Are BirdSong amps boutique amps?

No. Boutique amps are crafted by small home based amp builders.

Our amps are designed in Europe and handcrafted by professional builders in China.

The build quality is the same or even better, but the operational cost for building the amp is lower.

Boutique builders do custom work based on your specification, use exotic components or techniques, or design special models.

We don’t do that. We use time tested classic guitar amp circuits with the best commonly available components.



Can I mod my amp?

We do not recommend altering BirdSong amps.

Since the amp circuit is soldered on eyelet board, it’s easy to service and mod the circuit.

However, TUBE AMPS CONTAIN LETHAL VOLTAGES. Do not open the amp if you are not a qualified electronics technician.

But, there are some mods that are safe, even if you are not a technician. See the sections “My amp is too loud” and “Can I change the tonal character of my amp?”



My amp is too loud, what can I do?

An interesting mod is to replace the 12ax7 with a lower gian tube.

5751, 12AT7, 12AY7, 12AV7 & 12AU7 can all be used.

These are all pin compatible with one another, the only differences being the gain factor of each tube.

A tube with a lower gain factor gives you les volume, more headroom and allows you to get a better clean sound out of your amp. Experiment and see what’s best for you.

Tube typeGain Factor



Can I change the tonal character of my amps?

Another good mod is to swap the speaker.

Make sure the power handling (in Watts) and impendance (in Ohm) is the same as the original speaker, as well and the connection to the positive and the negative terminal.

The most commonly used guitar speaker brands are Celestion, Jenssen, Eminence, Weber and WGS.



Should I replace the tubes every year?

As this blog post from Hughes&Kettner explains, good working tubes should not be replaced as often as is generally assumed.

Assuming you play 25 hours per month (6 hours per week), preamp tubes should last more than 33 years.

However, new tubes can be fickle. If you encounter a tube with white milky substance inside, or if you hear a rattling or squealing sound, you should take your amp to a tech to get it serviced.



Can I replace the 6Z4 RECTIFIER TUBE with any other 6Z4 tube from another brand.

No. Our 6Z4 rectifier tubes are made to our specifications, and have another pinout than USA or European models.


Replacing the recifier tube will have no effect on sound whatsoever, and could possible damage your amp. So the only reason to replace this tube would be if it became defective.

You can get a 6Z4 replacement in our webshop.