The EAR 823MQ is a variant of the 822 EQ designed for use in the midband. It is slightly simpler, with the frequencies set closer together in order to give more precise control over this critical spectrum.
The EAR 822Q Pultec type equalizer has been designed to be highly flexible and thus useful in a wide range of applications. Passive equalization networks combined with valve input and output buffers are used in order to minimize disturbing side effects such as phase shift and ringing. The audio circuitry conforms to the EAR principles of simplicity and subjective "transparency", with low distortion at all normal signal levels. A "clickless" bypass switch allows easy comparison between the processed and direct paths. Variations in response include low pass, high pass, band pass and high or low frequency shelf with variable Q and turnover frequency.
The recent trend towards ever-more-complicated equalizers and filters has not resulted in any real increase in flexibility, and certainly not in quality.
The EAR 822Q "Pultec"-type equalizer is a relatively simple passive device that has been designed to be highly flexible and therefore genuinely useful in any application. As always with EAR products, the highest possible sound quality is of the essence, and the filter circuits are used so as to introduce the minimum possible of disturbing side effects in the way of phase shift and ringing, thus preserving the essential qualities of the signal intact.
It is a characteristic of this device that subtle equalization changes are not masked in effect by the distortion often due to inadequate active filters. Variations in response include low pass, high pass, band pass and high or low frequency shelf, with variable Q and turnover frequency.
The EAR 823MQ is a variant of the 822Q designed for use in the midband. It is slightly simpler, with the frequencies set closer together in order to give more precise control over this critical spectrum.
EAR 823MQ Features :
- Operation - Passive equaliser with balanced valve output
- Maximum output level (1% distortion) - +25dBm
- Input and output impedance - 600 ohm nominal, balanced and floating
- High cut frequencies - 6k, 10k, 20kHz; shelf 0, - 18dB variable
- Bypass switch - no level change, clickless
- Operation - Passive equaliser with balanced valve output
The history behind E.A.R. and designer Tim de Paravicini :
There are very few modern designers in the audio field who can claim as much as Tim de Paravicini. No aspect of the recording and reproduction chain has been left untouched, no aspect of circuit design not further researched and developed.
As early as 1965, Tim was involved in custom design work for rock and roll bands - manufacturing his own public address equipment, and modifying existing studio equipment to realize even greater potential.
Tim de Paravicini works by a simple premises:
If he designs it, it must be a better design than anything else, or he will not manufacture it.
His sole goal is taking audio to the furthest possible point of development. Current research is taking him further along this path than any single competitor.
There are very few modern designers in the audio field who can claim as much as de Paravicini.
No aspect of the recording and reproduction chain has been left untouched, no aspect of circuit design not further researched and developed.
As early as 1965 Tim was involved in custom design work for rock and roll bands; manufacturing his own public address equipment, and modifying existing studio equipment to realise even greater potential. A move to South Africa from England saw a further development of his own unique design genius, and the launch of his own professional amplifier product, sold simply as “de Paravicini”.
While working in South Africa, Tim had a chance meeting with representatives of the Lux Corporation, and in 1972 was invited back to Osaka, Japan, and offered a job as audio designer. Tim soon put together some very interesting designs for Lux, including the remarkable C1000/M6000 pre/power amplifier combination. One of his own favourite designs from this period was the Luxman 3045 tube mono block. At the time, this was the only mono block design available in the audio field, and backed up de Paravicini’s preference for locating the power amplifiers close to the loudspeakers. Tim also designed the actual output tube for this amplifier, the 8045 power tube. As always with his designs, the output transformer was a custom de Paravicini design.
In 1976 de Paravicini returned to England, and very quickly made an impact as a design consultant, initially working with the ALBA Radio Corporation, and Tangent Loudspeakers. Tim was also responsible for the later ranges of Michealson and Austin tube amplifiers, including the TVA10 and M200 mono blocks.
Within a year, he had set up Esoteric Audio Research Ltd., and was marketing the remarkable EAR 509 100 watt professional tube mono block power amplifiers. He developed a unique output transformer/tube interface circuit called “balanced bridge mode”, in which all the electrodes (except the control grids) have their own separate windings on the thirteen-section, biflar wound, output transformer. In addition, the amplifier has no overall feedback, something of a de Paravicini trade mark. Technically this amplifier proved that tubes are capable of performing equally as well as transistors in a laboratory, with a specification that included a power bandwidth of 9-85,000 Hz, -3dB, and also proved that tubes are capable of better things than the “retro” sound some manufacturers look for. Subjectively the 509 amplifiers were a big hit. Although aimed at the professional market, several Hi-Fi magazines picked up on the 509’ss, and compared them to the then State of the Art domestic High End equipment. The fact the 509 beat all of the competition at the time helps explain why the 509 is still in production today. the 509 was designed by de Paravicini to have no sound; trying to sum up the 509 is hard, it does not offer the warm ‘comfortable’ tonal quality which so often mark most tube amplifiers out. They are remarkably clear, transparent, with firm realistic bass, effortless top end, detailed and very alive.
In the twenty years since 1976, Tim has designed a mammoth catalogue of Hi-Fi and Studio components, both for Esoteric Audio Research and for other domestic audio companies. Currently the ‘E.A.R.@ professional product range includes a tube capacitor microphone, built with a rectangular gold spluttered capsule. A design which easily betters the classic European designs. Tube microphone preamplifiers, tube equalizers, record cutting systems, analogue to digital converters (for CD mastering) plus custom components and servicing for some of the Worlds most famous recording artists. His is most famous in the studio industry for the stunning analogue tube master tape recorders. These units have very special custom designed heads, and are capable of digital levels of signal to noise ratio, with a bandwidth in excess of 8Hz to 80,000Hz!
