Ampeg - Sub Blaster [schematic]
- chicago_mike
- Tube Twister
CD4013 :
Pins 9,11,4,6 go to ground.
make sure on your layouts / transfers that pin 4 goes to ground. It should not be floating.
So I get it to create the lower octave, but my dry signal is not clean, not full swing. Have to double check some soldering.
Pins 9,11,4,6 go to ground.
make sure on your layouts / transfers that pin 4 goes to ground. It should not be floating.
So I get it to create the lower octave, but my dry signal is not clean, not full swing. Have to double check some soldering.
Skyline FX 2013
- chicago_mike
- Tube Twister
SUCCESS!!!!
99% anyways!
Okay I need help here. I have the octve signal, and everything else is great.
I do NOT have a J175.
I DO have though
J201
J111
2N3820
2N3819
I noticed the J201 is used in the Boss Octaver...Could I just use that and see what happens?
99% anyways!
Okay I need help here. I have the octve signal, and everything else is great.
I do NOT have a J175.
I DO have though
J201
J111
2N3820
2N3819
I noticed the J201 is used in the Boss Octaver...Could I just use that and see what happens?
Skyline FX 2013
- chicago_mike
- Tube Twister
OKay so swapping in a J201 Almost works.
In the Boss schematic, theres a couple extra parts to do, an extra resistor tying one of the pins back to Vref.
But I do get a pre octve, Octave and post octave signal ( of some sort ).
In the Boss schematic, theres a couple extra parts to do, an extra resistor tying one of the pins back to Vref.
But I do get a pre octve, Octave and post octave signal ( of some sort ).
Skyline FX 2013
- chicago_mike
- Tube Twister
So in theory, on paper.
Tie the Drain to a 100k to Vref.
Tie 1meg to gnd to the gate After the 100K resistor coming out of the CD4013.
Change the 100K to a 1MEg.
All I did so far was the 100K vref mod.
Going to try the others right quick and see what I can see.
Fuck if this works!!!!
Tie the Drain to a 100k to Vref.
Tie 1meg to gnd to the gate After the 100K resistor coming out of the CD4013.
Change the 100K to a 1MEg.
All I did so far was the 100K vref mod.
Going to try the others right quick and see what I can see.
Fuck if this works!!!!
Skyline FX 2013
- chicago_mike
- Tube Twister
Now, to clean it up and see if theres any way to clean up the tracking. If not thats fine.
But, its working.
But, its working.
Skyline FX 2013
- chicago_mike
- Tube Twister
Adding a little gain make up stage after the passive Big Muff style tone control.
Changing the 100K resistor coming off the cd4013 to a 330K...this value is in the EBS, the DOD and a couple other octave pedals. All using an N Fet.
Might put in a switch to change out the .22 in the Octave filter and switch between that and a .1 or a .06 as I have a drawer full of .064's.
Octave pedal is still working though. So I can confirm with a couple mods that yes its a verified build.
Changing the 100K resistor coming off the cd4013 to a 330K...this value is in the EBS, the DOD and a couple other octave pedals. All using an N Fet.
Might put in a switch to change out the .22 in the Octave filter and switch between that and a .1 or a .06 as I have a drawer full of .064's.
Octave pedal is still working though. So I can confirm with a couple mods that yes its a verified build.
Skyline FX 2013
- chicago_mike
- Tube Twister
IM gone for a month on tour and she is going on my pedal board.
Skyline FX 2013
- mictester
- Old Solderhand
Information
MODS!!chicago_mike wrote:LADIES AND GERMS!!!!!!
the previous schematics have some incorrect areas.
I had issues with poor tracking of the sub octave. A huge improvement was achieved by making U4a a clipper (like a TS clipper with a pair of diodes around the output to the inverting input). I then did an active low pass filter (-18 dB/octave) with a bit of gain (to recover the loss due to the clipper) and a turn over point at about 1.4 kHz. It really tracks well now!
"Why is it humming?" "Because it doesn't know the words!"
- DavidRavenMoon
- Breadboard Brother
Information
Please post a schematic!mictester wrote:MODS!!chicago_mike wrote:LADIES AND GERMS!!!!!!
the previous schematics have some incorrect areas.
I had issues with poor tracking of the sub octave. A huge improvement was achieved by making U4a a clipper (like a TS clipper with a pair of diodes around the output to the inverting input). I then did an active low pass filter (-18 dB/octave) with a bit of gain (to recover the loss due to the clipper) and a turn over point at about 1.4 kHz. It really tracks well now!
Does it track correct when playing chords? I heard the EBS octaver could do that - looking at the EBS schematic I assume it depends on the filter design in front of the frequency detection.mictester wrote: I then did an active low pass filter (-18 dB/octave) with a bit of gain (to recover the loss due to the clipper) and a turn over point at about 1.4 kHz. It really tracks well now!
- chicago_mike
- Tube Twister
Food for thought
This is a very popular octave pedal for bass. Its red in color. the schema is the service schematic. So I have nothing else for it.
Perhaps we can add the tone controls to the ampeg unit?
This is a very popular octave pedal for bass. Its red in color. the schema is the service schematic. So I have nothing else for it.
Perhaps we can add the tone controls to the ampeg unit?
- Attachments
-
- OCT_07_schematics.pdf
- (23.68 KiB) Downloaded 355 times
Skyline FX 2013
- chicago_mike
- Tube Twister
The official schematic was published earlier.
It was from Ampeg themselves. In the DIY layout there is a missing connection from the CD4013.
I would trace your signal before the 4103..the gain structure feeding it, just to see of those opamps are working correctly.
For Octave pedals...its a simple circuit.
It was from Ampeg themselves. In the DIY layout there is a missing connection from the CD4013.
I would trace your signal before the 4103..the gain structure feeding it, just to see of those opamps are working correctly.
For Octave pedals...its a simple circuit.
Skyline FX 2013