In fact the opposite may be true. Also low gain helps the following preamplifier not to overload.
What is needed for a head amplifier or a front end amplifier or booster amplifier is low gain, high quality, low noise.
Low gain is compatible with high quality [Everitt].
Low noise figure is very important. The front end noise performance will dictate the overall performance of the whole system till listener's brain. (Even if the music signal is listened through YouTube for examole). Of course even more important is low noise acoustics, the closer we are to the producer's brain in the signal path the more importat the link of the chain is. The slightest defect in the beginning of the chain will be magnified by all subsequent amplifying or processing stages. (Including plug ins). Note: Sound insulators may create extra need of sound absorbers as more acoustic energy may be trapped in the recording room. (The best sound absorber is the open window but it is the worst sound insulator [BBC]).
The Pleiades V6 head amplifier is an attempt for ultra low noise. And minimum number of components signal path. Usually a 6MΩ Pleiades bias resistor allows operation of the one electron tube with very low anode voltage, relatively high anode current for such low anode potential, reduced heater voltage, lower temperature, low secondary emission effects therefore low noise.
Low anode voltage also brings in the desirable signal peak processing properties of electron tubes, for example loudness [Hamm] with less amplifying stages as the supply rail is already small.
The RCA 7586 Nuvistor electron tube can also be used with half power consumption, (under 1/2 Watt).
The Pleiades V6 depending on the input, output transformers used is noramalu flat in elecrical frequency response between balanced in and balanced out. For approaching the ideal of flat frequency response from producer's brain to listener's brain Pleiades (R,L) wave filters can be used between mic and the head amp. They are of the type of inductor in series with resistor and the total connected to pins 2,3. See preview posts on cascading Pleiades filters.
Further reading:
The Pleiades bias - euroelectron
Operating features of the Audion - E. H. Armstrong
Communication Engineering - Everitt - chapter XV, Class A amplifiers
(Can be download for www.archive.org)
A study of noise in vacuum tubes and attached circuits - F. B. Llewellyn
Fluctuation Noise in Vacuum Tubes - G. L. Pearson
(From www.archive.org too)
The Neumann U47 (with deliberately reduced heater voltage), BBC report
http://downloads.bbc.co.uk/rd/pubs/reports/1954-23.pdf
The RCA type BA-2C microphone booster amplifier
manual and schematic from www.coutant.org
http://www.coutant.org/ba2c/
Studio Engineering for Sound Broadcasting - BBC
Engineering Division Training Manual - 1942 - The British Broadcasting Corporation
Acoustics of radio and television studios - Guilford - BBC
High Quality Sound Production and Reproduction - Hadden - BBC
Elements of Sound Recording - Frayne, Wolfe - (Hollywood)
Tubes vs Transistors (vs operational amplifiers), Is there an audible difference? - Russel O. Hamm - JAES
Flat frequency response from producer's brain to listener's brain, Sound Picture Recording and Reproducing Characteristics - D. P. Lowe, K. F. Morgan - JSMPE
Cascading Pleiades Filters - euroelectron
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