Ampeg B-15N Portaflex 1965 - Blue Checkerboard with Original Trolley, Utah Speaker
From Reverb article, "Gear History" by Will Sacks, October 19, 2017:
In 1960, The Ampeg Company, Inc. introduced the first combination amplifier dedicated to the bass guitar: the B-15. Conceived in 1958 by the late legend Jess Oliver (aka that dude who first put reverb into a guitar amp), the B-15 grew up alongside our modern music industry. Like a lot of the popular sewing machines at the time, the B-15 stored inside of itself, as players moving from gig to gig only had to flip over the amp head to get moving. From its early days as a union-provided amp on the Manhattan Bass Club scene to its storied history inside the world’s elite studios, the Fliptop B-15 is iconic and inescapable.
Bass players of every genre and decade have favored the different flavors of the B-15 as a trusty sidekick in some of the most memorable performances in recorded history. Rick Danko used a B-15 with The Band and even used a B-15S on The Last Waltz. Motown fixture and demigod James Jamerson used a B-15 for all of his live performances as well as the majority of his non-Motown sessions in Los Angeles. As Eddie Kramer recounts, John Paul Jones would wheel his B-15 into their Led Zeppelin recording sessions. Hell, even Jimi Hendrix was known to plug into a B-15 or two, like during this performance on Dick Cavett.
B-15
The Portaflex B-15 model was first introduced in 1960 for $355. Geared toward acoustic bassists, this initial model featured extra porting options for use with upright basses. These B-15s are most easily recognized by the random flair navy tolex, the distinctive power knob, their shared tone control circuit, and the lack of a lucite light up logo.
At the outset, the B-15’s preamp section consisted of three 6SL7 preamp tubes and two 6L6GC power tubes. The initial design employed a 5U4GB tube rectifier, and even though a lot has changed cosmetically, the only change Jess Oliver made to the B-15’s actual circuit was the rectifier. The first B-15s were self-biased and outputted 25 watts of tube power.
At this point, the two channels had independent volume controls but actually shared an equalization circuit. Using the Baxandall-style tone control circuit, Ampeg’s bass and treble controls were located between the second and third 6LS7s. The initial B-15 featured two channels with three input jacks — one for each channel — and an extra “Stereo” input jack that sent signal to both channels simultaneously.
The first B-15s generally housed a Jensen P15N speaker, brilliantly set in Jess Oliver’s patented double-baffle design. The original design placed the speaker between two baffles with 15-inch ports, separated by ⅜ of an inch. The outer baffle had a 15-inch circular cut out and a bar across the center of the speaker cone...
B-15N
This new B-15 retained the same random navy flair tolex, yet added in two separate channels with separate bass and treble tone controls, an updated negative feedback resistor (which was changed from 6,800 ohms to Stereo input, and introduced a second jack on the first channel. This updated B-15 design would become the cornerstone for the rest of Ampeg’s B-15 output.
A few months later in 1961, the B-15 received three important features before the model number was updated: its hallmark light-up lucite insignia that would last until the amp was remodeled in 1968 and its tilt-back rod, which only lasted until 1964. These amplifiers from 1961-1962 are extremely rare, and you can tell them apart from any other B-15 because of the combination of navy random flair tolex and a lucite light up logo.
25 Watts All-Tube Power
1x15" Utah G15R Speaker (Period-Correct Replacement)
2x Silvertone 6L6GC Power Tubes
3x Ampeg 6SL7 Preamp Tubes
1x GE 5AR4 Rectifier Tube
FlipTop design for ease of Transport
Ampeg Trademark Blue Checkered Vinyl
Illuminated Lucite Logo
Guitar & Bass Voicings on Input 1
Miscelleneous Inst. on Input 2
Volume, Treble, & Bass Controls on each Channel
Ground Lift Switch
8ohm Ext Speaker Out
Ext. Amp Out
Hum Control Pot Located on Reverse
Original Trolley Included
This amplifier is in Very Good condition, showing signs of its age, of moderate -to-heavy use, and of careful storage. This is a two-owner amplifier, with its current owner having owned and played it since 1965 or 1966. Considering its "Vintage" status, the classic Blue Checkered covering is in fantastic shape, with expected minor and moderate wear and tear and minor loss. The pots have a slight scratchyness when adjusted while the amp is live and this may be rectified with a proper professional cleaning. The chrome housing on the head has an expected level of tarnish. The amp handle has been "rigged" with a replacement which functions properly but isn't the nicest thing to look at on this unit. The speaker was replaced early in this amp's life with a Utah G15R 15" speaker. It is unknown and unlikely that the existing tubes are original to this amplifier, though they are of a vintage nature and seem age-appropriate to this unit. The trolley is securely attached to the cabinet and appears to be original to this combo. One of the screws which secure the lucite logo to the mesh tube cover is missing to the sands of time. We have attempted to accurately and honestly portray the condition of this vintage piece and are happy to provide more photos per request. This amp has been tested and functions as intended. Pure Bass Heaven.
In 1960, The Ampeg Company, Inc. introduced the first combination amplifier dedicated to the bass guitar: the B-15. Conceived in 1958 by the late legend Jess Oliver (aka that dude who first put reverb into a guitar amp), the B-15 grew up alongside our modern music industry. Like a lot of the popular sewing machines at the time, the B-15 stored inside of itself, as players moving from gig to gig only had to flip over the amp head to get moving. From its early days as a union-provided amp on the Manhattan Bass Club scene to its storied history inside the world’s elite studios, the Fliptop B-15 is iconic and inescapable.
Bass players of every genre and decade have favored the different flavors of the B-15 as a trusty sidekick in some of the most memorable performances in recorded history. Rick Danko used a B-15 with The Band and even used a B-15S on The Last Waltz. Motown fixture and demigod James Jamerson used a B-15 for all of his live performances as well as the majority of his non-Motown sessions in Los Angeles. As Eddie Kramer recounts, John Paul Jones would wheel his B-15 into their Led Zeppelin recording sessions. Hell, even Jimi Hendrix was known to plug into a B-15 or two, like during this performance on Dick Cavett.
B-15
The Portaflex B-15 model was first introduced in 1960 for $355. Geared toward acoustic bassists, this initial model featured extra porting options for use with upright basses. These B-15s are most easily recognized by the random flair navy tolex, the distinctive power knob, their shared tone control circuit, and the lack of a lucite light up logo.
At the outset, the B-15’s preamp section consisted of three 6SL7 preamp tubes and two 6L6GC power tubes. The initial design employed a 5U4GB tube rectifier, and even though a lot has changed cosmetically, the only change Jess Oliver made to the B-15’s actual circuit was the rectifier. The first B-15s were self-biased and outputted 25 watts of tube power.
At this point, the two channels had independent volume controls but actually shared an equalization circuit. Using the Baxandall-style tone control circuit, Ampeg’s bass and treble controls were located between the second and third 6LS7s. The initial B-15 featured two channels with three input jacks — one for each channel — and an extra “Stereo” input jack that sent signal to both channels simultaneously.
The first B-15s generally housed a Jensen P15N speaker, brilliantly set in Jess Oliver’s patented double-baffle design. The original design placed the speaker between two baffles with 15-inch ports, separated by ⅜ of an inch. The outer baffle had a 15-inch circular cut out and a bar across the center of the speaker cone...
B-15N
This new B-15 retained the same random navy flair tolex, yet added in two separate channels with separate bass and treble tone controls, an updated negative feedback resistor (which was changed from 6,800 ohms to Stereo input, and introduced a second jack on the first channel. This updated B-15 design would become the cornerstone for the rest of Ampeg’s B-15 output.
A few months later in 1961, the B-15 received three important features before the model number was updated: its hallmark light-up lucite insignia that would last until the amp was remodeled in 1968 and its tilt-back rod, which only lasted until 1964. These amplifiers from 1961-1962 are extremely rare, and you can tell them apart from any other B-15 because of the combination of navy random flair tolex and a lucite light up logo.
25 Watts All-Tube Power
1x15" Utah G15R Speaker (Period-Correct Replacement)
2x Silvertone 6L6GC Power Tubes
3x Ampeg 6SL7 Preamp Tubes
1x GE 5AR4 Rectifier Tube
FlipTop design for ease of Transport
Ampeg Trademark Blue Checkered Vinyl
Illuminated Lucite Logo
Guitar & Bass Voicings on Input 1
Miscelleneous Inst. on Input 2
Volume, Treble, & Bass Controls on each Channel
Ground Lift Switch
8ohm Ext Speaker Out
Ext. Amp Out
Hum Control Pot Located on Reverse
Original Trolley Included
This amplifier is in Very Good condition, showing signs of its age, of moderate -to-heavy use, and of careful storage. This is a two-owner amplifier, with its current owner having owned and played it since 1965 or 1966. Considering its "Vintage" status, the classic Blue Checkered covering is in fantastic shape, with expected minor and moderate wear and tear and minor loss. The pots have a slight scratchyness when adjusted while the amp is live and this may be rectified with a proper professional cleaning. The chrome housing on the head has an expected level of tarnish. The amp handle has been "rigged" with a replacement which functions properly but isn't the nicest thing to look at on this unit. The speaker was replaced early in this amp's life with a Utah G15R 15" speaker. It is unknown and unlikely that the existing tubes are original to this amplifier, though they are of a vintage nature and seem age-appropriate to this unit. The trolley is securely attached to the cabinet and appears to be original to this combo. One of the screws which secure the lucite logo to the mesh tube cover is missing to the sands of time. We have attempted to accurately and honestly portray the condition of this vintage piece and are happy to provide more photos per request. This amp has been tested and functions as intended. Pure Bass Heaven.
USED
$3,499
$3,499