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Tube amplifier suggestion for 101 dB speakers

Hello All,

I've been using the Tyler Acoustics PD30s with Classé Sigma solid state preamp and amp combination.
These speakers have two 15" woofers and a horn tweeter, 4 ohm, sensitivity 101 dB.
The above combination is not the best, especially for complex rock music, the highs start to distort, they are harsh, just bad. Never had tube gears, but after reading a bit, these speakers apparently scream for tubes. Actually somebody brought over a hobbyist-made tube amp and yes, the speakers were tamed.
I'm willing to switch to a tube amp but prefer to keep the ss preamp.
Can anybody recommend a few good tube amp matches here, for a max of 3K new or used. Room is just a good medium size. I want something that I can keep for many years if possible and being somehow flexible to tube rolling.

Thanks.
128x128piramis

Showing 9 responses by piramis

piramis's avatar
piramis OP
14 posts
 
First post here but not my first Hifi rodeo. Check out the primaluna HP. It will come with EL34s. Roll those out and roll in KT88 or KT 120’s. I got from Upsacle audio. Ask to speak with Kevin. Before rolling tubes listen to the 34’s.

I’m using the PrimLuna HP/w KT88’s to drive SonusFaber speakers. They need power.
Yes, Primaluna HP has lots of video, demo, etc on the internet.
What I notice as a dilettante is that it uses  8 x EL34 and 6 x 12AU7 tubes from factory. Why is the high quantity of tubes, 14 compared to 4 + 4 in the Rogue ST-100, the latter being even more powerful with the same KT120s.
piramis's avatar
piramis OP
14 posts
 
You mentioned that you'd like to keep the ss pre, however I'm going to recommend that you try a tube preamp for a couple reasons. The preamp tubes can and will tame the treble. Preamp tubes generally live much longer. And lastly, rolling preamp tubes is MUCH more feasible, for example there are basically no nos 6550( a popular power tube) tubes left anywhere, whereas even the most sought after preamp tubes are available.
 Yes I'd like to keep the Classé Sigma pre because it has all the features I need in a preamp. But presently having no experience with tubes, I do not know which mix [tube pre + ss amp] or [ss preamp + tube amp] has more effect on driving my speakers or generally.
piramis's avatar
piramis OP
14 posts
 
All right, I've got interesting and helpful responses, thanks for each and everyone.
You could get a Rogue Stereo 100 100wpc tube amp for around 3 grand. It uses KT120 output tubes and it is a tube rollers dream.

This looks something serious to consider. I do not want to go with mono-blocks, I like the fact that it has balanced inputs and lots of power plus mode switch. The looks it's more of an SS look though. That meter on the top is for bias adjustment reading?
I see that there are auto/manual bias tube amps. In photography using auto mode is for those who don't know anything about photography. Is auto a good thing here with the tubes or manual is the way to go?
I noticed the Primaluna Dialogs are all auto, but the others more or less manual.



piramis's avatar
piramis OP
14 posts
 
shkong78 wrote:

The used ST-100 could be best starting point for you.

If you change stock 12AX7 to Telefuken( around 200$ per pair) and 12Au7 to Amperex NOS (around 120$ per pair), it sound very nice.
Tungsol KT 120 is good and not much choice for tube rolling.
It is not that difficult to adjust bias manually.
Once you do it, it keeps the value for several months or more.
The Rogue ST-100 definitely looks interesting to me as I said before.
Since I want to get involved manual bias won't be a problem, actually would prefer that.
By the way, did these amps have different generations thru the years? Probably not, but the only thing I see that the user manual from their website was issued in summer 2013.
piramis's avatar
piramis OP
14 posts
 
Thanks for the input.
Actually I'm learning as I'm reading about these different tubed designs, never had one before. And there is a lot to read and learn actually.
And am having a look at all these proposed units.
piramis's avatar
piramis OP
14 posts
 
How about Atma-Sphere S30, SETs from Dehavilland like Aries 845s, even the inexpensive Jolida SETs if you can find one.
Perhaps someone can chime in regarding experience with 300Bs when dealing with a 4ohm load? That would help him narrow things down a bit. Cheers,
Spencer
Actually yes, looking at the specs of my speakers, the logic says to go with SET amplifier.
The  Atma Sphere S-30 looks interesting, but is classified as an OTL type.
Now what?
piramis's avatar
piramis OP
14 posts
 
That's right, I'm not driven here by need of high power.
The speakers are highly efficient here with 101 dB, but also they are 4 Ω in impedance which I guess will limit the amp selection.
Here is the Atma-Sphere S-30 but they want 8 Ω and up speakers at least. This is an OTL type amp.
Then come the SET amps, I think this is the category what I need.
piramis's avatar
piramis OP
14 posts
 
I kind of understand now these particular types of tube amps and how should they be matched.
And more and more I think that the problematic thing here is the 4 Ω / 101 dB combination for the speakers I have.
So there is no need for high power, that's a SET amp then, class A and no need for biasing anything. Cool, but I need a stereo, preferably with XLR in. I can hardly find something used under 3K.
I thought a BAT VK-55 would be good, but that,s not a SET.
I'm telling this territory is not easy, a push-pull would be much easier to pick.

piramis's avatar
piramis OP
14 posts
 
I’m not looking for an integrated amplifier, never liked them, need the flexibility of a preamp.
These Line Magnetics are very rare in this NA market at this point, at least what I can see. They may be good though.
 Thanks.
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