March 2016

World Premiere!
Coincident Speaker Technology Dynamo 34SE MK II
A gateway product to high-end tube gear.
Review By Rick Becker

  Oh geez, not another Coincident review by Rick Becker? Well, yes, and for good reason in this instance. The original Dynamo 34SE was my go-to amp for the $5000 Entry Level Project back in August of 2014 and I eagerly snapped up the review sample for my personal low power reference and headphone amplifier. My review today of the Coincident Speaker Technology Dynamo 34SE MK II is to find out what improvements have been made. Getting back to the original, it was an outstanding performer with efficient speakers and a very high value at $1299. Here was an opportunity for a direct comparison review between that amp and the new Coincident Speaker Technology Dynamo 34SE MK II.

The first difference appeared immediately when I lifted the box from the floor where the UPS guy had set it. This amp was noticeably heavier. When I set it on the cabinet in the family room to break it in with the TV, it had to be angled on the top to provide clearance for the cable connections – something that I didn't have to do with the original. Still, it didn't seem that much larger and the form factor was virtually identical. After warming it up for a couple of minutes and bringing the volume up, it was evident there was a lot more power in this amp as it drove my Coincident Partial Eclipse MK II speakers to a much more satisfying volume with more control, particularly in the bass. I didn't realize it at the time, but breaking it in with the TV was a perfect way to achieve that task, as it precluded the temptation of critical listening with familiar music. College bands at half-time are a far cry from my usual favorite listening choices.

Fast forward to New Year's Day. I rolled the Coincident Turbo 845SE out of the rig where it had been used to entertain guests the night before with vintage LPs from Pete Seeger and Leonard Cohen. In its place went a 2.5" thick slab of architectural slate on which I placed the MKII – rock on rock. Just for kicks I thought I'd hook it up to my Kharma speakers for a gentle test run. The original Dynamo hadn't done very well driving them in my large 6000 cu-ft. listening room for anything other than soft background music. In connecting the cables I was reminded that the Dynamo, unlike the larger Turbo, has only one set of RCA inputs. That hadn't changed in the evolution to Mk II status. For the speaker cables there were separate binding posts for 8 Ohm and 4 Ohm speakers which were clearly marked and much easier to read than the black letters on the polished stainless steel chassis on the larger Turbo 845SE. The 5/16" thick back plate of brushed aluminum on the Dynamo Mk II was 1.25" wider than the original, so there was a little more space to make the connections and this was a welcomed change, particularly with the stiff, and now vintage, JPS Labs Superconductor+ cables.

The volume knob is another item that hasn't changed. There is still just a small, barely visible notch in the top edge to indicate its position. As before, I remedied this with a small piece of tape and a black marker, but I'll try and think of something clever before the review is finished – maybe another rubber band from a lobster claw. In any case, you will be using this knob a lot since there is no remote control. The attenuator has no detents and it is just as smooth as the original with a light, quality feel. I was running the Kronos Sparta turntable as the front end and my Coincident Statement Phono preamp, so the front end was first class and far more expensive than this amp is likely to meet up with in the real world. As with the break-in period with the Partial Eclipse Mk II speakers, it didn't take long to recognize the Mk II was significantly more powerful than the original. It drove my Kharma speakers (rated at 89dB efficiency, with a benign 8 Ohm load) with aplomb at reasonable listening levels. With rock music I would listen at about 88dB with peaks ranging from 90dB to 92dB – certainly not head-banger territory, but well within the range where the Kharma speakers really blossom.

At 95dB in my large room, the music began to clip noticeably, but without irritation. These measurements were taken at the listening position with the meter about 7.5 feet from the speakers when held in front of my chest – what I call a mid-field listening distance. I settled in for over a week, amazed at how good this combination was working. It was a time when I could relax with both the holidays and the Kronos review behind me. I felt no urgency to compare it with the original Dynamo or switch back to the much more powerful Turbo – nor did I feel anxious to swap in the high-efficiency Tekton Design speakers. Life was good.

With a mid-field listening triangle and the speakers placed in front of the long wall, the Dynamo presented a wide and deep soundstage. Players were nicely positioned on stage. Tonality was well balanced top to bottom. Timbre sounded accurate. The slight softening of the deep bass was a known characteristic of the Kharma Ceramique 2.2 model and it was no worse than with other fine amps. Attack, decay and dynamics all seemed very good. The music presented with proper sense of air of the recording venue. It was neither hard nor soft. There was really nothing overt to criticize and it was easy to simply sit back and enjoy the music. But eventually it was time to get down to work and start pumping iron.

When I put the Turbo back into the rig again there was improved focus, better micro-dynamics, tastier timbre, a little wider and deeper soundstage, more spotlight on the performers who were more finely pinpointed in space, and the air was clearer – all of which you would kind of expect from an amp from the same designer that cost four times as much. Surprisingly – but maybe not so, given the moderate listening level here – the attack, decay and dynamics seemed to stay pretty much the same, which is to say, not etched, not syrupy, not punishing...just right on. Chalk that up to beefy transformers, for which Israel Blume is well known. Or give some credit to the excellence of the Kronos Sparta with its rock steady speed control and excellent isolation from vibrations. If I had cranked the volume up, the much heavier Turbo would have easily pulled further away from the Dynamo as you would expect.

Normally I place my equipment on some kind of footer which usually increases performance. The narrow, deep and heavy Turbo has been an exception. At 85 pounds it is difficult to swap footers in and out without an accomplice. To expedite taking it in and out of the system I've built a dolly with a solid oak top from an end table and some heavy duty 2" swivel plate castors. The Turbo is so heavy that it comes with six factory installed footers so I put it on the dolly and left it at that. The Dynamo Mk II is another story. I started out with just placing it on a slab of slate, achieving the results mentioned above. After comparing it with the original Dynamo, I decided to tweak it with some Synergistic Research MiG footers resting on SoundDampedSteel IsoFeet, all on top of the slate. Three of the new MiG 2.0 footers will up the ante $249; a set of four IsoFeet will cost about $69, shipped to the USA. (I am still using the original MiG footers, two domes facing down, one up, for optimum focus.) The sound immediately improved.

The Coincident Speaker Technology Dynamo 34SE MK II is a significant improvement over the original Dynamo both in audio quality and the apparent ease with which it drives more difficult loads. The watts may be the same in quantity, but the quality of those eight watts per channel takes it a step up from the original. When you add the footers, the quality of the Mk II approaches that of the much larger and much more expensive Turbo SE. If watts are like horsepower then transformers and energy storage are kind of like torque in an internal combustion engine, and this is where the Mk II pulls away from the original model and closes in on the Turbo. Israel tells me the power transformer has been increased by 50% and the energy storage capacity, which allows the amp to provide much greater power for instantaneous musical peaks without clipping, has been increased by 70%. The MK II will be able to drive a much larger selection of speakers in a much larger room than the original.

The tubes in the original and the Dynamo 34SE MK II are Electron Tube brand from China, but the rectifier tube in the MK II has been changed from the "instant on" 5U4GB to the "soft start" 5AR4 to protect the amp from blowing fuses due to inrush surges in areas such as mine with high-ish line voltage (121V). I made this change in my original model and had zero problems since then, and noticed virtually no difference in the sound, though people who dance on the plates of vacuum tubes will probably argue this point. Differences in tube manufacturers and tube vintage will probably make more significant changes than this change in tube type. I didn't get into the sport of tube rolling here. (For sport, I much prefer rolling hills and high mountain passes on my bicycle.) Additionally, the capacitors used in the MK II have double the voltage capacity of the original to provide greater reliability in areas with unruly voltage behavior. Israel told me stories of areas with fluctuations to as much as 128V. This is not a problem in my neighborhood with buried cables and a recently upgraded sub-station about a quarter mile away. I do have voltage that is consistently on the high side, though.

The original Dynamo 34SE was certainly a delightful amp performing exceptionally well for its size and price when driving high efficiency speakers. With the Coincident Speaker Technology Dynamo 34SE MK II, you don't need to be so particular about your choice of speaker or the size of the room, though if you wish to play really loud, high efficiency speakers are obviously the best way to go. Would I recommend trading up from the original to the Mk II? If you've built a reasonably well balanced system around the original amp, probably not. You'd likely be better off tweaking what you already have, or look for a weaker link in your chain, particularly if you suspect it might be at your front end. If you're starting a fresh new system or simply know for sure that your current amp needs replacement, don't shy away because of the low wattage of the Dynamo 34SE Mk II. With moderately efficient speakers in a moderately sized room and listening at moderate levels that won't destroy your hearing, the MK II is a serious contender and a very high value. It is worthy of high quality speakers ten times its modest cost. These parameters should make it a relevant choice for a vast number of audiophiles – far more than the original design, for just a few hundred dollars more. Moreover, for anyone shy about getting into tube gear, at this modest price, there should be little fear and even less risk. All of the tubes used here (5AR4, 6SL7, and EL34) are common, current production available at reasonable prices. Another nice new touch on the MK II, the tube sockets are all labeled and easily read from above.

The EL34 tube is a very linear, neutral pentode tube, but in this amp it is wired in triode configuration and run in Class A which allows it to create a more holographic soundstage than if it were used more conventionally in a push-pull configuration. While it does not have the ultimate tonal color and palpability of my favorite SET tubes – the 2A3, parallel 300B, or the 845, neither does it have the cost, which can be a very comforting attribute by itself – particularly if your gear is sometimes at the mercy of kids, pets or a maid. That the EL34 tube in this amp gets so close to the quality of those more expensive tubes is a breath of fresh air for the industry. Anyone who has been leery of tube amps because of the expense should leap at the opportunity to hear this amplifier.

With Tekton Design Speakers
While I had been delighted with the performance of the Coincident Speaker Technology Dynamo 34SE MK II with the 89dB/W/m efficient Kharma speakers, I thought it necessary to compare the MK II with original Dynamo using the Tekton Design Lore Reference that performed so well in the $5000 Entry Level Project. It has an efficiency of 96dB/W/m and has an impedance average of 8 Ohms, making it a very easy load for either amplifier. First of all, moving from the Kharma to the Tekton illuminated the high quality of sound from these much more affordable speakers. Only in a narrow range at the upper end of the piano keyboard where I heard more metal and less felt than I cared for, did the Tekton fall noticeably short. For the difference in cost, I suspect many people would be willing to live with that shortcoming. And since the Tekton does not play as low as the Kharma, low bass was not an issue. Your subwoofer will take care of that if you need to go there.

Overall, with the easy load of the Tekton speaker the MK II produced notable improvements, but not as earth-shattering as Israel might like me to rave. There was a bit more dynamics, a bit more transparency, greater focus and inner detail revealed, but no Tsunami. The reasons, of course, are that the original was so darn good to begin with, and the Tekton is such an easy load for either amp. With a more challenging speaker such as the Kharma (although even this speaker is a relatively easy load for a tube amp) the differences between the original and Mk II would likely be more pronounced.

One difference is worth noting here. I used both amps with and without the above mentioned footers. The Dynamo 34SE MK II exhibited somewhat greater improvement with the addition of the footers, in spite of the fact that Israel included more stiffening and bracing in the chassis of the MK II. Standing on the factory feet, the MK II is better, yes, but by adding the footers, the Mk II improves even more than the original amp improves by adding the footers. Probably this is due to the 20% larger footprint of the MK II and I suspect much of the increase in weight from 22 lbs. to 30 lbs. is due to the larger power transformer and power supply. These very upgrades also increase the potential for higher quality music–a potential which the footers then unleash.

The Question Of Balance
When Louis Desjardins and company were here earlier to set up the Kronos Sparta 0.5 turntable and subsequently convert it to the full Sparta, they both commented on how nicely balanced my system was. I accepted that as a complement, but also realized the other side of the coin. Both of these gentlemen were accustomed to setting up rigs in the neighborhood of ten times the cost of my rig. My neighborhood is closer to that of Mr. Green Jeans. But my garden grows and I'm ever mindful of what the weakest link in the system must be. The front end took a giant step forward with the insertion of the Sparta turntable forcing me to shift my attention to other areas for possible improvement.

My audio buddy, Professor Tom, phoned to tell me he was flying down to Texas to examine petroglyphs along the Rio Grande and visit the Alamo while his wife attended a week long quilting workshop down there. (My visit to the Alamo a few years ago was one of the most moving experiences in my life. If you get the chance, go.) Tom wanted to know if I would like to borrow his recently acquired (used) Synergistic Research power cord and interconnect, both of which were much newer versions of my own cables. He got the long answer. ("No" is shorter than "yes".)

With the Coincident Speaker Technology Dynamo 34SE MK II on footers and driving the Kharma speakers I ran multiple comparisons of first the Synergistic Research Element Titanium power cord, then the Synergistic Research UEF Atmosphere, Level 2 interconnect (right at the front end, between the turntable and the phono stage), and finally both power cord and interconnect together. It was so enlightening I reveled in music until 3 am before finally emailing Tom that I was not going to return either of his cables. They were that good, taking the resolution up to the level of the Best Rooms I hear at the Montreal and Toronto shows each year. The good news here, for the Coincident amp, is that it was capable of acknowledging and conveying the excellence of the improved signal.

Resolution improved dramatically, revealing even finer gradations of tonal color. The sense of space became a lot more there, particularly on live recordings. My left foot, crossed over my right knee, never stopped bouncing. Very impressive was the silence of the amp. The S/N ratio is listed as 92dB (up from 88dB in the original). It is not specified, but if this is for 1 watt, A-weighted, this is an exceptionally good figure for a tube amp. With the volume knob set at normal listening level, I had to get my ear within a foot of the woofer before I could hear just a slight hum. The take-away here is the Dynamo 34SE MK II is worthy of much more expensive supporting equipment than it is likely to be paired with, given its modest price point. Yes, the cost of footers will up the ante a bit, but this is an amplifier that can start out in an entry level rig and stay with you until everything else in your system has been upgraded to first class components. It's that good.

Racing In The Streets
Having decided to purchase the amp, I took it to an even higher level of resolution with the application of AVM (Anti-Vibration Magic), the "blue tube goop" that I've played with for years. First I painted the fuse which locked in another advance with 24 hours of drying time. And then I opened it up and painted the solder joints of the IEC AC input. Again, with 24 hours of drying time, resolution took yet another step forward. The AVM is easily removed from the fuse with a finger nail, should you wish to mellow out the sound a bit, but adding the AVM in those two places produced an improvement in resolution roughly equivalent to the addition of the Synergistic Research MiG original domes coupled with the SDS Isofeet plates. Combining the AVM with the footers brought a level of resolution that enabled me to decipher song lyrics that would have escaped me without the aid of the album liner. Your hearing (or your personal taste) may not require such acute resolution, but it's nice to know that the amp is very tweakable in this regard.

Aesthetics
Ah, the soft glow which vacuum tubes impart to the darkened listening room while listening late at night. It's almost like having a warm fireplace in the room, except for the crackle of the burning wood and the embers that get spit out onto the rug. The Dynamo puts out enough light to let you know it's on and allow you to navigate the room without tripping on your pets, but it doesn't put out an enormous amount of heat. It won't require turning on the air conditioning in the summer, but you will still need to have the heat on in the winter. Or do what I do – ramp up the heat before the listening session, then turn it off for some serious quality time with your music. While you're doing that, warm up the amp. It takes just a minute, but you'll find the music improves a bit over the next 15 to 20 minutes, which is not uncommon with vacuum tube gear. Use the time to give attention to the music you want to hear.

Visually, the polished stainless steel chassis and transformer covers have become the signature of Coincident amps. It seemed a bit too much bling for me when I bought my first one, but like a polished silver buckle on blue jeans, it came to feel natural to me. And besides that, it counter-balances the house with the chrome exhaust pipes on the motorcycle in the garage. If you're more often in pin-stripe suits and tuxedos, well, handle these amps with white gloves so you don't get fingerprints all over them. When the dust collects, vacuum them first, and then clean them up with a little chrome polish. Me? Mostly I just use them for listening to music and let the dust collect. When we throw a party "dust the amps" magically shows up on the to-do list. It's really no more difficult than wiping down the piano black speakers. A soft paint brush cleans around the tubes. And besides, it makes my wife happy.

Headphone Amp
The MK II, like the original, comes with a headphone jack on the front panel. I'm not a headphone junky, though I've borrowed Tom's vintage Grado SR80 phones to help decipher my video notes for my show reports. Recently I've acquired the new Grado SR325e which is a large step up from Tom's SR80, but not as fine as their top-of-the-line models which I've coveted at shows. I'm able to listen without strain or pain and can easily separate my dialog from the music being played in the rooms at shows. It's a very useful, relatively high resolution tool for me that also allows me to get my foot in the door to headphone geekdom without taxing the bank account too much. So how do they work with the Dynamo?

Well, my first discovery was that the speakers do not cut off when you insert the plug. This was an inconvenience that required disconnecting each speaker cable at one binding post – it was easier for me to do this at each speaker than on the back of the amp. Tube amps like to see a load. If music is being fed to the amp and neither the speakers nor the headphones are connected, you will run into expensive trouble. So you have to remember to reconnect the speaker cable if you disconnect the headphones so it will be looking at a load... or, simply leave the headphones plugged in to remind you. Israel said 30 seconds without a load should not be a problem, but 60 seconds could spell danger for the transformer. Conversely, if you're going to play the speakers, remember to disconnect your headphones so you don't damage them. The headphone jack is padded down from 8 watts to 4 watts. Both my speakers and my particular headphones required about the same volume setting, but yours may differ. Those four watts at the headphone jack will drive just about any headphone made. You head-fi enthusiasts know this already.

Certainly, other amplifiers automatically cut out the speakers when you insert the headphone plug, but Israel said to do this he would have had to add more wire and change the circuit, which would have degraded the signal, or relocate the headphone jack to the rear of the unit. Neither option was acceptable to him. We wasn't about to compromise the transparency of the amp or the convenience of the headphone jack on the faceplate.

Sound-wise, the signal comes through with all the transparency, focus and certainly dynamics(!) that the amp provides for the speakers. The Mk II is extremely quiet so even with efficient headphones that require little gain, the music emerges from the proverbial black background. The EL34 tube is very neutral so any coloration or distortion will likely be the signature of your headphones, not the interaction of your speakers with the room. With the Grado SR325e the midrange that makes this brand so famous really lured me into the music as I lay on the floor in front of the amp. Not that it was particularly lacking in bass or treble, but neither extreme will tire you out in long listening sessions or distract you from the heart of the music which is almost always in the midrange. While the MK II serves as an excellent headphone amp, its larger form factor makes it less of a desktop amp than its predecessor and made me wonder if the next Coincident amplifier might be a dedicated headphone amp, more suitable for chairside listening. Israel denied such an amp was in the works and said that about 25% of the owners of the original model bought them to be used primarily for headphones. One thing is for sure... at 30 lbs., you're not likely to pull the MK II off your table if you forget to remove your headphones.

The Load Out
Given that the Coincident Speaker Technology Dynamo 34SE MK II is an integrated amplifier with a passive front end, it is a gateway product to high-end tube gear that will take you from Entry Level to First Class. Many people, me among them, revel in the sense of space and tonal color that tube gear evokes from recorded music. Unfortunately, far more people seem to fear tubes. (They probably also call an electrician to change a light bulb.) If ever I've seen a piece of tube gear that offers such high quality, with so little risk of investment and such reasonably wide application, the Dynamo 34SE MK II is it. Not only have I bought the review sample, if I were forced to sell off my amplifier collection, the Coincident Speaker Technology Dynamo 34SE MK II would be the last to leave. Once again, in an industry that so often caters to the ultra-wealthy, Israel Blume offers yet another outstanding product that can be afforded by people in the middle class who give high priority to the enjoyment of recorded music.

Specifications
Type: Vacuum tube stereo integrated amplifier
Frequency response: 20Hz to  20kHz
Output Power: 8 watts per channel
Headphone Power: 4 watts per channel
Tube Compliment: 6SL7 input/driver tube, EL 34 output tube, and 5AR4 soft start rectifier
Output impedance: 4 and 8 Ohms
Voltage selectable: 115V/230V - switch located on bottom plate
Sensitivity: 300 mV full output
Input impedance: 100 kOhms
S/N Ratio: 92 dB (up from 88 dB in the original)
Weight: 30 lbs. (Up from 22 lbs. in the original) 
Dimensions: 9.5" x 12.5" x 7" (WxDxH)
Price: $1499

Company Information
Coincident Speaker Technology
391 Woodland Acres Crescent
Maple, ON.
Canada L6A1G2

Voice: (905) 326-9345 
E-mail: iblume@coincidentspeaker.com
Website: www.coincidentspeaker.com