Wampler Pinnacle with Trimmers

[MAO]

Here is another IvIark layout I had modified to add 2 trimmers. To accommodate the trimmers, I added 1 row,  7 links, and 5 cuts.

I also moved a few components around to better fit the box capacitors and monolithic ceramics I use. I also placed 2 resistors diagonally so they would lay down a bit better.

Note: I've had to shield the input wires and tone control wires on every Pinnacle build to keep the pedal from squealing.



Here is a reverse image for the cuts



 

[Muadzin]

Sweet! I was planning to do a vero Pinnacle one of these days. This will come in most handy.

[Muadzin]

Verified.

Sounds exactly like another Pinnacle build. Scarily even. The only issue that I've found is that the volume doesn't turn completely. Even when completely turned down I still volume coming through. Like the final part of the sweep is missing. Personally not a biggy because the rest of the sweep seems fine  and who needs a silent dirt box anyway. That's what the stompswitch is for.

Substituted the 100K log pot for the volume for a 100K Lin pot as I like the sweep a million times better. Then again, that might be the cause of my problem.

[MAO]

Thanks Muadzin, this is still one of my favorite pedals...with the shielded wiring in place


The volume control issue sounds like a bad pot to me as lug 1 is tied to ground, either pot taper should still ground the entire output signal when fully counter clockwise as that should short lugs 1 and 2 which then ties the output jack tip to ground. Assuming of course that you have lug 3 going to the board and lug 2 to the output jack.

Although I have never experienced the following; I guess its possible your bypass switch/wiring may be allowing the straight dry signal to come through at all times.

I did once had a problem with a brand new pot giving me dead spots similar t what you are describing. I found the resistances between the wiper (lug 2) and lugs 1 & 3 didn't add up to the pot's value. I took it apart to see what was going on but could not resolve the issue. Replaced the pot and all was good.

[Muadzin]

Lug 3 to board and lug 2 to output. I follow that religiously. Even with pcb's. Why send the signal back to the board if it goes straight out again. One less wire is always better, right? I used shielded wire as instructed. I even used it on the output wire from the switch to the output jack. As I learned when you place several dirt boxes in a row its best to shielded wire on your basic input/output signal chain or expect lots of squealing from your last pedal.

I'll probably replace the pot some day, I've built up a stash of 100K pots so it should be no biggie.

[alltrax74]

Which side of the shield cable do you connect to ground ?
Or maybe it has no importance...

[MAO]

No difference, whichever side is more convenient. Just be sure to ground only 1 side to avoid ground loops.

A little trick I found helpful was to use a short jumper wire to connect the prepared shield to a grounding point on the board, jack, switch or wherever else convenient.  

Prepare the one side of the shield by twisting it and applying a little solder to keep it from unraveling, then attach a normal hookup wire from the twisted shield end to the grounding point.

Here is a picture I found via google that shows the general idea.



I believe I ran my input shield/jumper wires back to the bottom rail on the board. For the tone control, I wrapped all 3 shields together at the pots and ran a single wire back to the board.

[alltrax74]

Ok thanks !
I built 2 pinnacles with Mark's layout, one is dead silent and the other one whistles like hell at high gain and treble settings, so I'll use shielded wire on this one

[motterpaul]

I just built Mark's layout of the pinnacle, but to find the right resistance for those 20k Rs I just wired in a 20k pot long enough to dial in the right voltage and then measured it. For mine, 3.3k was the answer for Q5, but I found that 20k was all right for Q6. I just replaced the Q5 20k with a 3.3k.

Just be sure you put back the same J201, because a different one can bias differently (but full disclosure, I accidentally put back the wrong one and it still worked just fine with the 3.3k) - it just read a higher voltage, but did not whistle.

I have no shielding but it is dead quiet., Changing the resistor fixed that. Also, my 10R voltage resistor burned out twice (probably due to missing components). For example, my boost switch was not working, but I discovered I had left out the 10k r to ground (the one on the right). Anyway, I replaced that 10R voltage with a 1/2-watt, and I swear the whole circuit sounded better.

[strassercaster]

man this oedal was one of my first builds, i shielded every single wire and still got squealing . i am glad you guys figured out why. my bias is about 3.8 for both q5-6. I am going to take it apart and try nailing the bias . i am going with your sugesstion of socketing and using a 25k linear to dial in the bias. also i noticed that the settings on the pots affect the voltage. did you have the pots set at a certain level for biasing?

[MAO]

Be sure to read Induction's comments about biasing J201s in Wampler's pedals.

Black 65 with trimmers post