Wampler - PINNACLE II

fretzburner · Post by **fretzburner** » 15 Dec 2012, 04:06

My pinnacle LE build used lots of J201 to get close to the given voltages,maybe the original J201 were matched.

alexradium · Post by **alexradium** » 15 Dec 2012, 07:44

lukatosh wrote:Hello!...
Today i've build the limited version using my own layout posted a few pages earlier...

but... i'm a little confused...

I don't know exactly how the transistors should work... i know that some transistors need to be biased, but this pedal does not include trimmers as in the BSIABII...

on my build i just put there 6 x J201 transistors

does wampler use matchet j201?, they bias the pedal from the moment they build it? do i need to change some resistors values to bias the transistors?... from the 6 transistors, who needs to be biased?

i don't know if im being clear, my english is not so good.

i would like that my pedal works as it should.

BW uses selected jfets,he shows that in the latest factory video on YT.
either that or you put trimmers on drain to get the right voltages,4 to 5 Volts is ok.
Then you can substitute the trimmers for proper value resistor,metal film,so there is less noise.
More likely Q5 and Q6 needs this biasing.

Sonik Stach · Post by **Sonik Stach** » 15 Dec 2012, 21:02

alexradium wrote:BW uses selected jfets,he shows that in the latest factory video on YT.
either that or you put trimmers on drain to get the right voltages,4 to 5 Volts is ok.
Then you can substitute the trimmers for proper value resistor,metal film,so there is less noise.
More likely Q5 and Q6 needs this biasing.

That's exactly what I did on mine, Q5 & 6. But I've also swapped some of the others transistors to get close to the proper voltages.

batak_man · Post by **batak_man** » 28 Jan 2013, 14:04

is there anyone already succes build this without error?

Drain / Gate
Q1 4.72 / 0
Q2 8.98 / 2.99
Q3 4.78 / 0
Q4 8.98 / 2.99
Q5 3.59 / -1.68
Q6 3.86 / 0
@9VDC input regulated all switches up and all pots full "10"

Drain / Gate
Q1 5.01 / 0
Q2 8.98 / 2.99
Q3 5.05 / 0
Q4 8.98 / 2.99
Q5 4.18 / 0
Q6 4.19 / 0
@9VDC input regulated all switches down and all pots off "0"

btw is this voltage is valid?
How about if i add trimer in every j201, so i can bias the transistor to get this voltage
Any one already do this?

btw thx for this amazing forum

Sonik Stach · Post by **Sonik Stach** » 28 Jan 2013, 20:07

Exact match no, but with pretty close results yes (see my previous posts).
Trims are usefull for Q5 & 6, they're not really needed for the others, but feel free to experiment!
Other BSIAB designs have 1 or 2 trims.

batak_man · Post by **batak_man** » 12 Feb 2013, 14:01

Sonik Stach wrote:Exact match no, but with pretty close results yes (see my previous posts).
Trims are usefull for Q5 & 6, they're not really needed for the others, but feel free to experiment!
Other BSIAB designs have 1 or 2 trims.

glad to hear that the V result is pretty close
is the sound is pretty close to?

btw its wampler pinnacle use matsushita caps?

thx man

batak_man · Post by **batak_man** » 18 Feb 2013, 12:11

batak_man wrote:
Sonik Stach wrote:Exact match no, but with pretty close results yes (see my previous posts).
Trims are usefull for Q5 & 6, they're not really needed for the others, but feel free to experiment!
Other BSIAB designs have 1 or 2 trims.
glad to hear that the V result is pretty close
is the sound is pretty close to?

btw its wampler pinnacle use matsushita caps?

thx man

already answer via PM.

thx

thn.technik · Post by **thn.technik** » 18 Feb 2013, 17:35

Hi,

some small modification for gain and mode,
I use 3 positions switches to get additional "middle gain" and additional tone characteristic

in enclosure eagle files, feel free to use or modify

Intripped · Post by **Intripped** » 18 Feb 2013, 18:01

very nice layout thanks!
just a little tip: try to increase the size of the pads with the pshouse-drill-aid.ulp (google it)

thn.technik · Post by **thn.technik** » 18 Feb 2013, 18:23

Intripped wrote:very nice layout thanks!
just a little tip: try to increase the size of the pads with the pshouse-drill-aid.ulp (google it)

thx!, I just looking for sth like that "pshouse-drill-aid.ulp"

lukatosh · Post by **lukatosh** » 22 Feb 2013, 23:36

verified!, just need to tweak values of R25 and R15 to get 4.5v on Q5 and Q6

PCB, Lay, Schematic

Saludos desde chile!

thn.technik · Post by **thn.technik** » 23 Feb 2013, 07:59

lukatosh wrote:verified!, just need to tweak values of R25 and R15 to get 4.5v on Q5 and Q6

PCB, Lay, Schematic

Saludos desde chile!

Hi, from my experience with J201 forcing voltage value to 4,5V is not good solution,
most of J201 what I have get optimal working point at 2,6-6V , I mean hi gain without distortion
better solution is to adjust resistor by trimer for "optimal" sound, not just for forcing 4,5V
best solution is to match J201 to designed resistor values
anyway by changing resistor value are changing also original tone shape of pedal

for sure 1/2 supply voltage is best what it can be for DC bias for AC signal but it depend of transistor parameter
in original schematic you can clear see that real voltage is different than designed
In my clone Q5 is 4,01V and Q6 is 5,6V with original resistor values,
with trimer adjusting for high gain Q5 2,7V with 28K and Q6 6,3 with 16K but tone was different so i go back to original resistors.

Pozdrawiam z Polski

kenshiro86 · Post by **kenshiro86** » 10 May 2013, 09:08

Hi guys, can you tell me why on Q2 and Q4 have a voltage of 4V Drain? It should be 3V ...

Also on Q5, there are -1.68! I have a value ranging from -0.25 to -0.45 ... something wrong?

I replaced R15 and R25 with trimmers to calibrate and have the tensions of the original pedal, I also put the trimmer in place of R5 and R12 for the same reason ...

Will you help me figure out if I'm wrong and where?

kenshiro86 · Post by **kenshiro86** » 15 May 2013, 11:59

Help me, please :'(

jymaze · Post by **jymaze** » 16 May 2013, 14:01

Ok, what schematic do you refer to when you say R5, R12, R15 and R25?

Also I assume you are talking about source and not drain of Q2 and Q4. Drains should be at V+.

Your negative voltages on Q5 make no sense, are you sure you are measuring right? And what pins are you talking about?

It is all very confusing in your post. I may help, but I need clear data to look at.

kenshiro86 · Post by **kenshiro86** » 17 May 2013, 11:34

rmroza wrote:Yep, this is THE LATEST version from Wampler of the Pinnacle (see IvIark update above). Just recieved this week. No other JFETs. All Fairchild J201's. Attached is the traced PCB. BOM is correct. Voltage reading are as follows:

Drain / Gate
Q1 4.72 / 0
Q2 8.98 / 2.99
Q3 4.78 / 0
Q4 8.98 / 2.99
Q5 3.59 / -1.68
Q6 3.86 / 0
@9VDC input regulated all switches up and all pots full "10"

Drain / Gate
Q1 5.01 / 0
Q2 8.98 / 2.99
Q3 5.05 / 0
Q4 8.98 / 2.99
Q5 4.18 / 0
Q6 4.19 / 0
@9VDC input regulated all switches down and all pots off "0"

I'll take some measurement to see what the gain of the JFETs are and what not. Enjoy!

Equinox

I am referring to the tensions reported here ...

the schematic (the first, "Last Version"): https://www.freestompboxes.org/viewtopic ... 6&start=40

the negative voltage on the gate of Q5 is not the same that I have and I would understand if it is a problem or not ... also to the gate of Q2 and Q4 have more than 4 volts instead of 3 ...

The main problem is that with the different J201 circuit behaves differently and I wish I could set as it should ...

The second problem is that when I put it in the box begins to whistle over certain values of volume and gain ... any ideas on how to solve?

jymaze · Post by **jymaze** » 17 May 2013, 14:58

Ok, got it.

You are fine, the reported voltages in the post are for J201 with a VGS off, probably Wampler has to sort them pretty hard to get these values. All the J201 I ever got had a VGS off around 0.5V which would lead to voltages such as the ones you have on your build.

Conclusion: Your build is fine!

The whistling is another problem. First thing first: Check for any reason for positive feedback by making sure the wires going to the tone and volume pots are not too close to the wires going to the gain pot. Try to separate them by a quarter of an inch if possible (maybe use some plastic to make spacers). If they have to cross, make it perpendicular, running them parallel to each other is the worst. You can bundle the sets of wires going to the same pot together, no problem here. Make sure the wires are also well separated around the bypass switch. Also, make sure the casing of your gain pot is grounded by soldering a little wire from the lug tied to the ground to a spot of the casing that you have lightly sanded (to get a good solder grip). You can also ground the casing of the other pots, but it is less critical.

If that does not work, I have some other ideas, but try that first.

kenshiro86 · Post by **kenshiro86** » 17 May 2013, 21:42

First: THANKS!!

And secondly: i've tried these mods and...nothing :/ other ideas?

jymaze · Post by **jymaze** » 18 May 2013, 02:07

Is the whistle present only in boost mod (R3 and R9 tied to ground) or all the time?

Does it change when you are touching the ground plan with your finger?

What are the values you read at the drains of Q5 and Q6? Di you try to adjust your trimmers and hear if the whistle is vanishing?

First thing I would bump R2 to 33k to block some high frequencies that could cause HF oscillations. It is an easy thing to try. Any other mods I can think of would probably slightly affect the tone or the gain.

jimiguitar · Post by **jimiguitar** » 07 Jul 2013, 20:25

hello everyone i'am new here i have aquestion regarding viteks circuit from a early post i like to try it i like the way it looks

Wampler - PINNACLE II [traced]