Bigger Ben

The Bigger Ben started life as 2nd channel adaptation of the Mogwai. It employed huge transformers and was a Class A beast. With the development of the Mogwai SE, the Bigger Ben became redundant as the Mogwai SE is such an overachiever. With the development of the Suolo and Pendant monos, we had worked to push the boundaries of what we were currently offering. The Mogwai SE Rev 2 became the 1st to benefit from the trickle-down development process. The work led to further transformer improvements. We proved that larger transformers yielded increased resolution, clarity, and flatter frequency response.

With a request of a long-time customer who wanted a power amp for his headphone and wanted the widest bandwidth we could produce; we set about resurrecting the Bigger Ben.

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, 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.

Generation 2 of the Bigger Ben

The close of 2021 has brought out more than 18 months of a global pandemic. During these challenging times, we at ampsandsound strengthened our development efforts resulting in new generation of our classic amps.

Though octal input tubes provide a romantic character that had defined the ampsandound house sound, reminiscent of 1950s HiFi, the downside to this approach is a reduced noise floor and dwindling NOS options. With ampsandound moving to a 9pin front end, performance has been increased, NOS tube rolling has become nearly limitless, and yet we were able to enhance the sweetness and tone we are known for. The 9pin front end allows vastly increased options for tone rolling to find your balance and preference.

With our front end's new development, we have improved our amps further, including both subtle and significant changes alike. Notable takeaways include increased power output, reduced noise floor across all our amps, increased bandwidth.

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

8ohm power: 8Watts RMS @ 1khz
Noise on 8ohm tapp @ 300uV RMS

Power as measured with KT88 power tubes and SS Plug in rectifier
8ohm power: 6.5Watts RMS @ 1khz
Noise on 8ohm tapp @ 320uV RMS

32ohm power: 5Watts RMS @ 1khz
Noise on 32ohm tapp @ 340uV RMS

300ohm power: 5Watts RMS @ 1khz
Noise on 300ohm tapp @ 480uV RMS

Compatible with nearly every headphone.

Power and Noise specs are dependent on tube selection.

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 first priority.

Stereophille's Bigger Ben Review

Gramophone Dreams #47: Hana Umami Red, Musical Surroundings Nova III, Ampsandsound Bigger Ben Page 2

A Bigger Ben
The humans I admire most are the makers: those who physically make things with their hands, whether it's paper doilies, loaves of bread, or steel bridges. I venerate makers because the sacred rituals of fashioning objects force makers to understand the spiritual, cultural, and economic value of their work. That is why I chose to be a maker, not a merchant or a scholar. 

When I encounter other makers, I feel an immediate kinship, accompanied by a need to investigate the workings of their mind. Ampsandsound's creator Justin Weber is one of those people (footnote 4). He is one of the most inspired, natural-born builder-mechanics I've met. I admire him because he is an unusually sincere, humble human who creates some of the finest loudspeaker and headphone amplifiers I've encountered. Between design gigs, he works full-time as a social worker specializing in psychiatric and medical social work.