Exposure XX

In the past I owned a Exposure XX integrated amplifier, as there were good hearsay from enthusiasts.

Do not have the actual picture - so here's one from the internet just to show the unit's likeness.

Web pix of similar Exposure XX unit likeness

As per other true Brit's of it era, there were no speaker selectors or tone controls - the power on thump was to be expected!

Build quality of the unit was solid. So was the bass and lower-midrange.

Unfortunately the HF reproduction was dismal. Even tried to perform bi-amping with the Sugden A48B driving the HF and the Exposure XX driving the LF, since these were their strengths. The combination was NOT a good match as the resultant extreme high and low was good but the mid(s) were well ... PFT (internet slang)

The XX was however quite grunty and capable of punch after punch when driving my Celestion SL6S!

Hence as per the Sudgen A48B, I sold the Exposure XX within a month of acquiring it. Kept the other Brady creation for a much longer period before selling to a enthusist who treasures it.

Sudgen A48B

Another of my units which has since been sold.

The Sugden A48B circa early 1990's, was supposedly a Class-B integrated amp but ran quite hot. The side-panel house concealed heatsinks with the transistors mounted on them.

As per the true Brit's of the era, you could hear the standard THUD upon power-on. Another standard feature was no tone and speaker selectors.

Took about 30min to warm up. Once warm-up, the HF reproduction was 1st class. I remember being amazed by the reproduction realism of the piano upper notes.The mid reproduction tend to be skewed towards the upper frequencies. Bass reproduction was lack luster, without authority nor definition.

And the Sudgen was not grunty (compared to my other amps). I remember the necessity to turn the volume to about 10 o'clock to obtain an equivalent of the volume from my Audiolab 8000A at about 8 o'clock when driving the Celestion SL6S.

Sold the unit within a month (in stock form) after acquiring it.

Sansui AU-9500

Found the following pix in my library archives - still have the Sony CDP and the CD(s) in the background.

No need to go into any technical details and the alike since the AU-9500 is a well known unit and such information are readily available on the net.

Sold the AU-9500 a few years ago.

Reason for selling? Took quite a while to realised there were frequency cut-offs in the HF (when compared against the AU-9900A). Don't get me wrong - sounds superb with a truly sweet reproduction ... to the point of being mesmerizing!!! The phono section was one of the best I have ever came across.

Decided to let the old gal go in it's original condition since I had then acquired the AU-9900A (now with the matching tuner, TU-9900).

Regrets? None. Well ... maybe one - I did not take a pix of the internals beforehand.

Samsung DVD C370 (experiment as backup transport)

The Samsung C370 is definitely not a vintage hifi component.

I bought it for $39 (with remote!!!) from a local supermarket chain as an experiment to determine the viability of using a stock el-cheapo DVD player as a transport since it has SPDIF output for a DAC. Must say the choices of DVD players with SPDIF output is getting rarer nowadays. Most newer DVD players are ship with HDMI outputs instead of SPDIF or even TOS.

Samsung C370 paired to the Meridian DAC

Construction material is in the category of you get what you paid for! 

When playing a CD and shaken (not stirred!), music stops (unlike the CD650) but resumes from where it was playing from once the earthquake stops. Noise from the lens tracking mechanism can be a little distracting from about 1m away but hardly noticeable once further away. Remote is usable and handy though the information provided by the LED display on the C370 is minimal.

Initial (out from box) analogue output via RCA was louder than my Meridian DAC output, treble just a little bright, presentation just a bit larger than life but with acceptable details. Sounds surprisingly acceptable after a couple days of usage.

With the digital out to the Meridian DAC, the resultant audio is what you paid for (with a remote nevertheless!). Not in the Meridian transports league but worth consideration if the unthinkable happens and your transport becames incapacitated!!! Resolution improved after the 1st hour of usage but resultant presentation has a sort of muddleless to it.

Only good as backup transport for emergencies!!!

Pix of internals

Sony CDP-X7ESD

The Yamato of the original ES series.

Front view

Found the above pix in my digital archives. Will update them once I have the opportunity (and strength!!!) to dig the old battleship from my storeroom! It weights more than most of my integrated amps okay?

As per other ES CDP(s), it has separate transformers for the analogue and digital circuits. The audio board are dual-mono eg with a separate board per channel. The CDP has separate analogue (fixed and variable outputs) as well as XLR for each channel. Digital out is via TOSLINK and SP/DIF via a RCA jack. The remote is able to access all functions on the unit. Did note the X7ESD remote is not able to control my 333ESA.

How does it sound? In short, nothing short of SUPERB!!! For example, I could easily distinguish the triangle being chimed 2x on Phil Colin's 3-inch single release of Another Day in Paradise (see pix below) effortlessly!

 





Sorry not sure why the orientation is not correct, as I checked the pix(s) from the camera and it was ok ... until uploaded???

B&W 802 Series 3N

Recently assisted a professional musician recap his B&W speakers (for home use) as the mid reproduction had a "behind the veil" effect and the HF was not as open as it could be. Bass was nice in general but boomy.

I suggested an initial recap before performing any major changes since capacitors are normally the cause of tonal issues.

After inspecting the speaker cabinet, manage to locate the crossover boards at the (internal) base of the speakers. The following pix is taken of the lower compartment in the cabinet after removing the speaker connector panel.

Original crossovers inside bottom component of speaker

Access to the lower compartment of the cabinet was via an opening secured by 8-screws at the base of the cabinet - see below.

Base of speaker

Unfortunately I then discover the internal cabling linking the crossovers to the drivers were extremely short ... extending just 1cm out of the box!!!

After much trouble, finally managed to extract them troublesome critters out!!! You can see from the pix how short the cables are!

Original crossovers in speaker with base cover removed

Here's a close-up of the original crossovers. The crossover on the left is for HF and mid. The other crossover is for LF.  The yellow capacitors are Benings. No idea of the EC origin as these have been rebadged.

Close-up of original crossovers

Crossovers after recap except for the 26uF EC

Could not locate a single component replacement for the 26uF EC as it is a non-standard value, and, there was not enough space to install the larger polypropylene equivalents in-parallel (to achieve the required capacitance). Since the 26uF EC seems to be in good condition, left it in-place for the time being.

Checking via multimeter before and after recapping shows no diffrence in the impedence with the LHS/RHS of the HF and LF wired together - should be the case.

Hooking up the recapped speakers reveal initial improvements in the HF and mid clearity. Bass was now firmer as well.

2Weeks later

The owner reported all was fine expect the mid seem to be out-of-synch with the HF and LF. Hence the 26uF had to be replaced after all.

Since I was not able to locate a replacement 26uF capacitor, I decided to fashion a suitable replacement using available values. Had to mount the non-EC caps onto a DIY PCB board to provide a solid platform for the replacement caps.

Resultant replacement for the 26uF

Rear view of the 26uF replacement

Replacement#1

Replacement#2

When I (finally) manage to test the extracted 26uF EC caps, both showed approximately 28uF though they were label as 26uF. Values of the other original capacitors were within tolerance of the specified values (with larger variations).

Test for actual value of the 26uF EC

The following shows the crossover boards after the 26uF EC has been replaced.

Total recap of the crossover boards

After the 26uF EC was replaced, the mid reproduction now in-synch with the HF and LF. Previous recap without replacement of the 26uF resulted in the mid being out-of-synch with the HF and LF as the polyproplene caps were quicker than than the EC.

The happy owner reports the sound is still evolving as the caps are being run-in but a definite worthwhile improvement over the original!

DIY clone of the Rogers LS 3/5A with 23AB crossover

After listening to the LS 3/5A clone with the  replica 11ohm crossover, I decided to populate the 23AB board as it has the AB Butterworth enhancement for the tweeter. This is because I find the 11ohm crossover board presentation to be not as open as my floorstander e.g English reserve in nature (surprise surprise)

My objective was not to create a clone of the LS 3/5A but a DIY which would sound close to the capabilities of my floorstander. Benefits include cost effective replacement of parts and ease of doing so myself.

The following are the resultant after purchasing the necessary parts.

23AB crossover board after populating with components

Physical comparison of the 23AB (top) vs replica 11ohm (bottom) crossover

Since the Monacor MDM-2 and my hybrid insulator were available, I took the opportunity to replace the make-to-do foam in the LS 3/5A cabinet with them.

Changing insulators within cabinet - MDM2 on side and back panel; my hybrid insulator on top and bottom

How does it sound?

Testing ohm reading after hookup before sealing baffle to cabinet

I would say a more open and natural presentation than the replica crossover. Headroom from the presentation was a revelation when compared to the output via the replica 11ohm crossover.

For the first couple hours or so, there was no bass. Slight hint of bass was produced after the first couple hours. As time progresses, the presentation changes progressively. More bass was audible after 20hrs and again after 30hrs.

After about 40hrs of run-in, the presentation is with good detail and pleasant for hours of enjoyable fatigue-free listening. Bass from good recordings are reproduce with realism as well. The English accent is still present but not as strongly enforced as via the replica crossover.

Couple of weeks later, a visitor who owns a pair of BC1 with valve amps (for many years and still does) commented he was surprised my DIY speakers sounded like his BC1 setup!!!

That really made my day!

DIY Clone of Rogers AB1

While awaiting for the AB1 cabinet to arrive, I found the following DIY info(s) on the net. The cabinet ordered will be made from Birchwood ply as well.

A Quad enthusiast I know made his own DIY AB1 from normal plywood.

One example of a home built subwoofer for the LS3/5A
Example of another home built subwoofer for the LS 3/5A

When I received the cabinets, I was impressed! They looked pretty good and felt solid as well.

Cabinets received

Upon inspection, noticed there were some internal modifications vs the information from the websites above. External dimensions are the same as the original.

One difference is the length of the bass port. The original was 85mm vs 88mm on the cabinet. Another was the insert cutting for the B110 on the original AB1 cabinet - absent from the cabinet I received. And there were no pre-drilled holes on the bottom of the plith for inserting spikes.

After a while, I finally realised the absence of a means for the cabling to flow between the top and bottom chambers??? Looks like I will need to drill or file an insert on the separator - method for creating the inter-cavity punch thru really depends on the gauge of the cabling to be deploy for internal connectivity.

Apologies as I did not take any additional pixs of the AB1 internals as was in a hurry to get it going and forgot to do so! Hence will update the next time I open the AB1 up for maintainence.

The electronics are setup in the following manner. I used the same alternative woofer as per the LS 3/5A as I ordered 2 pairs from the UK. The cross-over inductor was a 15mH with 16gauge coils, and, capacitors were ordered from the US as local prices were simply not realistic.

Connectivity diagram is as per the 1st weblink above. The large inductor was place at the bottom of the lower chamber over a very thin layer of foam. The DIY crossover was placed onto the back panel (which has the banana sockets). Used my defacto standard speaker cables in the internal wiring for the AB1.

For the insulation, I followed the setup as per 2nd weblink above. Monacor MDM-2 were used in the sides of the top chamber. Inner ceiling of the smaller chamber and the sides of the lower chamber were lined with a DIY hybrid insulator which consists of yoga mat (4mm) adhered to a thin felt double layer using the 3M type 77 spray-on adhesive. This resulted in a hybrid insulation-layer which was about 20mm thick - see pix of sample leftover below.

MDM-2 at top and the DIY hybrid insulator created at the bottom

Close-up of DIY hybrid insulator

Monacor MDM-2 packaging

How does it sound?

DIY of LS 3/5A with AB1

Understand there are 2 school of thoughts on the matter. One camp prefer the LS 3/5A as a standalone unit while the other prefers using the AB1.

The DIY AB1 does make a difference to the presentation of the DIY LS 3/5A. You could hear the DIY LS 3/5A breath easier as some of the LF load has been offloaded to the AB1.

For me, the DIY AB1 is well worth the investment.

Kenwood LS-V510

I was helping my friend perform a tune-up of his Kenwood LS-V510 speakers.

Friend's speaker at my place

The LS-V510 are 3-way home theater speakers which weight about 15kg each. The model is not bi-wireable and rated at 180W on 8ohms. The speakers are above 900mm in height and are surprisingly power hungry for HT speakers - volume was at about the same levels as my DIY clone LS 3/5a when driving them via the Quad 33-303 setup!

Friend's speakers w/o grill

Listening to them in stock form, the HF and mid seem a bit muddle when used in a non-HT mode. Bass is plentiful but can be a bit muddle when you crank up the volume as the speakers were just place on the floor.

Once the woofer was removed, you could see there are only some sound dampening material at the bottom of the cavity. Rest of the internal cavity was bare.

The tweeter is a encased in a stand alone box-like unit. I added some foam around the casing of the tweeter.

The mid is encased in a small canister like enclosure inside the cabinet, with only foam at the rear supporting the driver. I added more foam around the enclosure parameter.

Added more foam to the top portion of the speaker cavity - areas where the tweeter and mid driver was located.

Furthermore, added some spare foam pieces to the lower cavity to help reduce internal echo(s) from the woofer.

Upon usage again, you could immediately hear the difference from the tweeter and mid. Difference in the HF and mid clearity were like night-and-day!!

Unfortunately bass from the woofer had hardly changed. Since we did not have the necessary capacitors and/or replacement inductor to upgrade the crossover, my friend decided to live with it for a while before deciding on the next step of action.

One possible followup action is to obtain some rubber padding or spikes for the base of the speaker.

The following pix of the crossover board shows an air core and 3 steel core inductors (0.33/1/1.2/1.5mH) with 3 bi-polar capacitors (8.2/10/3.3uF). The EC are all house brand items

Will update this thread another day once I hear from my friend again.

DIY clone of Rogers LS 3/5A with replica 11ohm crossover

I initiated the DIY speaker project of the LS 3/5A clone as I was looking for an easy-to-fix and cost-less(aka lower cost) replacement for my mainstay speakers as when something does break, it would cost an arm and leg to put right again.

Searching the net for possibilities I came to realise the BBC LS 3/5A was probably the most cloned of the  (classified as a mini-)monitor class speaker . Hence one would be spoiled for choices of parts and/or alternatives from around the world!

For the curious, please refer to the following websites.

The Unofficial LS3/5A Support Site
KEF, BBC and the LS 3/5A


I shelved that realisation before I was reminded of it's potential a few weeks later. I was at a local AV show and heard the new LS 3/5A V2 being demo with the new AB2. The reproduction was acceptable to my ears but unfortunately ... the cost wasn't (would definately burn an extremely large hole in my pockets eg abt GBP1650+GBP1450 or GBP3000)!!!

Hence I decided to proceed with a DIY clone of the infamous mini-monitor.

I was prepared for the fact my resultant clone could/would be inferior to the real thing since there is a large cost difference and the review of available DIY clones on the net are close but no cigar.

My objective was not to create a 100% clone of the infamous speaker (as per many others) but to create a usable high quality drop-in substitute for my mainstay speakers which would not cost an arm and leg to repair if any component gives-in.


The following are some of the items to consider before proceeding with any such projects.

Cabinet
Would it be cheaper to arrange for a local carpenter to do the job or buy from overseas?
After much investigation, discovered it was much cheaper to procure a cabinet made from Birchwood ply overseas rather than to commission one locally (surprisingly!?!?)

Each cabinet was provided with a bare 23AB crossover. Will populate the 23AB once I manage to acquire the parts.

Dampening
How much is required?

Found the answers at the following websites.


Explanation of difference between Soundproofing and Sound Absorbing
TNT case studies on stuffing material in speaker cabinets
http://www.g4dcv.co.uk/ls35a/repair.html

Have ordered Monacor MDM-2 and felt layers but not delivered yet. Hence will use misc foam cuttings in the meantime

Cross-Over
11ohm or 15ohm?
After reading The HiFi News LS 3/5A Shootout and discovering the fact that all new LS 3/5A are 11ohm,  I bought a replica of the 11ohm crossover. 

Drivers
KEF(s) or the proper replacements, or, use modern alternatives?

History of Kef Drive Units from the 1960s and 70s
Summary of various KEF B110(s)

Since the required KEF models required are no longer in production and the objective was not to create a 100% replica, I bought a pair of original T27 SP1032 from eBay, and, an alternative replacement for the B110  as prices for the KEF B110 are getting silly. Actually the prices for the T27 SP1032 are getting silly-ier than those for the B110(s)!!!


Cabling (internal)
Thickness? Length? Silver or OFC?

The 11ohm crossover replica came with all the necessary cabling. Hence no worries. 


Cost for clone parts?
How much will it cost to DIY a clone? What is the average price for a decent USED pair?

Please perform a careful assessment for the total cost of  parts required to assemble a pair of clones vs the average cost for a decent used pair in your area/region.

Maybe hard to believe but I have came across DIY-ers who got carried away and invested over 70% of the cost of a decent used pair to build a clone!!! 

Please note it is highly unlikely you would be able to recover the cost for a DIY unit. Whilst the original speakers seem to have appreciated in value over time.

You should finalise how much you would spend on a DIY clone of the infamous speakers, before initiating such a project (or similar). Then compare against the cost to purchase a decent used pair (in your area/region) before proceeding. Otherwise your ROI (return on investment) maybe impacted.


Initial test

Most of the necessary components arrive before the cabinet.

Could not wait to test the usability of the various components!!! Hence I assembled the various components and placed them into a make-to-do cabinet from a pair of chilly bins!!!

Before sending signals from the amp, I verified the speaker setup to be about 11ohm with the T27 and woofer connected to the crossover.

Sounds (surprisingly!!!) pretty decent without any dampening except for a piece of foam on the back panel. Too bad the styrofoam cabinet was rather fragile and the screws kept popping out every once in a while!!!


Cabinet arrives

After opening the box

Cabinet internal construction

Baffle with cover

Front and back view

My DIY clone

Since I have not receive the Monacor MDM-2 yet, I redeployed various pieces of foam I had lying around for insertion into the cabinet.

Initially did not use any rubber seal between the baffle and the cabinet - just to try out a before and after scenario.

There was a definate noticable tidy-ness in the presentation with the rubber seal in-place.

T27 with the alternative woofer on the baffle and the felt layer  for  crossover mounting and dampening from tweeter

Just before sealing - with  replica 11ohm crossover

Completed  before applying cover

I then used a frequency analyser app for the iPhone to ensure the frequence coverage was to expectation (know it is rough gauge as professional equipment are expensive).

iPhone with Frequency Analyzer app

Initially the bass was non-existant. After the 1st 30mins or so, there was a hint of bass. More bass became audible after an hour later.

After 20hrs, the presentation began to open up.

At about 30hrs, bass from the woofer started marching in.

In the beginning I used my original late model 303 with my 2nd 33 to drive the new toy. After the first 40hrs or so, you could start hearing the limitations of the original late model 303. I then switched to my 2nd recapped 303 to drive the clone.

Bass from the woofer started to stamp it's authority after about 60hrs after usage.

Minimum run-in time seem to be about 100hrs for most clones on the net.


How does it sound so far?

After 60hrs of usage, the presentation is well behaved and very English in nature. Presentation of details was pretty good but lack the open-ness when I have gotten used to from my floorstander (equipped with a horn loaded tweeter).

Nevertheless the performance of the clone was impressive ... enough for me to invest in the AB1 cabinet with the required parts for it's crossover.

After doing some research on the net, I decided to try populating the 23AB crossover board which came with the cabinet to hear the difference from the KEF inspired circuitry. Will do so once I manage to locate the necessary parts for it.

Hence do keep an eye out for the 23AB crossover and AB1 in the very near future!

Sansui TU-9900 (***Update#2****)

After trying for the past couple years, finally managed to secure the legendary TU-9900 thru eBay!

Was extremely disappointed when I received it - the original glass on the faceplate was cracked even though it was packed double box??? Otherwise the unit looked like new.

Upon unpacking 2nd box

During daytime

Lights visible during the evening

When I contacted the seller, he promised to make it right and gave me the option of ordering a perspex replacement (cost on him) or time for him to locate an original glass replacement. I opted for an original glass replacement. Within a couple of weeks, he sent the replacement over.

Boy was I shocked to see what was in the mail!!! Not only did he sent me an original glass replacement for the faceplate, he sent a complete replacement (original) faceplate with the glass in a well wrapped package!!!

Replacement received from the USA

I can't say enough of the after sales service support received from Rich Crowl of The Soundwell - 1st rate After Sales Service and truly as Good as GOLD!!!

While awaiting the arrival of the replacement glass, I tested the TU-9900 and it seem to be working fine. Unfortunately all the stations sound thin eg bass-less. Otherwise details were superbly reproduced - confirmation when hearing songs or instrumentals I listen to often. I have not done the due diligence yet (since it is working fine) as been busy with another project.

On the back, the TU-9900 has a pair of RCA(s) for variable and fixed output connectivity, as well as other facilities which I had not had time to explore yet.

After locating the service manual and reviewing the schematics, I decided to recap only the PSU board as it is a low power unit.

Top view of TU-9900. PSU board next to transformer and just next to back plate

PSU board after recap

After the recap and run in of about half a day or so, the bass was back ... and in heaps!!! Really sounds superb with rich details and solid bass.

Well worth the patience to acquire the TU-9900!


10Dec2014

Finally had time to extract the unit from storage to replace the cracked glass.

Adding the below as did not take a picture of the rear in the original post.

Rear of Sansui TU-9900

2Mar2015

Came across a webpage at FMTUNERINFO on possible DIY upgrades to make the TU-9900 even better. Have not tried any of the mods yet

Sony CDP-361

Was helping my friend sell his pristine condition CDP-361 since he was overseas (has since been sold). He was ok for the unit to be posted in my blog.

The CDP-361 is one of the newer generation of remote capable CD players of the mid-80's. Well built but a feather-weight when compared to my ES-series units. Even so, the CDP had no issues with CD-R or my test CD with transparent areas in the TOC (table of contents)! Body was steel all round (thin but still the real thing).

Since it was a budget CDP, it was not surprising to discover that the transport mechanism was not to the standard of the Philips CDM-2 eg will not play non-disruptively thru all the rock-n-roll of a quake aka pickup and shaken not stirred (to coin a phrase from the movies) during play!!!

As per typical Sony CDP(s), there are only the analogue outputs via RCA and a TOSLINK for digital out.

With volume control for the headphones

Only TOSLINK for digital out

With covers removed

Angled view from rear

Close-up of the main board with everything including the analogue audio components (on LHS side of board)

Suppose the unit would be great for a modder since there is so much empty space within the chassis for all the add-on(s) once could dream of!!!

How does the unit sound?

Pretty good for a stock unit. Details are reproduced with above average quality - enough to enable one to distinguish various instruments in most music genre without requiring much concentration. Good overall reproduction of the CD fed, though not to the standard of a ES-series CDP.

While testing the unit to ensure it was in ok condition, discovered the CDP can be picky on the type of inter-connect utilised - preference for plain but good quality pure copper interconnects.