A-50 Head

A-50
The A-series are the original Andrews amps. The design and tone is inspired by classic “plexi” style amps of the late 60s.  We start with the classic 50 watt plexi design. Then we add bias test points and voicing refinements to eliminate the need to bridge two channels. Then we install a post-phase inverter master volume control and added slightly more gain to achieve the cranked tone at reasonable volume levels. Additionally, original plexi amps have a capacitor on the volume control that boosts treble.  This was originally good idea because vintage guitar cables, effect pedals caused a big loss of treble as did well-used “greenback” speakers. With the advent of modern cables, effects and a variety of speakers available, the treble boost can sometime be too extreme. Some players get their amp modified to remove this capacitor.  We have reduced the effect of the boosting capacitor and added to pull switch to switch it complete off when desired.  A great deal of time and effort were spent selecting the perfect components to create a finely tuned tone machine that will take you back to the best of those classic vintage British style sounds and improve reliability.  The A-50 amps feature hand-wired construction, American-made transformers, custom designed chassis, heavy duty turret boards, compact size and reasonable weight.  The “small box” heads also more portable than the giant vintage designs.  Tube layout consists of three 12AX7s and two EL34s.

FEATURES:

Hand-Wired Construction – Sometimes call “point to point” wiring ensures solid durable long-lasting reliability. There are no copper traces to burn or peel away. All components are hand soldered to heavy duty turrets, tube sockets, pots, switches, etc.  The amps are road ready and roadie tough.  Sockets are mounted to the chassis rather than the boards so that heat and vibration don’t break down the solder connections, the board or other components.

American-Made Custom-Wound Transformers – The A-50 amps feature very high quality USA transformers that meet our stringent specifications to meet the exact requirements of the amp designs.  The power transformer is custom wound to deliver lower plate voltage than the off-the-shelf units that many other builders are using.  The lower voltage delivers a “browner” sound without the harshness heard on similar amps.

Straightforward Dependable Single Channel Design – Simple to operate, solid classic design.

Custom Designed Chassis and Turret Boards – We utilize very heavy-duty G10 turret boards and custom designed chassis. We custom design the critical parts to insure that every part in mounted it the correct location for optimal tone, stability and durability. Using the custom components adds to the manufacturing costs but we feel it is necessary to achieve the highest quality product.

Compact size and reasonable weight – See specs below.

A50TMB-front-edit

 

A-50 Head Specifications:
Size: 9.5″ High X 10.5″ Deep X 21.75″ Wide
Weight: 35 lbs
Tubes: Two EL34 and three 12AX7
Audio Power Output: 50 watts RMS before clipping
Speaker outputs – Two – 4/8/16 ohms switchable
Specifications and price subject to change without notice.
Price:  $1899

 

 


Note – The amp is in the photo is an older version.  New versions now have a midrange control.

 

For a lower powered lighter weight version of the A-50, check out the A-22.