Duocast questions

[ch ra]

Hi, I am ready to add the pots to my Duocast PCB but I have some questions before I get started.

Most important question--I'd like to test out the circuit before I wire the switches. That simplifies troubleshooting when something inevitably goes wrong. The problem is that I can't figure out what the second switch is doing--I can't really see any references to SW2. What does SW2 do in the circuit? Is there an easy way to test the circuit without fully wiring the switch--i.e., a jumper to keep the switch always on or always off.

Second, less important question: I couldn't find the recommended enclosure so I am gonna use a 1590XX. This means I have a lot of extra space to play with, but this raises some questions before I start drilling. I am thinking that I may be able to squeeze in a FET boost like an SHO right after or right before. Would that sound decent? Or how about a harmonic percolator? I have both PCBs built, so thinking that might be a good bet. But I am open to others. Please don't say, just try it--I probably will but if you have an idea of a small circuit that would do the trick that would be good to know.

Thanks!

 

[twebb6778]

According to the schematic SW2 activates the LED for the high gain mode. The other poles for this switch will bring the high gain trimpot into the circuit and determine which level control is active. To jumper you can use an alligator clip or just solder a lead between the pads.



I think a SHO would be awesome after this!

 

[Jbanks]

Hi, I am ready to add the pots to my Duocast PCB but I have some questions before I get started.

Most important question--I'd like to test out the circuit before I wire the switches. That simplifies troubleshooting when something inevitably goes wrong. The problem is that I can't figure out what the second switch is doing--I can't really see any references to SW2. What does SW2 do in the circuit? Is there an easy way to test the circuit without fully wiring the switch--i.e., a jumper to keep the switch always on or always off.

Second, less important question: I couldn't find the recommended enclosure so I am gonna use a 1590XX. This means I have a lot of extra space to play with, but this raises some questions before I start drilling. I am thinking that I may be able to squeeze in a FET boost like an SHO right after or right before. Would that sound decent? Or how about a harmonic percolator? I have both PCBs built, so thinking that might be a good bet. But I am open to others. Please don't say, just try it--I probably will but if you have an idea of a small circuit that would do the trick that would be good to know.

Thanks!

I think a 1590xx might be too shallow. The point of a 1590BBM is that it’s extra deep to house the transformer. Otherwise, it’ll be too shallow. 1590BBM is ~1.5” deep. 1590XX is 1.386” so it might be a little bit short.

 

[Jbanks]

I think a 1590xx might be too shallow. The point of a 1590BBM is that it’s extra deep to house the transformer. Otherwise, it’ll be too shallow. 1590BBM is ~1.5” deep. 1590XX is 1.386” so it might be a little bit short.

Stompboxparts.com and lovemyswitches.com both have BBM enclosures. I got a cool like green one. Also search for Gorva enclosures. Those are those sleek curved enclosures. Those will also be deep enough to house the transformer.

goof luck!

 

[zgrav]

you can search forums to see how others have used wires to move the transformer to another spot in the enclosure so it will fit in a shallower box. Not hard to do.

 

[ch ra]

I've tested the height w/a pot in place and height should not be a problem. I am using a substitute transformer, and maybe it is smaller than the one that is recommended. Maybe that was a mistake, but folks here and at DIYSB seemed to think it will work. We will see!

One vote for SHO after. Any other votes? Perhaps a Bazz Fuzz? or is output impedance too low for a fuzz to follow?

 

[ch ra]

According to the schematic SW2 activates the LED for the high gain mode. The other poles for this switch will bring the high gain trimpot into the circuit and determine which level control is active. To jumper you can use an alligator clip or just solder a lead between the pads.

View attachment 6999

I think a SHO would be awesome after this!

@twebb6778 I get it, so if I test out without SW2 wired at all, I should be fine, right? If I understand the schematic right, then without the switch there's no connections for the high gain elements.

 

[twebb6778]

@twebb6778 I get it, so if I test out without SW2 wired at all, I should be fine, right? If I understand the schematic right, then without the switch there's no connections for the high gain elements.

You can definitely test it without SW2 connected, just be aware that the 3PDT that switches between high/low gain also selects which level pot is being used.

I'd recommend shorting the middle leg of your Level 1 pot to the output if you're going to leave the switch out entirely.