Products

Head, SR-15:	$974.00 US
Combo, SR-15C:	$1,274.00 US
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Skyraider SR-15

Overview

The Skyraider SR-15 is an all-tube guitar amplifier designed to provide rich tube tone. The Skyraider SR-15is available as a head or a combo (SR-15C). It’s is a versatile tone machine that is loud enough for gigging and quiet enough for studio, rehearsal and home use.

The key to the SR-15’s tone is power amplifier overdrive.  Turning up the amp’s volume and letting the preamp signal overdrive the power tubes produces natural, harmonically complex crunch and distortion. 

Skyraider SR-15C Combo

However, clean tones are just a twist of the guitar volume knob away.  The SR-15 cleans up very well with changes in guitar volume.  With the amp at full volume, adjusting the guitar output produces anything from crystalline clean tones, to full on roaring distortion.   

The ‘Character’ switch provides further tonal flexibility by adjusting the gain and bass output using a simple three-way switch.

Finally, the Skyraider SR-15 thrives on overdrive and distortion pedals.  Set the amp volume for a suitable clean tone and slam it into creamy, thick crunch and distortion tones with the click of a switch.  Great for recording, practicing and getting a little extra slam at a gig!

Circuit Design

Tubes .  The Skyraider SR-15 features a 12AX7 tube operating in a parallel triode configuration for the preamp. 

Running the dual triode sections of the 12AX7 in parallel produces higher gain than a single section and lower noise than cascading one section into the other.  It also produces very warm tube tone.

Another 12AX7 serves as the phase inverter and two 6V6s make up the power amplifier producing about 15 watts of power.

Power Supply.  The SR-15 features solid-state rectification.  This means that devices called silicon diodes convert the incoming alternating current power into the direct current power the rest of the circuit needs. 

Many vintage and boutique amps use tube rectifiers because they produce desirable ‘sag’.  Circuitry downstream of the SS rectifiers in your Skyraider does the same thing.  You avoid the extra cost of tube rectification and the additional heat produced by the rectifier tube.  You get sag that is indistinguishable from a tube rectifier set up.

Controls .  A volume control and single tone control reside between the preamp and phase inverter.  The tone control rolls off high frequencies to voice the top end of the amp.

The lack of bass and middle tone controls restricts the amount of tone shaping, however it also reduces signal loss inherent in passive tone controls. 

The fewer passive controls in the signal chain, the larger the signal getting to the phase inverter and on to the power section.  This is a key factor in the Skyraider’s ability to produce more volume than expected from an 15-watt amp and to drive the power amp into the crunch and distortion zone.

Character Switch .  The Character switch does what its name implies: changes the tonal character of the amp. 

There are three settings:

1. Hot.  Ultra rich and warm tube tone.  Medium gain.
2. Burn.  Aggressive high-mids, controlled bottom end, classic crunch and distortion tones.  High gain.  Great for dark sounding humbuckers.
3. Melt.  Big bottom, aggressive throughout the frequency spectrum.  Roaring crunch and distortion.  Highest gain.  Great for producing ‘huge’ distorted tone from single coil guitars.

There you have it: simple, effective, useful tone shaping.  You’ll find that the switch positions match well with different songs and musical styles.

Skyraider specs

• Handmade, hand wired using an eyelet circuit board with Teflon wire and lead-free solder
• Each Skyraider undergoes a 59 point bench test prior to two playing tests
• 15 watts
• 2 X 6V6 power tubes, cathode biased
• 2 x 12AX7 preamp tubes
• Solid state rectification with ‘sag’ circuitry
• Volume, tone controls
• Character Switch, 3 position: Hot, Burn, Melt
• Rugged cabinet finished with black Tolex
• 18 ½” W x 8 ½” H x 8 ½” D
• 117/120 VAC, 60 Hz

SR-15C Combo Spec

 The SR-15C features the same chassis as the SR-15 head (see above).  Following are specs related to the combo configuration:

• 12", Eminence "The Wizard" ceramic magnet speaker, 75 watts.
• 20" x 20" x 12" cabinet with top vent and semi-open back.