Question about Audiophiliac review

[dth31]

First some background for my question.  I've built multiple pieces of Bottlehead equipment and loved every one.  Foreplay, Foreplay 3 extended, Seduction, Mainline, and Paramount 300B and 2A3 versions.  In my sonic experience, every piece of Bottlehead equipment has been clear, transparent and generally neutral.  The Bottlehead "sound" has never been warm or syrupy.  I've had some refurbished 1950's amps that sounded warm and syrupy, so I know the sound! 

Thus the basis for my question.  In the original Audiophiliac review, while Mr. Guttenberg obviously REALLY like the Moreplay ("Powerful.  Real oopmph.  Kicking butt.  I was feeling the rock and roll") and connected with it emotionally, he also stated that it is "more than a little rolled off in the highs".  With all due respect to Mr. Guttenberg (which is sincere) I do have a REALLY hard time believing that ANY Bottlehead product would be significantly rolled off in the treble based on prior experience with multiple Bottlehead products.  The Bottlehead website says the Moreplay is only down 1dB at 45K Hz-- NOT rolled off in the treble! Of potential interest, he did not listen to the Moreplay with a tube amplifier.

Mr Guttenberg used 3 different amplifiers in his review, all solid state.  I'm wondering if the relatively high output impedance of the Moreplay (around 3.2K ohms) wasn't a good input impedance match for the solid state amps he used, which may have made the Moreplay sound the way he described.  Of the 3 amps, the Schiit Aegir has a low measured input impedance of 11.5K in the lows and midrange, falling to 10K in the treble, although that is pretty flat.  The Pass Labs XA-25 had a measured input impedance of 47K ohms, falling to 34K ohms in the treble.  (Thanks to Stereophile for the measurements on the Aegir and XA-25.)  The 3rd amp was the First Watt F8.  I couldn't find any measurements, but the First Watt website says the input impedance is 100K ohms.

Any insights or user comments would be appreciated!

[Doc B.]

The Moreplay does sound like our other preamps to me (and considerably better than FP and FP3). Using current rules of thumb I might determine that the Aegir would present too low a load for the MP to be happy and that the other amps mentioned would be very good loads. But this one combination being no bueno is not specifically mentioned in Steve's review. It could be the cables from the MP to any amp were long enough to create a rolloff. Or not, we don't know. The most important thing to remember as an audiophile is that everyone hears things differently. And also consider that whatever Steve heard it was not holding him back from adding the MP to his list of recommended products for 2021. Dave King - the guy who built the Moreplay that Steve listened to - thought Steve's description was different than what he heard. Dave also ran the MP into a SS amp. Hopefully he will not mind me quoting from emails he sent -

"Hey Dan,

well I finished the build last nite, hooked it up listened for an hour, had it on most of the day today, it's nice and warmed up now, and the verdict is: The Moreplay is GREAT.

I was expecting warmer and a bit tubular, which would benefit my all solid state system. What I hear is very linear, more natural "in the room" presence and better dimensionality. Pretty sure I don't need to tell you that tho! Congratulations you have a new fan."

After the review came out Dave and I had another exchange -

"I ended up really liking it's performance on every level...Personally I think the Moreplay hits that sweet spot between vintage and modern perfectly by leaning a bit more to modern. In fact I wonder how you did it with a relatively simple circuit."

What this all demonstrates is the reason I started making kits in the first place. I felt that trying to rely on other's opinions to acquire equipment I liked the sound of (i.e. the equipment review institution) was fundamentally futile for the exact reason we can see above. Everyone - respected reviewers included - hears things differently. I started building my own gear because it was a cost effective way to learn how various design decisions affect the sound. Seemed like a useful approach for others who try to filter through all the opinion too. So we started making kits. The cost becomes low enough that you can more easily afford to purchase the kit and determine if the sound suits you rather than relying upon opinions.

[dth31]

Hi Doc!  Thanks for the reply and Happy Holidays.

I trust your ears and measurements based on my past experience with many of your products.  I suspect Mr Guttenberg either mainly listened with the Aegir or maybe he just over-emphasized what he heard.  For sure he loved the sound and at the end of the day that’s what matters.  In any case, I’m going to try the Moreplay.  I’ve got 2 guitar amps that use 6V6 tubes, I like the sound of the tube, so makes sense to me to try it!

[David Joiner]

My system setup with the Moreplay (which I just completed a couple weeks ago) uses the Schiit Aegir, and I'm driving high sensitivity speakers, Zu DW's rated at 97dB/W/m. I don't hear any significant rolloff or softness in the highs at all.

Interesting, Schiit specs the Aegir at 22kOhms input impedance and with the Moreplay output rated at less than 3.2kOhms (2.1kOhms @ 1V in/1V out we are in the 10:1 ratio of input to output impedance, but the actual measured impedances mentioned by dth31 that started this post seem way too low to what Schiit rates the amp; is Schiit fudging? I assume we can trust Stereophile's measurements?

Either way, 22kOhms, spec'd, or ~11kOhms, measured, any rolloff is imperceptible to me. Doc B. is right, too, in Steve's video, that that wasn't the pre-amp/power amp combo that elicited the "more than soft" comment.

What I may questions, though, is Steve's pairing of the Aegir with the KEF speakers, rated at 85dB sensitivity and a recommended min power of 25W. The Aegir is rated at 20W per channel, so slightly under powered to be driving the low sensitivity KEF's to any volume maybe? Some softness in the highs from that setup? Steve didn't mention it.

Steve stated that the he had a First Watt F8 in the second system with the KEF's, but didn't give any indication that he listened to the Moreplay with that power amp, 25W into 8 Ohms, per First Watt's published spec's, and at 100kOhms, I can't see any issue with that setup tech-wise.

When Steve mentioned "...the highs are a little more than soft..." it was in the system with the Klipsch Cornwall's, but I didn't hear him mention what power amp he was using in the video; did I miss that he mentions using the Pass Labs amp? The specs for the XA-25 seem more than adequate paired with the Moreplay and Cornwall's - yet in his latest review of the Cornwall IV's (April of last year, yes I just re-watched it) he gave no indication of high end rolloff - but again, no specific comparison to the whole system or specific pre-amps or power amps and overall sound other than "Everytime I made a change [pre-amp and/or amp] the Cornwall sounded different" and "every little change makes a difference, a difference you can hear, sometimes for the better, sometimes not so good." Did one of the setups cause the highs to be soft?

So yeah, in the video, his "more than soft" comment wasn't referenced to any other setup, so, I guess, take his comment with a grain of salt; soft compared to what? The softness certainly may have come from another component in the system, or even the recordings he used in his review (listening to the Paul Ley recording, I'd say the highs are a bit soft to my ear but definitely not in the Black Keys recording) or just his ear. If I recall correctly in some past Audiophiliac video (yeah, I watch Steve's videos religiously), "Your mileage may vary."

To dth31, FWIW, with my Aegir and Zu DW's, the Moreplay is a definite winner setup (which also includes a Bluesound Node2i streaming Tidal and a Schiit Audio Bifrost 2 as the DAC (yes, I'm not using the internal DAC in the Node2i).

On to more tube rolling (ah, yeah, that bug has already bit me when I built my crack.)

Oh, one more thing, I noticed in my setup, too, that the gain in the Moreplay combined with the Aegir and DW's, that the volume can get pretty loud without using the entire range of the volume knob's 300 degree rotation, and Steve mentioned adding external attenuator resistors to "fix" that, but, really, is there an issue with the pre-amp gain being too high? What is the concern, and what will the attenuators buy me? I am able to control the volume from min to max even with the few degrees of knob rotation. (This is the same with my Crack Headphone amp with Senn 600's; 100 degrees or so of volume pot rotation, and I'm at max loudness.)

[Paul Birkeland]

There isn't a major issue with gain provided you have enough rotation in the preamp volume pot to give fine control.  For what it's worth, the gain of the Moreplay is about half of what most tube preamps offer, so this issue is naturally a bit mitigated. 

Soft highs when paired with a Moreplay would possibly be more of an issue with cable capacitance and input capacitance of a given power amp.  This is often indicated in a review where they will say something like "100K input impedance but drops to 50K at 20kHz".  That kind of spec indicates some input capacitance that can cause soft treble with a preamp like the Moreplay.

[dth31]

One of the reasons I initially asked the question about the “highs” comment was that Mr Guttenberg provided no context for his comment (ie which specific equipment in his review the comment pertained to).  And to be frank, I found the comment very hard to believe unless there was a component mismatch.

My Moreplay kit should ship next week.  Once it’s completed I’ll post my experience with a 2A3 Paramount, 300B SET, and PP EL34 amp.  My usual preamp with those amps is a Shindo Monbrison, so I’m curious to see how the Moreplay compares to the Shindo, too, even with an unfair and almost 20-fold price difference.

[Paul Birkeland]

I did once have someone bring over an Aurieges to compare against a Moreplay.  I'll be interested in hearing what you think.