Only about 250 EMT 250 units were ever built, each priced at $20,000 in 1976, and five of its six programs are not reverb. Most people load the plug-in, find the reverb, and stop there. The other five are where the box gets strange.
The four levers are stepped rather than continuous, which is a modeling decision and not a shortcoming. In reverb, lever one moves decay from 0.4 to 4.5 seconds across 16 fixed positions. Lever four gives predelay in exactly four values, at 0, 20, 40, and 60 milliseconds. That stepping carries into every program.
There is also a Noise toggle, and it is worth leaving on. It models the hardware's own noise floor, which is a large part of why the original never sounded like a clean modern reverb. The dry and wet control covers the full span from 0 to 100 percent, with wet solo there when you want the return alone.
Echo is monophonic, and it feeds back. Coarse time covers the same 0 to 300 millisecond span, and the fine lever adds the same 5 millisecond increments. Lever three switches job entirely and becomes high-frequency decay, with multipliers of x0.25, x0.33, x0.5 and max. That is how you get echo repeats that darken as they decay.
Running six programs across several tracks used to mean rationing DSP, and the 250 turning up as a native plug-in removes that arithmetic. Put echo on one guitar and delay on another. Nothing competes for a card.
Chorus is even more restrained. Lever three offers four variations, labeled I through IV, and that is close to the entire control set. You pick a number, you listen, you move on. It works better on electric piano and clean guitar than on anything with strong transients.
Both programs sum to mono when the front and rear switch sits in the rear position. That matters if you are checking a mix for mono compatibility. Comb filtering is exactly the kind of processing that falls apart when a stereo return collapses. Check it before you commit, not after.
In phase mode, it flips the phase of the comb filter, which gives you two distinct tones from one lever position. In echo, it mutes the input. That last one is the most useful. Muting the input while the feedback keeps running lets you freeze a tail and let it fade out alone.
Space is the program worth knowing about if you write anything ambient. It extends the reverb algorithm to roughly a 10-second decay, well past the 4.5-second ceiling in the standard reverb program. Lever four still limits predelay to 60 milliseconds, so the long tail arrives close behind the source rather than hanging back.
Back in reverb mode, levers two and three shape the tail by ratio instead of by frequency. Lever two multiplies low-frequency decay by 0.5, 1.0, 1.5 or 2.0 against the main decay time. Lever three does the same for high frequencies at 0.25, 0.33, 0.5, or max, measured at 6 kHz. Set a 2-second decay with the low multiplier at 2.0 and the high at 0.25. The bottom of the tail then outlasts the top by a factor of eight.
The four levers are stepped rather than continuous, which is a modeling decision and not a shortcoming. In reverb, lever one moves decay from 0.4 to 4.5 seconds across 16 fixed positions. Lever four gives predelay in exactly four values, at 0, 20, 40, and 60 milliseconds. That stepping carries into every program.
There is also a Noise toggle, and it is worth leaving on. It models the hardware's own noise floor, which is a large part of why the original never sounded like a clean modern reverb. The dry and wet control covers the full span from 0 to 100 percent, with wet solo there when you want the return alone.
The delay and echo programs work in opposite directions
Delay mode gives you two independent delay processors, one per channel. Lever one sets coarse time from 0 to 300 milliseconds in 16 steps. Lever two adds a fine offset of 0, 5, 10, or 15 milliseconds, and lever three decides which channel you are editing. Set the left side to 90 milliseconds and the right to 105, and you have a stereo spread no preset will hand you.Echo is monophonic, and it feeds back. Coarse time covers the same 0 to 300 millisecond span, and the fine lever adds the same 5 millisecond increments. Lever three switches job entirely and becomes high-frequency decay, with multipliers of x0.25, x0.33, x0.5 and max. That is how you get echo repeats that darken as they decay.
Running six programs across several tracks used to mean rationing DSP, and the 250 turning up as a native plug-in removes that arithmetic. Put echo on one guitar and delay on another. Nothing competes for a card.
Chorus and phase give you four positions and little else
Phase mode builds a comb filter by shifting the signal against itself. Lever one sets that shift from 0 to 15 milliseconds across 16 steps, and lever four still handles predelay. The rest of the front panel goes quiet. Short shifts give you the hollow, notched sound, and longer ones start to double the source instead.Chorus is even more restrained. Lever three offers four variations, labeled I through IV, and that is close to the entire control set. You pick a number, you listen, you move on. It works better on electric piano and clean guitar than on anything with strong transients.
Both programs sum to mono when the front and rear switch sits in the rear position. That matters if you are checking a mix for mono compatibility. Comb filtering is exactly the kind of processing that falls apart when a stereo return collapses. Check it before you commit, not after.
The front and rear switch changes meaning in every program
That switch is the least documented control on the panel, and it does something different in all six programs. In reverb and space, it selects between output pairs, a leftover from the original's one input and four output design. In delay and chorus, it sums the return to mono.In phase mode, it flips the phase of the comb filter, which gives you two distinct tones from one lever position. In echo, it mutes the input. That last one is the most useful. Muting the input while the feedback keeps running lets you freeze a tail and let it fade out alone.
Space is the program worth knowing about if you write anything ambient. It extends the reverb algorithm to roughly a 10-second decay, well past the 4.5-second ceiling in the standard reverb program. Lever four still limits predelay to 60 milliseconds, so the long tail arrives close behind the source rather than hanging back.
Back in reverb mode, levers two and three shape the tail by ratio instead of by frequency. Lever two multiplies low-frequency decay by 0.5, 1.0, 1.5 or 2.0 against the main decay time. Lever three does the same for high frequencies at 0.25, 0.33, 0.5, or max, measured at 6 kHz. Set a 2-second decay with the low multiplier at 2.0 and the high at 0.25. The bottom of the tail then outlasts the top by a factor of eight.
