TUBE AMP NETWORK WIKI


Click the accordions for more information on that topic. Please let us know if you see anything amiss.

SAFETY

Please review these safety tips before opening up, repairing, or building any amplifier.

  • UNPLUG IT – Never work on an amp that is plugged in. The exception is when you need to take live voltage measurements. While an amp that is not plugged in may have stored voltage, a plugged in amp will ALWAYS have stored voltage.
  • DRAIN IT – Give the amp time for the capacitors to drain. A capacitor can be like a battery, storing up high voltage for when it is needed. This means that even with the power off, it can store a high voltage for a long time. Give the amp 5 minutes to drain before working on it.
  • BLEED THE CAPS – Just because you let the amp sit does not guarantee that the high voltage has drained, in fact, always assume it HASN’T. There are a number of ways to do this. The easiest is to build a discharge jumper with two insulated alligator clips connected to a wire with a resistor in the middle. Use a value between 10K and 100K for the resistor. Clip one end to ground and the other to the positive (+) end of a filter capactior. Leave the jumper in place while you work and remove only when you are done.
  • TEST VOLTAGES – Make SURE the high voltage caps read a very low voltage. Aim for a few volts, no more than 10V.
  • PROBE WITH ONE HAND – Leaving the other hand in your pocket. This way, any stray voltages, or if you skipped the steps above, wont kill you. If you make a complete circuit by touching the amp with both hands, the current can flow through your heart, and that is obviously pretty bad. Learn to put one hand in your pocket while poking around an amp . Pick up a bunch of chopsticks while at the local Chinese restaurant. They make great poking around tools.
  • DONT:
    • Work on an amp while intoxicated
    • Work on an amp while tired
    • Work on an amp while distracted
    • Chew on lead based solder
    • Solder in shorts (one drop of molten solder will usually remind you of this fact)

TWO STROKE AMPLIFIER

There have been many questions asking for documents relating to the Two Stroke amp build as outlined in Dave Hunter’s book.

There are a couple corrections to the design in the book. A few parts have been modified as the values printed in the book were not correct. There are a couple parts that have been removed, and there have been some clarifications. The two files below represent the addendum to the book. Additionally, we have supplied a parts list in a checklist format with part numbers and potential suppliers.

REVISED LAYOUT

Revised layout including removal of one of the power tubes, and parts changes and corrections.

ADDENDUM TO INSTRUCTIONS

General notes, clarifications, and improvements to Two Stroke design from Dave Hunter

SCHEMATIC

When building the Two Stroke, it can be very helpful to refer back to the schematic. The Layout diagram shows how things are put together, but the schematic can help troubleshoot and understand the signal flow. Very handy. Please let us know if you find any errors.

PARTS LIST

PDF Checklist of parts required to build the Two Stroke and potential sources with part numbers.

IMPEDANCE CHART
Printable impedance chart to attach to amp. This lists which switch position to use with which tubes or impedances.

PARTS

Below is a list of suppliers for parts and links to their sites.

Amplifiers

This site has just about everything, especially the passives like Resistors and Capacitors. Please make note of dimensions as many parts come in different flavors, mounting types, and sizes.

Fabulous site for parts, kits, speakers, chassis, etc.

Part of the same family as Amplified Parts.

Great source for parts, kits, speakers, chassis, etc.

Much more than just speakers. Weber has great kits, chassis, an awesome selection of hard to find and unique tools, and of course… world class speakers.

Great source for tools and turret boards. Definitely worth checking out!

Kits

Fabulous site for parts, kits, speakers, chassis, etc.

Part of the same family as Amplified Parts.

Great source for parts, kits, speakers, chassis, etc.

Much more than just speakers. Weber has great kits, chassis, an awesome selection of hard to find and unique tools, and of course… world class speakers.

For kits that are clones of famous designs, this is the place. Dumble, Trainwreck, Marshall, Matchless, etc. A variety of build stages is available so you can get what you’re comfortable with.

More of a forum, but an attached site (Doberman Music) sells kits for the projects discussed. A great community of builders.

Speakers

The sites below offer the standard speakers, Jensen, Celestion, etc.

Fabulous site for parts, kits, speakers, chassis, etc.

Part of the same family as Amplified Parts.

Great source for parts, kits, speakers, chassis, etc.

For a more unique sound, try these “non-standard” options. Both the listed companies have great service and amazing product.

Much more than just speakers. Weber has great kits, chassis, an awesome selection of hard to find and unique tools, and of course… world class speakers.

Awesome sounding speakers with some really power behind them. Great pricing as well.

Chassis

Chassis can be bought blank and punched from Mouser or the sources below. The sources below are listed in particular because they offer pre-drilled and pre-screened chassis that are ready to be filled with parts.

Fabulous site for parts, kits, speakers, chassis, etc.

Part of the same family as Amplified Parts.

Great source for parts, kits, speakers, chassis, etc.

Much more than just speakers. Weber has great kits, chassis, an awesome selection of hard to find and unique tools, and of course… world class speakers.

Tubes

Eurotubes is a fantastic resource and great place for tubes. Bob is always willing to help with any question. What tube sounds best in what amp ? Bob will know and is not shy about helping!

Stompboxes

Great site with tons of information from one of the Stompbox experts.

This site has just about everything, especially the passives like Resistors and Capacitors. Please make note of dimensions as many parts come in different flavors, mounting types, and sizes.

Part of the same family as Amplified Parts.

The place to go to get non-standard pedal boxes. Cool designs to get away from the typical Hammond look.