volume setups

[Bishop Vogue]

finally got a spring reverb working but as I am about to put it together, I am faced with some choices while making a mix/volume control.  seems to me there are several choices to make here: pre volume (fig 1), or post.  for post, I usually see the same kind of setup (fig 2), but i guess there's other options (fig 3).  To the experienced builders out there... what's the difference?



(hopefully the image is visible...)

[Bishop Vogue]

in case the image is not visible:

http://s1276.photobucket.com/user/BishopVogue/media/volquestion_zpsab021ef3.jpg.html?sort=3&o=0

[Bishop Vogue]

and one more try for an image (someone tell me how to post an image!)

http://www.aronnelson.com/gallery/main.php/v/Schematics-etc/vol+question.jpg.html

[antonis]

You have to copy the DIRECT link and embed it in the "insert image" icon...

[antonis]

In Fig.2 you have a voltage divider - you bleed some amount of signal to ground..

In Fig. 1 & 3 you have a variable resistor (trimmer) - you put resistance agaist your signal..

[Bishop Vogue]

Thanks for the reply.  I do understand the difference in terms of where voltage goes, but is the effect exactly the same. 

What is the advantage of fig 2 over fig 3.  There must be one, since this is the most common setup and I am sure most
people would love to eliminate a ground wire from their builds if they could.

[bluebunny]

and one more try for an image (someone tell me how to post an image!)

First of all, find somewhere reliable and accessible to host your image - imgur.com is great, it's dead easy and you don't need an account.  Then use the button like you did in your first post.  Put the URL to your image between the [img] and [/img] tags.  Voilà!  

BTW, the link you had in your last post was to an HTML page, not to an image, which is why nothing showed up.  Here's the URL to your picture and how it should have looked:

[img]http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=51802&g2_serialNumber=1[/img]

[bluebunny]

My bad.  Didn't read antonis' first reply!   

[ashcat_lt]

First of all, the reverb tank always adds noise.  I would think you'd generally want to maximize your S/N ratio by keeping the signal as big as possible through the spring, and put the V control after.  This way the noise is reduced as you turn it down.

Thanks for the reply.  I do understand the difference in terms of where voltage goes, but is the effect exactly the same. 

What is the advantage of fig 2 over fig 3.  There must be one, since this is the most common setup and I am sure most
people would love to eliminate a ground wire from their builds if they could.

Figure 2 is a voltage divider on its own.  Figure 3 is half of a voltage divider, and depends on some external impedance to actually work.  In practice, Figure 2 will go all the way down to 0, but figure 3 probably won't.