Project files: New gainclones

What is it?
These are the board files for the gainclone amp and PCBs posted here. They (sort of) supercede the original files from this post – at least the PSU.

How big are the boards?

  • Amp: 2.4″x1.5″ (app. 61×38 mm)
  • PSU: 3.925″x1.95″ (app. 100×50 mm)
  • Bridge: 2.55″x1.6″ (app. 65×41 mm)

What is the status of the boards?
The boards are in version 1.0 or higher. They have all been built and tested.

Does it use any special/expensive/hard-to-find parts?
Not really. You can do what I did and splash out on 0.1% resistors and audiograde caps, but it definitely isn’t necessary.

Anything else I need to know?

  • The LED on the amp board is connected rail-to-rail which means that in a typical application it will drop around 70V, so it should be rated 1W.
  • If you use film caps thicker than 3mm for the bridge board, you may have problems mousing the diodes completely straight (as I had on the one I built)

Downloads:
Download design files here

Related information:
Note: Always read the “intro post” for additional important information about my designs.

You can find additional information about the LM3875 gainclone in the LM3875 build guide over at audiosector.com.

 

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Project files: Single voltage regulators

What is it?
These are small single-voltage regulators based on LM317-type regulators suitable for many supporting applications. The output voltage set via two resistors but not variable afterwards.

How big are the boards?
The smaller board measures 1.975×1.425″ (app. 50x36mm) while the bigger board measures 1.975″ (app. 50mm) square.

What is the status of the boards?
The boards are in version 1.1. I have built both version 1.0 and version 1.1 of both and they work fine.

Does it use any special/expensive/hard-to-find parts?
Not really. You can go overboard with low-noise/low-drop regulators and audiophile caps if you feel like it, but there’s no need for that.

Anything else I need to know?

  • The protection diodes (which are not required but still recommended) are MELF-style 1N400x mounted on the bottom of the board. The resistor for the LED is an SMD-type as well.
  • The heat sinks are Fischer SK104 (or equivalent) for the small board and Fischer SK129 (or equivalent) for the larger board.
  • Note that although you can get regulators rated at several amps, the DIP-packaged rectifier bridges are difficult to find in more than 1A ratings (although 2A exist).

Downloads:
Download design files here
For a small spreadsheet that can be used to calculate resistor values, output voltages etc. for the regulators, see the “download” page (or google to find an online calculator)

Related information:
Always check the manufacturer’s datasheet for the regulators of your choice to confirm all bypass recommendations, parameters and load conditions. This is especially important if you decide to use low-dropout (LDO) or low-noise types.
Note: Always read the “intro post” for additional important information about my designs.

Project files: Regulated PSUs – part 2

What is it?
These are variable-voltage regulated power supplies based on LM317/LM337(-type) regulators. These are useable for a wide variety of applications. You can use normal LM317-regulators or substitute higher-current LM350/LM338 or low-dropout LM/LD/LT108x types as the boards only use positive regulators. There are two basic versions, one version using small heat sinks (Fischer SK104-style) and one using larger heat sinks (Fischer SK129-style). Both boards are available in single and dual versions.

How big are the boards?
Small boards:
– single version 3.6×1.175″ (app. 91x30mm)
– dual version 3.6×2.25″ (app. 91x57mm)
Large boards
– single version 3.925×1.75″ (app. 100x44mm)
– dual version 3.925×3.5″ (app. 100x89mm)

What is the status of the boards?
These boards are in version 1.0. I have built and tested both dual versions and they work well. The single versions are exactly identical and should work perfectly also.

Does it use any special/expensive/hard-to-find parts?
No, all these parts are reasonably standard.

Anything else I need to know?

  • The heat sinks on these boards are not that big, so remember to watch the power dissipation – especially if the regulator needs to drop a large voltage.
  • These designs assume you are at least somewhat familiar with how the LM317-type voltage regulators function and operate.
  • Always check the manufacturer’s datasheet for the regulators of your choice to confirm all component values and load conditions. This is especially important if you decide to use low-dropout (LDO) or low-noise types that could have slightly different parameters.

Downloads:
Download design files here (large boards)
Download design files here (small boards)
For a small spreadsheet that can be used to calculate resistor values, output voltages etc. for the regulators, see the “download” page (or google to find an online calculator)

Related information:
Note: Always read the “intro post” for additional important information about my designs.

Project files: Regulated PSUs – part 1

What is it?
These are fixed-voltage regulated power supplies based on LM317/LM337(-type) regulators. These are useable for a wide variety of applications. There are two board versions, one intended to be supplied by a single AC supply in a voltage-doubled configuration and the other a more standard version that can be supplied from dual AC or unregulated DC. The latter version is also useable with the AUX supply on ICEpower ASX-series amplifiers (see comments below)

How big are the boards?
Boards measure 3.65×1.8″ (app. 93x46mm). The two board variations have identical dimensions.

What is the status of the boards?
The voltage doubled board is in version 1.1. I have built and tested v1.0 which had TO-220 diodes in place of the current DO-41 so there should be no issues here. The “normal” model is in v1.0 and at the time of writing I have boards on the way for this one. The only difference between the two board designs are the rectifier designs, so it should also work fine.

Does it use any special/expensive/hard-to-find parts?
No. You can go overboard on expensive regulators/rectifiers and audiophile capacitors if you feel like it, but no one is forcing you 🙂

Anything else I need to know?

  • The heat sinks on these boards are not that big, so remember to watch the power dissipation – especially if the regulator needs to drop a large voltage.
  • These designs assume you are at least somewhat familiar with how the LM317-type voltage regulators function and operate.
  • The “standard” regulator can be used with the AUX supply on an ICEpower ASX-series amplifier. For this application use resistors in place of the DA and DB diodes (check the ICEpower designer’s manual for values) and leave DC/DD diodes out.

Downloads:
Download design files here
For a small spreadsheet that can be used to calculate resistor values, output voltages etc. for the regulators, see the “download” page (or google to find an online calculator)

Related information:
Always check the manufacturer’s datasheet for the regulators of your choice to confirm all bypass recommendations, parameters and load conditions. This is especially important if you decide to use low-dropout (LDO) or low-noise types.
Note: Always read the “intro post” for additional important information about my designs.

DIY project files: General Information

This part of the blog is devoted to sharing design files for some of my various audio DIY projects. Please take a moment to read the following general information before downloading and using any files.

Each project post will contain a short description of the project(s) and some key information that you may need to know as well as a download link to the project files. The downloadable file for each project will normally contain:

  • The circuit schematic and board files in Eagle 6.x format
  • A set of Gerber files generated in Eagle with the Itead cam job (see below)
  • A set of renderings of the Gerber files (made with www.circuitpeople.com which I highly recommend)
  • Other files (BoMs, circuit diagrams, code samples etc.) as needed

In principle, I try to design my boards as compact  (some would say “cramped”) as possible using two layers where one is normally a ground plane. There is some dispute as to whether this is the right way of doing it for all boards, but it normally makes layout easier and the routing cleaner so it can’t be all bad 🙂 I normally follow the original schematics as closely as possible, but sometimes I make decisions on parts, configuration and placement because I had a specific application in mind when doing the layout. I try to select parts as a compromise between compactness and flexibility and I try to use footprints that does not leave you tied to a specific manufacturer’s parts.

My prototype boards are normally manufactured by Itead and the Gerber files included in the downloads are therefore made with Itead’s own customized cam job for Eagle. I have no affiliation with Itead at all, but I have used them extensively and the prices are good, the quality is more than decent enough for normal DIY use, and I have (so far) received good service for all my orders so all in all I have no hesitation in recommending them to others. If you prefer, you can of course use the Eagle files to generate Gerbers for your own preferred board house (Seeedstudio, OSHpark, batchPCB etc.), many of which also offer cam-jobs for Eagle to make this process easier.

Happy building!

 

Important! Since these are DIY projects, the usual DIY project disclaimers apply here:

  1. These files are intended for use by individuals in and for non-commercial DIY projects. Use in group buys through forums as well as any and all forms of commercial usage are only allowed with my prior written consent (that means send me a message to ask permission before you do anything…)
  2. These are DIY projects for people with at least some basic experience in building DIY electronics including soldering, measuring, troubleshooting etc. I will do my best to provide support via email but there are no promises of help expressed or implied if you can’t get a design to work properly, regardless of whether that is my fault or yours. 
  3. Some designs may involve hazardous voltages, mains wiring and/or modifications to existing equipment. Before undertaking any of these projects, be sure to verify that you have the required knowledge to do so and that you are not violating any laws or voiding any insurance polices or manufacturer’s warranties. 
  4. The project files are shared in good faith and and will normally have been tested to provide working designs that are safe for use. However, I have no access to any special labs or measuring equipment beyond what a normal hobbyist would have, so I cannot always verify everything  before posting a design. If you find any issues, please help me (and others) by sending me a mail.
  5. Lastly: I will accept absolutely no responsibility or liability for any errors/omissions in the files and/or for any loss of or damage to anything including (but definitely not limited to) persons, pets or property that may arise from the use of these files and the building and use of the circuits they represent.