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Tube amps and speaker ohms

In your opinion , do push pull amps work better with 8 ohms or 4 ohms. .I am under the impression the lower the ohms, the more power is demanded from the amp....Another question, are there low powered SET amps ,and high power SET amps?
I'm looking at a 40 watt 845 tube amp for my 8 ohm, 89 db speaker.. just cked the Thor has a 86 db W18 midwoofers(2 per cabinet) and a 88 db tweeter. Will an 845 amp rated 40 watts be able to drive the 86/88 db speaker? With authority, bass, mids, highs, in dynamic sound stage? Synergy? Or poor match?
bartokfan
bartokfan OP
664 posts
 
Divad i had a chinese KT88 amp very close in specs to the one you are looking at. I can only speak for my speakers, the amp did not have enough power. Manufacturers can say "amp has X amount of watts". but are they quality watts?
My Jadis Orch Refer rated at 40 watts, blew out the water a Rotel ss amp rated at 100 watts. Go figure. The quality of trans and specs of the tube is everything. In my experience the KT88 tube is better for higher sensitivity speakers.
I only like KT90 and 6550's,. Well I'll hear the 6550 first time in 2 weeks.
Good Luck
Paul
Baton Rouge
btw not a fan of B&W..too british
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bartokfan OP
664 posts
 
True i did swap the KT90's for th eKT88's w/o biasing. But also had a KT88 NEW intergrated for demo purposes. The amp did not perform on 88 db speakers. Divad may have better luck with his KT88. Both are chinese. Though cayin is chinese I consider that line on european standards. Ming da, and Melody are alos of european standards. The one Didad is refering to is not.
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newbee
4,767 posts
 
Tvad

The Tyler Signature Systems (1 Piece) have a nominal 4 ohm impedence and a minimal impedence of 3.5 ohms. I have driven mine with 160 wt amps w/6550s off an 8 ohm tap, 80 watt with KT88's off an 8 ohm tap, the PrimaLuna Five a 40wt amp with KT88's off the 4ohm tap (and 6550's as well), and my present Cayin a 70 watt amp w/KT88's off the 4ohm tap. The KT88's I was using are SED's. Power wise they all worked fine, the differences were in tone. I also used a 100wt high(ish) current ss amp and it in no way improved on the tube amps.

But, I also used another brand of KT88 in each of those amps and the sound of this KT88 was rolled off/enimic on both extremes and flat in the midrange. Very boring. I would have much preferred some of my 6550's, maybe even some of my old EI KT90's, if that was the only KT88 available to me. If I had speakers with no bass and a bright highs that particular tube might just be the tube needed.

I doubt that BF's experience has anything to do with Tylers Linbrook speakers impedence curve.

FWIW.
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