Preamp Mic / Line analog designed to 1974-1975 by Mr. Rupert Neve and his associates in Cambridge. This amp uses the same technology, the same topology and the same electronics as its illustrious big brother, the 1081. This model, and the accompanying series (3114, 3117, 33115, 33114 and 33117), is simplified and more compact than the infamous 1081. He equipped the "small" Neve consoles of the time (Melbourne) or Broadcast consoles (5315, 5316), while the 1081 equipped the 80 Studio Series consoles (8048, 8058, 8068 ) from the same period.
With a 3 band semi-parametric equalizer (against 4 for the 1081), it also has a high pass filter, a phase reverse switch and an on / off section of its correction.
The various names for the same model, 33115 - 3115 for example, designate electronically identical preamps but with slightly different cosmetics: "3" designating a different paint color : gray in one case, RAF Blue in the other, RAF meaning ... Royal Air Force (!).
The 33115 (or 3115, so), the most common model, had a little brother: the 33117 (or 3117). The latter was a pure-preamp totally devoid of equalizer. As for the 33114 (or 3114), he proposed, in addition to the functions of the 33115, a frequency setting of the high correction (set at 10kHz on the 33115), a wider choice of frequencies in the section of mediums (called Presence ) and a low pass filter in addition to the high-pass filter. In summary, the 33114, comprehensive but unfortunately relatively rare, had little to envy to the 1081 ...
To insiders, these preamps, like their counterparts in the 1081, working in pure class A at the stage of pre-amplification and EQ (BA438). Only the driver output, the BA440 series 33 ... or 31 .. and its counterpart, the BA340 series 10 .., use a different class of amplification called "AB" before attacking the output transformer of the module.
FYI, the BA438, BA406 and BA440 are submodules discrete transistors used to perform all the active elements of the preamps, but also all other assets of these consoles: they are indeed found in the routing and modules amps output line or monitoring consoles this generation. They are also identical to the BA338, BA306 and BA340 series Studio (you know, the 1081 and 8048 ...) with the exception of the disappearance of a diode temperature drift compensation and the addition of a system of fixing the sub-module on the main board. For the first few consoles that time had the bad habit of losing these famous discrete sub-modules when the ballads too much or when they began to heat up! Fortunately, the addition of a single small screw permits easily remedy this shameful ...
A few years later, these sub-modules transistor disappeared in "profit" of sub-modules equipped this time of Integrated Circuits (eg, the BA638) or hybrid (tansistors and CI) as the BA640.
Ah, last but not least, the microphone input transformer has an impedance of the original 1200 Ohms, but this may be reduced to 300 ohms if you want to use the preamp with a ribbon microphone. Remember, these little wonders of electronics have a microphone input gain of 80dB!
Of course, these preamps, originally intended to equip consoles (ah, a Neve console ...), complete lack of traditional connections. Their use outside their original container requires to put in a rack, to provide an independent power supply and a suitable connection, but that's another story ...
We talk about preamps, so once they are racks and ready for use, the rest is a breeze, right?
Little advice anyway, if you're lucky enough to own one of these trinkets ... Do install on your rack:
- A meter to monitor the level of signal modulation,
- An insertion (pre or post filtering section) for ... add a gate or a compressor.
FYI, it was intended when designing the modules, but is performed at module level routing on the original consoles.
These additions, oddly absent from all the racks for sale by both AMS-Neve by different specialists vintage equipment, will make your rack preamp the best discrete with a sound engineer or a musician can dream ...
Ah, just for musicians, remember to equip it with a high impedance DI input.
Sound quality ... Is it really necessary to talk about? It seems that time and history have already said everything about it ...
The electronics of 33115 is identical to that of 1081, the sound can be different? Of course, the equalizer is equipped with two bands mediums, but honestly, is it a handicap?