AMS RMX and DMX Repair and Service

Shipping your AMS to us for servicing

Typically, RMX or DMX units that we receive have at least one or two of these problems:

Why are multiple problems so common? In some cases a card failed, and a technician damaged a fragile ribbon cable or created some other problem while attempting a repair. A bad fan may cause components or cards to overheat and fail. A shorted card can take out a section of the power supply. In many cases a DMX or RMX stopped working, and was taken out of service for years -then while it sat on the shelf, other parts failed.

We begin by removing all the cards, cleaning and inspecting the chassis, cleaning all the edge connector sockets, cleaning all the contacts on the edge connectors, and replacing the main power supply capacitors. We then test the power supplies and fan, repairing any faults that are found. The foam stabilizers for the PC boards are replaced, if needed. After we confirm that the power supply voltages are ok we reinstall the cards, and install a new set of ribbon cables. The 5v fuse circuit is updated. About half the time, the unit now works. If it doesn't, we look for a bad circuit board. Frequently, more than one card is bad and in this case, replacing them with one at a time with good cards is not helpful. In this situation, we check your cards one by one in a working unit, to identify the bad ones.

The bad boards are replaced on a repair/exchange basis with spares we have on hand, and kept to be repaired another day. Faulty front panel controls are replaced, motherboard problems are repaired. (RMX's often have faulty front panel switches; we carry replacements.) The unit is thoroughly tested, and then kept running for several days for burn-in testing.

For early units, upgrades are available. Most DMX's can have up to 16 seconds of memory and can be fitted with lock-in (sampling), reverse playback, revised nudge editing, etc. Most DMX's can be fitted with an interface for MIDI, or the AMS Chorus Controller, which adds neat DMX functionality, and can interface to an Arp or Moog.

For RMX16's, we now offer a program upgrade that permanently installs all 17 of the original AMS reverb programs, in place of the original 9 programs. The 8 extra programs are Hall A1, Room A0, Room B1, Plate B1, Image P1, Reverse 2, Delay, and Freeze. They really sound good and add real functionality to the RMX16. (Until recently, only 3 of these programs could be installed and since they were stored in battery RAM, they were lost when the battery ran down.) The upgrade is $200. It is also available on our web store and can be installed by the user.

Does that sound simple or easy? We sure hope not, because it isn't! These units are extremely difficult to repair, and great caution must be used to avoid causing new problems. Repairing one faulty card can take hours.

What does it cost? Including new ribbon cables and power supply electrolytics, the base price for servicing a DMX is $860, an RMX is $750, payable in advance. If one or more bad cards are found or there are major power supply problems, the cost is typically $100-$300 more. Most DMX's run $860-$1100 to fully service. Servicing an RMX is usually $750-$1050. (With the RMX service we give you 3 extra reverb programs.) About 10% of the units we see have numerous problems that require several days of tech time to fully service; in these cases the repair bill can reach $1500 or more. Please note that all declined AMS repairs are subject to a $75 testing and evaluation fee. If you have any questions about repair costs or policies, please contact us.

If you have AMS that you might like to sell (in any condition) please drop us a line. We're always looking to buy old gear, for repair or spare parts. Thanks!