Services

I also do services to traditional tube amps when needed. If there is a need to replace tubes to an old amp, it is also possible that power supply capacitors have to be replaced. When servicing amps I always do general overlook to the whole amp to ensure that everything is working. If there is need for a larger service, I will contact customer before doing anything.

Modifications

Here are some examples of modifications that I have made to different amplifiers.

Silver Face Fender to Black Face

Many Silver Face owners have heard that his amp can be modified to Black Face with reasonable costs and efforts. Modification improves amps dynamics and distortion character. Price of this mod is 80 €.

Marshall JCM800/2203 + 2204

This amp has a legendary reputation in many rock bands and records. It is a good amp for hard rock etc. but it can also be improved with modifications. Bluetone Dusty Road Crunch-channel is based on this amp and is an improved version of it. The price of modification is 120 €.

Power Scaling/VVR

Many times there is a problem that you have a very powerful amp, but there is no way to get power amp distortion out of it without heavy sound pressure. Here are some examples how to make it.

Master Volume

There are a lot of powerful tube amps without any Master Volume. One solution is PPIMV (Post Phase Inverter Master Volume), which means that it is assembled after phase inverter tube. This way you get also this tube distortion with reasonable sound levels. The price of this modification is 80 €.

VVR

With PPIMV it is good to use also VVR (Variable Voltage Regulator), which means a way to adjust power amp output level dynamically. VVR is connected to amp power supply and it does not work in signal chain. With VVR you can adjust output level from full power to even bed room level.

In high gain amps VVR works best with PPIMV, which prevents power amp overload when power tube plate voltage and output level is very low.

Fixed bias amps (Marshall etc.) need their own VVR circuit and cathode bias amps (Vox AC30 etc.) need their own due to different technical architectures. At the moment VVR can be only used in amps with maximum 50 W output power.

The price of fixed bias VVR is 150 € and cathode bias 80 €.

Other modifications

I also do other modifications when needed. In this case you can ask an offer of them.