To improve the Mogwai SE we needed to go bigger with everything. The PS capacitance was increased, the choke nearly doubled its filtering and our output transformers doubled in size. The larger core of the output transformers led to the ability to out even a great variety of output impedances.
Providing 8ohm, 16ohm seemed ideal for the planers, the 32ohm is great for many low impedance orthodynamics. The 100ohm is selected to pair well with Audeze headphones and the 300ohm provides the high impedance match for ZMF and Sennheiser.
The input of Bigger ben unitizes input transformers for reduced noise floor, greater clarity, and sub-bass response. For this reference amplifier, we paired the finniest coupling caps, Jupiter copper foil in wax caps. The increases in micro-detail retrieval were remarkable.
Like many of our products, the Bigger Ben is a hybrid product, meant for both headphone and loudspeaker use.
Our circuit offers the ability to roll a wide variety of tubes inexpensively and bring increased power to headphones without any sacrifice of design choices that conflict with our values. The Mogwai combines the features of a full-sized two-channel power amplifier and headphone amplifier in a chassis that is suitable for desktop use.
The Bigger Ben utilizes single-ended Class A operation with zero feedback to provide the essence of our Classic Wonder sound; strictly old school SET sound, without having to spend hundreds if not thousands of dollars on tubes.
The performance of the Bigger Ben is made possible with custom wound ultra-high quality output transformers from Transcendar, which provide excellent frequency extension and a flat response.
The Bigger Ben does not use a voltage divider network but depends on transformers instead. We use multiple dedicated tapps for headphones to offer a dedicated selection for the widest range of headphones, and an 8-ohm loudspeaker tap to connect to moderately efficient loudspeakers.
The Bigger Ben displays its transformers prominently on the chassis. They're HUGE and frame in the tube complement, which can vary from a 6L6GC to a KT88.
Volume control is handled by the ALPS volume pot to allow attenuation and simplify the signal path.
The Bigger Ben differs from the Kenzie as it aims to provide powerful output while remaining true to classic tube design. As with all ampsandsound products, we strive for a neutral, non-fatiguing sound, and demand that all our products be ultra-quiet in operation. Quiet operation is not just a goal but a guiding principle that shapes all design and implementation choices.
Tube Selection: Input tube: 6SL7 or equivalent Output tubes: 6L6GC, EL34s, KT66, KT77, KT88, 6550s and KT90s A personal favorite is the Tungsol 6L6GC STR. Warm, strong, and tight bass.
Cathode Bias/automatic bias allows for easy tube changes without adjustment. Compatible with 32ohm-300ohm headphones using the labeled 1/4″ jack.
The Bigger Ben is handmade with pride in Southern California with US-sourced parts, including our precision transformers.
Wood Chassis dimensions: 15.75" Wide x 9.75" Deep
The noise floor is greatly reduced due to larger choke filtering and PS.
Input impedance is 10K ohm with a Stepped pot Input Sensitivity 3.1V for full power out with input transformers
Power as measured with KT88 power tubes and 5AR4 rectifier