Recent posts

#51

General Questions / Re: Low Rider 2Sk30 pinout

Last post by jimilee - February 26, 2026, 06:04:11 PM

What exactly is the Pinout on the 2sK30 transistors. On the Lowrider schematic the pinout is not specified. I understand that the bit with the arrow is the Gate but how do I know which one is the Drain and which one is the Source?

It says that we can use 2n5457 instead but they have different pinouts, right? How do we know which one is which?
I have attached an image with the section that shows these transistors.

Google 2n5457 pinout.


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#52

General Questions / Re: Low Rider 2Sk30 pinout

Last post by thomasha - February 26, 2026, 05:49:20 PM

Gate arrow is closer to source

This is actually a nice schematic.

I've seen some where the arrow is in the middle, where it's not clear.

#53

General Questions / Re: Low Rider 2Sk30 pinout

Last post by jwin615 - February 26, 2026, 04:49:19 PM

Gate arrow is closer to source

So S connects to VR
Though orientation probably doesn't matter.

#54

General Questions / Re: Low Rider 2Sk30 pinout

Last post by garfo - February 26, 2026, 04:37:57 PM

I tried editing the post, but couldn't.
I have attached an actual image with the bit of the schematic that is relevant.
I understand that the Arrow indicates the Gate. How do we identify the Drain and the Source?

#55

General Questions / Low Rider 2Sk30 pinout

Last post by garfo - February 26, 2026, 04:14:24 PM

What exactly is the Pinout on the 2sK30 transistors. On the Lowrider schematic the pinout is not specified. I understand that the bit with the arrow is the Gate but how do I know which one is the Drain and which one is the Source?

It says that we can use 2n5457 instead but they have different pinouts, right? How do we know which one is which?
I have attached an image with the section that shows these transistors.

#56

Open Discussion / Re: Craziest request I ever re...

Last post by matmosphere - February 25, 2026, 05:58:43 AM

Bro wants a Mackie 1604

That was pretty much my thought. Seems like a mixer is more or less what this guy wants.

I mean, just working through the design of something like that would be a huge time investment, let alone prototyping and troubleshooting. I don't think any one person would pay enough to make it worthwhile.

#57

Build Reports / Re: Polyphemus [One Knob Overd...

Last post by lars - February 22, 2026, 02:17:23 AM

One word to describe that build:
"Cleeeeeaaaaaannnnnnnn".

#58

Open Discussion / Re: Craziest request I ever re...

Last post by Aleph Null - February 19, 2026, 07:21:31 PM

Sounds like someone is trying to reinvent the mixing console.

#59

Open Discussion / Re: Craziest request I ever re...

Last post by flanagan0718 - February 19, 2026, 05:15:18 PM

This was mine. It seems like a lifetime ago. The video is a bit long but it was a fun build.

crazy build

#60

General Questions / Re: Rate/Mod Rate LED for Poly...

Last post by wizestwizard - February 18, 2026, 01:21:43 PM

Hey guys, recently had a request from someone to add a rate LED to a Polytrog I build for them. I assume it will follow the "rate" pot if I put it in parallel with the LDR LEDs? If I do this, should I put it after all of the vactrol LEDs and then lower R42 to ~250R? This is a complex circuit compared to what I normally mod, so want to make sure I cover my butt before I start poking around in it!

If I wanted it to pulse with the "mod rate" pot, where would be the best place to tap into that voltage? Thanks!

For the Rate pot you would put the LED in series with VC1-3_L, nt in parallel. Lowering R42 might compensate or prove unnecessary. For the Mod_Rate I'd try a 10k CLR and LED connected to pin7 of IC9_B first. Do it on a breadboard where you can easily disconnect the LED and see if it impacts performance.

These are just educated guesses.

This person is actually requesting another one built as a backup, and wants both the rate and mod rate slowed. They tested it against their own Polyphase and claim it's 2-3x faster as built, I didn't have one to test against but they sent recordings and it is indeed much faster even at minimum. The LFO section of this is pretty complex to my novice eyeballs, I'm going to see how the second one I built sounds stock but if I need to decrease the rates, is decreasing the pot values the way to go or would they need to be larger (which is not available probably, as they're both 1M lol)?