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Yup, you're right. Forgot those are in parallel. I kind of think of the first gain stage in a preamp like an OD pedal for boosting the front of an amp. Dial in too much drive early on and it's going to sound too compressed, lack bass/highs and won't clean up properly because it precedes the gain...

Awesome, thanks! Yeah, this will be highly individual and depend on your tastes. Just wanted to get a general idea since I got the board sitting here as well waiting to be populated. I think Robert posted the original Model feT FETs were biased to 4.25V which just seems insane to me at ~17V...

Nice work and lots of possibilities for mods for sure. Since it follows such a basic tube amp topology, you could probably look at just about any early Marshall or Marshall adjacent tube amp for tone filtering inspiration and build it to suit your tastes - like you did :D What did you end up...

I did something similar with an active bass that I added a switch to that bypasses the active preamp. It also disconnects the battery so I'm not draining it needlessly in passive mode. The pop when turning it back on is quite substantial and while the capacitors are charging up there's no sound...

That's 67mA per rail, so 134mA total for the TEC 2. If current draw of one circuit is 120mA, even the TEC 3 won't work because it's limited to 200mA total. Edit: Had a quick looksie and TMR 6-0523 will provide more than enough current (200mA per rail). Input voltage is 4.5-9V, so some form of...

Cathode leg could be touching the metal casing of the LED bezel by the looks of it. LED will always be on then because the metal bezel and by extension the cathode is grounded through the enclosure.

Always looking forward to these updates. Going to be a little sad when the build is finally over :D It sounds really good and looks 100% professional. Great job.

Let's say I have a JFET source follower where the drain is connected through a 100R resistor to a regulated 24VDC (+/-1%). Am I cutting it too close if I'm using FETs that are rated for 25V max drain-gate voltage, like 5457, J211, etc or are these rated rather conservatively?

Best ask @andrewsrea, as he's done a bit of a deep dive on the circuit from what I can tell.

Here's some info: https://forum.pedalpcb.com/threads/ami-spirit-of-76-median-compressor.22924/#post-303001

That's good to know. I've had noise issues with charge pumps on vero before. Layout is important too. Best to keep them away from audio signal paths.

Both based on the TC integrated preamp and the Fortin derivatives. Isosceles should be a bit more versatile since it can also be switched to the Fortin Grind. I'm not sure the Dirty Tree has been traced, so it's anyone's guess if they modded the circuits or kept it stock.

Might be an issue with the raster image. Maybe some pixel around the edges has the same color code as the RDG_WHITE spot color and this is causing problems. It would be better if you used vector graphics only.

Most isolated DC-DC converters have a maximum capacitive load spec. Exceeding this limit can kill the converter or at least result in serious start-up problems from what I read. For capacitors directly across the converter outputs it's easy enough to figure out the load, just add up the values...

One thing to look out for is that hFE ranges given on listings may not be particularly accurate. If it says hFE 50-100 my experience is most of them will likely be around 50 or slightly under, not 75. Of course, there will also be many outliers, so best to order 10-20 rather than singles unless...

Do voltage regulators include filtering and would they be lower noise than the zener diode approach?

That's a thicc boi. I like it.

Just looking through the build doc and I don't think the presence control will be doing much of anything with that large 220K series resistor (R15) and the tiny 25K pot. R15 should really be 22-33K. Presence pot could also be upped to B100K for a wider range of control.

Q1 is a unity gain buffer. A poorly chosen source resistor can negatively affect the output swing range of Q1 and thus provide less than unity gain, but there's a range of values that will work here and unless your J201s are out of spec or something else is going on, both 2.4k and 3.3k should be...

I ordered the board a couple of days ago and I'm very much looking forward to the build! Will definitely do a demo but I haven't even started sourcing parts yet, so it'll be a while. Already thinking of doing a couple of mods though. C6/R11 in the build doc are the raw mode values. Add a 2.2n...