E&OE Copyright 2010-
Under our ‘Bespoke Modifications’ service we also make special products to order. Recently we have had increasing demand for simple passive pre amplifiers and so have decided to feature them here. The beauty with this is there’s no standard product -
The average entry level build costs in the region of £200, but we don’t scrimp on the quality -
For more information on costings please contact us with details including the number of inputs required, details of the system it will be used with and we will design a unique passive to your requirements.
The Select 1.0 is a new passive pre amplifier from Audion that offers a very attractive and affordable way to control multiple sources. It is housed in a cut down version of the Premier chassis and naturally features the same aluminium and stainless construction materials. The classic Alps Blue Velvet is the volume pot is used and it’s combined with input switching for 5 line level inputs via the front mounted toggle switches. As shown in the picture below there are two pre amp outputs as well as a ‘Tape’ output which can be used to feed a recorder or headphone amplifier, so it also offers great flexibility when required (a little care with the impedances of connected items may be required if all the outputs are wired simultaneously, as a passive design means the source has to drive them all, but we can advise on this on an individual basis).
As you’d expect with a good passive pre amplifier the sound is open and natural, in fact it’s remarkably transparent for a product at this price level with no added grain to get in the way of the music. What’s more the absence of noise generating active devices means that it’s silent even when combined with very sensitive power amps and speakers.
Audion Select 1.0 passive pre amplifier: £490.00
Audion Select 1.0 passive pre amplifier with remote control volume: £953.00
The Micro 25 follows is the latest in long line of classic Croft pre amplifiers. This is the second model up in the range and is hard wired, hand made in the UK and unfussy in both appearance and usage. The Micro 25 uses three ECC83 valves for the line level stage and the MM phono input and has a auto mute on switch on that allows the valves to warm up for a few seconds before being fully operational (the LED changes from red to green to show when it’s ready to go).
I’ve long been a fan of Glenn Croft’s products and this latest range looks like it’ll be no exception -
Croft Acoustics Micro 25L Line level pre amplifier: £550
Croft Acoustics Micro 25 Line level & MM phono pre amplifier: £770
Croft Micro 25 version "R" Pre-
The Micro 25 “R” has a very substantial power supply, utilising two mains transformers supplying a regulated HT power supply with an 85A2 voltage stabilising valve. The line level stage and MM phono stage uses a total of five ECC83 dual triodes. More details to follow soon.
Croft Acoustics Micro 25RL Line level pre amplifier: £1,100
Croft Acoustics Micro 25R Line level & MM phono pre amplifier: £1,540
Audion Premier pre amplifier
The Audion Premier is valve pre amplifier that is available in two versions, a line level only model and a MM phono equipped version (as pictured here). Both versions features 6 inputs, have two outputs and a ground lift switch to ensure hum free operation in many different systems. The valves used are the Sovtek 6H23 (a 6922 equivalent) and the amplifier has a wonderfully open and transparent sound.
Audion Premier Line: £1,630
Audion Premier Line, with remote control volume: £2,093
Audion Premier MM Phono and line: £2,150
Audion Premier MM Phono and line, with remote control volume: £2,613
Music First Audio Copper TVC Classic pre amplifier: £1,920
We’d been eagerly waiting for the launch of the Music First Audio passive magnetic (or TVC, short for transformer volume control) pre amplifier ever since we learnt of its inception late in 2001.
The reason we were so excited about this pre is that it offers the benefits of passive pre amps without many of their flaws -
Unlike conventional pre amplifiers which use potentiometers for attenuation the Music First Audio preamplifier uses a transformer instead, which has the benefit of isolating and impedance matching sources and power amplifiers as well as breaking ground loop and reducing noise.
The volume control is basically a high grade Elma 20 position switch which connects different transformer windings via hard wired, silver plated Teflon covered wire. It features 6 inputs, two of which are balanced XLR connectors and the other four are standard phono RCA connectors. Output is via single ended or balanced and there is also the facility to add 6 dB of gain and lift the ground to reduce noise.
The transformers have a wide and flat Frequency Response of 10 Hz -
So far we have pitted this against a variety of active pre amplifiers that cost several times as much and it has always shown up colourations in the alternatives, whether it be glare from a transistor pre or euphonic bloom from some valve designs. We think this is an absolute bargain bringing unheard levels of transparency to almost every system.
It is available in brushed aluminium or anodised black (as pictured below).
Croft Acoustics Micro 25RS
New top of the range Croft pre amplifier. Over the ‘R’ version featured above, the ‘RS’ adds an improved line output stage (which naturally benefits the phono stage which also passes through it), improved components/socketry and HT regulators. It’s split into two of the standard Croft chassis with the power supply separated from the audio stages and to allow sufficient room for all of the components (including the substantially over rated 550va transformer). More details to follow.
Croft Acoustics Micro 25RSL Line level pre amplifier: £2,200.
Croft Acoustics Micro 25RS Line Level and MM phono pre amplifier: £3,080.
The Silvercore Pre 324 is a TVC (Transformer Volume Control) where all the wiring, including the transformers themselves, is done with 99.99% pure silver. The 324 features larger transformer and 24 steps of volume control. It features 3 inputs (they can be either Balanced XLR, single ended phono or a combination of both) and XLR or single ended phono outputs. Internally the signal has short signal paths and the dual mono nature of the twin volume pots gives great channel seperation.
The frame of the enclosure is made from a choice of either Delrin (a white acrylic like material) or Zebrano wood (as shown here), with top, bottom and rear panels being made of laser cut polished stainless steel.
This is an exceptionally transparent pre amplifier, with a level of resolution that is quite disarming. It displays the delicacy and subtlety that only the best silver wire can reveal. If this makes it sound like it is overly analytical or polite then I have mislead you, for it has a substance and tonality that is completely believable. This is a remarkable pre amplifier, and is highly recommended for any high resolution system.
Silvercore Preamp 324 in Delrin: £4,120
Silvercore Preamp 324 in Zebrano wood: £4,370
Audio Note M3
The M3 uses a choke smoother valve rectified power supply and 5687 valves driving HiB double C-
Audio Note M3 Line level pre amplifier: £POA at manufacturers request
Audio Note M3 Phono & Line level pre amplifier : £POA at manufacturers request
The Bespoke Audio Company may be a new name on the hifi scene, but the founders of the company, Harry and Lucy, have had many years of experience developing and building transformer volume control pre amplifiers.
Their ethos is refreshingly different, not only is their attention to detail, fit and finish bordering on the obsessive, but they aim to offer a unique buying experience that lifts this from just being another piece of (exquisite) hifi to something that is as personal to you as a tailored suit.
Almost every part can be customised to your needs, from the connections and features through to the cosmetics -
Internally there are two large multi tapped transformers that are the heart of the pre amplifier, these provide 46 steps of volume control, almost twice the number featured on the majority of other TVC pre amplifiers. The transformers are wound on custom made bobbins, featuring oversized cores enabling colossal overload margins (30 volts -
The example pictured here has 3 unbalanced inputs (via gold WBT Nextgen sockets), 3 balanced inputs and both balanced and unbalanced outputs -
The volume control is motorised and remote controlled, yet it does so quietly and smoothly, and without spoiling the excellent feel of the control when used manually. Hidden underneath is switching for lifting the ground if required (they are also hidden on the internal views, look for the two semi circular pieces towards the rear of the chassis).
I spent an all too short, but very enjoyable period listening to the Bespoke Audio Company pre amp, and as ever with a very good TVC it’s almost impossible to describe the sound -
Except of course it isn’t, and nothing ever can be, but rather than defining the presentation or tonality, it’s what it reveals that others miss out on that defines the sound of this pre amplifier. Great transparency is a given, but there’s also a delicate touch, and a layering to the presentation which keeps individual sounds well placed and separate, both in terms of their tonal identity as well as their physical space in the sound stage. There’s a naturalness and effortlessness too, no doubt in part due to the cotton covered wiring, with no fear of the sound ever becoming hard or aggressive.
In summary this is an incredibly well evolved product for a new company, and one that should set the benchmark both for sonic's as well as the whole buying experience -
Dimensions: Height 110mm, Width 305mm,Depth 345mm
Finish: completely customisable, seemingly limited only by imagination
Price: from circa £9,000, depending upon specification