Treble Boosters

For the 100th distinct web page on and the 50th site blog post, I have published an article on one of the perennial topics of conversation in Brian May enthusiast circles: treble boosters:

I cover some background information and restrict the discussion to three treble booster variants related to Brian May and Queen, the current 3-in-1 BMG Treble Booster Classic unit developed by Nigel Knight of Knight Audio Technologies for retail by Brian May Guitars, Brian’s KAT RED-18 strap-mounted treble booster and the Fryer Sound colour series (TB Touring, TB Plus, TB Super and TB Deluxe). There are embedded videos from Jamie Humphries demonstrating the Fryer treble boosters for Guitar Interactive and Frank Campese demonstrating the 70s setting of the BMG TB Classic.

DigiTech Red Special Pedal

The fourth article for my musical equipment section covers the DigiTech Brian May Red Special pedal. It contains original photographs and PDF user manuals of this, and the other two DigiTech Artist’s Series pedals (Jimi Hendrix and Eric Clapton Crossroads), some additional photographs of the rack mounted version of this pedal that Nigel Knight built into Brian May’s back-up, touring and guesting rig, and an embedded demonstration video by Frank Campese.

The KAT Groundbreaker Hum Eliminator

The new Groundbreaker from Knight Audio Technologies (KAT) is a fully transformer-coupled ground (earth) isolating interface that eliminates unwanted hum and noise caused by system ground loops. It is suitable for studio and live environments and is configured to accept both balanced and unbalanced signals. If your amplifier is exhibiting ground loop hum, simply connect a Groundbreaker to the amp’s input via a patch cable then connect the output of your effects chain, delay, chorus or treble booster pedal to the input of the unit.

Although similar products have been available (e.g. from Mike Hill Services) for some time, this unit is priced competitively at £64.50 recognising that multiple units will be required to fully eliminate ground loop hum depending on the configuration of the guitar rig. If you have read my other blog posts highlighting new and forthcoming KAT products then you will already appreciate that every KAT product is backed by Nigel Knight’s expertise as an electronics designer and many years of experience building and maintaining equipment for Brian May of Queen. This product works well in one, two and three amplifier outfits or when connecting mains powered effects (e.g. a Boss CE-1 Stereo Chorus pedal); eight examples of which are illustrated in the diagrams below.


  • 1/4″ TRS (tip, ring and sleeve) input and output jacks allow for balanced or un-balanced signals
  • High impedance input to maintain signal clarity
  • Fully passive, requires no power source
  • Uses bespoke mu-metal shielded high quality transformer for sonic transparency
  • Housed in a rugged solid steel enclosure

KAT Treble Booster Plush DIY Kit

In his latest YouTube video, Nigel Knight (the guy who does Brian May’s electronic work) demonstrates how to assemble one of his excellent KAT treble booster Plush kits. The video is speeded up for the impatient amongst us. It is a must watch for any electronics enthusiasts who are also into Brian May gear.

The KAT treble booster Plush kit can be obtained direct from KAT (Knight Audio Technologies) at £49.50:

Information from Nigel’s website:

“This is a full kit of parts that will enable an electronics beginner to build a very high quality KAT treble booster. The components provided are the best for the job in-hand. They are the same components used for the builds of many KAT treble boosters and Fryer Sound TB Touring, Deluxe and Plus. The circuit board has been specially designed for the kit so that the build can be easy with all components identified on the board. The case is the same powder-coated, silk-screened folded steel unit used for the TB Touring, Deluxe and Plus, so rugged, durable and yet, attractive.
Sound-wise, this treble booster has been developed to emulate the 1980s era of Brian May’s tone with approximately 33 dB of gain, so think Queen from the late 70s through to the end. Think Wembley… Think Live Aid!
So, what’s in the kit?
Well, everything you need to successfully build the TB except for a few hand tools and a battery.”

Fryer Treble Booster Deluxe

New treble booster day: a beautiful deep purple Fryer Guitars Deluxe to complement my other purple gear. I thought that I didn’t need any more treble boosters, but I was evidently wrong; the tone of this one is certainly powerful, rich and fat, like a benign dictator of a country you’ve never heard of. Information reproduced from the Fryer Guitars website:

• 34 dB gain
• Punchy rich sound with a balance between fatness and treble definition
• Evokes the Brian May sound on late 1970s Queen albums News of the World and Jazz.
• Fattest sounding and most output level of the 3 Fryer ‘no knobs permanently plugged-in’ pedals TB Touring, TB Super and TB Deluxe.
• Uses the same harmonically rich sounding transistor as Treble Booster Super and Treble Booster Special pedals.
• Powered by either a 9 V battery or 9V DC adaptor (2.1 mm diameter negative centre jack, 100 mA or greater current capacity).

The hand made pre-production model is available until the screenprinted box version becomes available in late 2020. Price is $AU235.00 plus international shipping by Express Post International EMS (signature on delivery and tracking).

AmpliTube Brian May

IK Multimedia of Modena in Italy has released a Brian May collection for their industry-leading AmpliTube Custom Shop guitar amplifier and effects PC, MacOS and iOS modelling software in August 2019. Costing £99.99, it is available as download direct from the IK Multimedia and Brian May Guitars websites or the Apple stores.

This emulation software is one of the cheapest and most straightforward ways to recreate many of Brian May’s tones, especially the complex three amplifier, twin delay Brighton Rock solo. It is ideal for quiet practice when used with a suitable interface such as the iRig HD2 and monitor headphones and as a travel outfit. Renowned professional guitarist Jamie Humphries helped develop the tone patches and you can watch him demonstrate the software on this official video:

Brian May Guitars Treble Booster Classic

Made in the U.K. and engineered by Brian May’s electronics guru, Nigel Knight, this compact, multi-mode treble booster pedal combines three uniquely-voiced circuits that faithfully replicate Brian’s most recognisable tones from the 1970s, 80s and 90s. The tones representing each decade have been meticulously modelled on the actual vintage equipment used by Brian during each period of his career – his germanium transistor Dallas Rangemaster from the 1970s, the silicon BC149 transistor powered Cornish TB-83 installed on his pedal board throughout the 80s, and an original 1998 Greg Fryer strap booster.

Nigel Knight analysed every nuance of the original circuits to realise an authentic reproduction of their tonal responses and output profiles. This 3-in-1 treble booster provides amateur enthusiasts and professional guitar players alike the opportunity to select the distinctive sound of their favourite Queen era using a switch and level control based on the lathe-turned aluminium control knobs fitted to Brian’s Red Special guitar. Whether you seek to replicate the heavier Queen tracks such as Stone Cold Crazy, the live sounds of the 1986 Magic Tour or explore your own ‘New Horizons’ with Brian’s more recent works, this will be the only treble booster you will ever need. Available now from Brian May Guitars and Knight Audio Technologies: