How to access a GUI element in an instantiated prefab?

Hi,

I have created a Prefab which contains a slider, for example sliderResonance. Now, when I instantiate the Prefab from code, I cannot find a way to access each individual sliderResonance and set its value from code.

You can think of this application as collection of softsynths; I want to create several identical "musical instruments", each which can play their own sounds. The user shall be able to load many of these, thats why I instantiate them from code.

Now, another part of the application, the sequencer, needs to be able to access and modify any of these sliders individually.

Example code:

 public class TB1 : MonoBehaviour {
 
     public Transform Synth1;          // This is the Prefab, which works as expected when alone    
 
     void Start()
     {
         Instantiate(Synth1, canvas[canvasApp].transform, false);
         Synth1.transform.localScale = new Vector3(1, 1, 1);
         Synth1.transform.localPosition = new Vector3(0, -334, 0);
 
         Instantiate(Synth1, canvas[canvasApp].transform, false);
         Synth1.transform.localScale = new Vector3(1, 1, 1);
         Synth1.transform.localPosition = new Vector3(0, -1000, 0);
     }
 
 }

Now the above seems to work fine; the Prefabs are loaded into the game, and they work as expected. BUT when I try to access the sliders, see code below, only one (random) gets accessed, I guess it is because they have the exact same name, since they are instances of the same Prefab:

    Slider test1 = Synth1.Find("sliderResonance");
    test1.value = 50;

How on Earth do I access a specific one??? Sorry for being quite new at this; all help is appreciated.