Amplifiers and Preamplifiers
Amplifiers provide the function of providing a signal to the loudspeaker that is a faithful copy of the signal derived from the CD or Vinyl source. The process of amplification is one which can introduce a number of harmful effects if not achieved correctly. For example – distortion, hum and noise can easily be introduced by poorly designed equipment. Importantly – power amplifiers must have the ability to control the loudspeaker such that it does not produce spurious sounds which are not a faithful reproduction of the original.
Broadly speaking – power amplifiers used for high quality sound reproduction are either solid state or vacuum tube based systems. Both types have advantages and disadvantages.
There are some very good solid state amplifiers available on the market – and the AQVOX XT is no exception. Being of a brand new innovative design using ring emitters transistors in the output stage, and having one of the shortest signal paths of any amplifier, the XT promises to be something very special. Due for release in November 2010 the XT promises to be one of the finest solid state amplifiers available at any price.
Despite the “old technology” employed – modern vacuum tube based amplifiers are enjoying a renaissance on account of their warmer sound than their solid state rivals which many audiophiles find more pleasing to the ear. On paper at least vacuum tube amplifiers appear to be grossly inferior in terms of specifications compared with their solid state counterparts, but listening tests do substantiate the preference by many that the vacuum tube based amplifiers are more musical, and therefore sound more like a live performance.
The SAC SILK Glowmaster power amplifiers are amongst a new breed of vacuum tube based power amplifiers that are not clones of the original Williamson design, on which the vast majority of vacuum tube power amplifiers are based. The heart of these superb sounding Glowmaster amplifiers is the superb SILK output transformers that in our opinion are more than a match to better known makes such as Audio Note and Tango.
It is the exceptional quality and highly developed SILK output transformers that make the Glowmaster very special and stand out from the crowd. In addition their innovative design which sets them apart from the rest. Whether you want the refined sound of the Pure Class A push pull Glowmaster KT88 or the stunning high powered Single Ended Glowmaster GM70 the reproduction of the highest quality is assured. Fpr owners of high sensitivity loudspeakers, who prefer single ended amplification - the NEW Silk Minute is a highly cost effective integrated amplifier, from this highly regarded marque.
The combination of passive preamplifiers such as the superb sounding SAC SILK STA522A transformer volume control - with the Glowmaster power amplifiers is an awesome combination. The STA522A is arguably the best passive preamplifier ever made, on account of the exceptional hand wound attenuator transformers that these use. These open up the sound to a new level – and provide a spatiality and separation seldom heard, resulting in an uncanny realism, which really makes you feel you are witnessing a live performance.
A balanced version of this wonderful preamplifier is planned for the future from the HQ Acoustics stable.
The YS range of unbalanced and balanced preamplifiers are an excellent partner for the SAC SILK Glowmaster where additional flexibility is required, whilst retaining the much desired “Valve sound”. These hand crafted units offer exceptional value for money and provide the audiophile with the opportunity of owning a fully balanced vacuum tube based system from source to loudspeaker. The YS preamplifiers use the innovative Class A, + wave auto-balance circuitry which offers wonderfully realistic, dynamic, open-sounding music.
As a solid state alternative – vinyl lovers should look no further than the AQVOX 2Ci balanced phono preamplifier which not only have highly accurate RIAA characteristics but also compensation for NEUMANN characteristics as well, which means that Vinyl discs cut on a NEUMANN lathe will be faithfully re-produced. Being fully balanced – it is possible ( if your turntable / arm is suitable) to wire your Moving Coil cartridge a balanced source. This has a major advantage of virtually eliminating hum and noise normally associated with the high gain needed to amplify the extremely small signals generated by moving coil devices.
The ability to connect either the YS Balanced P1 MC vacuum tube phono preamplifier or a AQVOX 2Ci fully balanced phono preamplifier though a YS A1 or A2 balanced line amplifier to the Glowmaster KT88 will provide an incredible performance – low noise – full dynamics – and best of all a holographic sound with superb instrument separation.
Balanced line technology
Balanced lines, inputs and outputs have been used in professional audio for many years, and this technology is now becoming used in domestic audio systems. A practical balanced interconnect is not always as straight forward as it might appear.
Balanced connections in an audio system are designed to reject external an internal noise , such as from the power wiring and from crosstalk of adjacent signal cables. The basic principle is to obtain the signal by subtraction using a three wire connection. In many cases one signal wire (the in phase or hot) senses the output of the unit sending the signal whilst the other ( phase inverted or cold) senses the units output socket ground and the difference gives the required signal. Any noise voltages that appear identically on both lines ( common mode signals) should be cancelled out by the subtraction.
A True Balanced Vinyl system
Record Deck / Arm - Revolver Replay fitted with Aqvox MC Premium or Prestige moving coil pickup
Interconnect - Aqvox XLR / SME pure silver
Balanced Phono Preamplifier - Aqvox 2Ci
Interconnect - Aqvox XLR / XLR pure silver
Balanced line amplifier - YS Audio A2
Interconnect - Aqvox XLR / XLR pure silver
Power amplifier - SAC Silk Glowmaster KT88
This combination is fully balanced thoughout the chain, and benefits from low noise and hum