Another Power Cord Comparo?

My Kuzma Stabi SD set up, with 12 inch arm and Benz Micro LP cartridge, still same as before. However, I never though switching power cords to the AC speed controller(left) can make so much changes to the sound

Agree or not, power cords do make a difference to the sound of hifi that we hear. My experiences with power cord, or any other audio cable, is well documented in these pages. However, almost all the power cord swapping I made was direct to electronics, such as power cord to CD player, or cassette deck, pre-amp & power amps surely. Love the journey so far.

However lately, I am a little baffled when I swapped power cords to the AC speed controller of my Kuzma Stabi SD turntable. Why am I baffled, you asked? Well you see, unlike a CD player or cassette deck, the AC speed controller has no electrical connection what so ever to the turn table, tone arm or cartridge! The AC speed controller only powers the belt drive motor, which only point of connection to the turn table is the rubber belt, which is mechanical! So, in a way you can say electrical changes the working properties of mechanical, if the sound I heard is different from swapping each of the 4 power cords below? I will run down what I distinctly heard with each power cord below:

    

Audi Agile Concept Tuning is a shielded power cord design. However in this application, it just sounded very un-refined with white hash, not very good for a shielded design 

First up, the Audio Agile Concept Tuning power cord. Once plugged in to the Kuzma AC speed controller, the music has a nice rhythmic sure foot ness to the sound, as some would recognize as PRAT factor. The tonality was very neutral balanced high, mid & low. Bass was bold, solid and nicely tuneful. Mids are un-colored but the highs is where this cable fails. There's a constant white hash mixed in to the high frequency reproduction which results in a somewhat streaky and shrill treble. Cymbals are splashy & high hats sound edgy & hardened. May be that was why the Kuzma CAR-30 cartridge sounded the way it did? Because at that time of the Kuzma CAR-30 review, this power cord was used and perhaps the Kuzma was just reflecting the contributions of the Audio Agile Concept Tuning power cord? Was I being fair to the Kuzma? I think it might be time to re-visit that cartridge in the near future..........

  

Supra Lorad 2.5 power cord is a very soft and nicely shielded design, which I used in a variety of application, but doesn't seems to work well enough for this AC speed controller use

The Supra Lorad 2.5 power cable is next. Once I swapped the Supra in, replacing the Audio Agile, the first & immediate relief is the high frequencies. Gone are the splashy cymbals and hardened high hats. The white hash that's mixed in to the music's high frequencies are much, much reduced too, but nevertheless, I still heard a bit of the white hash. Much like the Audio Agile, the mids are neutral but bass is a little less tuneful, or bouncy as they say. Bass body is no longer as bold, but still maintained a nice degree of solidness. Overall, this is a much better cable, for the Kuzma AC speed controller for it's sins of omission which is for all purposes, less offensive, but no less enjoyable.

PS Audio Punch power cord. I have more than a few PS Audio power cords used in my hifi system, and it's one of my go to power cords usually. Not sure why it's the worst sounding cable here?

Next up replacing the Supra Lorad, is the PS Audio Punch power cord. This is the thickest and least flexible power cord of the group. I had to wrestle it like a cobra before I could get it to plug in to the Kuzma AC speed controller IEC socket. And once plugged in the weight & the rigidness of the PC Audio Punch power cord caused the light weight AC controller to stand on it's hind legs! I had to put a weight on the AC speed controller for a day to keep it on all 4 feet. Once I started listening, the sound ain't that pretty either! 

The PS Audio sounding so slow, that I have to re-calibrate the speed controller for 33 &45 rpm a few notches faster. Next problem is the bass, which is fat & muddy. Mid range is totally over warm to the point of sounding over riped. The highs are rolled off and surprisingly, not too refined either! The only good thing was that the white hash is gone! I waited a few days, hoping for the power cord to settle down, and hopefully things will improve. However it still sounding more or less as described above even after 2 weeks in the turn table system. I had come to a point where enough is enough!

To be fair, I later used the PS Audio Punch power cord on my Teac UD-501 DAC and it sounded extremely pleasant & nice, which took off some of the digitalis grain from the streaming music. Well at least it didn't go to waste...............

    

This Gotham 85025 cut from reel power cord & Copper Color plug combo really surprised me for it's low cost to performance ratio. Possibly one of the best DIY power cord one can make

The last and final candidate is a DIY effort where I bought Gotham 85025 cut from reel power cord and self terminated with Copper Color Rhodium plugs for both IEC and NEMA ends of the power cord. I must remarked that from my experience using those China made Copper Color plugs, they are some of the best value, nicely built and great sounding plugs, if your budget does not stretch that far or you may feel Furutech plugs are not required. The Copper Color plugs are probably the best China made plugs you can buy today.

Sorry, I digressed. I proceeded to remove the PS Audio Punch and use this Gotham power cord instead. The moment the needle first dropped, I knew I am experiencing musical bliss again. Yes, the AC controller speed had to be tuned down again for 33 & 45rpm, after the PS Audio adjustment. Once the speed was set right, everything is nice and balanced, with a top down coherent of frequency reproduction. No more white hash audible in the highs either. The highs were clean yet refreshingly airy, smooth with no trace of edginess or hardness. The mids are nicely rounded and projected slightly up front, which makes the vocals stand out from the music. The bass starts & stops accurately, with clean note to note transfer, and no hang overs. The cables are not overly thick, slightly stiff, but still very bendable and at the very least, no need to wrestle it like a cobra.

Of the 4 power cords I tested here, I found the Gotham cable & Copper Color plug combo most balanced & satisfying to listen to. So impressed with it, I made another set of the same combo to power my Linn LP12 Mose kit external power supply box for the Hercules Gold II board.     

I can neither explain or validate what I experienced with the 4 different power cords and how it effects the sound of the turn table, despite being non electrically connected. It's just another of those things in hifi that baffles the mind. If you are reading up to here and think you have a good explanation to my experience, please comment below. I am looking forward to learn from you guys too!

More Mober For Linn Sondek LP12

Mober sub-platter for Linn LP12 tur table, though Cirkus compatible, I much prefer the sound when mated to it's intended partner, the Mober bearing.

In my last story about the Mober sub platter, as started with my desire for the latest Linn Karousel bearing upgrade, but the prohibitive pricing of Linn lead me to looking else where. Along came the Mober items purchased from Edmund Chan who makes these Mober products & ships out of Hong Kong. 

Doing the Mober bearing upgrade, much like the Karuosel, requires the Vahalla or Hercules power supply board to be moved out of the turn table, in to a separate external box. That means my Hercules II Gold power supply board will need a box to be housed in. Fear not, Mober has a solution in the form of a Mose kit!

In the process of reading up on the Karousel vs Mober bearing, it would seem to me that Edmund had started putting the Mober bearing in to the market 2 years ahead of Linn! However, the emergence of Karuosel has made Mober to introduce an improved version with collar mount option, compared to the 3 point mount of the previous design, as in Linn's Cirkus bearing. Competition does indeed spark innovation in this case!

Now let us go through the build pictorial:

Mober(left) bearing vs Linn Cirkus(right). Notice how much bigger the Mober bearing is at the bottom? The Mober bearing also offers collar mount, which I feel in much better than 3 point mounting, as the stress points are even out with collar mount.

The bridge comparison, left is the Mober supplied unit which came as part of the bearing package. Compared to the Linn supplied unit, notice the bearing thru hole in the center, which is much bigger diameter with the Mober unit. Also note the heavier steel gauge used, and that improved wire hold down design, which is far more rigid compared to Linn's fragile looking P-clip, not shown here.   

On the back is similar story, the Mober parts exudes quality build that Linn can only dream about!

The Mose casing to house my Hercules II Gold power supply board. This 2U design casing is aluminum extruded and finished in satin black for an overall high quality look & feel.

The back panel of the Mose box, a multi pin socket provides easy & removable wiring option from the turn table.

Even the IEC socket provided with the Mose is a gold plated audiophile grade item, Mober has put in much thought to his products!

Inside the Mose box is an added AC board for LED indicator at face plate, and rerouting all Hercules II Gold cabling requirements to the multi pin socket.

The Mose box with the Hercules II Gold power supply board fitted.

The completed Mose box, with a blue indicator at front face plate, when powered up.

Fitting of Mober bearing commence! The Mober bearing is first collar mounted on to the Linn Kore sub-chassis. This is followed by the motor & 33 & 45 rpm switch on the top plate.

M for Mober!

The wire hold down clamp as seen here in white is much easier to work with, compared to Linn's P-clip design. Just lift the clamp high enough to slip the cables through, then tighten that hex key.

The finished project, with Mober's L shaped power supply board to accommodate the much bigger bearing. the multi pin cable from Mose box shown earlier is attached to this L-shaped PS board. Also seen here with tone arm cable & multi pin cable being clamped down respectively. 

An older picture for comparison, with Linn's Vahalla board in place with Circkus bearing. The Hercules II Gold board is basically a 2 speed version of the Vahalla!

And lastly the whole turn table assembly sits on the Linn Trampolin II

The finished project, with the newly Oak finished plinth. This project is like a total rebuild, and since I am at it, I also swapped the Koetsu Black cartridge to serve on the Linn LP12 turn table. 

The Linn LP12(top tier) with the Mose kit & Marantz PH-1 phono stage below deck, sitting on my Spyder rack.

The sound of the finished project is excellent from the first needle drop! The initial sound was fast and exciting, with little to no back ground noise. LP surface noise is largely reduced as well. The bass is now truly powerful and tight! The Linn finally has the bass power to rival my Kuzma turn table. No more  Linn's flabby, "mong cha-cha" bass of the old. The Mober bearing package, with it's sub platter really brings the Linn LP12 detail retrieval ability & clarity to a whole new level. The good part is Linn's much fabled mid-bass is now clean, and doesn't intrude and cloud the male vocals anymore. Treble is much extended, airy and clear like a breath of fresh air! The noise level after the Mober bearing & Mose kit installed is near zero or un-audible now. After a few days, as the 3 springs that suspends the Linn settles down, the treble begins to soften a touch, and some semblance of the Linn LP12 sound character re-emerges, but just enough to remind you that this is still a Linn LP 12 after all.

I feel the Mober kits offer very high value for money in each & every way one looks at it. The Mober kits are well made, with good materials, high quality finishing and much design details that only someone with an intimate knowledge of the Linn LP12 can think of. Best of all, the Mober kits are much, much more affordable than the Scotland made stuff, yet suffers no sound penalty or build quality. I think the Mober kits may somewhat sound a little different if compared to using all Linn parts catalog, but on the whole, Edmund Chan is a person who understands the Linn's engineering philosophy well, and doesn't stray too far from where the apple tree is. I now have much respect and high regards for the Mober kits. If you have a Linn LP12 turn table at whatever vintage, do give the Mober kits a go!

Given today's Linn aftermarket diversity, and Linn's endless catalog of up grade parts, I can tell you there no 2 Linn LP12 in the world that is exactly same anymore, after leaving the showroom! A celebration of diversity I guess.....

Facelift, Wood Plinth Refinishing For Linn Sondek LP12

My original Linn LP12 plinth in Black Ash, total strip down. This is not the first time I've done this!

Choosing my stain option, which I choose a rich shade of red laquer

 

The finished result! Beautiful......

From another angle at Ricky's workshop

This project was almost 6 months in the making. I had planned to refinish my Linn LP12 wood plinth, as I was kinda bored with the original Black Ash color scheme.

And since I am stripping everything down to do the refinishing of the plinth, I might as well do some upgrades! At the time, I was keen to get Linn's latest Karousel bearing design, but was horrified upon hearing the cost. Fear not, it's Mober to the rescue and I ended buying not only Mober's bearing design, but also the matching inner platter & out board PSU upgrade kit. All those parts came just a day before the MCO lock down in May, and Ricky's furniture workshop had to close as a result.

Ricky's workshop was allowed to resume operations by 3rd October and he went in to work on my Linn LP12 plinth straight away. After more than a week, I couldn't believe my eyes when I saw the result of the refinished work, as in the pictures above!

Ricky also does speaker cabinet repairs or any other hifi wooden bits refinishing as well. He is well known amongst those classic Thorens & Garrard turntable folks for supplying beautiful custom plinths. He is also a classic hifi & LP collector. So if you're reading this, that means Ricky shares your passion for good sound!

Ricky can be contacted at 019-3379357, should you require his services.  

Something New For Something Old..........

Now, what's this?

This project has been in the making since April, as all the parts have become available since May but no progress until now. Can you guess what is this item featured on the picture?

Art frame? Or something else?

If the keen eyed amongst you already know, post your answer in the comment section please.

Stay tune for updates on this project as it will start moving soon!

 

Mighty Mober For My Linn Sondek LP12, Mober SSP 12 Sub Platter

Julien, my friendly Linn LP12 kaki, who is also my hifi COP, a.k.a. Chief Of Poison, introduced me to the world of Mober, an after market parts vendor for the Linn LP12. In fact, Mober's parts catalog is so complete, that you can actually choose to build a whole LP12 out of Mober parts list! However be warned that if you do that, I suspect the actual end product, an LP12 look a like may not sound much a like the Linn version either.........

Also when reading in to Mober's story, I found that Edmund Chan, the Mober man is also the man behind Hercules PS by Stamford Audio, which I use to repleced the Linn Vahalla PS and still loved till date. That already gave me a healthy dose of confidence on Mober's stuff. At one point, Mober was so controversial in the Linn forums, because there were just as many pro Mober fans vs Linn purist, which resulted in a war on almost every topic posted. It got so bad that Linn decided to shut down the forum totally. Edmund and his henchmen were thrown out and denied membership, forever! Yeah, I know how up tight those Linn purist can be!

As I discussed with Julien, my buddy(who denies his poisoning abilities) about the Linn Karousel bearing option, that everyone is hot over heels about, but the high cost factor remained in my doubt and so in one brilliant stroke, Julien suggested I look in to the Mober alternative. Mober's store is on Ebay and he ships out of Hong Kong. After going thru Mober's Ebay store, I ended up not only with Mober's bearing, but also an Mober SSP12(which is Mober's sub plater) and also Mose+ out board casing kit for my Hercules II Gold PS board. You see, before Linn's Karousel, Mober was already selling his bearing of a similar design. And like the Karousel, Mober's bearing mount is much bigger, so much of the original LP12 inner pieces will either have to be changed or modified! The inner brace bar which holds the Cirkus bearing will need to have the bearing fitting hole enlarged, but Mober sent me a replacement to fit with his bearing instead. The Hercules II Gold PS board won't fit either, so it will be moved outboard with the Mose+ casing kit! 

Now you can see, why I was so hesitant in considering the Karousel bearing! With so much changes, the cost was just adding up big time, if I had stuck to the Linn parts bin! With Mober's more reasonable pricing, that move was a whole lot more palatable, financially. Actually, if you scour the www carefully by searching for Linn LP12 parts, you'll find much after market bit's & pieces for your Linn, some very well designed, others down right wacky & possibly rather tweaky by looks. I am just saying this, that in the Linn LP12 universe, there exist a whole lot of other options other than the original. 

Mober box arrived via FedEx

Inside the Mober box

I ordered all the stuff as mentioned above, made my payment and in about 10 days or so, the Mober box arrived by FedEx. As you can see, the box is very well packed. The first item I can easily play with is the Mober SSP12 sub platter, which does not require me to disassemble the turn table just yet. All the other parts will have to wait until the current MCO to finish, when we come out of the lockdown, as I would like to refinish my black ash plinth too, while at it. So will have to wait until my buddy's furniture workshop re-opens for business.

Mober recommends that when using his bearing, to pair with the SSP12 sub platter for best results, however, the Linn Cirkus LP12 sub platter can still be used. Since the SSP12 sub platter is compatible with the existing Cirkus bearing, it will be an easy swap in. 

The difference the Mober SSP12 and the Cirkus sub platter is obvious. Mober's have a pale gold coating in the center of the top spindle. Where it's not so obvious is where the biggest difference lies, at the tip of the bearing shaft! Linn's patented bearing shaft tip is rounded off versus Mober's which is bearing fused, much like those old Thorens sub platter design from the late 50's and early 60's. Otherwise, nearly all other design aspects of both the sub platter looks identical, save for that matt aluminum finishing on the Linn, and shiny surface of the Mober. So how does that Mober sub platter sound comparatively to the Linn?

From left: Linn sub platter, then the shinny Mober sub platter on the right 

Linn sub platter, look at the rounded tip of the bearing shaft 

Mober SSP12, with the bearing fused at the tip as the focused point of the bearing shaft

The swap over was relatively easy, I pulled the Linn sub platter out from the turn table, wipe clean the shaft from the bearing oil with a piece of tissue, then re-lube the bearing and proceed to drop in the Mober sub platter. Allow some time, about 10-15 minutes to let the bearing shaft sink in by gravity, best not to use force. Once the sub platter sits in nicely, time to fit the outer platter on, and record matt, now your're ready to spin LPs!

From the very first moment the LP started spinning again, I heard a distinct, sharp high mid frequency range poking out of the overall frequency spectrum. While this makes vocals pop out and stabilizes imaging better, I much preferred Linn's overall top to bottom frequency coherence and evenness. I also note that the Mober sub platter is subjectively quieter in the musical background too. Otherwise, all other sound quality character remains largely un-changed. The bass is still solidly filled up and gutsy, the mid range comes with the peak as mentioned, and treble remains airy & refined. 

Over a few weeks, that mid range peak started to be reduced to almost un-detectable, except with certain LPs or songs, I could still hear it. That's the problem with audio, once you've heard it, it's very difficult to unhear it. From time to time or song to song that peak high mid just sticks out enough to remind you about the Mober! I actually find this type of sonic character very much like sitting one's hifi equipment on 3 pieces of downward pointer footings, but the Mober being a whole lot more discreet. One of the main reasons I never use those tipsy downward pointing footers on my hifi equipment. 

I am hoping that once I pair this sub platter to the Mober bearing, this anomaly would disappear totally for a perfect & coherent match. I also suspect that with the neutrality of the Benx Micro LP cartridge also pushed the Mober towards this slight peak in the high mids, and I suspect my other cartridge the warmer sounding Koetsu Black which is more sympathetic, may be a better match with the Mober items.  Let's see......

The Linn sub platter just before removal

The well sit in Mober SSP12 after 15 minutes, fits nicely too

With that being said, I believe that Mober sub platter & bearing kit is best used as a set. The Mober SSP12 when used with an existing Cirkus based Linn LP12 turntable, the compatibility may rest on a few other items too, such as cartridge, cable & turn table set up. That makes this so called up grade a small gamble, and YMMV is all I can tell you at this point. Well, at least till I get all the other Mober items in to my Linn Sondek LP12. Not sure when that is possible in the current pandemic & lockdown situation........................... 

My Linn Sondek LP12 is back in action again. For Linn purist, in which this photo I shared on Linn FB group, the LP clamp used here is a crime punishable by crucifixion! For me, as long as it's floating my boat, who cares?

 

IEC Socket Improvements?

IEC power socket

 

Typical standard factory installed power cord with molded 2 pin plug

 

As some of our avid readers will know that I have 2 cassette deck in my collection. I have a Teac V-670 & a Nakamichi DR-2. Both decks came with a standard factory power cable built in to the back panel, with molded 2 pin plug, as pictured above.

In my past DIY tom foolery, I also know that replacing that standard factory power cable with 2 pin plug with an IEC socket, which would then allow you play & experiment with power cords can bring about sonic differences or sound advantage. So I went about and did just that to both my cassette deck.

In any IEC socket replacement project, the major work is in drilling, cutting & filling out that rectangle hole, in which the IEC socket needs to sit in to. The Teac V-670, with it's plastic body & rear panel was a relatively simple task. All I need was to heat up my cutting knife and slice thru the plastic back panel to create the approximate opening, do so filling to even the finishing, solder the wires to the L &N pins of the socket, make sure to get the polarity right. Drill in 2 screw holes and use 2 pieces of self tapping screws to tightened and you're done! My work was completed in less than half a day.

With the Nakamichi DR-2 going thru the socket process is not so easy. Due to it's high build quality, the Nakamichi had proper steel 2U chassis, with a 2 layer steel back panel! I had to first drill, cut & file on the inner back panel as part of the 2U chassis. Then have to align the hole on the outer back panel, by drilling, cutting & filling over the same rectangle hole, but only this time, I need to be more precise as this is cosmetically exposed. It took me more then 2 days to complete the job!

Now that both the tape decks got an IEC socket, I can start to play with power cords. I had a piece of Gotham 85025 power cord measuring 1.5 meter & terminated it with US style NEMA-5 & IEC Copper Color plugs. These are realistically beer budget priced plugs with decent build & sound quality plugs. 

Copper Color power plugs, available in choice of copper, silver, gold or rhodium coating. IEC side is also available. Very good value for money to build & sound performance ratio. Serving most of my HT plug requirements now. Goes well with Gotham 85025 power cords too 

Now with my power cord completed, I can start listening for sonic bonuses. First up is my Teac V-670 cassette deck. Now with the capability to use the Gotham power cord, I find the Teac gave much better clarity and vocal focus. A layer of white or tape hash just wiped away. Highs are crispier, more well defined and bass is now less wobbly. The addition of the IEC socket & after market power cord brought a world of sound improvements to my Teac cassette deck!

Next to be played is the Nakamichi DR-2, now plugged in using the same Gotham power cord, nothing can prepared me the big counter surprise!  I was expecting some kind of sonic bliss, even if small, as from my knowledge, Nakamichi had a much bigger transformer & superior power supply design, with multi stage regulation. With an improved power supply in the Nakamichi, I was some how still expecting some improvement if not as dramatic in sound quality. I listened real...... hard, but I heard no difference what so ever in sound. I mean it still sounded as well as it could be, before or after the installation of the IEC socket & use of aftermarket power cord! However, as I listened on....... hoping to hear some sound difference, all I got was same old, same old, no better, no worse for sound!

So in the end I have to accept the conclusion that NOT all equipment may benefit from the fitting of an IEC socket or after market power cords. I think most do, but others like the Nakamichi do not. I think some equipment's power supply design is already well optimized, and will leave no scope of benefit from using after market power cord. Unexpected, but true!

And I just wasted 2 days of blood(really), sweat(elbow grease, lots) & tears(no sonic rewards)...........

                                                      

 

Fused In Gold, Bussmann, Aucharm & AMR Hifi Gold Fuse Comparo

Here is the Aucharm 13 amp gold fuse, compared to a standard grade Bussmann 13 amp fuse that comes standard with most high end equipment or power cord terminated with BS plugs

If you look at tweaks, and if you're like me, having toyed with almost any novelty that hifi tweaks dom has to offer, and scraping the bottom of the barrel for shit to write home about, eventually you'll come to this, Hifi Tuning Fuses! Now, I know I am not the first to write about it, and certainly will not be the last to do so too, but perhaps this multiple fuse comparo will interest your attention for just a few short minutes? 

I know based on web site statistics, now days the average attention span is 3 minutes or less, and the music producers knew about it a long time ago, that's why since pop music became available, the genre never broke the 3 minute long rule, until Freddie Mercury & his band Queen came about with a song called Bohemian Rhapsody, which is more than double the standard 3 minute time format!

Sorry I digressed, but this topics about the BS 13 amp fuse got me all hot & bothered, you know why? Because that little shinny gold tipped ceramic body fuse does changes the sound! And with each fuse brand, the sound is different too! For better or worse, only once you plug those pesky little gold fuses and you'll find out!

From here on I will attempt to describe each of the 3 gold fuses that I have in hand and how I used them in my system to get the sound & picture quality to my preference.

Bussmann 13amp gold fuse for bass prowess

First, I'll start with the Bussmann gold fuse. In hifi application, Bussmann BS(British Standard, not the other BS) 13 amp is the de factor choice of many hi-end equipment manufacturers in markets like Malaysia, or the Commonwealth, where the British Standard to 220V - 240V power delivery is used. And until now, virtually all my 13 amp fuses are this standard Bussmann grade, until I got one of Bussmann gold grade came with one of the MSHD plugs that I bought. Compared to the standard Bussmann grade, this gold fuse does sound slightly more muscular in the bass area. Bass comes across as BIG, BOLD & strong! the result is kick drums kicked harder, plucking of double bass has more force, and bass lines are solid, yet tuneful, and easy to follow without muddiness. I didn't fine much difference in the mids, but perhaps, top end was just a tad more refined! 

 The Bussmann gold fuse, with it's standard ceramic body & printing looks just like the usual standard grade, except the matt looking gold coated tips on both end caps. In other words, it is not a visual stand out from the standard Bussmann, in terms of appearance & sound. Certainly useful for those who want to squeeze a little more bass energy out of the system. 

Aucharm 13 amp gold fuse, for spot lighting high frequencies against a pitched dark sound stage or back ground

Next up is the Aucharm 13 amp gold fuse. The Aucharm looks better finished compared to the Bussmann, not make it off all three, with it's nice shinny gold coating on the end caps, and a very striking blue hue ink printing on the ceramic body.

Sound wise, the Aucharm is the direct opposite of the Bussmann, it's main focus lies in the upper frequencies. Top end is a little emphasized, but that may be the way because the treble is contrasted to the background is so......... dark, and completely hash free! If my hifi system presentation is correct, it sort of gives a slightly spotlighted effect on the cymbals & high hats, and percussion instruments. However, there is also a small downside to this fuse, that way it highlights the high frequencies, with some female vocal recording when she is coming to her hi-octave falsetto, there could at times be a bit ear pinching. I must say say it doesn't happen with every recording but just with the odd few CDs that I listened to, so happens. 

The good part is, the Aucharm is very affordably priced if you just look at Lazada or Ali Express.

   

AMR 13 amp gold fuse shows maturity in refinement & overall well balanced sound properties of a well tuned product, as can be expected froma hi-end equipment manufacturer like AMR

 

Lastly is the AMR 13 amp gold fuse. This is the most expensive fuse of the lot, at just the edge to my give up to purchase pricing, but it didn't stop me from getting 3 pieces. 

However, it's pricing does show a voicing maturity resulting overall balanced sound from top to bottom frequencies, and very refined top end. Bottom end is not as gutsy as the Bussmann, but nevertheless still nice and tuneful. the over all presentation is quiet, and free from hash(though not as dark background as the Aucharm). It also doesn't spot light the highs like the Aucharm. So in essence, it's just a very refined, quiet and noise free tuning. And like all well tuned products, it never lets a hair down, or have any rough edges to the sound. Everything is where it should sound like, but just more refined & less noise. 

So, in the end how did I used the fuses to tweak my hifi & HT systems? Yes, plural, because I have stereo separated from my multi channel HT system. 

First up, in my stereo system, I only used the AMR & Aucharm gold fuses. I used the AMR in the power line where all my pre-amp & sources are powered. Then I used the Aucharm in the power  lines that drive my power amp. I loved the refined balanced on the AMR for my sources but as I had a bit of rowdy bass response in my system, I would use the Aucharm in the lines that drive my power amp to tightened the bass and give and overall darker sound stage.

In my HT system, I used  the AMR again, to power all my source, AV Receiver, EQ and power amp. the Aucharm powers all my auxiliary items like Google Chromecast & Arcana HD Fury. And lastly the Bussmann Gold to supply juices to my twin SVS subs as I want the bass to rock my HT room, especially when watching those earth quake or natural disaster movies!   

As hifi tuning fuses are another controversial topic, if not more controversial than cables such as power cords, your comments & brick bats are welcomed in the comments section!

Tweeter Dimming, DIY Tweeter Pad

Are you suffering from high frequency fatigue each time your are listening to music on your stereo system? Is your HT system too bright sounding, that your ears bleed from gun shot sounds and what nots? Maybe you only experience high frequency love bites on certain CDs or LPs?

The above symptoms common with many beginner set ups. They are a result of a variety of possible causes. Chief amongst them are poor speaker to room placement, seating position error, room modes to speaker interaction, poorly matched equipment, cheap or fake silver cables, wrong tweaks application, and probably many , more reason caused by poorly set up system. On the flip side, is bass boom, or simply not enough bass. Well, that's another side of the problem.

Saw this tweak available for lunch money and thought maybe I should just try it for fun, even though my system never exhibited any of the high frequency symptoms as mentioned above. My system at some point many moons ago did exhibited some of the high frequency issues but I have since learned to fix them on a fundamental level, i.e. fix the source of the issue, not treating the symptoms with band aid. I think this tweak clearly belongs to the band aid category, if one is looking to fix an overly hot tweeter issue!  

The tweeter pad came as a pair, it's a square felt like material die-cut with generic tweeter hole and comes with double side tape on one side for easy application to tweeter. 

My PMC IB2i before tweeter pad treatment

And tadaa! with tweeter pad treatment

I bought the item and went home with the merchandise. As I started to play some music, I started the first 30 minutes just listening my system as is. Then I stopped the music, and put on the tweeter pad to the tweeter on my speakers. The whole process is rather easy as all it took was 10 minutes or less.

I restarted my music, the very same music I played 30 minutes ago. Right away, I noticed some minor difference to the sound. The good thing is that the vocal size became 50 cent sized(using old Malaysian coin standards, which are much bigger in diameter than the current 50 sen coin), which is certainly a good thing for vocal biased audiophiles. The cons(in any tweak no matter the cost, there is always pros & cons! You invariably win some & lose some too!) are, my system had lost it's spatial cues, yes, the back ground was blacker(if there's such a thing!) but the sound became less airy too! Yes, the vocal was now super focused, but it sounded like the singer needed lozenges to sooth his or her throat, i.e. vocal sounded dry! I kept the tweak on my tweeter for a few days, just to let it settle down, hoping the cons will be reduced in time, or maybe we just get used to the sound!

However, it was not to be, I still hear the cons as mentioned above more then any pros the tweak made to my system. I finally decide to remove the tweak for good. Maybe pass it on to someone who need a band aid for hot tweeters. My advise is to work on fixing the fundamental issues if one's system has a problem. Band aids are just that, they help your to cover up the rough spots, but at what price? What other compromise? I think band aids like this can work if your speakers are truly stuck in position due to home minister approval requirement, or for room aesthetics matter, then it may be a solution. However, it's not my preferred solution.    

Bass Tuning! Bose Acoustimas Series Woofers

Dr Amar G Bose started his career as a Professor in MIT. Later he would start the Bose Corporation by licensing his amplification algorithm for American military use & the likes of NASA. It was much later that consumer products like the Bose 901 series speakers hit the market. The 901 series speakers was a polarizing product as people in general either loved or hated it. The Bose 901 series speakers does hold some scientific promise, but was the result reflective of those published scientific papers? That's what makes it so polarizing.

Many years later, Bose moved away from conventional box speaker products and started moving in to the Acoustimass series of satellite speaker with sub woofer combo. Still very based upon the earliest premise of Direct/Reflect Sound Technology, but also add to the premise that low frequencies, a.k.a. bass becomes omni-direction below 80Hz. This comes at a time when urban living became more dense, homes got smaller, but people still wanted good sound with room filling bass. And judging by the Accoustmass series sales numbers, it was a home run!

Now, I know many audiophiles have some kinda beef with Bose, due to the construction & materials used, and that smoothing, well rounded, limited bandwidth sound ani't what we call hifi either. However, to the other 98% of the world population, that didn't really matter at all, despite those high price tags which resulted in fat margins. Fast forward to recent years, Dr Amar G Bose wanted to cash out, hence sold Bose Corporation to Apple Inc. Apple already own Beats By Dr Dre. And now Apple have merged both entities to become Beats By Bose!

I started with a little history & background of Bose, because I am squarely in the 2% of the worlds audiophile population, yet I am one of the few who loves Bose products for what they are today, lifestyle. My household is just all Bose sound mostly, in the non audiophile areas. And lastly, I find the Acoustimass bass modules, or woofers just so useful to have around, especially the passive ones. they are easy to integrate in to any existing sound system, and with guarantee extra room filling bass. What else do you want? Me, I always find the Acoustimass modules bass to be a little flabby, and when playing loud, port chuff becomes very apparent, especially the older series 1 models. Which is what I have exactly in my home office/study area.

And here, I set about doing something about that port chuffing sound. This DIY work is rather easy, and I think every Bose Acoustimass woofer user should try it. Do you know you can tone down that flabby bass & port chuff sound by just stuffing the Bose Acoustimass woofer? Here's a step by step guide how to do it. 

Bose Acoustimass series I bass module.

Once turn around, you will find back panel access screws & speaker input & output connectors.

You'll need to unscrew all the screws on the back panel, including those holding the 4 feet.  Do not unscrew the speaker terminal screws.

The back panel open, revealing all the internals inside, you will notice there is already some poly fill inside. Those white fluffy pillow fill. Just look at the materials used by Bose, woodchip board, crappy looking Pasar Road drivers & cheap x-over parts. Nothing special, but industrial grade only.

A closer look at the cross-over, all stuck to the rear panel.

Add more polyfill or pillow fill, there are generally 3 types on window fill, you can have foam or feather, both sadly are no good for this application. Then you have polyfill of various density, which will work for this case. What I have is of rather high density polyfill.

After filling the accessible side of the box to about 70% including the original polyfill. I stop and work on closing back the rear panel, making sure all the wires are still connected and in contact. As it quite common for Bose Acoustimas bass modules to fray & delaminate around the edges & corners of the box, so I wrap my module corner & edges with black duct tape to keep it protected. Even if the Acoustimass bass modules are designed to lie down, they can be placed in various positions, those liitel red feet you see are actually rubber door stoppers available from your local hardware shop. 

The bass quality after stuffing of polyfill in to the Bose Acoustimas bass module is tighter, cleaner and certainly less bass port chuffing effect. The immediate feeling is that the upper bass has been toned down, with slightly less kick and an overall bass volume reduction. So in essence, you gain some and you lose some. but for me it certainly an easy mod that takes just 20 minutes or so and it work a joy. Here are some other Bose Acoustimas bass modules that have gone thru similar bass tuning process.

Bose Acoustimass series III, I use this to complement the main hifi rig in my man cave. I loev this passive sub because even though it's one box, there is actually 2 units of  6.5 inch drivers inside running in stereo configuration! 

Here is how the Bose Acoustimas series III looks inside, still 2 units 6.5 inch drivers inside working as stereo pair. The box chamber design is totally different, but you can still access the box via the back panel where the speaker connectors are located. With simplified construction, all you need to do is to uncrew 6 screws in back panel to be accessible to the chamber which I have circled in RED. You just need to stuff the polyfill in to the chamber(as circled in RED) by 30-50% for bass tuning, results depends on your preference & room acoustics interaction.

I not only use Bose in my home, but also inside my car too. I use this Bose Acoustimass Canon in my car boot to augment bass to the OEM system in my car. I also need a 2 channel amp to drive this too. Again my main issue here is port chuffing & car interior panel vibration.

There are 3 chambers inside the bass canon. You can stuff polyfill in to the center chamber as circled in RED by 50-70%. As I preferred tight bass in my car, I filled the middle chamber by up to 70%. The chamber is accesi8ble via the tuning ports with end caps on the long port side. You just need to unscrew all the screws around the tube diameter on the end cap. For my interior panel vibrations, I added sound dampening materials to them. With panel vibration gone and bass tuning to very tight less, I some times can sit in my car, after reaching the destination. just to finish the song, before getting out!  

Bose Acoustimass Canon for home theater use. No I don't have this, but one of my buddies used to have it in his HT den, back then in the 1990's. These Bose Acoustimass Canons were considered high end at the time! I remembered my friend demo-ing Top Gun movies in his Dolby Digital 5.1 HT system. They were pretty convincing back then. However, the Bose Acoustimass Canon is very rare now, and hard to find in the used market.

There you go, now you know my fetish for Bose Acoustimass bass module!