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Tag: Knight Audio Technologies

The KAT Groundbreaker Hum Eliminator

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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.

http://www.deacyamp.com/index.php?route=product/product&product_id=52

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.

Features

  • 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

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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:

http://www.deacyamp.com/index.php?route=product/product&product_id=77

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.”

KAT Studio-D Deacy Style Amplifier

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Following up on the recent story of the KAT Studio-One all-valve practice amplifier, Nigel Knight has released details of the other part of his R&D endeavour over the past few years. Nigel recently announced:

Brian was never happy that we had to discontinue the production of the Deacy Amp replica, but the decision to do so was based purely on the fact that we could no longer source transistors with the correct characteristics that matched the original, either locally or globally and certainly not in the numbers we needed to extend production. So from the point that Deacy Amp replica serial number 0150 rolled out the door, I was on a bit of a mission to design its replacement.

This then, is the Studio-D. It is germanium Deacy’s silicon brother if you will. After years of trawling through transistor specifications, we finally found a set that could be configured to provide the same responses as the original AC125, AC126 and AC128 transistors. We are still using the original Deacy circuit, transformers and components albeit with the odd bias-tweak here and there and it still fires into a single 6.5″ twin-cone speaker. The resulting amplifier sounds magnificent and we’re really pleased with it.

The Studio-D is equipped with an adjustable battery simulator (DABS Unit), HF tone trim pot (that mimics the tone dulling effect of putting a tea-towel over the amplifier) and a built-in attenuator that has been optimised to the speaker and Deacy responses and, like the Studio-One, allows you to dial-down the volume.

KAT Studio-One Practice Amplifier

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Nigel Knight recently revealed a prototype 1 W (max), all-valve 2 x 6.5″ bedroom/studio combo amplifier. The styling and overall cosmetic appearance pays homage to the legendary Vox AC30 used by Brian May.

The valves (vacuum tubes) are biased such that at each stage, the grid starts to go positive at exactly the same point that a Vox AC30 would at full volume.

The KAT Studio-One guitar amplifier features:
• Two newly developed KAT DSP 6.5 TC speakers which have an on-board filter network that tailors the frequency response to give the full bodied mids of Brian’s Deacy amplifer but without the high frequency fizz audible in many 6.5″ twin-cone drivers.
• A built-in attenuator that has been developed in-line with the speakers to ensure the same tone is produced at all output levels. -24 dB attenuation brings it down to almost whisper level whilst still producing jangly cleans and smooth full-on distortion.
• Plywood cabinet construction.

Nigel has deployed all his electronics design expertise and experience producing and maintaining Brian May’s gear to offer the holy grail that amateur Queen players have been seeking for some years: the full on Wembley ’86 tone in your home, or Project BMIB (Brian May in your Bedroom) as I’m calling it. [Other Vox AC30 + Deacy amplifier emulation BMIB solutions are available, such as the Fryer Guitars Mayday effects pedal.]

Nigel has recorded a short demonstration video in the link below using a KAT STB Stomper and Retro Sonic chorus pedal. The amplifier is still at the prototype stage and is not available for general sale yet. Note that corner protectors have been made but are not fitted to the prototype illustrated in these three images (photo credit Nigel Knight).

Update as of 25 September 2022. I recently bought three units and have released a brief (6m 43s) YouTube video in which I unbox them and show you around the inside and outside as well as a quick demonstration through my KAT Brian May rig. Please also check out my gear page for this amplifier here:

https://dsgb.net/gear/studio-one

Vox VBM-1 Amplifier KAT Speaker Modification

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Knight Audio Technologies (KAT) has developed a “drop-in” speaker upgrade for the popular, discontinued Vox VBM-1 Brian May Special amplifier. It costs £35.00 + shipping direct.

An alternative upgrade option which some people have carried out involves buying a Dai Ichi brand DC65-30 speaker (still available from Wagner Online in Australia at the time of writing) and fitting a 390 microH 1.3A ELC16B radial inductor (choke), RS part no. 6755576 and a 2.2 microF capacitor, RS part no. 7270473.

However, this original option is ultimately more expensive and involves soldering. Check out the product on the KAT website and view the straightforward installation video on Nigel’s YouTube channel.

http://www.deacyamp.com/index.php?route=product%2Fproduct&product_id=51

Text from the KAT website:

“This is a brand new speaker/filter combination enabling VBM-1 users and Deacy Amplifier-style project builders to get their amps closer in tone to the real Deacy Amp.

The KAT DSP 6.5 TC has been developed primarily as a replacement for the Celestion G6 unit that is sadly no longer in production. It has an on-board filter network that tailors the frequency response to give the full-bodied mid range tones of the real Deacy but without the HF ‘fizz’ that seems to dominate most 6.5″ twin-cone drivers.

A by-product of this development was the realisation that this unit could be dropped straight into the Vox VBM-1 giving immediate results. The Vox VBM-1 is a great amplifier, but, it is a little let-down by its stock speaker unit that tends to suck-out the precious mid range tones and enhance the unwanted high frequency ‘fizz’. The KAT DSP 6.5 TC is a straight swap-out with the stock VBM-1 unit with no soldering required to undertake the works. Just 11 screws and 6 minutes will have the works completed and the tone of the amplifier improved many-fold!

The KAT DSP 6.5 TC can also be used in your own Deacy amplifier-style projects to give your amplifier that great Deacy ‘honk’!”

Brian May Guitars Treble Booster Classic

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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:

https://shop.brianmayguitars.co.uk/bmg-accessories/bmg-tb-classic.html
https://deacyamp.com/collections/products/products/bmg-treble-booster-classic

KAT Superpot

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For those readers who are not Brian May enthusiasts, I’d like to draw your attention to this innovation by Nigel Knight of Knight Audio Technologies (KAT): the BM RS Superpot. It is an Alpha brand dual-gang 250 kΩ linear (B) taper potentiometer fitted with a 1 MΩ resistor and a 2.2 nF capacitor. It was designed by Nigel to serve a specific purpose: that is to create a volume potentiometer with a shallower response curve than a standard logarithmic/audio (A) taper to increase the range over which Brian can control the transition from ‘sparkly cleans’ to sweet overdrive while performing on stage. Nigel flew out to Portugal to fit it to the Red Special before the Lisbon Queen + Adam Lambert concert on 7th June 2018. Check out the post on Brian’s Instagram account below:

https://www.instagram.com/p/BjqXKVIBsuw/

R. G. Keen’s 1999 article entitled “The Secret Life of Pots” at Geofex.com explains the theory behind modifying the taper of linear potentiometers in an easily assimilable format:

http://www.geofex.com/Article_Folders/potsecrets/potscret.htm

Nigel explains: “When you cascade potentiometers you end up with a super-log pot, so the effective end result is a ‘forced’ log taper. Secondly, because after about halfway round the volume sweep of the RS, the pot is no longer really being used as a volume control, but more of a distortion drive which requires a more linear taper. So the new pot is more log at the bottom and more linear at the top. This allows better control over the cleans and smoother transition through the various stages of distortion. In fact, there is no discernible point where the distortion comes in with this configuration. It just slowly feeds in from the cleans.”

“The function of the capacitor is to compensate for high frequency losses while the resistor is there to pull the bottom leg of the pot to ground. The pot (short for potential divider) can’t ‘divide’ the level if it has no reference to the two points it is dividing between. The new pot gives Brian an array of tones that used to reside within about half a degree of pot movement (if you could find the sweet spot in the dark)”

Nigel has published a diagram of the pot shown in the image above. You can download it here and on the KAT website:

KAT Brian May Red Special Superpot DiagramDownload

From summer 2023, Nigel is offering KAT Superpots for sale at £20 plus shipping:

https://deacyamp.com/products/kat-rs-superpot

Fender Stratocaster Conversion to Brian May Specification

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I have completed converting my 2012 Fender American Standard Stratocaster to Brian May Specification. It has Adeson pickups, a custom switching PCB module based on that fitted to the Guyton RS Transporter designed by Nigel Knight of Knight Audio Technologies, Anotone aluminium Strat style control knobs, Fender branded Schaller locking tuners and roller bridge saddles. I designed the custom pickguard in CAD and CNC cut it myself using my Stepcraft 2/840 CNC machine. You can find full details of the project here:
https://dsgb.net/projects/maycaster/