Deltatrippers:
These days, a dip to 3.7 Ohms in the bass is almost considered moderate given how many speakers drop below 3 Ohms (and even down to 2 or below). To answer your question, the problem with most tube amps driving speakers featuring large impedance dips in the bass is that the amp can't deliver enough current to control the woofers - bass response is flabby and ill-defined.
A real-world example is all of the people out there trying to drive WattPuppies with $4,000 tube amps and getting Sony rack-system bass. Perhaps the best example is the CAT JL-1's mentioned in one of my previous posts, which were the original CAT monoblocks from the late 90's and only rated at 100 watts per channel - they were designed to drive the very inefficient MBL 101B, a speaker which also features wild impedance swings. The output transformer alone in these 192 lb. amps weighs 55 lbs. The bass performance of those amps sounds like a 500 watt Krell. Here is an interesting thread that discusses the CAT amps at length:
http://forum.audiogon.com/cgi-bin/fr.pl?aamps&1099200096&openfrom&1&4
My best hi-fi buddy ran the CAT JL-1 Limited Edition amps (the LE's were $50,000, featuring incredible parts quality) for a few years and they are indeed the king of the jungle. With big symphonic music, a high quality DSD recording, and high-output speakers, they will knock you through the listening room wall on peaks.
I do not know how the Triton would perform with low impedance speakers, but it uses KT88 output tubes, which are difficult to make, the result being frequent tube failure. With KT-88's, it's all the more important to have a knowledgeable, reputable supplier.
These days, a dip to 3.7 Ohms in the bass is almost considered moderate given how many speakers drop below 3 Ohms (and even down to 2 or below). To answer your question, the problem with most tube amps driving speakers featuring large impedance dips in the bass is that the amp can't deliver enough current to control the woofers - bass response is flabby and ill-defined.
A real-world example is all of the people out there trying to drive WattPuppies with $4,000 tube amps and getting Sony rack-system bass. Perhaps the best example is the CAT JL-1's mentioned in one of my previous posts, which were the original CAT monoblocks from the late 90's and only rated at 100 watts per channel - they were designed to drive the very inefficient MBL 101B, a speaker which also features wild impedance swings. The output transformer alone in these 192 lb. amps weighs 55 lbs. The bass performance of those amps sounds like a 500 watt Krell. Here is an interesting thread that discusses the CAT amps at length:
http://forum.audiogon.com/cgi-bin/fr.pl?aamps&1099200096&openfrom&1&4
My best hi-fi buddy ran the CAT JL-1 Limited Edition amps (the LE's were $50,000, featuring incredible parts quality) for a few years and they are indeed the king of the jungle. With big symphonic music, a high quality DSD recording, and high-output speakers, they will knock you through the listening room wall on peaks.
I do not know how the Triton would perform with low impedance speakers, but it uses KT88 output tubes, which are difficult to make, the result being frequent tube failure. With KT-88's, it's all the more important to have a knowledgeable, reputable supplier.