FET Valve Ultra 350

willpower45 · « **on:** 3 Jun 2010, 11:50 pm »

If used well within the capabilities of the standard Ultra 350 (medium sized room, easy to drive 91dB speakers), would the double die option improve the sound?

avahifi · « **Reply #1 on:** 4 Jun 2010, 07:18 pm »

With 91 dB efficient speakers, I would not expect the Double Die option to be of any great extra value to you.

However, if you are ordering the amp new, the option cost ($264) could be of real value if you ever switched to low impedance, low efficiency speakers or if you wanted to run a couple sets of speakers or more at the same time.

Best regards,

Frank Van Alstine

Wayner · « **Reply #2 on:** 4 Jun 2010, 08:16 pm »

Isn't a 3db increase in speaker efficiency like doubling amplifier power? If so, going down 3db, would cut the apparent power in half (88bd).

Wayner

ricmon · « **Reply #3 on:** 5 Jun 2010, 01:02 am »

While using my previous Ultra 550 with 90dB speakers I burn one too many tweeters. I wish that the "double" option was available as I ended up moving to a different manufacture. I really like the sound I was getting from my AVA setup but if you want to get the best out of your speakers I suggest the "double" upgrade.

good luck

Brett Buck · « **Reply #4 on:** 5 Jun 2010, 03:56 pm »

Quote from: ricmon on 5 Jun 2010, 01:02 am

While using my previous Ultra 550 with 90dB speakers I burn one too many tweeters. I wish that the "double" option was available as I ended up moving to a different manufacture. I really like the sound I was getting from my AVA setup but if you want to get the best out of your speakers I suggest the "double" upgrade.

Could you elaborate a little more? Why does running a conventional amp blow up tweeters, and why does having a "double die" fix it?

Brett

Tone Depth · « **Reply #5 on:** 5 Jun 2010, 06:07 pm »

Recommended for very difficult loads and for those that want to play unreasonably LOUD. http://avahifi.com/index.php?option=com_content&view=article&id=129&74a0ad6b5f7a1df0ef4ab98b8fffbb41=5c588f8df6023ba297579046a0dbce23

I remember reading about Ricmon being one of those in the second category.

Quote from: Brett Buck on 5 Jun 2010, 03:56 pm

Could you elaborate a little more? Why does running a conventional amp blow up tweeters, and why does having a "double die" fix it?

Brett

Wayner · « **Reply #6 on:** 5 Jun 2010, 06:11 pm »

Speakers generally get blown up with insufficient power. What happens is that the power supply and output transistors start to clip and deliver a chopped off sine wave, that chopped sine wave is now pulsating DC. DC to a speaker is bad because it "freezes" the speaker, time wise, and does nothing but create heat. Heat melts the voice coil wire and silence is the outcome. That is why I always like an amp that has as much power as I can afford.

Besides, ricmon likes to listen to his music LOUD!!!!!!!!

Wayner