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Using digital preamp to tube power amp questions

A while ago I was looking into trying tube amplification in my system and received a lot of good advice here. However, at the time I was using Martin Logan electrostatics and just couldn't get comfortable with issues related mostly to the inordinately high current requirements of these speakers. Recently, though, I bought a pair of Serie Reference 3A monitors which I seriously like and decided to pursue the idea again.

The reason for this post is to seek advice regarding the use of a digital preamp (Peachtree Nova) with a tube based amplifier because of the latitude I have with its large number of digital and analog source inputs. If the benefits of using tubes come primarily from the use of the preamp, I'll not pursue this issue. However, if those of you having experience with a similar setup have had good success I'd appreciate hearing from you. My current setup is this: Shanling CD-S100 CD player - Peachtree Nova as preamp - Behringer UltraCurve DEQ 2496 equalizer- Peachtree 220 amp - Martin Logan Ethos or the Reference 3 A's, depending on which speakers I decide to keep.
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broadstone OP
277 posts
 
Czarivey, input sensitivity for the 300SE is 0.75V for full output. The best I can determine is that the pre out voltage of the Nova is much higher than that so it seems that it should work.
ZD, I really don't know enough to make an informed decision about PP vs SE for my purposes. It would make sense, I suppose, to choose the more powerful amp if I were to choose to continue using the Ethos' as long as the current capability was adequate. On the other hand, if my understanding of their personalities is correct, SE would likely better suit my tastes. Also, price has to be a consideration in my consideration.

It looks like I've got some more studying to do.
atmasphere's avatar
atmasphere
7,068 posts
 
If you want to use a Single Ended Triode amplifier, you will need a speaker with a lot more efficiency! For best results, whatever the power rating of the SET is, it should not be driven past about 20-15% of that value. For best results.
broadstone's avatar
broadstone OP
277 posts
 
Atmasphere, much of your advice given to me in the past on this subject was during a time when I was committed to my ML's but now that I have started using these Serie Reference 3A's and I'm pretty sure I'm staying with them. These have an efficiency rating of 92 or 95 depending on which article I've read and the amp in question here has a power rating of 30-40 WPC. Is that something I can live with using a SE amp?
almarg's avatar
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almarg
8,673 posts
 
Jim (Broadstone), according to the manual the 300SE is rated at about 10 watts, which actually is a bit more than is typical of many amps which utilize a single 300B output tube per channel. Cary also produced a 300SSE stereo amp, BTW, which used two 300B's in parallel per channel, rated at 20 watts.

Also, if the sensitivity of your 3A speakers is anything like that of the currently produced Reference 3A MM De Capo BE, a note of caution: Based on these measurements the 92 db sensitivity rating of that speaker is arguably optimistic by as much as 6 db (which is a factor of 4 in power terms).

Finally, keep in mind that the most important factor affecting how much power may be required will often and perhaps usually be the dynamic range of the music that is listened to (i.e., the DIFFERENCE in volume between the loudest notes and the softest notes, with well recorded minimally compressed classical symphonic music often being the most challenging genre in that regard).

Best regards,
-- Al
broadstone's avatar
broadstone OP
277 posts
 
Al, I have a call in to Mr Goka of Divergent Technologies to get what I can from him re this subject of sensitivity as well as his recommendations for upgrades or cap replacement for these 2 decade old speakers. I'm actually afraid to mess with them too much, though, they sound so good the way they are.
BTW, most of what I listen to has a fairly limited dynamic range and I listen to symphonic music only occasionally so, hopefully, that won't be a significant issue.
Thanks for pointing out the model number; I just knew that it was 2 monoblocks sharing the same chassis and thought they were the SE, not the B's. In reading the online 300SSE manual myself the rating published there is, indeed, 20 WPC. Considering the owner's opinion re the power rating, I'm beginning to wonder what the model really is. He did say it was a custom chassis and I haven't yet seen it.
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