Threshold s150 or Forte 4a amplifier?

The brushed aluminum top sound like a good idea it will match the faceplate. I think I will do that as well, my mod was a litte crude (prototype) now that I know this mod is for real it's time to refine it some. I'll keep alook out for some donar heat sinks but as my amp runs cool that can wait a bit I have a piece for the bottom. Maybe I should have kept my mouth shut and bought your S150 as a thought acurred about tri-amping in the future. lol Good luck with the Mod Grizzly.

Contact Jon Soderberg [vintageamp@earthlink.net]. He might be able to help you getting the heat sinks.
He used to work at Threshold and repairs/modify all Threshold/Forte equipment.
He is a great guy and does avery good job. He had worked on my Threshold T2, DAC 1e and a S450e that I had.

Thanks for the info!

I switched to Forte Model 4/4a amps many years ago and have never looked back. Few amps can truly "outclass" them, and even then... at MANY TIMES the price. The only drawback I can pereceive is their handling of low bass, which is just a tiny bit thin and, well... lacks a modicum of control. Many will argue this point... please have at it :^)

For my subs, I use Adcom 555's, which are fabulous sub-bass amps... though they're just a smidge gritty on mids/highs... IMHO. Some will disagree... and that's okay :^)

Few truly affordable amps can faithfully reprodruce all frequencies extremely well. My solution is to bi-amp as above. It works for me.