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TROUBLE-SHOOTING

 

There are a number of possible symptoms of something not quite right, some may be interfacing, others we will touch 

on as well. No need to panic. We have sold hundreds of these units and barely any have ever had a problem with hum or inter-
facing to other gear. However, 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. A very blackened fuse is a big hint 
that a short occured. Try replacing the fuse with a good one of the same value and size. If it blows too then prepare to send the 
unit back to the dealer or factory for repair. The fuse is a protection device and it should blow if there is a problem. If the unit 
works with a new fuse, fine. Check the MAINS VOLTAGE SELECTOR if one is fitted. Some of our models are able to have 
them and some don’t. It should be set correctly for your mains voltage. 

LIGHTS BUT NO SOUND 

- First try plugging the in and out cables into some other piece of gear to verify that your wires 

are OK. Next check the front panel, try BYPASS. If you have sound now it might be a good idea to turn up the output levels to 
about 1 o’clock (rather than fully counterclockwise which is “minus infinity”. The XLR inputs and outputs are transformer bal-
anced and floating. “Floating” refers to a very useful feature of transformers where they can be used without a ground reference 
- this prevents ground loops before they happen rather than electronically cancel them. It does require that both PIN 2 and PIN 
3 be connected (but not to each other). To interface to unbalanced units you should connect PIN 3 to Ground or PIN 1. Brain-
less solution - use the 1/4” unbalanced inputs and outputs to interface to unbalanced gear. 

LEVELS SEEM TO BE WRONG, NO BOTTOM 

- Several possible scenarios. Manley uses the professional standard of +4 

dBm = Zero VU = 1.23 volts AC RMS. A lot of semi-pro gear uses the hi-fi reference of -10 dBm = Zero VU. This is a 14 dB 
difference that will certainly look goofy and may tend to distort. Often there are switches on the semi-pro gear to choose the 
pro reference level. We do not provide that kind of switch because of inevitable compromises in the signal path. If the loss 
looks close to 6 dB and it sounds thin then one half of the signal is lost. The cause is probably wiring again. One of the two 
signal carrying wires (the third is ground / shield on pin 1) is not happening. Check the cables carefully because occasionally 
a cable gets modified to work with a certain unit and it seems to work but its wrong in other situations. If only one side of the 
Limiter exhibits this problem, it may be a problem in the Limiter. See the next item. 

ONE SIDE WORKS FINE BUT THE OTHER SIDE IS DEAD

 - Let’s assume this is not wiring. We are pretty sure it is the 

Limiter. If it were solid state you would generally send it back for repair. Being a tube unit, you can probably find the prob-
lem and fix it in a few minutes. Not too many years ago, people could “fix” their own stuff by taking a bag of tubes down to 
the corner and checking said tubes on a tube tester. These are practically extinct but no prob’. Most Manley gear is two chan-
nel, meaning you can swap tubes to determine the bad boy. Do two at a time just watching that they are the same number. Be 
careful - there are some high voltages inside the chassis and tubes can get pretty warm, but if you can replace a light bulb you 
should be able to cruise through this. Before you remove a tube, just take a look at them powered up. They should glow a bit 
and they should be warm. If one is not, you have already found the problem. The tube’s filament (heater) is burnt out or broken 
like a dead light bulb. The other big visual symptom is a tube that has turned milky white - that indicates air has gotten into the 
tube, or “the vacuum leaked out”. Either way, replace the tube. Call us, or look for a tube supplier on the internet. Manley can 
ship you a tested one. Back to swapping - before you pull a tube, pull the power out, let the unit sit and cool and discharge for 
a minute or two, then swap, then power, then check. Gentle with those tubes, don’t bend the pins by trying to insert them not 
quite right. A little rocking of them as you pull them out or put them in helps. When the problem follows the tube you found 
the problem - a bad tube. No soldering, no meters, one screwdriver - easy. 

HUM

 - Let’s assume it knows the words. Once again - several possibilities - several cures. Most likely it is a ground loop. 

The two most common procedures are: try a 3 pin to 2 pin AC adapter (about a dollar at the hardware store) which is better 
than messing up the power cable by bending the ground pin until it breaks off. Method two - cutting the shield on one side of 
the cable (PIN 1). This is done by some studios at every  female XLR to “break” all  loops. You may get a loop simply from 
the rack. All the other gear in the rack is “dumping” ground noise onto the rack rails. Try removing the ELOP

®

 from the rack 

so that it is not touching any metal. You may have cured a non-loop hum. Some gear radiates a magnetic field and some gear 
(especially if it has transformers) might receive that hum. A little distance was all it took. A cool method of reducing all sorts of 
hum and noise is to use the new 60-0-60 balanced AC power transformers available from Equi=Tech and Furman. It costs more 
but works best. Hum is more likely with the unbalanced inputs and outputs because these signals are ground referenced. A 
common situation is using the limiter in a way that significantly boosts the low level signals and what may have started out as a 
little hum becomes nasty. Check out the gear feeding the Manley or use less limiting and make-up gain. 

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Summary of Contents for TUBES RULE ELOP

Page 1: ...THE ELOP OWNERS MANUAL TUBES RULE 3 31 11cd...

Page 2: ...TS SECTION PAGE INTRODUCTION 3 FRONT PANEL 4 REAR PANEL 5 OPERATION NOTES 6 ADVANCED TRICKS 8 MAINS CONNECTIONS 9 TROUBLE SHOOTING 10 INTERNAL ADJUSTMENTS 12 SPECIFICATIONS 13 TEMPLATE FOR USER SETTIN...

Page 3: ...te the photo resistor with an LED rather than electro luminescent elements which are often slow and unreliable We also use a solid state side chain to drive the LEDs The Limiter also features a BYPASS...

Page 4: ...e This prevents image shifts and an instrument should stay where you panned them Limiting individual sounds is usually done with the switch down where each side is independent of the other E METER Sho...

Page 5: ...rsions of the ELOP were unbalanced only This version has both transformer floating balanced and unbalanced transformerless inputs The outputs are similar offering transformer floating bal anced XLR an...

Page 6: ...ther than copy UREI designs because frankly our circuit sounds better and cleaner Back to this matter with fixed time constants We get requests to modify our ELOP for more controls but we get even mor...

Page 7: ...riable time compressors which seem to give Opto units competition our Variable MU is at the top of that list Where the LA style limiters are not always appropriate is for percussion and for mixes wher...

Page 8: ...usly we pull out this trick when two tracks are stepping on each other and EQ isn t making enough room for clarity Trick 4 Drive the compressor from an AUX send and return it to a channel Once you hav...

Page 9: ...voltage at which it will operate 100 120V Operation Uses a 1A MDL SLO BLO fuse 220 240V Operation Uses a 0 5A MDL SLO BLO fuse Waste Electrical and Electronic Equipment WEEE Information for customers...

Page 10: ...E SIDE WORKS FINE BUT THE OTHER SIDE IS DEAD Let s assume this is not wiring We are pretty sure it is the Limiter If it were solid state you would generally send it back for repair Being a tube unit y...

Page 11: ...er gear is doing worse you just haven t found out yet Your unit will have been factory calibrated and tested twice before you received it Sometimes parts drift a bit in value over the years or you hav...

Page 12: ...de to reflect the actual gain reduction accurately You will probably need to increase the oscillator 10 dB to get Limiting Switch from BYPASS to IN Me ter switches to OUTPUT Adjust GAIN controls to ge...

Page 13: ...units after serial number MELOP B716 shipped after 6 2003 use yellow LED lighting Meters switch to read OUTPUT or REDUCTION STEREO LINK Side Chain High Pass Filter 100Hz or 200Hz THD Noise 1kHz 4 dBm...

Page 14: ...NK STEREO IN BYPASS GAIN REDUCTION TEMPLATE FOR MANLEY ELECTRO OPTICAL LEVELLING AMPLIFIER PHOTO COPY THIS PAGE AND STORE YOUR SETTINGS WITH THE TAPES OR OTHER SESSION NOTES LEVELLING AMPLIFIER ELECTR...

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