® TLAudio user manual Ivory 2 Series 5052 STEREO VALVE PROCESSOR TL Audio Ltd, Letchworth, Herts, SG6 1AN, UK email: info@tlaudio.co.uk web: http://www.tlaudio.co.
CONTENTS 1 INTRODUCTION 2 PRECAUTIONS 3 INSTALLATION 3.1 A.C. Mains Supply 3.2 Microphone Input 3.3 Compression Balanced Line Input 3.4 Unbalanced Line Input 3.5 Instrument Input 3.6 Insert Points 3.7 Sidechain Insert Points 3.8 Line Outputs 3.9 Nominal Operating Level 3.10 Ventilation 3.11 Rear Panel 4 OPERATION 4.1 Input Stage 4.2 Microphone Input 4.3 Line Input 4.4 Instrument Input 4.5 30dB Pad Switch 4.6 90Hz Filter 4.7 Phase Reverse 4.
1. INTRODUCTION Congratulations on purchasing the Ivory 5052 Stereo Valve Processor by TL Audio! The Ivory 2 Series consists of a range of hybrid valve signal processors, which utilise low noise solid state electronics in conjunction with classic valve circuitry to produce audio processing units offering very high quality signal paths with the unique valve audio character.
contribute to the smooth, open sound of the unit, along with a triode valve stage that forms part of the gain make-up circuit. A four band valve EQ stage is included, providing up to 15dB of cut or boost on each band. The LF and HF bands provide swept frequency controls with a choice of shelving or peaking response. The LM and HM bands are fully parametric with variable control of gain, frequency and bandwidth.
2. PRECAUTIONS The Ivory 5052 requires very little installation, but like all electrical equipment, care must be taken to ensure reliable, safe operation.
PEAK INST 100 dB 30 EQ PRE Hz PH REV 0 dB +20 +12 LIMIT LIMITER SECTION dB LIMITER ON (PULL) +5 0 1 LIM 48 0 INST INPUT 2 COMP2 +10 dB -20 2 1:5 MIC MIC -30dB SLOW 12 90Hz 20 GMU INST PEAK 5 dB EQ S/C RELEASE 0 FAST KNEE SLOW LINE INPUT 2 DRIVE MIC 48V 1:10 1:30 RATIO ON ATTACK 1:1.
3. INSTALLATION 3.1 AC Mains Supply. The unit is fitted with an internationally approved 3 pin IEC connector. A mating socket with power cord is provided with the unit, wired as follows: Brown: Live. Blue: Neutral. Green/Yellow: Earth (Ground). All mains wiring should be performed by a qualified electrician with all power switched off, and the earth connection must be used. Before connecting the unit to the supply, check that the unit is set for the correct mains voltage.
- Pin 3 = Signal Non-Phase (“-” or “cold”). Unbalanced inputs: - Pin 1 = Ground (screen) - Pin 2 = Signal Phase (“+” or “hot”). - Pin 3 = Signal Ground. 3.3 Balanced Line Input. The 5052 has a 3 pin XLR socket on the rear panel, which will accept both balanced and unbalanced line level inputs. The mating connector should be appropriately wired as follows: Balanced inputs: - Screen = Ground, - Tip = Signal Phase (“+” or “hot”), - Ring = Signal Non-Phase (“-” or “cold”).
3.4 Unbalanced Line Input. An unbalanced line level input at a nominal level of -10dBu is also provided, on a 0.25” mono jack socket. The mating plugs should be wired as follows: - Tip = Signal Phase (“+” or “hot”). - Screen = Ground. 3.5 Instrument Input. Each channel has a 0.25” jack socket on the front panel (see Figure 2). A 2 pin (mono) jack plug is required, which should be wired as follows: - Tip = Signal Phase (“+” or “hot”), - Screen = Ground.
The insertion points are balanced, and operate at a nominal level of +4dBu. 3.7 Sidechain Insert Points. The sidechain insert points allow access to the 5052 compressor sidechain (i.e. for frequency conscious compression – see section 4.20) and are interfaced via a 3 pin, 0.25” switched jack socket on the rear of the unit. The pin connections are: - Sleeve = Ground, - Tip = Send, - Ring = Return. The sidechain insert point is unbalanced, and operates at a nominal level of -2dBu .
Unbalanced outputs: - Screen = Ground, - Tip = Signal Phase (“+” or “hot”), - Ring = Ground. 3.9 Nominal Operating Level. A switch on the rear panel allows the line inputs to be matched to equipment at a nominal operating level of +4dBu or -10dBu for unbalanced signals, and +18dBu or +4dBu for balanced signals. Most professional equipment requires +4dBu (approximately 1.2V rms), but some small mixing consoles, portable tape recorders or domestic audio equipment require -10dBu (approximately 225mV rms).
4. OPERATION 4.1 Input Stage. The Input Gain control sets the level of the mic, line or instrument input into the 5052 preamp stage. The signal source is selected by the 4-position switch adjacent to the Input Gain control. Input choices are Mic 48V (for condenser microphones that require phantom power), Mic (for dynamic or most ribbon microphones), Line and Instrument.
4.3 Line Input. A line level signal should already be at about the correct operating level, but this may be checked by monitoring the level with the VU meter set to ‘I/P’. The input gain should be adjusted until the meter reads about 0VU at normal audio level. 4.4 Instrument Input. The front panel instrument input socket is suitable for low level sources such as hi impedance microphones, pick ups or passive guitars, and higher level sources such as active guitars and keyboards.
microphones picking up the same signal at the same time. An example of this problem is when recording a snare drum with one microphone on the top snare skin and a second microphone on the underside skin of the snare drum. Because the two microphones are picking up the same signal at the same time, phase cancellation can occur. By inverting the phase of one of the microphones this problem can be rectified.
drive digital recorders. It is important to distinguish the difference between the output gain knob and the gain make-up knob in the compressor section. The gain make-up control is only active when the compressor is switched on. The output gain control is always active but will have no effect on the compression characteristics of the signal. 4.10 Bypass.
design, as with other TL Audio compressors, uses a technology based around a transconductance amplifier rather than a VCA design. This transconductance amplifier design is known for being able to retain the full frequency range and natural character of the audio signal, even when compressing the signal quite heavily. The Ivory 5052 is also capable of more severe compression based around the optional Hard Knee mode if this is desired.
4.14 Threshold. The Threshold is the point measured in decibels that any compression comes into operation. The Threshold control is variable from +10dB in the most anticlockwise position to -20dB at the most clockwise position. Any signal below the Threshold passes through the unit unaffected; while signals above the Threshold are reduced in gain (and are thus ‘compressed’). This does depend on the Soft or Hard knee to some extent as the Soft knee is more gradual around the Threshold point.
and Release on the 5052 - for instance, should a very short transient occur the time constants tend to become shorter, to prevent a slow release leaving a “hole” in the signal after the transient. Also, a fast release setting will be extended by a slow attack setting. Due to this automatic nature of the time constants, the controls are simply labelled ‘Slow’ to ‘Fast’. The speed of the Attack and Release should in general be able to work with the tempo of the signal.
Unlike the Output Level control, the Gain Make Up control is active only when the ‘compressor on’ switch is engaged. Once the Gain Make Up has been adjusted, use the Output Level control to set the overall output level of the 5052. 4.19 Compressor On. This switch enables or disables the compressor stage, thus allowing an A/B comparison to be made between the original untreated signal and the compressed signal. Any gain make up applied to the signal only becomes active when the “Compressor On” is enabled.
The 5052 is equipped with a pair of illuminated VU meters. The associated Meter switch enables this meter to monitor each one of four parameters. When switched to ‘I/P’, the meter reads the audio input level just after the preamp stage. When switched to ‘O/P’ the meter reads the audio output level, and is calibrated to read 0VU when a +4dBu signal is reached at the main XLR line outputs of the 5052 (or 10dBu at the unbalanced line outputs).
reduction of a narrow band whilst simultaneously boosting an overlapping broader band of frequencies, for example. Used individually or in combination, the filter bands allow comprehensive equalisation of any audio signal. 4.23 Cut/Boost Control. Each of the four EQ bands has a +/- 15dB gain control that is used to apply cut or boost at the frequency selected by the Frequency control.
removed without upsetting the rest of the frequency spectrum, or a single frequency needs to be boosted to create a particular unique sound. A proven technique for identifying frequencies is to set the Q control to its minimum (narrow) position, apply a reasonable amount of boost in that EQ band, and then sweep the Frequency control around until the problem (or desired) frequency is found (since boosting will make the frequency prominent).
4.29 Output Limiter. The 5052 output limiter provides responsive yet natural control of output peaks making it ideal for preventing overload in digital recorders. Digital recorders will distort in a very unmusical way when overloaded to any degree, so an output limiter is an ideal way of preventing over-modulation occurring.
controls automatically become the ‘master’ for that stage, and channel B becomes the ‘slave’. This means that when processing a stereo source or stereo mix, channel A’s controls can be used to process both left and right signal paths simultaneously – providing very quick and accurately matched stereo processing. Channel B’s controls for those 3 processing stages effectively become inactive, meaning that only one set of adjustments is required to process both signal paths.
The card feeds the converted output signals of channels 1 and 2 to the SPDIF phono output. The sample rate is switchable between either 44.1kHz or to 48kHz, and the card can be clocked to an external digital source via the BNC wordclock input. When clocking the DO-2 to an external source the sample rate setting on the DO-2 needs to be set to match the external sample rate, otherwise correct locking may not occur and audible clicking may appear on the digital output.
connector at one end split into two mono jack or XLR connectors - one for send and one for return). The most likely positions that insert points are located on a mixer are in the channel, group and stereo master sections. Patching the 5052 into the channel insert point means that any signal passing through that channel will pass directly though the 5052.
5.2 In Use - Mono tracking mode Having connected the 5052 - checking that the input operating level switch is at the most suitable setting (see section 3.9) - it’s time to put it into action! Here’s a simple step by step guide, starting with single channel processing of a mic signal. 1. We’ll assume that a condenser microphone is connected to the channel 1 5052 mic input, and the +48V phantom power is engaged by choosing the ‘MIC +48V’ setting of the input selector switch.
6. When gain reduction is taking place, you should notice that the output level is reduced. By switching the compressor ‘in’ and ‘out’, you can compare the levels and the subjective sound quality of the original and compressed signals. With the compressor active, use the Gain Make-Up control to set the level so that when disabling the compressor, there is no level drop. This way you can A/B the original and compressed signals without the levels changing. 7.
5.3 In Use - Stereo mixdown mode. Now we’ll assume that the 5052 is connected via its line inputs/outputs to the master insert points of a mixer (see ‘Connections’ section 5.1). Set the input selector switches on both channels to ‘LINE’, and activate each of the 3 stereo mode switches (Comp, EQ and Limiter) so that channel 1 can be used as the master for both L and R signals of the stereo mix.
have found the Sovtek brand to offer a good balance of quality and affordability. Q: What is the life expectancy of the valves in my TL Audio unit, and how do I know when the valves need replacing? A: We would normally estimate around 4 years, but much will depend on the way the units are used.
provides a much higher signal level than a microphone does. Also, mic inputs are of low impedance whereas a line output is generally high impedance: this mismatch often results in poor frequency response and increased noise levels. So always ensure that the line output of any TL Audio product is connected to the line input of any mixer or recorder.
greater than 50mS prevents this problem, which is why adjusting to a slower release setting will cause the distortion to disappear. For the same reason, source signals with little or no LF content will not be subject to this effect. Additionally on the 5052 a ‘Hold’ circuit is designed into the compressor stage. This delays the onset of the release by around 10mS, and as a result the above effect is minimized. 7. SPECIFICATIONS Line Inputs: Balanced via XLR, switchable +4/+18dBu nominal level.
Phase Reverse: Effective on all inputs. Insertion Point: Balanced, via normalled TRS send and return jacks. +4dBu nominal level. Bypass Switch: Bypasses Compressor, Equaliser and Limiter sections. Compressor: Transconductance amplifier / valve configuration, with dual envelope feedforward and feed-back sidechain. Threshold continuously variable, +10dBu to -20dBu. Ratio 1:1.5 to 1:30. Attack continuously variable, programme dependant, typically 0.4ms to 40ms.
Q variable 0.7 to 7. HF: +/-15dB, 3kHz to 20kHz. Peak/Shelve response. Q = 1.5. Output/Limiter: Output fader centre detented at 0dB. Maximum gain +15dB. Limiter post fader, threshold 0dBu to +20dBu. Balanced output via XLR, +4dBu nominal level. Unbalanced output via jack, -10dBu nominal level. Stereo Operation: Independent selection of Compressor, Equaliser and Limiter for stereo. All selected controls stereo ganged, Channel 1 operates as master.
valve signal level and constant over the frequency range. Valves: Three off 12AX7A twin triodes, postioned at the Input stage, Compressor and Equaliser. Ceramic bases with precious metal contacts. Stabilised HT and heater supplies. Power Consumption: 30VA. Internally set for 230V or 115V AC operation. Dimensions: 19” rack mounting, 3U high. 483mm (19”) W , x 133mm (5.25”) H , x 250mm (10”) D behind front panel. Shipping Weight: 9kgs.
8. SERVICE Should the 5052 require service, it must be taken or posted to an authorised dealer with a description of the fault. Please retain the original packing for possible future use, and ensure the unit is suitably protected during transit. The manufacturer cannot accept responsibility for damage caused during transportation. The 5052 is supported by a limited warranty for a period of one year from the date of purchase.
FIG 1: BLOCK DIAGRAM
