2 Recapped Refurb'd dbx 303 Cards Marshall Time Modulator, Tape Eliminator. DM

Matched set of two Refurbished dbx 303 Cards for Marshall Time Modulator, Tape Eliminator, and Eventide H910 / H949 Harmonizers.

These cards were used in the Eventide H910 / H949 , Marshall Time Modulators, Marshall Tape Eliminators, and other products. Many times when these products fail, the dbx cards in the units are faulty.

This listing is for a set of TWO cards. For Eventide models we also have sets of three cards (one encode, two decode) available in a separate listing.

Most of these dbx, Eventide, and Marshall models used dbx 303 Type A cards -- these are the early version (identified by the 4 vertical trimpots on each card) and they are very unreliable. When we encounter gear with these older cards, we dispose of them and install later version cards like the ones in this listing.

This card set is the result of a service regimen that we have developed for servicing Eventide and Marshall gear. The cards for sale have been recapped, fully serviced and calibrated, adjusted for minimum distortion, and grouped in matched sets of 2 for Marshall models. This is a very labor intensive process.

For Marshall Time Modulators and Tape Eliminators, one card is used for the input (encode) and one card is used for the output (decode). The photo shows 2 typical cards. When we test and QC these cards we mark then ENCODE or DECODE for best matching. The cards you receive from us may differ slightly in appearance, and may be Rev. B, C, or E cards, but they will be exact replacement cards, in excellent condition.

If you’re a DIY’er, you’ll need to study a schematic to understand jumpering and options for the use of these cards. All connections are via a 12 male Molex pins. The card requires +/- 15 volts DC. The dbx system has the capability of doubling dynamic range in outboard gear and recording systems. If you have an analog system with a dynamic range of 40 db, the dbx system will increase it to 80 db. Thanks to the ingenious RMS Detector circuit, accuracy of the dbx system does not require any kind of matching or precise calibration of encode and decode levels. We will include schematics upon request.

Note: these cards were designed by dbx to be used in noise reduction systems for tape recording. Stephen St. Croix of Marshall Electronics developed an improvement for these cards that optimized the VCA filters and RMS Detector pre-emphasis circuits for use in outboard gear. This 303 card version was used in all Marshall Time Modulators and Tape Eliminators. These updated cards work great in Eventide gear but can't be mixed with original Eventide 303 cards. If you';re replacing cards in an Eventide product you'll need to replace all 3 at the same time.

These cards sets include a service bulletin with background info and install tips, and a sheet that identifies all the calibration trimmers. If you also want a copy of the schematic, please request it when you order.