FS: Neve EQs
HoosierSnd
Two Neve 33135 EQ/preamps, custom racked in a single rack space with custom
outboard PS. From Neve broadcast console.
In Excellent condition, non-smoke studio only.
Bands: 3.3kHz-10kHz; 250Hz-8.2kHz; 20Hz-330Hz and
shelf eqs 27Hz-270Hz and 3.9kHz-20k
Lit switches engage EQ and Phase Reverse.
Preamps have stepped gain from -70 to +10 db and continuous trim.
From a reply to an inquiry I made to AMS-Neve via their website...
The material below is a direct quote. The "I" in the first paragraph is the
lady who directed my email to Neil Holcombe.
"NOTES from AMS-NEVE I forwarded your enquiry to Neil McCombie, one of our
Analogue Engineers, his reply is as follows:
"The 33135 Channel input amplifier was designed specifically for the BBC and
only supplied to them in 35mm wide module custom consoles. This Mic/Line Pre
amp
and EQ unit had a very special output stage designed to feed external
transformers and have an output drive capability of +36dB into 10k ohms (the
input Z of the pre fade insert return transformer). The output stage of the
module itself is electronically balanced at a level of -10dB. "
steve V. johnson + studio V
Original Music Recordings
All Popular, Ethnic & Formal Musics
Bloomington, Indiana
Geoff...@my-dejanews.com
In article <199806060036...@ladder03.news.aol.com>,
The one item I would take issue with is that this module is designed to drive
a T1801 output transformer with a 6dB step up ratio. This implies that,
correctly set up, the electronically balanced output of the module is
normally -6dBu for 0dBu input.
I believe that the module was specifically designed to have a maximum output
swing of +30dBu which was the +24dBu the bridged output reached before
croaking plus the 6dB in the T1801. I doubt that you'd get it to swing the
extra 6dB's to +36dBu even with that transformer, and never in a month of
sundays without it! (> <input type=
-----== Posted via Deja News, The Leader in Internet Discussion ==-----
http://www.dejanews.com/ Now offering spam-free web-based newsreading
Geoff...@my-dejanews.com
In article <6lajm5$5m0$1...@nnrp1.dejanews.com>,
I don't know what happened there but Dejanews truncated my post by two
paragraphs and replaced the ending with that weird line!
Oddly enough it nearly happened again and seems to occur if you preview the
message and return to edit, and then send it without reading the full text...
Weird! Never happened before!
Anyway, the summary of the missing paragraphs is that these are excellent
modules in any case, whatever the maximum output swing (which is greater than
any other Neve module I know of) and they merit a story with a bit of unusual
history....
Coming soon!
Geoff Tanner
phoeni...@earthlink.net
HoosierSnd
Hi Geoff,
Altho I can't find your reply (which I normally file and hoard), I think I
asked you about these before... All I can remember about your comments is
something like, '...over 24db of headroom. Not bad!' with some sort of grin
indication.
Thanks very much for your comments on the AMS Neve statements!
steveV
Geoff...@my-dejanews.com
In article <199806061645...@ladder03.news.aol.com>,
hoosi...@aol.com (HoosierSnd) wrote:
>
> Hi Geoff,
>
> Altho I can't find your reply (which I normally file and hoard), I think I
> asked you about these before... All I can remember about your comments is
> something like, '...over 24db of headroom. Not bad!' with some sort of grin
> indication.
>
> Thanks very much for your comments on the AMS Neve statements!
>
As you'll see from this offering my memory does play tricks but at least I own
up!
Lovely modules!!!!
Here's what happened today....
Well it just so happens that I also had a pair of Neve 33135a Channel
Amplifiers back at my workbench for test/repair so I thought this was a good
opportunity to see what the maximum output level of the beasts really was!
The problem was that they were mounted on a 19" x 1U tray with terrible
wiring to the 43 way rear connectors (indeed each module had two halves of a
larger connector which could slide unrestricted across the gold pins, Yuk
!!!) and the power supply had to be seen to be believed! Built into a steel
box with hinged lid and leather handle, it had a collection of electrolytic
caps glued to the bottom of the case and series resistors (Groan!) as the
only filtering applied to drive two of these modules. The case had the words
"Rupert's Rejects" written on the outside with a blue marker pen . . . .Very
droll, I imagined any tech with a conscience would also have rejected it!
I rebuilt the power supply in the same case using a larger rated transformer,
and IC adjustable regulators with beefier capacitors. . . . and all except the
transformer mounted on a Radio Shack (!) printed circuit board.
I also removed the "reject" title and fitted a mains fuse.
So, on to testing the modules, except my weary eyes spotted that transistors
had been replaced on the BA769 output stage and two of them were loose, with
broken printed circuit tracks! A good tip to spot this sort of thing is that
Neve always mounted transistors on small plastic spacers. These lifted the
transistor off the PCB and, in the case of BC441/BC461 output stages, if the
spacers aren't fitted the finned heatsinks hit components and prevent the
transistor from pressing hard against the board. Whoever pushed the 769 back
into its sockets pushed the heatsinks instead of the PCB and that caused the
tracks to break... all for the sake of replacing a tiny plastic spacer!
So, a spot of soldering of new transistors and repairing the broken tracks,
it was on to testing the modules, except the wiring of the broken connectors
didn't look right so, in the absence of a diagram, I checked the connector
against the wiring of the PCB, it didn't make sense!. . . .a little history
lesson is needed here!
The 33135 was a custom 35 series module that was designed when Neve had taken
the plunge into the manufacture of IC based circuitry. In fact Neve had taken
longer than many other manufacturers because the IC op amps of the early days
(741's, 748's, etc.) were never considered adequate in performance compared
to the discrete op amps that Neve manufactured (BA238, 338, 438, etc.). The
Mullard TDA1034 (and derivative 5534) IC's changed this and much research was
undertaken to establish the correct parameters to use these IC op amps.
The IC based circuits had started with a vengeance around 1976 with the
introduction of a range of Eurocard sized PCB's that included BA535 (Dual O/P
amp), BA536 (8 x 2 Audio switcher), BA537 (Triple dbx VCA), BA538 (Quad I/P
buffer), and BA539 (Triple 10 way mix card). These "building blocks" were
used in several large orders for program switchers including, I believe, RTE
(Dublin) and RTV Dubai.
From 1977 all IC consoles started to appear including the 5422 and
derivatives, the AIR custom consoles and N78, the 8108 project!
So the technology marched forward into the regular amplifiers and the BA438
became the BA638 and the BA440 became the BA640. The PCB line amplifiers of
the BA53* series had proved useful (a lot less bulk than a 1272!) but, at
5.75" high, a new smaller range of line amplifiers were being designed at
3.5" high to replace them. These two PCB's (designed, I believe, by Rob
Frayling-Cork) materialized as the BA766 balanced output card and BA767 Dual
line amplifier card. Both cards were available in at least four different
versions (with or without transformers, etc.) and were used exclusively on
BBC Broadcast Consoles. . . . except for the applications I put all these
PCB's to as Special Orders Manager!
Anyway, the 33135 was developed around this era and is unique because of the
push-pull output used to drive the externally mounted T1801 transformer. The
transformer had to be mounted externally as it was wider than the 35mm module
and the chunky lamination stack mocked the weeny T0126 transformer mounted in
the sibling 33114 & 5 modules! The module was also unusual in having a single
input and a transistor switched relay flipped the single input to mic or line
input stages. A contact on the sensitivity switch toggled the relay as the
switch went from line to mic input settings. The power for the module was +/-
18 volts for the audio and 24v for the relay and "bimdicator" EQ ON lamp
(where fitted).
On the 33135a's I was testing there were a number of links serving no
sensible purpose that I removed and, as soon as I get replacement connectors
from the UK, I'll replace the broken connectors and ALL the horrid wiring.
But on with the testing!
The module has a rear trim pot to set the gain (a luxury on a Neve EQ!) and
this had a range of just 2dB, adjusting the balanced output level between
-8.2dBu and -6.2dBu. The front panel trim pot on top of the sensitivity
switch adjusted the gain +/- 2.9dB. My guess of -6dBu output was nearer but I
thought the range of adjustment a little odd. . . it might to due to a
component change.
So, it was time to crank up the Lindos Analyser and see what kind of signals
this module could get up to!
I set the sensitivity switch at 20dB gain, turned up the trim pot and
increased the input level until I saw clipping. . . .Well, I'm going to have
to eat my words this time because it reached +28.8dBu (@ <0.1% THD) before
clipping started. If added to the 6dB gain that a T1801 would have provided
the output would have reached at least +35dBu so that +36dB output wasn't so
far fetched (Sorry AMS-Neve!) albeit it would have really clipped at that
level.
This beats a previous record I held when I built a custom Neve DA90 rack that
had transformers with 600 ohm output limiting resistors. This rack had to
drive +26dbu into 600 ohm (Lord knows why!) and meant that the (Sowter)
transformers were singing away at +32dBu!
Most 33135's are extra dark sea gray but the 33135a's I was testing are dark
brown. Also, very unusual for a Neve console, they were fitted into the
broadcast console upside down! That is, the gain switch was at the bottom and
the Isostat switches with phase and EQ at the top. All the silk screening was
inverted to match this configuration. I believe that these consoles were used
to replace those of another manufacturer (Audix?) and the décor and other
equipment in the control room was this dark brown color. I would imagine that
the chances of getting replacement brown aluminum custom knobs for these
modules is pretty slim!
So, my memory played tricks and the module can indeed reach incredible output
levels. To help anyone else who has to check one of these modules I've listed
(my interpretation of) the connector pin out below.
Taking pin 1 as the top of the module…
3 = Ground and input cable shield
4 = 0v amp supply
6 & 8 = Balanced input
11 = 0v relay dc
13 = +24v relay dc
15 = pre eq ins send (-15dBu)
17 = pre eq ins return
19 = -18v amp supply
23 = +18v amp supply
33 & 35 = Balanced Output
40 = 0v
42 = Chassis
(There is a slot for a polarizing key at pin 37)