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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
Post removed 
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.
eagleman6722
217 posts
 
Divad, I am running a Tube Audio Design-60 with Vandersteen 2CE sigs (86DB I think. This amp runs 60 watts ultra and can be switched on the fly to triode (30 watts). This amp has plenty of juice for the vandys. I listen mostly to classic rock at room filling but, not loud levels and the vandys really sing. See Larryx7s post above. The TAD-60 can handle many EL-34 type tubes and is easy to bias. Check out the reviews on this amp. I haven't heard many other tube amps to compare but, I bet that it competes very well with amps in its $1300 class...

Eagleman
Post removed 
newbee
4,767 posts
 
Tvad, This info came from the horse's mouth. I've never seen it in print, its what Ty told me.

Re impedences, there was an excellent thread in which Duke participated, within the last 6 months, where in not only were speaker impedence loads discussed but amp output impedences were also discussed. Amp putput impedences are seldome discussed and their impact is not generally understood. Most folks assume they are constant but they are not, they rise and fall with frequencies and have considerable impact of the sound which is produced by a speaker. You might be able to ferret it out by looking up some of the threads in which he participated. And, I think you are right the Ralph could help explain, but I can't recall if he participated in that particular thread. Maybe you could start a thread and get a discussion of this going and invite Duke and Raplph to participate. This may help you. Good luck......
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