diff --git a/src/reskit/soundtrack/engines/echo/engine.rs b/src/reskit/soundtrack/engines/echo/engine.rs
index 192881e..6178f61 100644
--- a/src/reskit/soundtrack/engines/echo/engine.rs
+++ b/src/reskit/soundtrack/engines/echo/engine.rs
@@ -1,5 +1,4 @@
-use std::{collections::{HashMap, HashSet}, error::Error, cmp::{min, max}};
-use linked_hash_map::LinkedHashMap;
+use std::{collections::HashSet, error::Error, cmp::{min, max}};
 use linked_hash_set::LinkedHashSet;
 use crate::reskit::{soundtrack::types::{PatternRow, Note, Channel, OctaveFrequency, Effect, Instrument, NoiseType, DcsgChannelMode, InstrumentType, CombinedAssets, Sample}, utility::print_warning};
 
@@ -63,11 +62,10 @@ const ESF_SEMITONE_B: u8        = 11;
 struct InstrumentSet<'a> {
     fm_ids: HashSet<u16>,
     psg_ids: HashSet<u16>,
-    module_set: &'a Vec<Instrument>,
-    total_set: &'a Vec<Instrument>,
+    module_instruments: &'a Vec<Instrument>,
+    total_instruments: &'a Vec<Instrument>,
     module_samples: &'a Vec<Sample>,
-    total_samples: &'a Vec<Sample>,
-    default_psg_id: Option<u16>
+    total_samples: &'a Vec<Sample>
 }
 
 pub type EchoEvent = Vec<u8>;
@@ -313,10 +311,10 @@ fn get_events_for_channel( channels: &mut [Channel], active_channel: usize, row:
             invalid_channel => return Err( format!( "internal error: get_events_for_channel: invalid channel {:#04X}", invalid_channel ) )?
         };
 
-        // Hop one layer of indirection from `instrument` by getting it from instrument_set.module_set,
-        // then finding the index of that instrument in instrument_set.total_set.
-        let original_instrument = &asset_set.module_set[ *instrument as usize ];
-        let instrument = asset_set.total_set.iter().position( | instrument | instrument == original_instrument ).ok_or( "internal error: could not locate instrument in combined instrument set" )?;
+        // Hop one layer of indirection from `instrument` by getting it from instrument_set.module_instruments,
+        // then finding the index of that instrument in instrument_set.total_instruments.
+        let original_instrument = &asset_set.module_instruments[ *instrument as usize ];
+        let instrument = asset_set.total_instruments.iter().position( | instrument | instrument == original_instrument ).ok_or( "internal error: could not locate instrument in combined instrument set" )?;
 
         // Do not set the same instrument if it was already set before
         if &channels[ active_channel ].active_instrument != &Some( instrument as u16 ) {
@@ -330,7 +328,12 @@ fn get_events_for_channel( channels: &mut [Channel], active_channel: usize, row:
                     print_warning( "this is a psg channel, seting the default psg instrument so your note can still play..." );
                     if row.note.is_some() {
                         // Set "__reskit_default_psg_instrument"
-                        let instrument = asset_set.default_psg_id.ok_or( "internal error: no default psg instrument to apply" )?;
+                        let default_psg_id = if let Some( position ) = asset_set.total_instruments.iter().position( | item | item.name == "__reskit_default_psg_instrument" ) {
+                            Some( position as u16 )
+                        } else {
+                            None
+                        };
+                        let instrument = default_psg_id.ok_or( "internal error: no default psg instrument to apply" )?;
 
                         events.push( vec![ ESF_SET_INSTRUMENT | channels[ active_channel ].id, instrument as u8 ] );
                         channels[ active_channel ].active_instrument = Some( instrument );
@@ -344,7 +347,12 @@ fn get_events_for_channel( channels: &mut [Channel], active_channel: usize, row:
         if channels[ active_channel ].active_instrument.is_none() && ( ESF_PSG_1..=ESF_PSG_4 ).contains( &channels[ active_channel ].id ) {
             if row.note.is_some() {
                 // Set "__reskit_default_psg_instrument"
-                let instrument = asset_set.default_psg_id.ok_or( "internal error: no default psg instrument to apply" )?;
+                let default_psg_id = if let Some( position ) = asset_set.total_instruments.iter().position( | item | item.name == "__reskit_default_psg_instrument" ) {
+                    Some( position as u16 )
+                } else {
+                    None
+                };
+                let instrument = default_psg_id.ok_or( "internal error: no default psg instrument to apply" )?;
 
                 events.push( vec![ ESF_SET_INSTRUMENT | channels[ active_channel ].id, instrument as u8 ] );
                 channels[ active_channel ].active_instrument = Some( instrument );
@@ -391,7 +399,7 @@ fn get_events_for_channel( channels: &mut [Channel], active_channel: usize, row:
 
                     // Remember, instruments will always be listed first in the output source file, followed by pointers to samples
                     // So the minimum sample offset is the number of instruments
-                    events.push( vec![ ESF_NOTE_ON | channels[ active_channel ].id, global_sample_index as u8 + asset_set.total_set.len() as u8 ] );
+                    events.push( vec![ ESF_NOTE_ON | channels[ active_channel ].id, global_sample_index as u8 + asset_set.total_instruments.len() as u8 ] );
                 }
             } else if channels[ active_channel ].id == ESF_PSG_4 {
                 // Find the single (and it should only ever be a single) Effect::DcsgNoiseMode attached to the channel
@@ -832,20 +840,8 @@ fn get_delays( events: Vec<EchoEvent>, channels: &mut [Channel], ticks_to_wait:
 pub fn get_events_for_row( channels: &mut [Channel], module_instruments: &Vec<Instrument>, module_samples: &Vec<Sample>, asset_set: &CombinedAssets, subrows: Vec<&PatternRow>, ticks_to_wait: u8 ) -> Result<Vec<EchoEvent>, Box<dyn Error>> {
     let mut events: Vec<EchoEvent> = Vec::new();
 
-    let mut index = 0;
-
-    // Find the index of the default psg instrument, if it exists
-    let default_psg_id: Option<u16> = module_instruments.iter().find_map( | item | {
-        if item.name == "__reskit_default_psg_instrument" {
-            Some( index )
-        } else {
-            index += 1;
-            None
-        }
-    } );
-
     // Generate InstrumentSet which is used to validate when instruments are set on channels
-    index = 0;
+    let mut index = 0;
     let fm_ids = module_instruments.iter()
                             .filter_map( | instrument | if matches!( instrument.instrument_type, InstrumentType::Fm2612( _ ) ) {
                                 let result = index;
@@ -872,11 +868,10 @@ pub fn get_events_for_row( channels: &mut [Channel], module_instruments: &Vec<In
     let instrument_set = InstrumentSet {
         fm_ids,
         psg_ids,
-        module_set: module_instruments,
-        total_set: &asset_set.instruments,
+        module_instruments,
+        total_instruments: &asset_set.instruments,
         module_samples,
-        total_samples: &asset_set.samples,
-        default_psg_id
+        total_samples: &asset_set.samples
     };
 
     // Get events for each subrow (part of the total row for each channel)