MANLEY LABORATORIES, INC. THE MAHI OWNER'S MANUAL TUBES RULE brought to you by the clever folks at: MANLEY LABORATORIES, INC. 13880 MAGNOLIA AVE. CHINO, CA. 91710 USA TEL: (909) 627-4256 FAX: (909) 628-2482 email: emanley@manleylabs.com website: www.manleylabs.
CONTENTS SECTION PAGE INTRODUCTION 3 MAINS CONNECTIONS 4 GETTING STARTED 5 MOVING RIGHT ALONG 6 LEARNING ABOUT TUBES 7 BIASING YOUR AMPLIFIERS 8 SIMPLE TROUBLESHOOTING 9 REPLACING A TUBE OR LAMP OR FUSE 10 TUBE FAQ 11 MORE SILLY VACUUM TUBE QUESTIONS 12 OPTIMIZING YOUR SOUND SYSTEM 13 & 14 CREDITS 15 SPECIFICATIONS 16 WARRANTY 17 WARRANTY REGISTRATION 18 2
INTRODUCTION THANK YOU!... for choosing the Manley MAHI monoblock amplifiers for your loudspeaker driving requirements. You have possibly chosen this product because you auditioned it in a store or heard it at a hi-fi show and were impressed with the sound. It may have been the right combination of price, power, features and styling for you. It may have been because you know the Manley Labs reputation for quality, reliability, and integrity.
MAINS CONNECTIONS Your MAHI's have been factory set to the correct mains voltage for your country. (Well, that is what we intended to do when we knew where they would be initially shipped.) The mains voltage that we built these MAHI's to operate with is marked on the serial badge, located on the rear of the chassis. Check that this complies with what comes out of your wall.
GETTING STARTED PREPARATION FOR INSTALLATION Budget a suitable space in which to place the amplifiers and associated interconnect and mains power cables. This space should be free of strong external magnetic and RF fields, and reasonably removed from strong loudspeaker-generated acoustical fields. This space should also be free of excessive heat or dust and large enough to permit easy flow of cool air to the top, bottom and sides of the amps.
MOVING RIGHT ALONG... NOW THAT YOU HAVE ALL YOUR CABLES PLUGGED IN, you may now connect the IEC power cord to the MAHI and to an energized power outlet. (Unless you live in California and are in the middle of a Rolling Greyout®™.) Fire up all your upstream devices first: sources, preamplifier, and such and allow them all to finish their turn-on cycles so your MAHI will not be amplifying any of their waking-up noises.
While we're at it, and since this is a TUBE Amplifier, let's TAWK about TUBES: As with all tubes, certain parameters degrade with age. This is due to decreasing cathode emission, a natural process found in all tubes. There are just so many electrons on that cathode and one day, they will have all jumped off. An excessive increase in noise level or very unstable output tube bias can indicate the need to replace a tube.
BIASING YOUR AMPLIFIERS DON'T WORRY! IT IS SUPER-EASY! Convenient test points for checking the standing current of each EL84 output tube is available on the top of the chassis, near the output tubes. The test points are connected to each tube’s 10-ohm cathode resistor (inside). Everything is clearly labelled on the chassis because we know you guys are prone to throwing away informative Owner's Manuals. Tube bias is a frequent source of confusion and misinformation, especially as it pertains to output tubes.
TROUBLESHOOTING Here are some suggestions to try out in the event you encounter some of the symptoms below. If you encounter some other symptoms, then maybe you have some other problems that we don't know about. HUM: Forgot the words. Try a mains ground adapter if they are legal in your country. They are also called 3 pin to 2 pin adapters or “cheaters” and are available in hardware stores. There should be one ground in your system and only one.
MAINS FUSE: If this has blown, A Very Bad Thing has occurred. See page 3. B+ FUSE: The B+ fuseholder is located on the rear chassis near the speaker binding posts. If all of the sardine NONE of the tubes show any bias reading at all, and the lights are on, and no tunes will play, you might have popped a B+ fuse. This fuse is here to protect the output transformer from a rogue tube or some other strange event.
TUBE FAQ A few general all-too-frequently-asked vacuum tube questions from the manleylabs.com FAQ as found on our website are answered here in case you don't have internet access (which we don't doubt because after all you bought vacuum tube amplifiers, didn't you?): (Don't take that comment personally. EveAnna still drives air-cooled Volkswagons... We're not perfect either.) FAQ #16. Do you sell tubes? I don’t know what you’re talking about. FAQ #16a. I need to retube my Manley amplifier.
More silly vacuum tube questions... FAQ #16f. Should I turn off my gear between uses? While power cycling is a factor for ultimate tube life, there also is a fixed number of electrons that can ultimately jump off the cathode. In general we do recommend if you aren’t using the gear for more than a few hours you should power it down. Do you leave the lights on in your house when you are away? FAQ #16g. But it sounds different when you first turn it back on.
Optimising Your Sound System This section is full of Hutch's little hints that may help you get the most out of your stereo - and it may not cost anything or cost very little. Probably, you know most of this, but hopefully some of it may be new or refresh your memory or just be refreshing reading in a manual. A very important factor is your speakers. Hopefully you have good speakers and they are appropriate for your power amplifier.
More Helpful Hints from Hutch... You may have bought a great system but there is a good chance that you are only getting a fraction of its potential. Very frequently we have experienced top quality electronics sounding unimpressive simply because acoustics were ignored. Even amongst studio engineers, few can really tell the difference between good speakers in a bad room and bad speakers in a good room - but they all know good speakers in a good room and very likely so do you.
CREDITS MANLEY MAHI An EveAnna Manley Production Featuring concept, layout and industrial design by EveAnna Manley. Starring: Paul Fargo for Input Innovations Hutch for Output Outovations Mastered by: Baltazar Hernandez In keeping with our new tradition of naming fresh new Manley HIFI products after aquatic creatures, we set out to revisit the 50-ish watt monoblock idea to bring you the MAHI. From our collective creative brains issued forth all the clever circuitry and schematic design.
SPECIFICATIONS Input Impedance: 110 Kohm Input Sensitivity: TRIODE UL FB MIN: 175mV 155mV FB STD: 312mV 340mV FB MAX: 480mV 566mV Gain: 29dB Negative Feedback: MIN= 3dB; STD=6dB; MAX=10dB of global NFB Max. Output Power defined as power output reaching 1.5% THD @ 1KHz into 5 ohms: TRIODE UL FB MIN: 18W 20W FB STD: 27W 42W FB MAX: 28W 46W into 8 ohms: TRIODE UL FB MIN: 14W 24W FB STD: 24W 40W FB MAX: 25W 41W Signal to Noise Ratio Ref.
WARRANTY All Manley Laboratories equipment is covered by a limited warranty against defects in materials and workmanship for a period of 90 days from date of purchase to the original purchaser only. A further optional limited 5 year transferrable warranty is available upon proper registration of ownership within 30 days of date of first purchase.
WARRANTY REGISTRATION We ask, grovel and beg that you please fill out this registration form and send the bottom half to: MANLEY LABORATORIES REGISTRATION DEPARTMENT 13880 MAGNOLIA AVE. CHINO CA, 91710 USA Or you may FAX this form in to: +1 (909) 628-2482 or you may fill in the online warranty registration form found in the Tech Support section of our website www.manleylabs.
