K-502 Valve Amplifier Kit

It is no surprise seeing another build of the S-5 Electronics Tube Amplifier Kits. These valve amplifier kits are inexpensive, simple to build, fun and best of all, they sound great.

Pictured below is Scott's build of the inexpensive and popular K-502 Tube Amplifier Kit and Enclosure. The enclosure for this tube amp looks fantastic. Great attention to detail.

Scott only made a few changes to the circuit board; replacing the stock 0.22 uF polyester film caps with good quality Orange Drop capacitors. I lived with a stock build of the S-5 Electronics K-12M Tube Amplifier Kit for a while and I can tell you that this kit does sound very good in stock form. Scott also replaced the standard volume potentiometer with a good quality stepped attenuator.

For additional information and pictures of this tube amp project, see Scott's K-502 Tube Amplifier Kit and Enclosure page.

Related Tube Amplifier Projects:

• Barry's DIY K-502 Tube Amplifier Kit

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DIY Class A Mosfet Amp

Shown below is Jochem's first DIY Audio Project, a build of Mark's DIY Class A 2SK1058 Mosfet Amplfier project.


Jochem's build of this very simple Class A Mosfet amplifier uses the 2SK2221 Mosfet instead of the 2SK1058 that Mark used. The power supply has been modified slightly and uses two large toroid chokes for good filtering. The photographs below show the finished amplifier.



Jochem is very pleased with the results of his first audio project and is looking forward to completing more DIY Audio Projects in the future.

For additional information, pictures and schematics, see the complete project writeup of Jochem's DIY Class A 2SK2221 Mosfet Amplifier Project.

Related Post:

• Mark's Simple DIY SE Class A 2SK1058 MOSFET Project
  

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KT88 Single Ended Tube Amp

Alex has put together a single ended (SE) KT88 tube amp. His design was based around Mikael Abdellah's KT88 SE Tube Amplifier design from 2003. Alex has made some changes, such as the ability to switch the amplifier between triode and ultra-linear operation. A picture of his finished KT88 tube amp is shown below.


Alex has done some experimentation with different tubes. EL34 tubes can be used in place of the KT88 valves. The preamplifier tube is a 6N1P, but the 6DJ8 / ECC88 / E88CC family of tubes can be used instead. The power supply uses a 5U4-GB dual rectifier tube.

For additional information, pictures and schematics, see the complete page of Alex's DIY KT88 Single Ended (SE) Tube Amplifier project.

Related DIY Audio Tube Projects:

• Bruce's EL84 Push Pull Tube Amplifier
• Bruce's KT77 Push-Pull Tube Amplifier
  
• Bruce's KT88 Push-Pull Tube Amplifier
  

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diyAudioProjects.com Updated

The DIY Audio Projects website has been updated with a new template and some new categories. The general layout of the website has remained the same, but the new template should load quicker and cleanly across all browsers. The previous template did not load on some MAC browsers. To improve navigation through the site, a navigation bar has been added near the top of the page.


There is some new information on the site which includes:

• DIY Audio Schematics
• DIY Audio Technical and Reference Information
  

For the time being, new content is limited to some NAD schematics and a short page on Aperiodic Speaker Enclosures. However, some new projects and additional information will be added shortly.

Comments and suggestions are always welcome.

Cheers,
Gio.

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