First Watt F6 Power Amp (Part 1)

Here's a quick guide on the build of the First Watt F6 power Amp incorporating the the same same case and power supply as I used in the Aleph J videos.

[@glenk0]

Great vids! I’m building the diyaudio F6 now and have found your videos to be highly invaluable. Thank you for doing these and I hope you plan to share more projects in the future.

[@freiheit6398]

Great video. It really helps me with my own diy audio journey. Keep it coming!

[@jonlaws4493]

Suggest you use some thermal paste between the coupled Transistors, plus use a dot of superglue on the cable tie and package to keep in place.

[@thediyaudioimplementers1826]

Good tip!

[@jonlaws4493]

@@thediyaudioimplementers1826 another way would be to use some shrink wrap tubing !

[@qddk9545]

Nobody seems to understand convection cooling - the cooling fins have to point upwards, or your adjustments are wasted.

[@jonlaws4493]

Hi Lav, I am just gathering the bits for an F6 build and was wondering what snubber caps you used in your power supply. Do you have the BOM you can share? Also the rectifier diodes etc.

[@thediyaudioimplementers1826]

The latest BOM is available at DIYaudio. (PassLabs) Build Guides.

[@hornU2]

Noticed that you had the probes across R1 resistor (0.56 Ohms) when adjusting the bias. Shouldn't be the R2 resistor (0.47 Ohms)?

[@thediyaudioimplementers1826]

Either resistor will do as long as you adjust both boards with the same resistor.

[@kft590]

What did you use for the Rectifier Diodes? What was the size of your Transformer?

[@thediyaudioimplementers1826]

Vishay Bridge Rectifier, 35A, 600V, 4-Pin. RS part No 227 8772 I used two 300va 18-0-18, If you go to my channel 'Power Supply' video the info is there.

[@kft590]

@@thediyaudioimplementers1826 Are you using 2 Transformers for isolation or are you running each Transformer in parallel to increase the current? The reason I ask is because I am using a single 18v (400va) Transformer and I am not getting much current out of it less than 3 amps per rail.

[@thediyaudioimplementers1826]

@@kft590 please go to the AJ ‘power supply’ video the answers are there.

[@billkalina3089]

One thing anyone building this needs to know, is that the transistors (2sk170 and its counterpart) went out of production years ago. They're available on Ebay, but most are counterfeits. Real equivalents are available at the DIY store, made by Linear Sysytems. But what was once a 35 cent transistor is now what, 10 bucks a piece? Ridiculous, IMHO.

[@FeryNovianto]

LSK170 and complementary still available, but i never tried LSK.

[@brandonburr4900]

It is rediculou. Try finding genuine Toshiba parts and you will be shocked with the prices also.it is what it is. The are quality parts and it's a shame no longer in producdtion.

[@jonlaws4493]

@@brandonburr4900 it costs a lot to keep a product running if there is no significant volume demand.

[@imosolar]

Please can you make this amplifier for a price?

[@brandonburr4900]

When you start to add up the parts for this amp including the f6 complete kit, jfets, power transformer, bridge rectifiers, filter capacitors, wiring, solder, chassis and back panel kit (this alone is north of $400) from diy it will be hard to do this amp for $800 or more. And that doesn't include any labor 😀

[@wesleypowers]

yes, 5k