has anyone had a CLASSE AMP CA300 modded


i like the Classe sound on my ATC dual mids but feel it lacks a little of the finer details.
Has anyone had one modded and by who?
thanks john
mclsound

Showing 3 responses by gbart

I have upgraded the IEC power inlet and output binding posts of my CA-300 but that has been it. The input buffer OP amps may be worth upgrading. Also bypassing the +VE and -VE rails at of the output transistors as in the CA-301 versus only two points in the CA-300. Replacing the stock rail fuses with premium ones may also realize some improvement. These were eliminated in the CA-301, so it stands to reason the fuses must have some sonic influence.

PM me if you need schematics, etc. While these can be obtained from the Classé service dept., note that there are several issues with the original schematics. They have a few errors, which I pointed out to them at the factory, the document quality is not that great, and some parts, including the OP amps are not identified. I obtained the parts numbers from the factory, and have schematics that I updated and improved using Photoshop. The updated schematics have all parts identified, are very legible, and have the errors corrected.

http://img.villagephotos.com/p/2003-5/191557/2009226

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If this ringing is a problem in the CA-300, it should also be a problem with the CA-200/CA-400/CA-301/CA-401, since they all use virtually the same style heatsinks and transistor mounting method.
The bolts are very thinly plated plain brass. In addition, the mounting hardware is steel and is in the audio path. The terminations are ordinary tin or zinc ring terminals -- not great materials. My upgrade is to WBT Topline posts with pure copper, gas-tight crimped terminations. If these bolts were so great, you should ask yourself why Classé ditched them in favor of WBT posts ? The posts I installed are also higher up the WBT product line than the posts Classé has been using in their amps.