Triangulum Boost issue

[Teddeeh]

Hello. So i believe transistor Q 1 beeds to be flipped, and Q2 seems to have no effect atall if its in or out.
I get sound, i get boost, but i do believe there is an issue.

 

[Robert]

What's it doing wrong? I've built one of these and it's pretty much spot on with the original.

Q2 won't have any effect on the sound... This is a rather unusual method of high impedance pull-down for Q1....

I fully expected questions about this one because it's another one that sounds basically nothing like any of the demos unless it's run into a cranked high gain amp. It's awfully bright and thin into a clean / crunchy amp. (just like the original)

 

[Redredbettyz]

"I fully expected questions about this one because it's another one that sounds basically nothing like any of the demos unless it's run into a cranked high gain amp. It's awfully bright and thin into a clean / crunchy amp. (just like the original) "

I'll second that. I had an original for a few months. It's great to tighten up an already gainy amp that has a big bottom end to it. Other than that, I had a hard time finding much use for it. I ended up liking flexibility of the TC Pre style a bit more. IMO you can get pretty close, if not spot on to the Triangulum/33 style if you tweak the knobs appropriately, but to each their own.

 

[Teddeeh]

Soo. Im back with a more indepth issue. So i get a eq cut at the start. Very tinny high freq sounding. Then roughly 30seconds of continuous playing and then the eq starts to balance out and sounds how it should.
Ive seapped transistors, and ic’s. Same problem occurs.

 

[Robert]

So you're saying the sound changes over time without you touching the controls?

Does this happen just once at power on, or each time you bypass/activate the pedal?

 

[Teddeeh]

Yes. Takes 30 odd seconds for the sound to stop sounding soo shrill and tinny and sound decent. Every bypass time.

 

[Robert]

That's puzzling... Off the top of my head, make sure the 4u7 capacitor isn't installed backwards. This sounds like a capacitor charging and affecting bias.

You mentioned earlier that you thought Q1 needed to be flipped, you don't have it in backwards do you? The pinout is correct for a BC550 / BC549 transistor.

Try removing Q2 and see if that has any affect at all.

 

[Teddeeh]

Ima gonna go and replace the 4u7 cap and see if that makes a diff. I will try with the trannie change. All seemed to work as intended on pcb. Another build seemed fine. I dunno. Most likely bad component.