ATMA-SPHERE MUSIC PREAMPLIFIER model MP-1 Mk. 3.2 OWNER'S MANUAL Please study this document carefully before using equipment RoHS © 2012 Atma-Sphere Music Systems Inc 1742 Selby Ave. St.
CONGRATULATIONS! You have purchased the world's finest preamplifier and certainly one of the most unique. It has seen over seventeen years of development and represents a level of performance that others will be struggling to achieve for years to come if for no other reason than we control the patents. At the time of this writing, it is the only fully balanced differential all-vacuum tube design in the world that also supports the 600 ohm standard.
LIMITED WARRANTY ON ATMA-SPHERE MUSIC SYSTEMS PRODUCTS This warranty on your ATMA-SPHERE MUSIC SYSTEMS product, which is distributed and warranted by ATMA-SPHERE MUSIC SYSTEMS, shall remain in effect for three (3) years from the date of consumer purchase, provided the enclosed registration form is completed and returned to ATMA-SPHERE MUSIC SYSTEMS within ten days of purchase. WHAT IS COVERED: Except as specified below, this warranty covers all defects in materials and workmanship.
MUSIC PREAMPLIFIER SETUP AND OPERATION Unpack the preamplifier and its power supply carefully. Save the shipping container for future shipment (replacements are $75.00). Warranty may be void if the unit is shipped in a different container. If you do not have a container, contact ATMA-SPHERE MUSIC SYSTEMS for a replacement. Normally the tubes are installed; the types are marked on the boards. During operation, the MP-1 gets warm. Adequate ventilation is mandatory.
OPERATING NOTES (continued) Due to the low impedance operation of the MP-1, cable quality between the preamplifier and power amplifier is considerably less important. You may hear differences in the cables, but they will be minor compared to the differences you may be used to hearing in single-ended cables. Thus we have no recommendation for cables to be used between the preamplifier and power amplifier. On the other hand, the input cables may be very critical, depending on the source.
High Level Hookup The auxiliary inputs are high impedance. Thus you may use any input as a source for the MP-1. A single-ended source can also be used, by applying the signal between pin 2 of the input XLR and pin 1 (ground). The unused pin three may have to be shorted to pin 1 to prevent noise. Pin 2 of all the XLR inputs is the non-inverting input, per industry standard. The tape outputs are high impedance. Use a high quality cable for best results, and keep the cable as short as possible.
TROUBLESHOOTING TIPS (continued) Distortion Check the output tubes (6SN7, upper right in diagram) and the associated 6SN7 in front for defects. If any of the output pins of the main output XLR connectors other than pin one is at ground potential, distortion may result. One or both channels out Check all tubes. If OK, there are two fuses located on the right side of the power supply circuit board (as you face the front of the unit), one for each channel. Replace with the same type slow blow fuse (.
USAGE SUGGESTIONS (continued) Most cartridges with more than 0.15mv seem to work fine. The higher the output the better, tempered with a musical presentation. Some recommended choices: The Grado Statement and Master Reference, Lyra series, ZYX and Micro Benz. There are of course many others. If a high output cartridge is used, a jumper plug that replaces one of the phono tubes can be installed to reduce gain. Contact Atma-Sphere for details.
WARRANTY REGISTRATION FORM IMPORTANT: This form must be filled out and returned to ATMA-SPHERE MUSIC SYSTEMS within 10 days of purchase to validate the warranty! Please type or print clearly.
