Sagan Delay v2.1 delay time

[Bio77]

I finished one of these up this weekend.  I was wondering about the sound.  Are long delay times possible out of this? Mine makes a really awesome sounding slap back and short delay sound, but long delay sounds are not there.  Is this how this circuit is meant to sound or do I have a problem?

[danfrank]

The 3 transistors on the delay board (Q2, Q3, Q4) have to be put in reverse. Turned 180 degrees  of what the PCB silkscreen shows. That's why the guys who came up with it say to solder in transistor sockets in the 3 places so you can reverse them. One way will give you super short delays, the other way the delays will be longer.
I didn't believe it at first as the transistors are opposite of what the schematic shows, but it does make the delays longer.
Anyone have an actual explanation why this happens???

[Bio77]

Thanks Dan, I just noticed this in the build docs. Guess I should read everything next time 

[Boba7]

Hey guys,
Just out of curiosity, what's the maximum delay time on the Sagan delay (I guess the 3rd head gives the longest delay)?

[diablochris6]

Hey guys,
Just out of curiosity, what's the maximum delay time on the Sagan delay (I guess the 3rd head gives the longest delay)?

I've never really tried to time it out, but I looked at the equations for the PT2399 on Electric Druid's site to get a rough estimate. According to his formula, one PT2399 with a 50k time pot could pull about 600 ms. Since the three chips are pigggybacking off of each other, the 3rd PT could in theory pull of 1800 ms, but it will sound pretty gross and noisy. It wasn't really my goal to get those long times with this project.

[Bio77]

Just for completeness, reversing the transistors solved this. 

[diablochris6]

Just for completeness, reversing the transistors solved this. 

Glad it worked out for you! I'm not sure why rotating the transistors works, but it does. I haven't put a whole lot of brain time into this.

[Boba7]

Hey guys,
Just out of curiosity, what's the maximum delay time on the Sagan delay (I guess the 3rd head gives the longest delay)?

I've never really tried to time it out, but I looked at the equations for the PT2399 on Electric Druid's site to get a rough estimate. According to his formula, one PT2399 with a 50k time pot could pull about 600 ms. Since the three chips are pigggybacking off of each other, the 3rd PT could in theory pull of 1800 ms, but it will sound pretty gross and noisy. It wasn't really my goal to get those long times with this project.

Oh yeah, I would have no use for 1.8s of delay. Even 1s is way too long for me. Just curious what the maximum delay time was.

[Bio77]

Just for completeness, reversing the transistors solved this. 

Glad it worked out for you! I'm not sure why rotating the transistors works, but it does. I haven't put a whole lot of brain time into this.

Thanks to you Chris! This thing is awesome.  I'm waiting on the switching jacks for the FX loop,  then I post some pics.