Retro Hardware: Neve Class-A Channel Amplifiers, Part Three

Okay, let’s finish up the features of various class-A Neve channel amps. As I stated in an earlier installment these articles weren’t to be a comprehensive discussion of various Neve channel amps so much as to just share info on the modules whose information I have run across over time. I covet any and all information on modules that don’t get mentioned here, so please feel free to share, and I’ll make sure to pass it along!

I ended last time with the ubiquitous 1073. The next module, numerically, that I am aware of is a 1075. The 1075 appears to be a variant of the 1066 in that it shares all of the same features as a 1066 with the exception that instead of having a fixed 10kHz for its high-frequency shelf, the 1075 boasts five choices: 5, 7, 10, 12, and 16kHz.

 Neve 1075

Neve 1075

Interestingly (and this is something I neglected to mention in my earlier posts), the frequency selections on the 1075’s mid band ascend counter-clockwise up to the “OFF” position rather than ascend clockwise as the 1073 did. This appears to be true of all the modules that preceded the 1073. All subsequent modules followed the 1073’s clockwise ascension convention unless the mid band frequencies were borrowed from the earlier modules, at which point they maintain the earlier counter-clockwise ascension. HF shelf frequency options ascend counter-clockwise and LF shelf selections ascend clockwise an almost all class-A Neve modules. I find this interesting, and somewhat peculiar, because it makes sense to me that all bands on a single unit would follow a consistent approach rather than switching back and forth. There is no reason, of course, why Neve couldn’t do what they wanted, I’m just geeky enough that I’d like to know why they took this approach, and why the mid band differs on the various modules. Things that make you go, “hmmm”...

Next up is Neve’s 1076 channel amp, which shares all features with the 1073 with the exception of the use of 21-position rotary switches (instead of continuously variable potentiometers) for all cut/boost controls, making it essentially a 1073 whose settings you can fully log and recall (pretty cool!!). Also, unique to this module (and the 1082 discussed later in this post) is the fact that rather than having the frequencies for the three band’s of the EQ silkscreened on the faceplate, Neve, instead, engraved the frequency choices into the metal outer concentric rings for each band (the high-pass filter frequencies are still screened on the faceplate, however).  In place of frequencies the front panel screening includes cut/boost ranges in numerical steps, by 2, up to 10.  Whether these numbers indicate cut/boost in dB I don't know.  If so, then these EQs differ in that they have a total cut/boost range of only +/- 10dB (instead of the far greater ranges in the other channel amp models).  My guess is these are simply a random numeric designation much like the "0" to "10" screening on cut and boost controls of old Pultecs, but without more specific information this is only a guess.  If someone out there knows please speak up!! 

The last unique characteristic of the 1076 that I am aware of is that its cut/boost controls center at 12 o'clock as is common with most all modern EQs rather than centering down at 6 o'clock as all other Neve modules of the time did. 

Neve 1076

The Neve 1078 is a rare little powerhouse of a module in that is based heavily on the 1073 with the singular exception that its HF shelf offers the greatest number of frequency options for any of Neve’s class-A channel amps – six total, including 2k5, 4k, 6k, 10k, 13k, and 16k. I particularly find the 13k fascinating as I don’t think I have ever seen that frequency printed on any equalizer before (clearly the designers of the 1078 weren’t superstitious! :) Oddly enough there is no “OFF” position for this band (as was normal for all bands with switchable frequencies), so it is always ‘in’ if the overall EQ circuit is engaged. All cut/boost controls are continuously variable, and the rest of the modules specs out like a 1073.

Neve 1078

 

 

 

 

To create the 1079 module Neve started with a 1066, gave it the single source, transformer-balanced input used in the 1063 and 1070, and then fixed its HF shelf at 12kHz instead of the 1066’s 10kHz. Simple enough.

Neve 1079

The 1082 is next, though I will skip discussion of it for the moment in favor of the highly esteemed 1084. The 1084, along with the 1073, is again in current production today by AMS-Neve, demonstrating clearly the warmth that engineers have in their hearts for these modules. The 1084 is considered by many to be the most comprehensive class-A Neve channel amp ever produced (and I am very pleased to say that I am fortunate enough to own two vintage 1084’s equipped with Marinair transformers! More on the transformers Neve used in various modules in a future post).

Neve 1084

The 1084 can be considered a more feature-packed 1073 in that its mic/line input is the same, as is the EQ section, though in addition to 12kHz HF shelf Neve tacked on 10k and 16k positions as well. The peaking mid band on the 1084 includes a “Hi-Q” switch that narrows its bandwidth, and in addition to the high-pass filter a low-pass filter is also included which is selectable for cutting frequencies above 6, 8, 10, 14, and 18kHz. And the high-pass filter frequencies differ slightly from those on the 1073 in that it features 45 and 70Hz positions instead of the 1073’s 50 and 80Hz, respectively. Lastly, the 1073’s 360Hz position on the mid band is slightly altered to 350Hz on the 1084. All remaining features match those of the 1073.

 

So now that we have discussed the features of the 1084 let us jump back to the 1082 that I skipped earlier. This little oddity is essentially the same module as a 1084 with 360Hz in the mid band instead of 350Hz, and like the 1076, the frequencies are engraved on the metal outer concentric rings instead of being screened on the faceplate while all frequencies for the high-pass and low-pass filters remain screened on the faceplate.

 

Neve 1082

Next up is Neve’s 1089 module which, as far as I have been able to determine, is a 1073 with the line positions of the gain switch increasing clockwise instead of the counterclockwise increase of the 1073 (and most every other class-A channel amp). Microphone gain positions remain unaltered from the 1073 design, however. (I am fascinated to know why someone specified this minor difference from an otherwise stock 1073. If anyone out there knows why, please do tell!)

 

The last two all class-A Neve channel amps I am aware of are the 31102 and the 31109. These are the buggers found in the later 8058/8068 consoles (whose modules all used class-AB output blocks except for the channel amps, which, as far as I’m aware, were the last class-A modules Neve built). These two modules have a different color scheme than all previously discussed modules as they were built for consoles using Neve’s New Appearance Design (NAD) starting around 1975. According to Geoff Tanner, before this switch in aesthetics Neve modules were painted RAF (Royal Air Force) Blue Grey. NAD modules like the 31102 and 31109 were painted a slightly lighter Extra Dark Sea Grey and the knobs were black with blue caps in various shades depending on functionality. Modules for these consoles had their model numbers altered with the addition of a ‘3’ before the module (so a 1073 used in a NAD console was designated “31073”). Interestingly, the schematic of the 31102 that I have is actually labeled “1102” which would be the model of a RAF Blue Grey module with red/grey/blue Marconi knobs, but as the vast majority of these channel amps were built for NAD consoles, they are generally designated “31102.” Okay, enough of that, on to the modules themselves.

Neve 31102

The 31102 is most easily described as a mic input-only 1084 with the newer NAD color scheme. The mic input gain range is 10dB to 80dB on the 31102 (slightly wider range than the 20dB to 80dB on most others) and while it doesn’t offer the transformer-balanced line input of most other class-A channel amps the 31102 does actually have an unbalanced line input connection in the form of what is essentially a return on the rear panel connector. The microphone preamp section of the 31102 feeds an unbalanced output (a send, basically) at pin D on the rear of the unit with its unbalanced return at pin M. This unbalanced line input is how the module receives its line input sourced from a line input potentiometer located elsewhere in the console. This input is buffered with a simple, single transistor emitter follower stage (pcb model B106) that then goes on to connect to the EQ and output stages as in other modules. Because of this send/return arrangement racking up 31102’s for outboard use requires a wire jumper to connect pins D and M to complete the circuit. Otherwise it is essentially the same module as a 1084.

Early 31102s used the same 10468 mic input transformer used in other class-A modules (made for Neve by either St.Ives or Marinair) with later units using a new mic input transformer wound by Beclere who would go on to supply transformers for the 81-series recording consoles that were soon to follow.

The 31099 is the other channel amp commonly found Neve’s 8058/8068 consoles and is to the 1073 what the 31102 is to the 1084. Essentially, the 31099 is a 1073 with the same mic input only arrangement (with the same 10dB to 80dB range) and the insert/return/buffer design used in the 31102. All EQ and filter points are identical to the 1073.

Neve 31099

So that about does it for the descriptions of all the various, proper Neve class-A channel amplifiers that I have been exposed to. If you have details (and pics!) of class-A modules not covered here, please let me know! I would love to learn about them.

My next Neve installment will cover the only two all class-A microphone amp-only modules (with no EQ) that Neve ever made (as far as I am aware), compare and contrast the gain arrangements they used, and discuss the 1272 buss amplifier that has become so popular for modifying for microphone amplifier use (no, the 1272 wasn’t a mic preamp... well, not really anyway.... more on that next time.)

And then on to class-AB modules, dynamics processors, and more!

Thanks for reading.  -JC