Sunn model t preamp help

[Joel]

Built very carefully and fairly sure there's no solder jumps etc. all knobs work and it sounds pretty cool. But I'm not able to use the trim pots to bias q2 or q3 which hover around 2v and 9.6v respectively. J201s were from eBay and while swapping them has a minor effect on the drain reading the remain unaffected by the trimmer. Grateful for any thoughts on what's wrong. Can't get pic of the underside as I'd already stuck it into the enclosure...

[Joel]

Should add - I'm measuring the voltage by setting my multimeter to the 20 setting in the DC section, applying the ground probe to the ground on either the 3pdt or the DC power jack and then using the red probe to touch the drain lead before it goes through the veroboard hole.

[rex.himself]

This may sound a little silly but are you adjusting the right trim for the right j201?

From L-R the trimmers adjust Q1, Q3 and Q2 (took me a while to figure that one out myself)

[Joel]

..... I knew it would be something as simple / silly! Will check as soon as I finish work. Thanks so much!

Joel.

On 12 Dec 2016, at 9:12 AM, rex.himself [via Guitar FX Layouts] <[hidden email]> wrote:

This may sound a little silly but are you adjusting the right trim for the right j201?

From L-R the trimmers adjust Q1, Q3 and Q2 (took me a while to figure that one out myself)

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NAML

[Joel]

That's fixed it!!! Thank you so much. I was totally second guessing my build and the three that are also under way. I never would have figured that out so from the bottom of my newbie heart, THANK YOU!!!

Joel.

On 12 Dec 2016, at 9:12 AM, rex.himself [via Guitar FX Layouts] <[hidden email]> wrote:

This may sound a little silly but are you adjusting the right trim for the right j201?

From L-R the trimmers adjust Q1, Q3 and Q2 (took me a while to figure that one out myself)

---

If you reply to this email, your message will be added to the discussion below:

http://guitar-fx-layouts.42897.x6.nabble.com/Sunn-model-t-preamp-help-tp34803p34817.html

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NAML