Well after a number of years with an F5, I pulled the trigger on F5T boards and Toshiba JFETs. I plan to use the deluxe 5U case. Will document progress here!
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Looking forward to seeing your build, Mark! I’ve been putting off a few builds because I already have a stack of amps laying around. 😉 Your image above only partially loads, may be something wrong with the file.
Well this is interesting - two identical trimmers, one turns clockwise to get to zero ohms, the other one turns counter-clockwise to get to zero. Should make biasing the amp fun.
More board stuffing this morning. It's a pleasure not having to hack up the back of the case with a drill and dremel. The back has a front and back side - if you reverse it as I did, the Neutrik RCA jacks go in crooked. The stainless hardware is nice and everything fits.
Easy enough to flip it. I'm not sure why the inputs/output holes are inboard, on the F5 I built I put them outboard on the case so it wasn't such an issue.
So I went to work on the amp today, and one of the N channel boards was missing. Scoured the house and found nothing. So, I went into the trash and apparently a cat pushed the board and my head-mounted magnifier into the trash can I had placed next to the counter where I do my builds. After a very gross trip into the trash
🤮 and some rinsing off coffee grounds, I have them both back.
Lesson is don't leave stuff out when you have three curious cats in the house. 🐱
🤮 and some rinsing off coffee grounds, I have them both back.Lesson is don't leave stuff out when you have three curious cats in the house. 🐱
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Ha- they played hockey and one of them scored, slipping your stuff right past the goalie!
Glad to hear you found your missing parts.
Glad to hear you found your missing parts.
A tip for you - it appears you did the soldering on the bottom side of the board. Get a nice solder bead on the top side, too. Reflow some solder so you get more on those resistor leads and PCB pads. I had a cold joint once that was a bear to track down. Now it's habit to solder one side, then flip and do a 2nd round on the other side to make 100% sure I have good connections.
I'm looking forward to seeing your new turbo come to life!
I'm looking forward to seeing your new turbo come to life!
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I would echo this advice. For all of the solid state gear that I’ve repaired, the majority of the problems were from “wave soldering” on header and pcb pins that didn’t get enough solder into them. Over time, the weaker solder joints crack and make intermittent contact. Tracking them down is a major pain.
when soldering your components, hold a little longer (maybe an extra 2-3 sec) with your iron and feed in a bit more solder so it runs all of the way through the plated hole. With small signal transistors or other heat sensitive parts, use a small pair of forceps or small clip-on heat sink and attach it to the leg on the top side of the board to protect the device.
by the way: I like the clever wire loops you soldered in at the test points, Mark. This is a nice way to attach a probe while adjusting a pot and not having it slip off and hit something else on the board, thus causing another problem. Yep, been there and done that before 😉
when soldering your components, hold a little longer (maybe an extra 2-3 sec) with your iron and feed in a bit more solder so it runs all of the way through the plated hole. With small signal transistors or other heat sensitive parts, use a small pair of forceps or small clip-on heat sink and attach it to the leg on the top side of the board to protect the device.
by the way: I like the clever wire loops you soldered in at the test points, Mark. This is a nice way to attach a probe while adjusting a pot and not having it slip off and hit something else on the board, thus causing another problem. Yep, been there and done that before 😉
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Thanks - you'll notice that the test points have solder all the way through. Not sure why I didn't get enough on the other components but I'll reflow them for sure.
For those of you who are getting excited about this, I shipped a batch of
F5T semiconductors to the store yesterday...
F5T semiconductors to the store yesterday...