[ddoyle777]

A new amp from a new company. A report of discovery.
The first post is my narrative of finding Shaker Logic Audio.  The Enthrall review is in the second post.  So jump there if you don't want to read my report of discovery.
 
 
Why is it that every time you make a change in one component you need to change six more? I thought this wouldn't happen when I recently upgraded my headphones because I already had an amp powerful enough to drive anything on the market. I told my wife that I wouldn't need to buy anything else . . . and I believed it!
 
Maybe I better backtrack to the beginning of the story. So, in a scenario we are all familiar with, I was in search for a set of headphones. My primary set of headphones was the Audeze LCD-2s. It wasn't that I was displeased with the sound of them, it was that my neck couldn't take the weight anymore. I found I was passing up listening to music because I could only wear them for about a half an hour before my neck started aching. I knew there had to be better out there, so I went looking.
 
What I came across was the Fostex TH900s. There are plenty of reviews and impressions on head-fi, so I won't go into that here. But I was very impressed with them. They were very light and comfortable. I could wear them for an entire evening and not be fatigued - either physically or sonically. They handled Bach organ with power, which is a primary characteristic I want. But in one way they were very different from the LCD-2s. They were very low impedance and very efficient. The impedance for the LCD-2s is 50 ohms and they need lots of power to drive them. I had settled on the Schiit Lyr to drive them and, with the exception of the LCD-2’s weight, was happy with my setup. The Fostex are 25 ohm impedance and so efficient that you can drive them with an iPhone. The problem occurred when I hooked them up to the Lyr - an irritating amount of tube noise.
 
I had three choices. One was to return the Fostex to Headroom and stick with the LCD-2/Lyr, but my neck said no. Choice two was to live with the tube noise. Nope. Besides there was some speculation on the boards that the power of the Lyr would shred the efficient TH900s if I wasn't careful. At 2K for the Fostex I didn't want to worry about being careful. So the third option was to sell the Lyr and find another amp. Being a faithful and loyal member of Head-Fi that's just what I did.
 
My search took me all over the web with my primary resource being the boards here at head-fi. I had a number of threads bookmarked and read them diligently. I also knew that there was a high end audio store about 45 minutes south of me. So one day I made an unexpected stop at Fidelis AV in Derry, NH (www.fidelisav.com). I've bought a few things there and have found them good folks to deal with.
 
I was ushered into a room that was primarily for headphones. A rack with different amps, a collection of Grados and Audeze phones, and a couple of chairs. Bill went in search of some classical cds for me to play with, put them on the rack and said, "Have fun. Call me if you need anything." Then he left. I found a few appropriate cds and started to listen. I had come to check out a Musical Fidelity amp they had. It was in my price range and had gotten fairly good reviews. I listened to the Grados and then the Audeze using it and just didn't like it. To my ears it was a bit clinical and the treble was pretty aggressive. Time to move on. They had a Bryston something or other - didn't impress. They had a used Red Wine Isabellina that was very good, and very out of my price range. There were a couple of other amps that were kinda nondescript as well.
 
But, and here we get to the good part, sitting on the top shelf between an expensive Bryston and the Isabellina was a little box with a name I'd never heard of. It was a Shaker Logic Audio Enthrall. It looked out of place between the heavy hitters, but I was not moving toward anything else so I thought I'd give it a listen.
 
Wow! This little box was almost as musical as the Isabellina. I mean, it was really close, and at about 6 inches by 2 inches, I doubted it was a 2 kilobuck device (although with audio one never knows!). I listened on the Grados, and then the LCD-2s and then back to the Grados (btw they were the 325is for the curious). This amp was musical. I found myself settling back to listen to the music rather than being obsessed with the sound. I knew I was on to something when I realized that I had the same cd playing for about 30 minutes. The Enthrall was a simple looking beast. It had the plug for the phones, a power light, a volume knob and a switch called "optimize" on the front; no lcd panel, no meters, no elaborate controls. The back was just as simple - a place for the power cord, a set of RCA jacks and an power switch.
 
I put everything back in its place and went out to talk to Bill about the Enthrall.
 
He said it was made by a new local company (I'd figured that with the name - Shaker is probably something in NH) and the head of the company and the amp designer was their chief technician. This technician was unsatisfied with some of the high end products that he worked on for Fidelis and thought he could do better. The amp in the store was more or less a working prototype or something like that and it didn't appear that its as for sale. Bill gave me the address of the Shaker Logic website (www.shakerlogicaudio.com) and suggested that I contact them and see what sort of a deal they might be offering.
 
I emailed David Plummer and said I was interested in the Enthrall and what could they do for me. We exchanged a few emails and had a phone call. I was very interested and wanted to buy it. The amp retails for $795 and as soon as he built it he would send it over to Fidelis for me to pickup. In the meantime I spent some time reading the material on the website, especially about the "optimize" switch. I was pretty intrigued about that. More on that later.
 
A couple of days later I drove back to Derry to get my new amp.
 
I plugged in to my stereo and turn it on. When I plugged the Fostex in I heard a low buzz – ****, an ac hum. All this to leave a tube hum behind and now I've got an ac hum. Damn, damn, damn! It wasn't very loud, but you could definitely hear it during the quiet passages. And you know how it goes, once you've heard it you can't ignore it.
 
I emailed David - "Help! I've got an ac hum." He suggested a cheater plug. Nope, no difference. Then, to my surprise, he called me and said, "Let's get this taken care of." I've never had a component designer call me to personally take care of a problem. We tried a few different things, but nothing helped. “Let me think about this,” David said.
 
I was getting frustrated because I felt like I was so close to the system I was looking for. The amp, when it wasn't humming, was very musical. It handled Bach organ easily and the bass was solid. I knew that I could live with it if there was no hum.
 
A couple of hours he called back and said he had a theory but that he would need to purchase some headphones that were like mine - very low impedance and very high efficiency. He wanted to know what I had so he could try and duplicate the problem on the Enthrall he had in house. I offered to send him my Sennheiser Momentums so he didn't have to buy anything. (I was also hoping to speed things along, truth be told!).
 
I ran to the post office to get them on their way.
 
Over the next few days I continued to listen to the amp and was both more impressed and more depressed. I noticed that on higher impedance phones the hum wasn't present. I found I was listening more and more to the HD800s that had been put on a back shelf with the arrival of the LCD2s. There was plenty of power to drive them and they sounded very good. I preferred the Fostex more, but when the hum got too irritating I would switch to the HD800s and wish for the hum to go away.
 
I got an email saying that David had a fix. He also wanted to change the design of the amp slightly and the parts would be in soon. Was I handy with a soldering iron? If so he offered to walk me through a quick fix. Nope, don't know my way around a soldering iron and I didn't want to kill the amp. So I chose to send him my amp and wait for him to fix it.
 
During the waiting he called me to keep me posted on the progress and to "set my expectations" as he put it. He told me the problem was that the hum was because of (a) the way he routed the wires, which he had now changed, and (b) because ac throws out interference. He said that the hum was now down to a minuscule 108db down. I was impressed even though I had no idea what that meant. He said the only way to totally eliminate the hum with low impedance, high efficiency headphones was to completely take the ac circuit out and run it on battery. He told me to listen to the amp and if, at any point, I was dissatisfied I could return it for a full refund.
 
About a week later I had my amp and Sennheisers back and was ready for some more listening with a bit of fear and trepidation. Would the 108db down hum ruin the amp? Has the new circuitry changed what I like so much about it?
 
I have to be honest, when I plugged the Fostex into the amp I could still hear an ac hum. But it was way, way down in the blackness. I was listening intently for it and I did notice it. But when I put on music I couldn't notice it at all. Before I'd hear the hum whenever the music got quiet. Now, I couldn't. At first listen it seemed that whatever rewiring and praying over the amp that David did was going to be sufficient. I’ve been listening to the amp for well over a week since it returned and most days I can’t hear the hum when there is no music playing, and I’ve never heard it during quiet passages, and you know I’m listening for it!
 
I couldn't tell if the new circuits made much of a difference or not. The problem here is that I don't have a very good aural memory. I probably could hear the difference if I had an old amp next to a new amp. But I'd been without it for a week and I just couldn't remember that much detail. Was it worth the wait?
 
On to the formal review.

 

[ddoyle777]

Shaker Logic Enthrall Review
 
My biggest impression of the Enthrall is that it's transparent. Let me explain. I've listened to some audio equipment that goes out of the way to stand out. "Hey YOU!," it screams, "Listen to ME!!!! I've got great, booming, skull rattling bass. MY bass is so great that it overshadows all else!" Perhaps instead it says, "ear piercing treble here. You want treble - I've got your treble." Some equipment is designed to draw attention to itself at the expense of the music. We're usually impressed with these pieces, "Now that's bass," we say. But if we make the mistake of purchasing these we are usually very unhappy in a few weeks when we discover that we can't find the music in the midst of them. That's why the best amp is "straight wire with gain."
 
The Enthrall meets my understanding of straight wire with gain. It gets out of the way of the music. It understands that while it may be an important performer, it's not the star of the show. I find that, even though I'm trying to listen critically to prepare this review, I just can't. I find myself time and again sitting back and enjoying the music. I go to a track that I know well to hear how the amp handles it and the next thing I know I'm five tracks beyond "enthralled" by the music. The Enthrall is doing something very right here.
 
So, I think it's musicality is the prime characteristic of the Enthrall. What about the other stuff?
 
Working up from the bottom - The bass is excellent. I judge bass by two factors. The first is how well it reproduces the low pedal notes on Bach organ. This has to have both depth (it's not just reproducing the frequency, it's got to feel like it's three dimensional), and grunt. I'm not sure what the proper audiophile term for bass grunt is but to me it's the quality and gives the sense of air being moved that you can feel. If you listen to a really good speaker system Bach organ will sent vibrations through the air and floor to rattle things like your rib cage. It's a sense of presence which makes the music almost touchable. This is incredibly difficult with headphones. To achieve it you must have a great recording, a great pair of phones and a great amp. If any one of those three isn't there you wind up with ho-hum Bach. The combination of Anthony Newman on Newport Classics with the Fostex TH900s and the Enthrall give me depth and grunt as well as anything I've heard. It makes me feel like I'm hearing the Great Organ at Methuen sitting center balcony. The second quality I listen for in bass reproduction is speed. The note has to sound as quickly as it would if you were listening live. The kick drum has to have kick, the bass string should have pluck, and you should hear the bass drum instantly. There should be no sense of sloppiness in the formation of the sound. Personally, I'd trade lower notes for quicker bass anyway. I don't like sloppy bass.
 
The Enthrall / Fostex combo is great here as well. These are some radically quick phones and the amp keeps perfect step.
 
The midrange is exceptionally sweet. To my ears it just sounds right whether I'm listening to cello or voice or whatever. The midrange feels planted where it needs to be. There is a wholeness about the music that encourages listening. I'm at a loss to say more about the midrange because it's so unremarkable - there's just nothing wrong with it. Most reviews where midrange is talked about a lot are complaining about something. I have no complaints here
 
The treble is a little on the laid back side. It's all there but it doesn't have the aggressiveness that many amps I've heard have. For a while I couldn't listen to any music that had a recorder as it would just sheer my ears off. Even Michala Petri's sweet tone was unbearable. But with the Enthrall I can listen to my heart's content and my ears don't bleed.
 
The "optimize" switch
 
There's this little switch on the front of the panel. It says "optimize." Optimize what? When I was listening for the first time at Fidelis I wondered what it did so I flipped it and didn't really hear anything. Ah, another gimmick, I though and ignored it for the rest of the listening session. After all, if the basic amp couldn't do the job, I wasn't interested in some electronic trickery to fool me.
 
When I returned home I spent a bit of time on the Shaker Logic Audio website where David Plummer explained what the circuit did.
 
He writes: "The most striking subjective feature of the Attune Effect is that reproduced music takes on a "wholeness" and "rightness" that is akin to injecting life and body into the music." "The second important feature of the Attune Effect is to uncover instrumentation in the music that was previously all but unnoticed." Finally, he says, "Another readily apparent feature of the Attune Effect is to bring out spoken and sung details. Lyrics that were previously hard, even impossible, to hear are given clarity by making them more distinct."
 
The full document is available on the website (shakerlogicaudio.com)
 
Frankly, I didn't bother with the switch before I received the amp back in it's new and quiet condition. Since then I've listened intently to the off and on qualities it brings.  
 
First, it's is really subtle. It's not like hitting the mega-bass button on a boom box. I hear something to be sure, but it's subtle.
 
Second, it's not present with every recording. Maybe it only enhances bad recordings, or only good recordings, or some such thing. I'm not sure I'm able to narrow it down. David says it's more apparent with open headphones than closed. Since I've spent the great majority of my time with the closed Fostex I might be missing some of the effect it would have if I were listening to the HD800s. I'll get to the HD800s eventually and add my findings then.
 
Third, I agree that the music has a wholeness or rightness. I think the amp as a whole has thing and the "optimize" switch adds a bit of dimension to it. But let me try a few images to describe what I'm hearing.
 
Have you ever walked into a room and looked at a person who was just kinda bored, seen the way their eyes looked a bit dim. Then they turn and see you and brighten up. That's how I feel about the "optimize" switch - the music has a bit more life to it. No radical change, it's the same face, but the eyes show a bit of life that they didn't just a few seconds ago.
 
A second metaphor is that it feels like you have an almost fully inflated balloon, but it doesn't have the tautness and bounce it will have when you blow the last few breaths into it. The difference between the two states - mushy and taut is the difference between having the switch off or on. There's no "pop" when you flip the switch, it's subtle. But the more I listen, the more I can identify the position of the switch.
 
Finally, I've come to the conclusion that I'll just keep the switch on and let it do it's work where it can and not worry about it. It's a positive addition and I'm sure many will appreciate the fact that they can turn it off and hear the amp without anything. I'm just listening to music here and want to hear it the most lifelike, the most pleasant, the most realistic I can. So I'll take mine optimized please.
 
Conclusions:
 
First, I bought the amp. I didn't return it. I paid my own money for it so that ought to say something.
 
Second, it fits the bill for what I was looking for. It might for you, it might not - that's your call.
 
Third, working with David Plummer to get it right was a delight and kinda fun. It feels like I have been dealing with an audiophile craftsman and not an assembly line. I'm sure that has influenced me, but if the amp didn't perform I wouldn't have kept it.
 
If you've read this far you can tell that I'm not a numbers sort of guy, so if you have those type of questions go to the Shaker Logic Audio website. If you have user type questions I'll try to answer them.
 
For now, I'm really enjoying my library more than I have in a long time. The combination of the Enthrall and the Fostex are a winner.

 

[ddoyle777]

Reserved for Enthrall review with other headphones.

 

[nplummer]

How is the Enthrall working out now that you've had it for awhile? Let us know if there is anything Shaker Logic Audio can do for you.

 

[TIMITS]

Hi ddoyle77,
 
Pretty nice review of the Enthrall.  I checked out the Shaker Logic Audio website and noticed that they have another amplifier called the Attune. Have you had the opportunity to compare the two units?

 

[skullguise]

FWIW, I was at the same store, Fidelis, this weekend, and also heard the Enthrall; I didn't even know this thread was here, and never heard of the company before.  As with David, Bill sent me in the headphone room as well, turning on lights to see better.  They also had RWA, Bryston, and two Musical Fidelity amps. The Enthrall had a nice etched panel in silver, in a standard DIY type case.  A nice touch was the wooden volume knob....
 
They had on hand the Grado's (325, 80, and 125), the LCD-2's, and the Focal phones.  I had previously heard the Bryston driving the LCD-2's and - while it had plenty of power to handle them - I didn't like the combo.  Too bright.....
 
I tried two of the Grado's, the Focal, and then LCD-2's with the Enthrall, driven BTW by an Arcam CD player.  CD I listened to was a Chesky recording with Monty Alexander.
 
In short, the amp delivered nicely, in the all the nice ways.  I can pick apart certain frequencies, certain hi-fi attributes, but would prefer to limit to highlights.  It did most things well, but two things stuck out to me: details and soundstage.  Especially with the LCD-2's the soundstage was just great; even with the normally in-your-face Grado's it was very good.  I heard plenty of details in that space, and the well-recorded Chesky CD did very well even through the headphones.  The frequency extremes were good, even though I've heard better.  Bass was tight and tuneful, but not quite as deep as I've heard with other combo's.
 
The Enthrall had decent power to drive the LCD-2's; I had the volume turned up to 1:00 max, and it was comfy without any strain.  I don't tend to listen too loudly, but the music easily covered the sound of the room next door, with speakers playing loudly, 4 people practically yelling to each other, and both doors open.
 
BTW: the Focal didn't sound great through this amp, a bit too laid back for my taste....a tiny bit flat.....
 
I'll be keeping my eye on this amp for sure.....may bring my Senn 800's up next time.....also curious if they will get an Attune in, would be interested in trying some of its custom settings.

 

[ddoyle777]

I've been listening to the Enthrall almost daily for two months now and it hasn't lost any of it's luster.
I have spent most of my discretionary listening time revisiting old recordings that I really appreciate. Most are older orchestral recordings that were very well recorded in the 50s-70s stereo era. When I put my Fostex TH-900 phones on and flip the switch on the Enthrall I often wonder what I will hear that I've not heard before. Usually the is something is a wider soundstage, or the growl of the double bass, or some other detail that gives life to the recording.
I think I am getting used to this setup as I am now accustomed to hearing great sound. When I find a poor recording, I quickly switch to something else.
I have no buyer's remorse and I'm still very satisfied with the Enthrall.
 
TIMITS
I have never heard the Attune.  No desire either.
Part of the "downside" of my delight with the Enthrall is that I haven't even felt the desire to listen to the HD-800s.  (I know I said I would review the Enthrall with the HD-800s, but I can't bring myself to reach for anything but the Fostex.)  Maybe one of these days I'll get bored with the Fostex and move over to the Sennheisers, but not yet.

 

[Greeni]

Thank you for the great review. I share the same impression with you as regard to Musical Fidelity gear - clinical, also bleached in tonality, the PRAT just don't sound right to me.
 
How would you describe the tone of the Enthrall ? The RWA is said to be tonally rich sounding amp - and dare it should at those prices. How would the Enthrall flair with that ?

 

[ddoyle777]

Greeni,
 
I don't really think the Enthrall has a tone.  It's a neutral amp that lets the recording speak for itself.  If the recording was well done, you can hear the mastering engineer's work.  If the recording is thin and lifeless, that's how it sounds.  I have no idea of how it stacks up to the RWA as I've never heard one, but I did hear the used Isabellina at Fidelas.  I thought the Isabellina was marginally better (and it was quite a bit more for a used piece of equipment.)  
Maybe a metaphor will help.  I wear glasses and I'm a bit OCD about keeping them clean - I can't stand smudges and dirt on them.  So the Enthrall is like when you clean them properly with lens cleaner, and not just wipe them off on your shirt.  You put your glasses on and you can see clearly with no distortions at all.  The Isabellina would be like the day you first get the new glasses from the optician - just as clean but absolutely pristine - just that tiny bit better.
 
If you end up with an Enthrall you'll be hearing, in all it's fullness, whatever is on the recording.  If you are like me you will probably be returning to the better recorded albums and shunning the crappily recorded ones.