Ampeg SB-12 Tube Bass Amplifier (1967)
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Ampeg SB-12 Model Tube Bass Amplifier (1967), made in Linden NJ, serial # 056867, blue checked Tolex finish.
Ampeg's 1960s SB-12 was a slightly simplified, lower-powered line-up companion to the iconic B-15N, taking the place of the earlier Portaflex B-12N and B-12NL. This particular example is one of the last of Ampeg's "blue-checked Tolex era" from 1967, which gave way to a less distinctive black covering the next year.
At the time the SB-12 was primarily marketed as a companion amplifier to the upright Baby Bass. Ampeg legend holds that "SB" stood for "string bass" and was Everett Hull and Jess Oliver's preferred design for upright bass once the B-15s became more deliberately marketed for the electric bass guitar. Earlier catalogs proclaim the B-12 models to be for "upright bass primarily" and the B-15 models to be for electric or "upright bass if a deeper tone is desired".
Featuring a simplified single channel design, the SB-12's front panel still sports the familiar dedicated instrument and bass inputs alongside master volume, treble and bass controls. Two 7868 power tubes in push-pull yield approx. 25 watts of power into a single 12" speaker. This iteration of the model also had the fairly clever idea of connecting the speaker through the cabinet latches, eliminating the need for a dedicated cable, although this particular example has been converted to a standard 1/4" speaker cable connection. While less powerful than the B-15 this is still a lovely lower-volume bass amp, quite suitable for recording purposes with a versatile sound and the deep round response Portaflex Ampegs are famous for.
Height is 27 3/4 in. (70.5 cm.), 17 5/8 in. (44.8 cm.) width, and 12 5/8 in. (32.1 cm.) deep.
Cosmetically, this amp has seen some wear and tear over the years but overall is in fairly decent shape considering the less durable covering of this era. The signature blue-checked Tolex is overall intact, save for a few minor scuffs here and there. The chassis is clean overall with all the original knobs present. There's some light corrosion to the chrome but most of the decorative stenciling is still nicely intact. The grille cloth is clean and nicely intact with no notable signs of tearing or fraying and both the illuminated acrylic plate and metal logo are present as well. The handle is a newer correct replacement and as mentioned above, both the cabinet and head have modified speaker in and out 1/4" jack connections, forfeiting the original speaker connections through the cabinet latches.
Electrically, the amp is somewhat original. The speaker is a later replacement 12" Electro Voice, which both tests and sounds great. The power transformer is also a newer Hammond 272BX replacement. The output transformer is original to the amp and bears the code 682-651, dating it to the 51st week of 1966. Visible pot codes all date to 1966. The amp has seen our typical maintenance and servicing, including a grounded 3-prong power cord, some light speaker and baffle repair, replacement of electrolytic capacitors, replacement of any out-of-spec components, cleaning of all sockets, pots and jacks and power tubes biased to spec.
This SB-12 sounds great, making for a fine lower volume bass amp (set at "4.5" or below) offering a nice warm well-rounded sound. It can also double as a surprisingly rip-roaring guitar amp when cranked; in many ways a perfect home or small studio 2-in-1 recording amplifier. Very Good + Condition.
Ampeg's 1960s SB-12 was a slightly simplified, lower-powered line-up companion to the iconic B-15N, taking the place of the earlier Portaflex B-12N and B-12NL. This particular example is one of the last of Ampeg's "blue-checked Tolex era" from 1967, which gave way to a less distinctive black covering the next year.
At the time the SB-12 was primarily marketed as a companion amplifier to the upright Baby Bass. Ampeg legend holds that "SB" stood for "string bass" and was Everett Hull and Jess Oliver's preferred design for upright bass once the B-15s became more deliberately marketed for the electric bass guitar. Earlier catalogs proclaim the B-12 models to be for "upright bass primarily" and the B-15 models to be for electric or "upright bass if a deeper tone is desired".
Featuring a simplified single channel design, the SB-12's front panel still sports the familiar dedicated instrument and bass inputs alongside master volume, treble and bass controls. Two 7868 power tubes in push-pull yield approx. 25 watts of power into a single 12" speaker. This iteration of the model also had the fairly clever idea of connecting the speaker through the cabinet latches, eliminating the need for a dedicated cable, although this particular example has been converted to a standard 1/4" speaker cable connection. While less powerful than the B-15 this is still a lovely lower-volume bass amp, quite suitable for recording purposes with a versatile sound and the deep round response Portaflex Ampegs are famous for.
Height is 27 3/4 in. (70.5 cm.), 17 5/8 in. (44.8 cm.) width, and 12 5/8 in. (32.1 cm.) deep.
Cosmetically, this amp has seen some wear and tear over the years but overall is in fairly decent shape considering the less durable covering of this era. The signature blue-checked Tolex is overall intact, save for a few minor scuffs here and there. The chassis is clean overall with all the original knobs present. There's some light corrosion to the chrome but most of the decorative stenciling is still nicely intact. The grille cloth is clean and nicely intact with no notable signs of tearing or fraying and both the illuminated acrylic plate and metal logo are present as well. The handle is a newer correct replacement and as mentioned above, both the cabinet and head have modified speaker in and out 1/4" jack connections, forfeiting the original speaker connections through the cabinet latches.
Electrically, the amp is somewhat original. The speaker is a later replacement 12" Electro Voice, which both tests and sounds great. The power transformer is also a newer Hammond 272BX replacement. The output transformer is original to the amp and bears the code 682-651, dating it to the 51st week of 1966. Visible pot codes all date to 1966. The amp has seen our typical maintenance and servicing, including a grounded 3-prong power cord, some light speaker and baffle repair, replacement of electrolytic capacitors, replacement of any out-of-spec components, cleaning of all sockets, pots and jacks and power tubes biased to spec.
This SB-12 sounds great, making for a fine lower volume bass amp (set at "4.5" or below) offering a nice warm well-rounded sound. It can also double as a surprisingly rip-roaring guitar amp when cranked; in many ways a perfect home or small studio 2-in-1 recording amplifier. Very Good + Condition.