THE AIKIDO BASED PREAMP, AS BUILT BY JD LABS
A LISTENING IMPRESSION/MINI-REVIEW
Note: The following is the opinion of the writer based on his personal assessment of the equipment. Not being an electronics person, there were no laboratory tests conducted and listening tests were purely subjective in nature. While some portions of this review may be affirmed by other owners of this preamp, others may at best be skeptical or even dismiss the entirety as sheer nonsense and product of the writer’s wild prejudices or biases.
This is not intended to persuade, induce or cajole readers to commission the builder to make similar preamp to him/her. The writer is not related to Mr. Jojo Dijamco by affinity or consanguinity nor has a financial stake in his endeavor. Additionally, the former is not an employee or was hired as a PR person or agent towards the promotion, sale and distribution of any of JD Labs products.“There are no good or bad circuits, only good and bad uses for circuits.”
John Broskie in Tube CAD Journal
BACKGROUNDThe Aikido preamp is a novel circuit designed and published by John Broskie. It can be applied to a variety of tubes for line, phono stage, etc. The circuit is basically a low noise, low distortion, low output impedance, no global feedback loop one. This allows the employment of less than stellar power supply without much of the penalty one might otherwise pay. The Aikido circuit sidesteps the power supply failings by including them in its normal operation. It eliminates power supply noise by injecting the same amount of power supply noise into the top and bottom of the two-tube cathode follower circuit. Since both of these signals are equal in amplitude and phase, they cancel each other out, as each triodes sees an identical increase in plate current, so that the output remains steady in spite of the power supply voltage fluctuations.
EQUIPMENT AND ACCESSORIES USEDAmong equipment used were modified B&K EX-442 power amplifier, KEF Q1 bookshelf & a 12 year old KEF Q90 floor standing speakers, modified Cayin CD-50 tube output cd player, Marantz DV 6001 dvd audio/video/sacd player with feature capability of turning off the whole video section, including the HDMI and front panel display for optimum sound quality, modified Omni AVR, modified Isobar power filter/surge suppressor. Audioquest Midnight, QED F-200, QED Qudos, MIT Terminator 4 and DIY braided NEC automotive wires were used for speaker cables. For interconnects Ixos 103, Acoustic Research and Audioquest Emerald were employed.
Used in comparison were modified AMX Overture integrated amplifier fitted with quad matched Electro-Harmonics 6CA7 power tubes and Valvo-Mullard ecc82 preamp tubes, and Sonic Frontiers SFL-2 (with separate power supply in another chassis) preamp fitted with 8 pcs. Amperex 6dj8’s, using the unbalanced outputs.
ROOM AND ACOUSTICSTests were done in the living room of the writer approximately 5 m x 6 m in size with concrete walls and with no acoustical treatment except for two floor carpets 3 m x 1.5 m in dimension. Furniture are all carved wooden pieces.
TEST CD’SJust One Night (Eric Clapton-Mobile Fidelity/Reprise), The Sky Is Crying (Stevie Ray Vaughan-Sony), Abraxas (SACD-Sony and CD Mobile Fidelity-Sony), Give It Up To Love (Mighty Sam Mclain-Audioquest), Come To Find (Doug MacLeod-Audioquest), Blood, Sweat & Tears self-titled album (SACD-Mobile Fidelity/Sony), Dark Side Of The Moon (SACD Pink Floyd-EMI/Toshiba), Discovered Again (Dave Gruisin-FIM/Sheffield), Schemes & Dreams ( Pat Coil-Sheffield), Benoit-Freeman 2 (David Benoit/Russ Freeman-Peak/Concord), Peculiar Situation (Earl Klugh-Windham Hill), The Best of Fourplay (Warner), The Utimate Collection (David Benoit-GRP), Brazilian Sketches (Jim Tomlinson-Premium/Candid) Best Audiophile Saxophone (Various Artists-Premium), Sinatra-Jobim (Repulse/Warner), The Best of Jane Monheit (Premium/N-Coded), Singles 1969-1981 (SACD Carpenters-BMG), Famous Blue Raincoat 20th Anniverary 24k Gold Edition (Jennifer Warnes-Cisco/Porch Light), The Hunter (Jennifer Warnes-Private), Let It Go (SACD/HDCD Clair Marlo-Rounder/Sheffield), A Collection (SACD Alison Krauss-Rounder), Alison Krauss + Union Station Live (SACD-Rounder), Lonely Run Both Ways (Alison Krauss-Premium/Rounder), Forget About It (Alison Krauss-Premium/Rounder) and several others I can’t seem to recall as of the time of writing.
I barely knew Mr. Dijamco, otherwise known as JojoD, Master Jojo or Idol, depending on who you speak to. He was introduced by Gerry Sta. Maria (an acquaintance who later became a friend). In the span of several months knowing Jojo (who I confess also became a friend) I came to respect him, not only because of his work, but as a person. He’s fair, honest, hard working and diligent. He can be charming but can be straightforward and (almost) brutally frank. In Tagalog, he can be termed as “diretsahan at medyo suplado.” But he’s very knowledgeable and capable electronic-wise.
Although Jojo already modified several of my gears with surprisingly excellent results, I’m a little hesitant to commission him to build an Aikido based preamp. This despite hearing his own (I understand the very first Aikido he built). Although I was impressed by the clean and dynamic sound of it, I admit that I fear I might outgrow the need if I have one. I also admit that I was thinking, just in case, of the low resale value of non-branded gear if I decided to sell (mea culpa). I sought the opinion of several persons and they unanimously opined that the Aikido is for keeps.
The preamp project was initially discussed last March 2009, but was building was only commenced on July. I initially specified the use of four 12au7 tubes (the two tubes at the back which I understand are for power supply can be interchangeable with pairs of 12at7’s or 12ax7’s).
THE UNIT’S CASE AND EXTERIOR The unit’s sturdy black, powder coated and well-built case was made of steel plates and can be modularly assembled. It has a simple face plate fitted with a power switch (red LED indicator blinks continually for 40 sec until power stabilizes) and two controls: polished aluminum gain and source selector knobs. Three high quality line level inputs and two RCA outputs, all gold plated and IEC-type provision for detachable power cord were provided. The closed steel case (secured by roundhead metal screws) was provided with vents (the tubes were intended for the interior of the chassis) for heat dissipation/convection (one row at the top of the case and one column for each of the two sides). I requested a small 10 cm x 10 cm grill “window” at the top plate on the top of the tubes so I can see when they light up (I was dissuaded, but still insisted for vanity/frivolousness). Four standard chassis feet were installed at the case bottom.
WHAT’S INSIDEInside, the components were neatly laid out in three small in-house fabricated, high quality pcb’s (mounted sturdily) and provided with an e-core transformer at the left side. Jojo’s explained that this was made so that future upgrade (in the event John Broskie suggests/recommends a further “tweak”) can be implemented easily as compared with relacing the whole board. I understand that HIGH QUALITY but non-boutique components were utilized to bring down the cost to a larger clientele. But Jojo didn’t prevent me from requesting for boutique parts. He likened it to a chef preparing a dish out of his own formula, using his selected condiments. “The key to good, sound engineering, aside from planning and long periods of testing from experience is proper implementation”, he added. He also talked about his previous experience of trying to employ boutique capacitors which yielded less than satisfactory results. “If you can build something, using high quality and reliable components, with the least cost, that is sound engineering”, he advised me. The unit is FULLY REGULATED.
I ended up deciding on the standard version.
NOW TELL ME HOW DOES IT SOUNDS The unit was run-in for approximately forty (40) hours by the builder, prior to turn-over. I installed two Valvo-Mullard ECC 82 (12au7) for the front tubes and two RCA 12at7 black plates for the back tubes. After setting up at home, I let the unit (and the whole system, of course) warm up for about 20 minutes. My initial impression was the background’s impressively very quiet. I planned to relax at that time but was unable to. I am bombarded with details: vibrant percussions, dynamic swings, “throaty and coarse” tenor saxophone, you can feel the air being blown, punchy and deep bass, crystal clear vocals (I can almost feel the singer’s breath next to me). I can’t keep still!
The Aikido forced me to get involved and listen and feel. I can’t classify it as being warm (like a CJ) or neutral. It’s not tiring nor harsh. It’s not polite either. A little forward, yes, but not to the extreme sense. It’s fresh, clean, involving and invigorating with tons of detail!
I suspect some magic was done either by Jojo or Mr. Broskie or both of them. Or maybe I was put on a spell where my ears were instructed to hear only good music. Or maybe this is really a voodoo preamp (with components flown-in from Haiti)! The planned 1 to 2 hours of initial listening was stretched to more than 4 hours. I felt the unit before finally retiring for the night and it was warm but certainly not hot.
I was advised that the optimum sound quality can be achieved after 100 hours of use. To think that I have only logged-in a total of 22 hours distributed just over a week’s time. The sound, which I perceive to be already excellent, can still improve? That, I still have to see and hear!
In the course of my tube-rolling (limited only, I don’t possess a stash of tubes), the best combination I came up with is the two Valvo-Mullard 12au7 and two 12ax7 RCA black plates combination (out of my existing Valvo, RCA, GE, Sylvania, Raytheon, Matsucrapa and Siemens stock tubes).
HOW DOES IT COMPARE WITH MY OTHER EQUIPMENTI beats the “modded” AMX hands down. Although, as of writing time I felt that my Sonic Frontiers still have a slight edge in the mids, overall, the Aikido readily betters it up considerably!
COST-BENEFIT COMPARISON The benefit (music enjoyment) is much more than the cost. Every single centavo I paid for the unit is thoroughly justified!
CONCLUSIONI will be owning this gear as long as I’m capable of hearing and failing that, I’m passing it on to my son!
Additional Note:
Portions of background information was sourced from John Broskie’s website. Sidings were designed, built, painted and installed by the owner, as well as other aesthetic enhancements. UPDATE 12 October 2009
The following is a continuation of an earlier review. The writer had prior advice that changes in sound quality WILL occur midway leading to being fully broken-in, which by experience of the builder may be at least two hundred (200) hours of run-in/usage. Notes were kept of the SQ changes every ten hours of usage. The same set of equipment were used except for some interconnects and speaker cables that were employed starting on the 120th hour. These were DIY solid core silver wire interconnects (purchased at Twisted Jewels on US ebay), provided with ground and shield conductors and about 0.90 m long, terminated with gold plated Amphenol RCA’s; DIY (tin or zinc plated, I’m not too sure) braided Hitachi stranded copper Ga 14 automotive wires (6-wire braid, purchased locally) terminated with Monster RCA’s. The silver IC from cd and sacd players to preamp were twisted (approximately 5 twists per foot) while the IC from preamp to power amp was loosely braided (3 wire braid). There are those who will question the accuracy of the review since some cables were replaced about midway leading to the 200th hour. I maintain that the newly employed cables were installed during the stage when the preamp is at its “worst” performance. Aside from that, I want to realize the full potential of the system when the all the components reached their optimum levels.
I noticed a gradual change in SQ that started at 80+ hours, which continued and reached its height at about 120+ hours. Though not necessary bad per se, by my standards, there was a noticeable loss in detail: the midrange became very liquid and sss-mmm-ooo-th, almost sibilants-free; the highs became softer, as if you’re listening to a tt playback, the bass lost some punch and definition and considerably softer too. If you are the type of person who likes detail and got used to the crisp and punchy Aikido sound during the initial listening hours, you might be turned-off, disheartened, puzzled or may even have a panic call to the builder. It’s as if Jon Bonjovi turned into Sinatra in a matter of days (or weeks for the busy ones).
Honestly, I felt I had a different preamp then. Quite warm at that! This “warm period” continued until the 170th hour when the details in the HF started to come out. On the 180th hour the bass became bigger though still softer as compared to the early stage. Pardon me if I sound silly but it’s like a butterfly trying desperately to get out of the cocoon. You knew the bigger bass was already there and trying to come out but cannot. “Parang pigil na pigil!” Translated: “Bitin na bitin!”
On the 190th hour, the detail in the mid was already present, the highs were already crisp and brilliant, the bass was robust and a little punch was already evident. On the way leading to the 210th hour, the bass regained its former glory: full-bodied and punchy, and as a bonus became deeper even when compared to the initial listening hours. I’d like to call this deep and detailed bass as a “singing bass.” The mid is detailed and lovely and the sparkling highs will make even a melancholy one smile.
I also noticed that the preamp top cover is less hotter to the touch as compared to the early days.
I am not too sure if there will be further improvements. But how do you improve on an already excellent product? Rest assured I will welcome them if there will be.
I hope my mini-review may be of use to those who already owned an Aikido and on the early stages of listening and to those who are contemplating on having to build themselves one or planning to commission someone to build units for them.
I stand at attention to salute the builder!
Mabuhay ka Ka Jojo!
