Transitioning from SS to tube amplification

Thanks, Grinnell. I really like these speakers and, so far at least, am pretty happy with the combination as described. I seldom listen at volumes that most would consider loud so, perhaps can keep the PL Prologue One. I currently have the preamp volume level set at 10 o'clock and the Prologue set at 9. Just to see what the results would be, I cranked the pre up to what I would call very loud. Because I heard no clipping, does this mean that the amp and speakers these speakers are compatible? I know that there are features built into their later models which make them somewhat more desirable but I'm wondering if there is any significant sonic difference.

Hi Jim (Broadstone),

I think I may have mentioned in one of your past threads that if the sensitivity of your Reference 3A speakers is comparable to that of the Reference 3A MM de Capo BE, per the measurements for that speaker shown here the 91 dB figure may be optimistic by around 5 dB or so.

Nevertheless, for solo guitar recordings, and for a considerable majority of recordings in most genres, I would certainly be surprised if the 35 watt capability of your amp proved to be insufficient.

A point to keep in mind is that what is usually the most significant factor in determining how much power is required is not volume or perceived loudness per se, but the dynamic range of the music that is being listened to. Meaning the DIFFERENCE in volume between the loudest notes and the softest notes, with well recorded minimally compressed classical symphonic music generally being one of the most demanding genres in that respect.

Many and probably most "pop" recordings, for example, are compressed to dynamic ranges of less than 10 db, which means that less than 10 times as much power will be required to reproduce the loudest notes as will be required to reproduce the softest notes. While many classical symphonic recordings will have dynamic ranges in the vicinity of 30 db (requiring 1,000 times as much power to reproduce the loudest notes compared to the softest notes), or in a few cases even more than 50 db (requiring 100,000 times as much power to reproduce the loudest notes compared to the softest notes; and no, that is not a typo).

For example, I have more than a few well engineered classical symphonic recordings in my collection which when played at modest average volumes of 75 db or so at my listening position, with the softest notes being in the 50 to 60 db area, will reach brief dynamic peaks of 100 to 105 db at the listening position. So most of the time the amplifier is putting out tiny fractions of a watt when playing those recordings, but brief dynamic peaks will require a great many watts.

From a subjective standpoint, though, loudness tends to be perceived based on the average volume of the music, not on the basis of brief dynamic peaks that may last for only a fraction of a second. Bear that in mind when considering Grinnell's comments.

Finally, with respect the 10 o'clock and 9 o'clock level settings you mentioned, keep in mind that those settings don't necessarily imply very much with respect to power. The relation between volume control settings and volume levels relates more to the gains and sensitivities of the equipment than to the maximum power and maximum volume capabilities of the equipment.

Best regards,
-- Al

Try setting the PL volume @ maximum and then adjust the PT's preamp volume accordingly.

I assume the PL does not have pre/out amp/in connections, which would be better.

Anyway, depending upon the PL's design, running its volume pot @ max should pretty much remove it (as much as possible) from the signal/music chain.

Knowing the impedance curve of your speakers will help determine how tube-friendly they are. FWIW, 8 years ago, I transitioned from a 300w dual-mono solid state amp w/e-stats to 35w tube mono-blocks w/box monitors - rated at 89db. Fortunately, they have a relatively flat impedance curve. Back then, the music reproduction was pleasant but fairly boring. Now, it's dynamic and captivating. Both acoustic and electric guitar sound phenomenal. What has changed is years of tweaking ALL cables and power supplies. Recenty,I swapped out $50/ft speaker cable for $1.79/ft wire. Huge improvement! Thanks to the amazing members of the Audiogon community, I've learned that it's all about the synergy. YMMV.

Yes, Al, I took your previous explanation to heart and found that the best example of dynamic range in my favorites collection Is I n the overture from Tannheuser relative to the relatively quiet lead in to the overwhelming brass. The range in this case, using an SPL meter, was about 50 dB starting at about 48. With the current setting on the Prologue the max volume is about 103 for this piece which is way more than I could take for very long. However, it sounded pretty accurate. Also, I reviewed the charts you referred to and the sensitivity is substantially lower than advertised and consistent with your previous comments. It's a disappointment but I can get by with it until I decide where to go next. I'm impressed with what Ive read about other PL amps and am tending toward staying with this manufacturer with one or another of their models, perhaps a dedicated power amp. For the music and volumes that I most listen to the current setup is quite satisfying. BTW, the mention of the clock dial setting was part of what the previous owner recommended to avoid clipping. In messing with various settings and volumes I've not been able to hear any so far.

Delay, thank you and I'm sure what you're saying makes good sense to those who have a better technical understanding of these things but I need a little more explanation to get my head around it. Also, what makes it a little more difficult is the fact that, right or wrong, I've always avoided maxing any controls thinking that that was an area where undesirable things start to happen. One thing I tried was to take that setting up to about 3 o'clock on the Prologue and at one point in a fairly loud playback I got a somewhat boomy sound of a lower mid frequency. Lowering the pre strength cured the anomaly

Steakster, it's good to hear that you had success with a similar setup and I thank you for sharing it. The bottom line here, I suppose, is that I truly like both the MMC's and the Prologue but I want to maximize within the constraints of my budget, of course, and need to decide which component to concentrate on. The most obvious or practical solution may be to find a more sensitive speaker.