Red October XL

 

The Red October Xl is one of our flagship Personal Audio Tubed Integrated Amplifiers, providing our example of true 300B DHT/SET Sound. This is a sound true to source and without the warm euphonic signature of 60s HiFi being midrange centric. It’s a sound that goes back to Western Electric, where spatial cue held as much import as tone.

Red October XL leverages all we have known and learned from the Red October pushing our performance targets even further.  For several years we have been quietly developing the next generation of transformers. These include new outputs, power and input transformers; each optimized to increase the performance of the Red October circuit.  

The new output transformers now 30watt cores specifically wound to increase interleaving couldn’t fit out a Red October chassis and as such modest increases were made to accommodate these much large outputs. Additionally the chassis plate thickness was increased again to 11gage steel plate for further isolation and structural rigidity.

We redesigned out power transformers berrying the 5v filament winding closer to the core to reduce vibration or unwanted resonance. Though not changing audible performance we were able to reduce mechanical noise. The XL now utilizes our Gen 6 power supply, with even further enhancements to noise floor.

A hallmark of the statement equipment has been oversized input transformers for balanced to single-ended conversion. Although ideal suited to mid tier to flag ship level balanced outputs, we’ve come to realize that not all dacs are at this level. Redesigning input transformers (reconstituting a forgotten design) and allows us to extend the benefits of Bal to SE conversion for all balanced dac regardless of their performance level.

People love the 300B for its true to life vocal representation and it’s sense of clarity and space, it is the ultimate Directly Heated Triode. The Red October XL incorporates this famous tube in a circuit that traces its roots back to the Agartha. However instead of a circuit board implementation, the Red October is entirely hand assembled using point to point wiring and turret board constriction. Every component is hand selected and chosen for performance: Jupiter foil wax coupling capacitors and an excellent 24 step stepped attenuator are standard, the Red October has no compromises. Our skilled team assembles each unit entirely by hand. There is not a single IC, voltage regulator, or silicon chip in the Red October, this amplifier is built in accordance to classic techniques and will last a lifetime because of it.

Our goal with the Red October XL was to honor the 300B, to do so we did a classic implementation with a single gain stage, zero feedback, and close attention to grounding techniques. The result is a deeper connection with your music, and an inky black background on headphones with no hum noise. Thick structural chassis work, significantly improved transformers surpass the performance of the Red October, with obvious increase side by side.

The font end of the Red October XL uses a 12AX7 as an input tube. We chose this 9 pin high gain front end due to its ability to deliver a faster and more lively presentation. It also helps that 12AX7s are accessible in both old and new stock form. The front end of this amp is paired with a massive tube rectified dual mono power supply that ensures tight bass and earth shattering slam on any headphone you plug into this amplifier.

While the Red October XL may look like a single amplifier, it is actually true dual mono amplifier built on top of a single chassis. The only shared components are the input tube, volume control, and output jacks.  The power supply, power transformers, output transformers, and even the turret boards are all separate. The result is class leading mono block performance with the convenience and ease of a single chassis. The Red October XL is a DUAL MONO amp on a single stereo chassis.

When people talk about ampsandsound products, they often talk about our transformers. The Red October XL uses the best transformers we have ever developed. These developments come from years of R&D from the same team we have used for the past 16 years. This relationship has produced our house sound and allowed for real development/ generational performance increases. The power transformers are massively over spec’d and the output transformers (30 watt cores) have an incredibly wide bandwidth; exceeding the performance of conventional choices. Red October XL has shockingly low distortion measurements given its single ended nature.

Like the transformers we have taken great pride in our metal work. The Chassis is hand fabricated and built with 11 gauge steel. The result is a 98 pound amplifier that feels solid as a rock. To give the Red October XL a clean look, we covered the transformers and power supply with a gorgeous damped cover. The style is brutalist, but when colors are chosen, the amplifier truly warms the soul visually.

While many things set the Red October apart from its peers, its most unique feature is the different output impedances, 5 in total. Unlike others who use voltage divider networks to create these different impedances, our transformers are wound with taps for each impedance. The result is the ability to perfect match the Red October with nearly every single production pair headphones in existence (as well as speakers). This also gives the Red October five distinct sonic profiles for every headphone allowing the listener to choose what sounds best to them.

We call the Red October XL a tube integrated amplifier for personal audio use because it also contains a speaker switch and a pair of 8ohm binding posts on the back. With 8 watts of power, the Red October can easily power a reasonably efficient pair of speaker to deafening levels. The speaker selection switch allows you to select between the headphone outputs and the speaker outputs enabling the Red October to truly be the center of your audio system.

When it comes time to connect your components to the Red October XL, you have two choices, a pair of high quality single ended RCA inputs, and a pair of XLR inputs. The XLR inputs us an input transformer to convert the incoming balanced signal to a single ended signal for the amplifier. The input transformer allows you to retain all the benefits of balanced cabling along with providing better bass and a quieter background.

The Red October XL is everything we could have hoped it to be. It is truly a marvel to behold, and we are proud to call it our new flagship amplifier.

Compatible with nearly every headphone.

Input sensitive: with 12AX7 input @ 2V P-P

Noise: @ 300ohm/HiZ 1.1mV RMS

Noise: @ 100ohm 1.1mV RMS

Noise: @ 32ohm 650 µV RMS

Noise: @ 8ohm LoZ 530 µV RMS

Max Power @    8ohm   @ 8 watts RMS

Max Power @   32ohm   @ 6.2 watts RMS

Ultra-wide bandwidth; 8hz to 24khz @ 1 watt -2db

THD 1Watt @ 0.3%
THD 2Watt @ 0.4%
THD 3 Watt @ 0.5%
THD MAX @ 0.53%
Noise ACV=0.105mV 

Power and Noise specs are dependent on tube selection.

Actual size is 13”deep, 19” wide and 10”tall. (98lbs)

Amp weighs in at 98lbs/1126lbs shipped in a large Pelican style case.

Black base/Back cover/ Black cage with Black Mesh, please look at Red October for color choices. 

Additional colors are possible as a special order... please call or email for details.

All ampsandsound amps are handmade in Southern California with custom hand-wound output transformers and U.S. sourced parts.

Our amps are hand-made by a small team with quality being our priority.

Additional colors are possible as a special order... please call or email or for details.