@barry
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Sorry, I am totally confused at what board we are talking about and the exact question.
I do not offer a “killer svt” PCB. I do have a Guitar/Bass Driver PCB that is based on an SVT which is a preamp that has 9 stages of overdrive or Gain which is shown in the schematic and included with the build document.
GuitarPCB has the Mod Boards to make it happen.
Don’t just make a copy of something. Build like a PRO!
It could be as simple as adding a blend control with our Buff N Blend circuit to your circuit or perhaps an Active 3 Band EQ available in our Tone TwEQ board. Try some easy mod switching using our DPDT or Roto-Tone boards. How about adding order switching to multiple circuits inside an enclosure with either our 3PDT Toggle Board or the 4PDT Board w/ LED? Like I said don’t just make a copy of something. Mod it, and make it your own. Our 3PDT wiring boards have spare pairs of power and ground pads making it super easy to wire up Combo Builds like a Pro.
Not sure about something? Post a question in the Support Forum!
I will be working on a resistor chart for comparison tonight and tomorrow.
In the meantime please verify all the capacitors one by one since I cannot see them.
If all the capacitors are in order per the new schematic compared to the board then I need you to do some basic troubleshooting steps that I do every time I have a problem with a build. And yes I have to troubleshoot builds even though I have built a couple thousand circuits.
Here are the basic mandatory troubleshoot steps:
- Pull the board out from the enclosure and lightly pull on all off board wiring making sure it is connected well
- Triple check all off board wiring connections to 3PDT and IN/Out Jacks.
- check the physical connection and interaction while inserting a cable in each jack. Look for proper contact
- re-flow the solder for ever single component whether it looks great or not (have solder handy)
- check solder joints on all off-board items like 3PDT and In/Out Jacks. (re-flow if needed)
Report back after you have verified all capacitors and did all troubleshooting tips above.
If you have an Audio Probe this would also be very revealing to quickly show the problem area of the board
Thanks.
Here are some more:
Idea #19 courtesy of Chris the Master Exploder
Idea #20 courtesy of Big O “Clean Dirt”
Idea #21 courtesy of Chris The Bass Station
OK thank you.
Tell me the value of these two red Wima capacitors.
Top value =
Bottom value =
Verify proper orientation of FUZZ pot. Lug 1 pot to Lug 1 board silkscreen.
Since you are using 2N5088 install in the same orientation as the board silkscreen.
@ Stefanie D – I am not sure if it will be this year. I have some things to take care of on my end but I have strong desire to get there and enjoy everything it has to offer. Klaus will be a big help with that as well. Eric’s pictures were amazing.
You should post that picture on Instagram and give me a shout out there.
Yes it has been assembled. There could be a manufacturing error but that is rare, though possible.
There is too much missing information we absolutely need to do a proper troubleshoot.
Lets start with this:
- Set T2 at the center position of the rotation
- What transistors are you using?
- What are the voltage readings for all 4 transistors?
List them in order:
Q1 thru Q3
E:
B:
C:
etc…
Q4 is:
D:
S:
G:
The information will be very revealing and may lead to a solution. If not I will need more important information.
It is only significant if you cannot bias your JFET.
Test the Drain of Q4. Make sure you can adjust T1 so that the Drain voltage of Q4 reads between 4.5v to 6.5v
If you can get a satisfactory voltage reading then everything is fine.
Also if you are using 2N5088 transistors Q1 – Q3 they do align with the board silkscreen now but if you are using BC549C then you would have to install them opposite the board silkscreen.
Very nice and thanks for sharing!
So what can you say specifically regarding incorporating the Buff N Blend that sticks out to you?
Hi,
The only thing we did was add a resistor to the final stage. It will not cause you a problem but you do need to put a 33k resistor in there. You could also use 20k, 22k or 27k as well if you need to. After doing that you will need to adjust your trimmer T2 to bring the Boost Level up so it is not attenuating the circuit which maybe be the case now?
If you try turning up T2 first you will have to turn it back down after installing R24. That is the reason for the new resistor to keep you from attenuating the whole circuit.
The only other thing is technically you should use a 1N5817 for D4 but it will work with a 1N4001 as well.
If you still have issue after placing the resistor in R24 there is some other issue that needs to be investigated.
Well done and thanks for sharing!
My grandfather was from Austria. He came here when he was 8 (1906). His father was an officer in the Austrian army. 1800’s during Franz Joseph. I actually have a picture of him in his extraordinary helmet. This is also why my grandfather was named Francis Joseph.
I may be related to those who own Haus Steindel. It is on my bucket list. I was so jealous of Eric when I found out he was there.
I used to say I am just a guitar player too. That will change.
If everything was built exactly by the BOM though it will work (schematic and BOM has been the same).
Otherwise post some photos.
I am sure you will figure it out.
Where are you grabbing a build document that says CLR is R19? I have double checked both new and old SWAH version build documents twice and they both say R31 is CLR. I am happy to correct a typo but I cannot find it.
From the current Build Document:
https://guitarpcb.com/wp-content/uploads/2021/09/SWAH-v5-2021.pdf
UPDATE: It must be an older downloaded doc with a typo that was stored for use.
Always check for a new doc before building in case of an update. Appears as if this was updated back in Feb 24. It does not happen often but is always best in case of a typo or potential mod update. Also double check the schematic when ever there is doubt or questions. Even if schematics are not your forte many items like LED are easy to find (see image above) and you will note that the resistor preceding D6 is R31 the CLR.
My best guess then is that R31 is not populated (causing the LED to blow) or you are using a wiring board in which case the CLR needs to be populated there as explained in the image above.
Of course always ask here just like you did when in doubt. Again we go through many checks to prevent problems but it is always possible that some small item might leak through the cracks.
Besides what I carry in my SHOP
Mouser, Tubes & More and Digikey.
