National-Dobro Model C Tube Amplifier (1938)
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National-Dobro Model C Model Tube Amplifier (1938), made in Chicago, serial # B2085-S, black fabric covering finish.
This interesting Chicago-made amp dates to the late 1930s, a well-preserved example of some of the earliest creations in vacuum tube instrument amplification. This little pre-war amplifier was made by National-Dobro before the company re-organized into Valco during WWII. National-Dobro made many of the best engineered amplifiers of the era, and even this small off-center gem is no exception.
Documentation from that era being rather thin, considering the rapidly-changing designs and aesthetics of the now unified National and Dobro companies, these amps can be difficult to date with precision. Fortunately, National appears to have used the same serial number format for everything including products made as subcontractors. The number and the amp's elongated rectangular cabinet (a design initiated after the company moved east to Chicago) indicate the amp was made around 1938. This particular amp is most similar to the more boldly branded National or Dobro Model C, with the exception of having an 8" speaker as opposed to a 10". This may have been the more humbly adorned "Supro" version of the amp, or made for one of the many jobber brands the company subcontracted for.
The amplifier features two inputs and a single volume control and on/off switch. A dual-6V6 power section yields around 8-10 watts into a single 8" National-Dobro branded "electro-dynamic" field coil speaker. The cabinet mounts the speaker and power unit side-by-side and is covered in a thin black leatherette covering with rounded circular cutouts for the speaker and a silver grille cloth underneath. Unlike on National-Dobro's more expensive amplifiers, there's no latching rear cover for the speaker, tubes and the control panel. For nearly another decade, amplifiers made by National-Dobro would aesthetically still very much resemble these pre-war predecessors, save for the speaker grille cutouts; circular in these earlier amps as opposed to the later squared-off or "shield logo" appearance.
Height is 11 in. (27.9 cm.), 12 1/2 in. (31.8 cm.) width, and 7 3/4 in. (19.7 cm.) deep.
Overall this 85-or-so year old amp is quite well-preserved. The rather fragile thin cabinet covering shows minimal signs of wear; a couple very small scuffs here and there, but overall it's one of the cleanest amps of this era we've had the pleasure of featuring. The steel chassis is beautifully clean and shows no notable signs of corrosion; both the model tag and volume control plate are present and in exemplary condition. Even the original handle is intact and still has plenty of life left in it.
Electrically, this little amp is nicely original. The National-Dobro-branded G8RS field-coil speaker is in great shape and sports the original cone, which after a little TLC still sounds terrific. Both the power and output transformers are original to the amp, as is the volume pot and on/off switch. The amp has seen our typical maintenance and service, including a 3-prong grounded power cord, replacement of all electrolytic filter caps, cleaning of all sockets, pots and jacks and power tubes biased to spec.
This fabulous and beautifully compact specimen of a fairly rare and early pre-war amp has a sweet sound at lower volume, but surprisingly loud roar when dimed! Overall Excellent Condition.
This interesting Chicago-made amp dates to the late 1930s, a well-preserved example of some of the earliest creations in vacuum tube instrument amplification. This little pre-war amplifier was made by National-Dobro before the company re-organized into Valco during WWII. National-Dobro made many of the best engineered amplifiers of the era, and even this small off-center gem is no exception.
Documentation from that era being rather thin, considering the rapidly-changing designs and aesthetics of the now unified National and Dobro companies, these amps can be difficult to date with precision. Fortunately, National appears to have used the same serial number format for everything including products made as subcontractors. The number and the amp's elongated rectangular cabinet (a design initiated after the company moved east to Chicago) indicate the amp was made around 1938. This particular amp is most similar to the more boldly branded National or Dobro Model C, with the exception of having an 8" speaker as opposed to a 10". This may have been the more humbly adorned "Supro" version of the amp, or made for one of the many jobber brands the company subcontracted for.
The amplifier features two inputs and a single volume control and on/off switch. A dual-6V6 power section yields around 8-10 watts into a single 8" National-Dobro branded "electro-dynamic" field coil speaker. The cabinet mounts the speaker and power unit side-by-side and is covered in a thin black leatherette covering with rounded circular cutouts for the speaker and a silver grille cloth underneath. Unlike on National-Dobro's more expensive amplifiers, there's no latching rear cover for the speaker, tubes and the control panel. For nearly another decade, amplifiers made by National-Dobro would aesthetically still very much resemble these pre-war predecessors, save for the speaker grille cutouts; circular in these earlier amps as opposed to the later squared-off or "shield logo" appearance.
Height is 11 in. (27.9 cm.), 12 1/2 in. (31.8 cm.) width, and 7 3/4 in. (19.7 cm.) deep.
Overall this 85-or-so year old amp is quite well-preserved. The rather fragile thin cabinet covering shows minimal signs of wear; a couple very small scuffs here and there, but overall it's one of the cleanest amps of this era we've had the pleasure of featuring. The steel chassis is beautifully clean and shows no notable signs of corrosion; both the model tag and volume control plate are present and in exemplary condition. Even the original handle is intact and still has plenty of life left in it.
Electrically, this little amp is nicely original. The National-Dobro-branded G8RS field-coil speaker is in great shape and sports the original cone, which after a little TLC still sounds terrific. Both the power and output transformers are original to the amp, as is the volume pot and on/off switch. The amp has seen our typical maintenance and service, including a 3-prong grounded power cord, replacement of all electrolytic filter caps, cleaning of all sockets, pots and jacks and power tubes biased to spec.
This fabulous and beautifully compact specimen of a fairly rare and early pre-war amp has a sweet sound at lower volume, but surprisingly loud roar when dimed! Overall Excellent Condition.