Branston Amplifiers

Our range of hand crafted boutique valve amplifiers. Each amplifier is unique - e.g. by choice of gain stages, tone control, effects, speakers, valves, covering, varnish, magnetics, capacitors, potentiometers, and internal layout design. Each one has been named, along with its serial number. Not only will you have a beautiful unique amplifier, but you will also have access to its test results, a list of parts used, and photos and videos and recordings made during its production and testing. These can be collected together into a booklet and/or DVD, so that you get the full history of the the amp. We will also include build information so that it can be kept in tip-top condition throughout its working life. Each finish is designed to look good from the start, and improve with wear and tear.

The Mistress range

This is a Limited Edition run of six vintage inspired amps. Tim Branston's amp came in for repair autumn 2013, and after a bit of work, it sounded immense. And that's where a plan started to hatch...
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Donna-Lee fascia, side on
The design is based on the classic 3x ECC83 pre-amp valves, and 2x EL84 12W output valves that you find in 50s and 60s 18W amps. An EZ81 valve rectifier gives it the classic valve "sag" we expect from early 60s and 70s British blues recordings.

The production chassis are formed from laser cut aluminium, and the cabinets are hand assembled from CNC cut FSC 9mm birch ply. The cabinets are then hand profiled and finished, before they are introduced to their speakers and chassis.

Several variations are available, including clean / dirty switchable gain, TMB tone controls, power stages up to 50W, fixed bias, and silicon rectifier. You can have the faceplate facing front or back. We even offer the more traditional vinyl coverings, if you're into that kind of thing.

There are currently enough parts to build two more of these (Mar 18), and they will be based on the last two builds - Donna-Lee for the Classic and Rosie for the Custom.

The BBB range

The BBB range started off on the original test chassis - an old Dell server power supply - which used to be called Test Dog. It was made into an 18W push pull amp - the pre-prototype Mistress. A pair of oversized HiFi Ultralinear transformers were accidently purchased from VVT on the Isle of Wight, and fitted. The results were astonishing. When that circuit was moved over to a hand-beaten & drilled bespoke chassis, the Test Dog became redundant.

The next circuit to move onto the chassis was a 10W single ended 6L6 amplifier, based on Piotr Stanisz's Black Dog Rebel 10. Unfortunately the output transformer I used was too small, and the over-sized power transformer did not have enough poke, voltage wise, so that got shelved for a bit. However, I did need to test a 6L6 based output stage, so a phase splitter and another output valve were added.

There were things about the new circuit that were problematic - the additional phase splitter stage threw a lot of voltage at the output valves, and the additional gain was making the amp feed back between valves. A set of switches were added to re-configure the various stages of the amp, allowing it to behave like a single ended, medium gain or high gain amplifier. The final amp had a total of something like eighteen switches, and still no stand-by. It was to used as a design tool to help customers decide which configuration to have the amp.

One thing the amp had an abundance of was balls - the oversized transformers gave it plenty more than it needed. Because of this, it got called Bertha. Big Balled Bertha was how it started, and the name has stuck. The amp was demo'd, among two other amps, to two studios, both of which went for Bertha.

The first BBB-30 Studio was built in July 2015, and delivered to CDS studios on the 25th of that month. It has a mere nine switches and an external bias control. The person who ordered the amp for the studio now owns the amp, and loves it.

Due to various constraints with borrowing the amp, a copy was made in June 2017, incorporating the ultralinear taps on the original output transformers. Due to interest in this model the first of a limited edition build of three signature BBB-30 amps was built in March 2018, incorporating the most requested features.

Features of the BBB-30UL Studio
  • "Modern" AC bypassing on the pre-amp stages, to keep the bottom end tight before overdrive
  • Rigid single strand wiring infra-structure, in silicone sleeving
  • External bias measurement and control
  • Nichicon PW 8000hr HT filter caps 
  • Plenty of extra solder tags for tweeks and mods
  • Relay switching between gain levels
  • Footswitch or manual switching control
  • "Deep" switch on Dirty channel 
  • Negative feedback (NFB) on / off switch for power control
  • "Rebel" configuration for TMB tone controls
  • Composite hardwood cabinet, using repurposed beech, finished in Osmo, by Joe Welden
  • Easy access thumb screws for back panel
  • Sovtek 12AX7 / 5881WXT valves
  • 20% and 43% capacitor linked Ultralinear tap power control
  • Two 4, 8 and 16Ω output jacks
  • Fixed or cathode bias switch on output valves
  • Single ended or push-pull operation
  • 1/2 or full power switch defers distortion to the phase splitter or output valves
  • Line out jack (can run without a speaker)
  • Output protection dumps load to a power resistor.
This comes in two more stage friendly version - the SBB-50, which has smaller American style transformers, and gives a more twangy sound, like the SCS range, and also the BBB-30 Standard, which has the same dimension transformers, and same output power as the BBB-30UL.

Both of these amplifiers are configured with fixed bias, NFB, full power, push-pull mode, with 5881 output valves. The depth switch has been replaced with a Depth rotary switch, and a frequency compensation switch has been added to increase the dynamic possibilities for humbuckers.

The SCS range

The SCS range are aimed at people using pedals, or just want to plug straight into the amp and play. The front end pre-amps and phase-splitter configuration are based on the Treble channel of the classic British Treble and Bass channel amplifiers. The back end and power supply are a more modern design, employing the smooth power of 6L6 and 6V6 output valves.

The current range of cabinets are hand built in the UK, by cabinet builder Joe Welden, and they are crafted in the same building as the chassis. The demo SCS20 is housed in a composite beech cabinet – the timber for which has been reclaimed, machined, selected, and then joined into the cabinet before being filled, sanded and oiled. Several finished are available, including mineral oil, hard wax, natural polyurethane, and Osmo (satin). The wood can be inked or stained any colour, and “knocked back” to reveal more of the wood detail, as on the BBB-30UL cabinet.

SCS Models

The 6V6 SCS-20 has been described as having a sound with “glassy mids, where the notes pop out at you, and no loss on the top frets”. The sound reminds me of some of the older classic American 6V6 amps, and of aluminium resonator guitars.

It is powered by a pair of cathode biased 6V6 output valves. It seems to perfectly match the qualities of single coil pickups on Strat’s and Tele’s and 10” Alnico speakers, which it was initially built and tested with. It works well with a wide range of guitars, pickups and cabs, and has been tested, very successfully, with, amongst others, an LP studio guitar, The classic British 4x12 angled cab, and a wide range of pedals and multi-fx.

The SCS-50 is a 6L6 powered, fixed biased amp, which use smaller interleaved transformers. These are lighter amps and have a clear, intense sound, and are aimed at modern players who require a clean sound that works well with a wide range of effects pedals.

The FRO

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