Modifications

Of course there are many tweaks and modifications to upgrade a amplifier to a better level. You can upgrade the volume pot, or do several other things. There are two modification i want to tell you about.

The Black Gate modification:

As you maybe know the AI500 is a push pull amplifier. Because of that there is a couple capacitor between the two cathodes of the two tubes. These capacitors are directly in the signal path. With the Black Gate modification these capacitors are replaced with Black Gate's capacitors. The sonic improvement is stunning. More space, detail, air, better stage and a more relaxed sound. The Black Gate capacitors need much time to run in, about 100 hours. Directly after the upgrade you will here the difference, but that's not all you get. The sound will change constantly during the burn in period. First a very tight bass, later it will become bold. This will disappear after +/- 80 hours. What's left is a far much better sounding amplifier with the sonic improvements noted before. The sound improvement it's not subtle . You won't recognize your amp back, and that's a promise !
My own amp has this modification. I can only recommend it.

Also the line and phono stage can be upgraded with Black Gate's. The improvement is smaller than the one mentioned above, but very noticeable. Read what other people say about this upgrade in the What do other people say section

The Border Patrol Power supply:

Border Patrol is a company in the UK which is specialized in tube amplifiers. They have there own brand of kits and also services Audio Innovations products. They have modifications for almost any Audio Innovations product. There power supply can be used on many products from many different brands. Even the Audio Note auditorium in the Netherlands uses them on there amplifiers. The Border patrol Power supply replaces the original power supply in the Audio Innovations 500. A cable is connected between the amplifier and the new PSU. It seems this upgrade also makes a big difference in the total sound quality of the Audio Innovations 500. I planned to upgrade my amp with this PSU soon. There is one negative point to this upgrade.
It's very expensive. The PSU cost about € 1000,= and that's very much money for an psu.