Gonzalez, that went beyond Ampeg’s best models, the new company generated a great deal of interest and proved Oliver was still a major force in the business.
In truth, his early line was built around one basic amp, but the Powerflex’s Jetsons-like approach to the Porta-Flex (patented in the name of Oliver Jespersen, but held by Hull) offered store owners a modern alternative to the popular Ampegs, with internally connected speaker cables, retractable AC cords, and an improved dolly. The light-up panel was another impressive step ahead of the competition.
Expanding into public address equipment, the company began building an outrageous speaker designed to perch atop telescoping stands, filling the air above the crowd with sound instead of trying to blast through clothed humans, one of the best sound absorbers known. These “Sound Projector” cabinets had a great reputation in the hi-fi world (having been designed and patented by NASA consultant John Karlson) and dispersed a wide pattern horizontally, with a tight vertical spread, making efficient use of power. Oliver was way ahead of its time with this ingenious (but potentially tipsy) rig.
Before the end of the decade, Bloom amicably reclaimed his machine shop and Oliver moved across the bay to Linden, New Jersey, as sole proprietor. Work on guitars and basses with Mike Roman (of Ampeg Horizontal bass fame) did not lead to production, but an electric pickup for the vibraphone turned into a fourth patent for Oliver Jespersen, and the unit was hawked to Deegan, the leader in vibraphone manufacture. This deal fell through and for a short time, Oliver marketed the device himself, with the endorsement of musical wiz Gary Burton, before Ludwig picked it up for their Musser line (seeing Burton 20-odd years ago with a very young Pat Matheny in tow was certainly a night to remember – check out Hank Garland’s fabulous Jazz Winds From A New Direction for his stellar teenage debut).
The Oliver company managed to keep its head above water in the turbulent late ’60s (while Ampeg was losing big bucks), but an offer from former Ampeg salesman Edmund Finger for a new factory and distribution led the company back to New York (Westbury, Long Island).
Retaining 51 percent of the company, Oliver became president. Finger had a knack for making money while working full-time for music jobber Bugeliesen & Jacobson, he was on the side pulling $150,000 a year out of Ampeg to pay himself and a small group of subcontracted salesmen – when Oliver was only getting $10,000 as VP! When Unimusic took control of Ampeg, he was forced to move on.
Finger hoped to get into the inexpensive student market, but Jespersen proved true to his roots and in a small power struggle (partly over Finger selling other manufacturers closeout amps on the side), Jess ended up back on his own in West Baylon, New York, in the mid ’70s. Undercapitalized in a volatile and fast-changing market, the company fizzled, moving Jess on to a long-running repair business out of the comfort of his basement shop in Massapequa Park, New York; free of the hassles from partners, payrolls, rent, etc. Almost 25 years later, he’s still tinkering away on new designs and still passing out business cards for Oliver Sound.
Powerflex Combo Amps
Oliver’s initial offering introduced the amazing Powerflex Series to the world, featuring “…the patented telescoping amplifier unit which automatically elevates the amplifier section out of the speaker enclosure.”
Any inherent problems with flipping an Ampeg Portaflex head upside down and into place were alleviated with this motorized take on the basic design. Flicking on the recessed power switch activated the tubes and a built-in motor, which would raise the head from its resting place. Vice-versa, switching the unit off slowly retracted the head, an astonishing sight to the uninitiated.
“Twenty-two new amplifiers for guitar or bass” were available, ranging in price from $450 to $1,260, with all employing one of two basic amplifiers. Each of these tops could be had with a variety of speaker configurations, ranging from a single 12 to four 15s. Reverb and tremolo were standard on the 502, with the 500 being essentially the same circuit, sans effects.
Two channels were standard, the first having controls for volume, treble and bass; the second including midrange and Ultra-High.
A pair of fixed-bias 7027A tubes easily generated 60 watts RMS from the B+ of 525VDC provided by a 5AR4 rectifier. A 6AN8 medium-mutriode/sharp-cutoff pentode performed the phase inversion and driver functions, a la Sunn. A high-fidelity 6EU7 twin-triode (amplification factor 100) was used in each of the two-stage preamps, with the 502 also including a third 6EU7 plus a 6DR7 dual triode for the tremolo and reverb sections. Intensity of the tremolo was controlled by a photocell, as on blackface Fenders.
While still in Brooklyn, the line settled into three basic speaker configurations; 500/502, designated a single 15″; 500T/502T, twin 12s and 500F/502F, twin 15s (500D/502D, twin 15s in dual enclosures, one with the built-in head and one without). Separate heads were available; the basic PA100X, the reverb-equipped PA100XR and the reverb/tremolo model PA100XRT.
Specified for use with the Oliver-built/John Karlson-designed PA speakers, circuit-wise they were almost identical to the Powerflex models.
The line carried over to Linden, along with the company, as shown on a May 1, 1969 pricelist. Work on a more traditional line including one-piece combo amps and two-piece piggybacks was started there and these showed up in the company’s press release regarding its move to Westbury, Long Island, and the June, 1970, pricelist showing the new address.
Uniflex and Duoflex Amps
Complementing and eventually supplanting the Powerflex Series, the Uniflex (combos) and Duoflex (separate components) lines featured a reworked control panel and offered the musician a second choice in power output. A smaller 35W amplifier powered the single-channel, single 12″ G120R guitar (a.k.a. “Little David”) and single 15″ B120 bass Uniflex models.
Solidstate rectifiers, 6L6 power tubes, 6EU7 phase inverters, and smaller transformers were just a few of the major electrical differences between the old and the new. A two-channel version of the 35W amp with reverb and tremolo powered the single 15″ G150R and the twin 12″ G200R.
Dressed up with the new control panel, but keeping the old 60W guts, the twin 15″ G400R completed the guitar amp line, coming in $150 less than the comparably outfitted (and soon to be retired) Powerflex. This amp was also available with a single 15″ as the G300R “Special Vibraphone” model, paired with the Oliver Electro-Vibe pickup. Again, the new model was priced over $100 less than a comparably equipped Powerflex, marking the beginning of the end for this patented, but somewhat pricey, design.
A comparable, but effect-less 60W piggyback bass head was available as the single 15″ B150, the twin 15″ B200 and the four 15″ B600. Equalization on these heads included Bass, Midrange and Treble, plus Ultra-High on Channel 1 and Ultra-Low on Channel 2. Ditto on the Powerflex price comparison here, too. The new bass amps became the mainstays of the company and were also sold with the Sam Ash brandname.
At the top of the 1970 line sat the short-lived Model 300W. While specs were not given for this $1200 set, the four 15″ speaker cabinet appears to have been the same as that used with the $799 B600, leaving one with the impression the additional $401 went toward a much more powerful head, especially since it was only a single-channel design. Dimensions were listed as 10″ X 31″ X 10″, as compared to 9″ X 19 1/2″ X 10″ for the standard 60W heads. The “W” designation was unique to this model – was this Oliver’s answer to Ampeg’s 1969 SVT? According to Jess, the amp never made it to production and possibly was not even built as a prototype.
By the July 15, 1972, pricelist the remainder of the Powerflex stock had been sold, with the G120R and the four 15″ bass amps joining them in retirement. This left a small and consistent line for the last years of the company. Holdovers included the G150R, G200R and G400R guitar amps; B120, B150 and B200 bass amps; and the PA100X and PA100XR heads.
New versions included the placement of G400R and B120 heads into twin 12″ combo cabinets, which became the G2400 and B212; plus additions at both the bottom and the top of the line. A “240 watts PMP (92 RMS)” head was offered with reverb as the PA200XR and without as the B240. Reverb/tremolo guitar versions apparently were never offered and according to Oliver, only a handful of the large amps were actually made. The power transformers had been purchased from Conrad Sundholm of Sunn and a few NOS pieces are still hanging around in the parts bin.
The bottom of the line extended a bit lower with the addition of a bare bones 35W amplifier with only Volume, Bass and Treble controls, the B100 single 15″ combo and the H100 head (also available with reverb as the H100R). These single-channel amps had a narrower control panel than the larger models. As PA systems grew in the ’70s, it became popular to have more than two channels, hence, the PA150XR with “4 channels, 8 inputs, extra features.”
Closing out the new additions were a four 12″ cabinet for PA and the OP1 Orbital Power Projector rotating horn. This Leslie-style horn cabinet can add a pleasant effect to low-power guitar setups and offers an interesting and relatively inexpensive alternative to chorus stompboxes. With Ludwig given an exclusive on the vibraphone pickup, the G300R was dropped, and there you have the basic story of Oliver amps.
A pricelist from August 1, 1974, shows the address for the last real factory, in West Babylon, New York, and a basically unchanged line, save for the deletion of the four 12″ cabinet and the addition of the larger OP2. Shortly thereafter, the factory was shut down, with Oliver keeping the name for conducting business from his basement shop in Massapequa Park, where he has been repairing amps of all makes and doing warranty work ever since. The last NOS Oliver amp, a leftover G400R, was sold from there just a few years ago after being converted from the extinct 7027s to 6L6s.
Oliver Jespersen, being the honorable kind of guy he is, managed to pay off all his credit accounts after closing the factory and dissolving the corporation. He actually received a letter from Paul Lovgrin, the president of Eminence, commending him for not leaving them holding the bag when he “…went out of business.” Since owners of corporations are not held liable for their company’s debts, this is a rare occurrence. Since then, Oliver has kept busy doing the things he’s been doing for years, namely playing music and working on amps and instruments. Next month we’ll interview this old-timer in depth and look at his numerous contributions to the music biz over the last 50 years.
Prototype/early production model Powerflex amps with silver grillecloth. Front to back 500, 502F, 500D. Extra knobs on 502 are for reverb and tremolo.
This article originally appeared in VG‘s Nov. ’99 issue. All copyrights are by the author and Vintage Guitar magazine. Unauthorized replication or use is strictly prohibited.