TNT Manley Laboratories, Inc. Tel: +1 (909) 627-4256 13880 Magnolia Ave. Fax: +1 (909) 628-2482 Chino, California 91710 www.manley.
CONTENTS SECTION PAGE INTRODUCTION 3 BACK PANEL & CONNECTING 4 FRONT PANEL 5 BEGINNINGS 6 IMPEDANCE 8 TUBE CHANNEL 10 COOL CHANNEL 13 TROUBLESHOOTING 19 CURVES 20 MAINS CONNECTIONS 24 SPECIFICATIONS 25 APPENDIX 1 - TEMPLATE FOR STORING SETTINGS 26 3/15/11revCD
INTRODUCTION THANK YOU ! For choosing the Manley TNT Microphone Preamplifier. The name of this mic preamplifier “TNT” is a reference to the two different channels, one that is Tube and the other No Tube. We see people today hungry for a variety of preamps as a means of getting a variety of sounds and tones from the start.
THE BACK PANEL FUSE 1A @ 117V FUSE .5A @ 220V OUTPUT MIC TRANSFORMERLESS OUTPUT DOES NOT BYPASS TRANSFORMER & XLR OUTPUT MODE +4 UNBALANCED OUTPUT MIC OUTPUT TNT 13880 MAGNOLIA AVE., CHINO, CA 91710 PHONE (909) 627-4256 FAX(909) 628-2482 +4 BAL N9512423 CAUTION: RISK OF ELECTRIC SHOCK. DO NOT OPEN. REFER SERVICING TO QUALIFIEDPERSONNEL ONLY 1 3 8 www.manleylabs.com -10 UNBALANCED TRANSFORMER ISOLATED 9 10 SERIAL NUMBER MANLEY LABORATORIES INC.
THE FRONT PANEL FLAT PHASE 180 0 IMPEDANCE Ω 10K 2400 600 GAIN TUBE CHANNEL INSTRUMENT 50 30 3MEG 1MEG 300K 4 45 60 65 25 5 -2 55 20 2 TRIM B 6 70 0 +2 -4 OFF +4 -6 +6 -8 +8 -10 B 7 10 PHANTOM ON 40 35 P 80 Hz P BY MANLEY LABS FILTER ON OFF 8 PHASE 180 0 +10 9 FILTER IMPEDANCE Ω 2M 2K INSTRUMENT 10M 1M 300K 300c 100K 11 40 45 TRIM 50 35 60 65 25 20 12 B 13 70 0 -2 55 30 3M 600 300 15 GAIN COOL CHANNEL 60 Hz 120 Hz FLAT P PHANTOM 3
BEGINNINGS At the 3D Preamp Summit, the topic of “vintagestyle” electronics came up, not because of huge desire from the engineers but more as a designer topic relating the headaches of recreating transformers and obsolete parts accurate enough to be comparable to the original.
The TNT was getting interesting. We now had a tube preamp from the SLAM! on one side plus two solid state preamps working together on the other side, and each of those 3 circuits had a unique sound or subtle flavor yet there was some common theme or style. The tube channel is based on a JFET / Vacuum Tube Triode cascode circuit that is quite unusual in that it is a blend of old and new components. The cascoded combination allows for high gain, low noise, and low distortion without using negative feedback.
Perhaps it is because those near opposite characters of the two circuits, that when combined or blended the audible benefits and strengths of each prevail, while the weaknesses of each are minimized. Of course, the better each circuit is optimized, the closer they tend to meet in the middle (transparency). Perhaps it is because the approach of respecting both voltage and current; it results in a form of optimal power transfer.
At very low impedance settings with dynamic and ribbon mics another effect can come into play. Damping is a term normally associated with speakers that refers to the fact that a dynamic speaker comes to rest faster and is better controlled when connected to a very low impedance amp. (It was one of the biggest selling-point features when early solid-state amps with tons of negative feedback first came out.
The Tube Channel The left side (T) or channel one, is almost an exact replica of the SLAM! Mic Preamplifier and audio path. The only differences are the addition of the Impedance switch and an additional shunt regulator on the phantom power. The latter reduces noise and provides a softer start & off with the phantom power switching – less thump and less chance of input transformer magnetization.
Tube Channel Continued If the transformer is driving some heavy resistive load like some piece of vintage gear still set up for 600 Ohms then you can expect some high frequency rolloff and maybe a shift in the distortion and clipping towards the tubes and away from the transformer.
Consider the singer, headphones on, and getting a blend of their voice through bone conduction and those phones. All too often there is something in the chain with a polarity problem and it is usually a vintage mic or the headphones, but can also be caused by a wiring mistake or a power amp.
THE COOL CHANNEL Solid State or Right Channel The No Tubes side of the TNT gives you a range of colors and might even be considered a contrast to the Tube side. Or maybe not. If one has strong ideas that tubes and transistors sound vastly different then the TNT might be a little unsettling. For what it is worth, both the Tube side and Solid State side of the TNT are pretty clean representatives of their technologies.
The Impedance switch also has markings on the right hand side that are for the INSTRUMENT input only. How a magnetic pick-up reacts somewhat depends on the impedance it is driving. This effect is diluted because most guitars and basses have those volume and tone controls that pretty much set the maximum impedance the pickup will ‘see’. The pickups also have to drive a length of cable, which often has appreciable capacitance and may roll off some highs.
Any particular tips using the NT channel? Techniques specific to the solid-state side of the TNT are not daunting. Most likely the first thing to get your attention will be the LED metering because it is a bit unusual. The two bottom LEDs show the first few stages of the preamps or what is going on with the stepped gain switch, but BEFORE the Gain Trim knob. The top two LEDs show that Gain Trim Knob and the final output. The bottom GREEN LED shows “SIGNAL PRESENT”.
Like most mic preamps, the TNT has high-pass filters to remove unwanted low frequencies. The most common situations to use it is for vocals to minimize “pops”, wind noise, and air conditioning rumble or leakage, or for sounds that have little low frequency information anyway, like acoustic guitar or high hats. The basic idea is removing the garbage before it gets recorded.
The IRON knob may disappoint some who expect a radical and obvious effect. It can be subtle, especially for mid-range dominant sounds like vocals and guitars because, for the most part, a transformer affects the extreme lows, extreme highs, and to some degree the dynamics. This control is build around the actual output transformer and, lets face it, a good audio transformer shouldn’t be particularly colored and messy.
The ¼” transformerless output has a switch on the back panel that allows it to PROPERLY drive +4 dBm balanced inputs, +4 dBm (pin 2 hot) unbalanced inputs (rare enough), and –10 dBu unbalanced inputs. In each case, a very stable and very low output impedance is given that does not suffer and cause common mode rejection problems when driving less than perfect cables and inputs.
TROUBLESHOOTING There are a number of possible symptoms of something not quite right; some may be interfacing, others we will touch on as well. If you suspect a problem, the following paragraphs should help. NO POWER, NO INDICATORS, NADA - Probably something to do with AC power. Is it plugged in? Check the fuse on the back panel. A blown fuse often looks blackened inside or the little wire inside looks broken or it’s resistance measures higher than 2 ohms.
Audio Precision 06/26/06 18:06:03 TUBE CHANNEL DISTORTION FFT -20 -30 -40 -50 -60 -70 -80 d B -90 -100 -110 -120 -130 -140 -150 -160 2k 4k 6k 8k 10k 12k 14k 16k Hz FFT SPECTRUM of THD Residual @ 1kHz Audio Precision TUBE CHANNEL DRIVEN JUST 2 dB HOTTER 06/26/06 17:55:11 -20 -30 -40 -50 -60 -70 -80 d B -90 -100 -110 -120 -130 -140 -150 -160 2k 4k 6k 8k 10k 12k 14k The TOP graph shows the distortion harmonics just prior to full clipping.
60s Switch ONSET OF DISTORTION SPECTRUM -20 -30 -40 -50 -60 -70 -80 -90 -100 -110 -120 -130 -140 -150 -160 2k 4k 6k 8k 10k 12k 16k 14k 70s Switch ONSET OF DISTORTION SPECTRUM -20 -30 -40 -50 -60 -70 -80 -90 -100 -110 -120 -130 -140 -150 -160 2k 4k 6k 8k 10k 12k 16k 14k 60s - 70s SWITCH FREQUENCY RESPONSE AT VARIOUS GAINS & COMPENSATED with TRIM POT +10 +8 +6 +4 +2 60 -5dB +0 70 -5dB -2 70 0dB 60 -4 0d B 70 0d +1 -6 B -8 60 +10dB -10 20 50 100 200 500 1k Hz 2k 5k 10k
COOL CHANNEL Gain Switch @ 20, Gain Trim @ 0. 4x IRON SETTINGS + BYPASS THD+N Ampl vs AMPLITUDE at 25 Hz 100 50 T 20 IRON +3 10 5 2 1 % 0.5 0.2 IRON 0 IRON 1 0.1 0.05 0.02 IRON -1 0.01 -15 -10 -5 +0 INPUT LEVEL. (CLIP) 0.003 -20 1/4” OUT dBV +5 +10 +20 (SAT) TUBE CHANNEL THD+N Ampl vs AMPLITUDE +15 100 50 20 25HZ 1/4” 10 5 2 % 1K 1/4” IRON DIP3 1 0.5 0.2 0.1 TRAN 0.05 0.02 0.01 0.
COOL CHANNEL IMPEDANCE SWITCH RELATIVE LEVELS 5 4 +3 dB 3 2 2M 1 2K 600 0 -1 0 50 150 250 600 300 300C -2 -3 dB -3 -4 -5 Microphone Output Impedances The middle horizontal line suggests a range of typical microphone output impedances. For example, many mics are approximately 150 ohms, so for those, changing the TNT Cool Channel Impedance switch alters the level by 2.5dB going from the highest setting to the lowest.
MAINS CONNECTIONS Your TNT has been factory set to the correct mains voltage for your country. The voltage setting is marked on the serial badge, located on the rear panel. Check that this complies with your local supply. Export units for certain markets have a moulded mains plug fitted to comply with local requirements. If your unit does not have a plug fitted the colored wires should be connected to the appropriate plug terminals in accordance with the following code.
SPECIFICATIONS TUBE CHANNEL (Left Channel) GAIN RANGE MIC INPUT IMPEDANCE INSTRUMENT INPUT IMPEDANCE +10 dB to +80 dB (20-70dB in 5 dB steps) 600, 2400, 10,000 Ohms 300K,1Meg, 3 Meg Ohms FREQUENCY RESPONSE 10 Hz to 30 kHz 5 Hz to 45 kHz .
P 0 TRIM B +2 +10 +2 +10 +4 +6 +8 +4 +6 +8 +4 +6 +8 PHANTOM ON OFF PHASE 0 180 FILTER 60 Hz 120 Hz FLAT INSTRUMENT COOL CHANNEL 1M 300K 100K 10M 3M INSTRUMENT INSTRUMENT COOL CHANNEL 1M 300K 100K 10M 3M COOL CHANNEL 1M 300K 100K 10M 3M IMPEDANCE Ω 2M 2K 600 300 300c PRODUCER INSTRUMENT FILTER MICROPHONE 600 300 300c 2M 2K IMPEDANCE Ω 60 Hz 120 Hz FLAT POSITION PHANTOM ON OFF PHASE 180 0 PRODUCER INSTRUMENT FILTER MICROPHONE 600 300 300c 2M 2K IMPEDANCE Ω 60 Hz 12
