Monday, May 1, 2017

Plinius 2b and VII

Had a surprisingly hard time trying to locate pix for these units on the internet - they were hardly any, not even on Plinius own site. Only managed to locate the following on a NZ audio magazine site.

The Plinius Plint from AudioEnz


For Plinius fans who wish to know a bit more of the original Plinius history in NZ, checkout the following NZAudio interview with Plinius Founder, Peter Thompson.

Before the internet era, I was informed by a local Auckland hifi reseller Plinius came about much alike the history of Lamborghini and Ferrari - Lamborghini made his fortune selling agriculture equipment after WW2 and bought a then much desired Ferrari, only to be severely disappointed; had a bad spate of words with Enzo himself before deciding to show the world what a Ferrari should have been, with his own brand of super cars!

I was introduced to the Plinius 2b & VII in 1988 while flatting in Auckland, New Zealand. My flatmate took home a set of the "Plint" for evaluation, to replace a Rotel integrated amp since the Rotel could not drive a pair of Celestion SL6s properly.

From memory, the Plint sounded decent up to 30% of the volume dial. Between 30-50%, it lacked the punch but still maintained it's poise with dignity.

That was until my flatmate decided to leave it at 50% on the volume dial as he wanted to enjoy the music in the garden - after all, it was a beautiful Summer's day.

About 30min later, our nose picked up a strong burning smell in the air! We started checking around the house but could not locate any smoke nor anything burning. It was not until we enter the living room that we hit the jackpot - the smell was chokingly strong there! After more nos-ing around, we were surprised to discover that it was coming from the Plinius VII!!! Needless to say ... no more good audio that day.😏(true account, not made up)

My flatmate returned the Plint on the next working day. Later that week, he returned with a then brand new Plinius 3100B (article for the near future) and a traded-in Luxman C-02. He retained this combination till we dispersed to our own ways, about 1.5 years later.


Plinius 2c (with extra dial but less buttons; looks similar to 2b). From AudioNZ

Plinius VII from local NZ eBay equivalent site

Saturday, April 1, 2017

Original Mission Cyrus 1&2


When I saw the announcement of a new Misson Cyrus One integrated amplifier, it brought back memories of my original UK made Misson Cyrus 1 & 2 amplifiers.

Mission Cyrus pix from Google
Misson Cyrus 2 pix from Google

There are many reviews for the Giant Killer and it's successor on the net, so there's no need for me to repeat them.

Years ago I was visiting a relative overseas and he had the giant killer hooked up to a pair of big AR floorstanders using the original Monster Cable speaker cables. Source was a 300-CD Sony library player ... it sounded delightful and I remember just enjoying the music from his setup. A few months after returning home, I came across the opportunity to own a Cyrus 1&2 from the reuse market.

I do remember re-selling the Cyrus 2 quickly afterwards but kept the giant killer for a few months longer. I finally parted with the Cyrus 1 by selling it to a local Cyrus amplifier collector as I could not locate the preferred AR speakers for it.

Sometimes I do regret selling the Cyrus 1, as it was a simple amplifier which just delivers the performance reliably time after time. The component which often failed after many years of operation is the flick ON-OFF switch. Oh well ...

Wednesday, March 1, 2017

Mission PCM 4000

This brings backs memories ...

PCM4000 pix from internet


Mission produced an extremely good and sweet sounding CD player in the form of the PCM4000 in the late 1980's. 

Both the PCM4K and PCM7K deployed the infamous Philips TDA1541A DAC chipset along with the Philips CDM2 transport, and the Philips RC5 IR remote facility. These CD players ran quite warm, even with the enlarge heatsinks vs their Philips equivalents. As per their Philips equivalents, the units were largely made of plastic.

I had truly very fond memories of the PCM4K as it always sounded "just right". And the larger display was a nice touch as you could view the displayed information from afar. 

Unfortunately the CDM2 deployed on the Misson PCM4K and PCM7K seem to be it's Achilles heel. For some unknown reason, my PCM4K and PCM7K did not enjoy service longitivity??? I bought a used PCM7000 after the CDM2 on the PCM4000 gave way. A few months later the CDM2 on the PCM7000 gave up as well! These back-to-back Mission CDP failure(s) really put me off Mission CD players ever since. The CDM2/10 on the Philips CD650 seem to be still going strong.

Wednesday, February 1, 2017

Technics 808 series - 1st Technics fully remote control component system

Was browsing thru www.audio-database.com a few days ago when I stumbled across the pix(s) of the 1st stereo set I ever own - Technics 808 series of slimline components.

Pix from internet - Technics 808-series package

The 808-series was the 1st Technics fully remote stereo set of components, primitive by today's  standards but advance for 1980. My set was in silver as per the pix above and consists of the following components.

SE-A808  - Power amplifier which can be converted into a monoblok

ST-K808  - Integrated Quartz tuner (with presets), pre-amplifier and built in-timer

SH-R808 - Remote control module

RS-M45   - High performance cassette deck

SL-D33    - Direct drive turntable

SB-L50    - 3-way floorstanders


Purchased the set as it was the best deal in town then - was on a "shoe string budget" as still in secondary school. Major purchase decider was the then advance and rare FULL IR remote facility.

Looking back I always wondered if I should have saved up for a proper set based around the then new Sansui AU-717 ...

Reproduction quality of the set was typical of many Japanese sets from that era - neither here nor there. Not suitable for detail listening but good for rock, heavy metal (and the alike) after you crank up the volume!

Cost for the IR remote facility justified for itself when songs I liked were played on any of the sources!!

Personally I find the cassette deck to be the best component in the setup - you can click on the component list(s) above for more information on them. The other memorable item was the Quartz synthesizer tuner as the station lock was just superb.

Anyway ... the Technics 808 set was extremely reliable and perform flawlessly for well over a decade (even after the speaker cone surrounds gave way).


On a sadder note, I wish my parents had advised to leave the money in the bank instead of splurging on a hifiset. Long story short - If I had left the money in the bank account, it would have accumulated (if untouched) to quite a large sum today! Could then have bought a much better setup (actually enough to buy a house!)... sob sob

Thursday, December 1, 2016

Basic Tube amp from PRC (***Update#1***)

I came across the following mighty mouse on Amazon USA with many good reviews. It was being marketed under a different brand. However, US items are 110V and not suitable for local consumption unless you are willing to invest in a proper voltage conversion unit. For the cost involved, it was simply not worth it.

When I browsing on the China version of eBay (aka TaoBao), I came across the following amp - with specifications and looks matching the Amazon unit and available with a 220V transformer. Hence I bought a unit. It was likely to be the OEM version for local consumption.


Did have doubts of the "looks only" issue eg with different internals. 

A month odd later, the unit arrived. Weights about 9kg. Assembling and setting up was a breeze.

Initial power up and usage proved to be a shocking surprise! For the price, I was speechless by the delivery of the sound quality and workmanship of the unit. 

Apologies no pix of the internals - good thick quality blue PCB with audiophile components which included RIFA 429 poly caps!!!

With less than 20hr on the amp, it is proving to be extremely good value for money. The unit runs hot as it is a SET valve unit operating in Class-A mode with a modest 8W RMS per channel output - more than adequate grunt to drive my LS 3/5A+AB1.

Will provide more update next month once I have time to burn in the unit.


1Jan2017

After listening more to the PRC amp, I realised the reproduction of certain mid and HF tones were a little off. Checking the Amazon link for the non-OEM version, I discovered many reviews recommend replacing the Chinese military spec PRE tube with a Sovtek 6SL7. There were also reviewers recommending replacing the EL34 tubes provided but with just as many indicating to keep the EL34.

Hence I ordered the Sovtek 6SL7 to test the waters since it is not a hefty purchase. Once installed, the improvement was apparent after about 15-20mins. Initially there was a slight high pitched HF in the reproduction with the 6SL7. That slight HF pitch never return after the first 30mins. The reproduction of the voices was now more natural. Actually it was beginning to sound like my previous set-up with the Quad 33-303 acting as the amplifier, if you were listening to the PRC amp in passing aka not in-depth listening.

Am currently contemplating the next recommendation from the Amazon reviews - to change the EL34 ...

Tuesday, November 1, 2016

Analog-to-Digital Converter

I had an issue with the limited number of input sources for my older design units eg limited to single or only two sets of inputs.

Since my DAC is in-use most of the time, I decided to invest in a Analog-to-Digital (A2D) converter for consolidating the tuner output to the DAC. 

That was the easy part ... Had to search hard before purchasing the below as I did not realise how difficult it was to locate such a unit! Most of the market was geared towards Digital to Analogue (D2A) converters. Prices for the available A2D converters were quite shocking as well.

Analog to Digital converter from PRC
Bought the above from PRC since I was buying new batteries for my laptops at the time. The unit was delivered in a nice white box with magnetic latch. Inside the box was a manual in English (surprisingly), a short pair of normal RCA cables and a multi-voltage PSU unit. The unit has two outputs (RCA & TOSLINK) on one side with the LHS-RHS RCA analogue inputs and power connector on the opposite end.

Operation is simplistic as it operates in single direction only eg A2D not D2A. 

Initial testing with the RCA digital output was disappointing - low output volume and the audio quality was mediocre. Changing to TOSLINK, the difference was like night and day! Using a normal TOSLINK cable (about $6 from PRC) and the normal RCA analogue cable provided, my ES tuner sounds as good as the previous direct connection to the amplifier. 

Hence I am now able to use the DAC as a source consolidator for the older vintage amplifier units in my collection.

Saturday, October 1, 2016

DIY PROAC 2.5 Clone (Part- 3)

Continuation


Finally, the custom made clone cabinets arrived! It was delivered in a wooden crate with a label indicating the contents have a combined weight of 56kg!

Clone cabinets delivered (top of wooden crate removed)
Front of cabinets after un-boxing
Rear of cabinets after un-boxing

The physical dimensions were to specifications and the purchased bass port fits perfectly!

Testing how the bass port fits into the rear port opening. The crossover will be position opposite of the end of bass port, with most of the weight support by the bracing. Will use a velcro mechanism to hold the crossover to the internal wall

Since I requested for the bracing, had to literally force foam onto the bottom half of the cabinet. This is necessary to reduce unnecessary reverberations there. Had open-up a B&W 800 series before and that's what they use as well.

Putting foam into bottom half of the cabinet

Will be using MDM-2 in the top half of the cabinet.

MDM-2 for top half of cabinet
Forming top portion of MDM from package to fit top of cabinet, with cut along the edges
Fitting MDM inside top half of cabinet

Initial insertion of the ScanSpeak drivers onto the cabinets provided such a prefect fit I did not even have to deploy the screws for the first week of initial testing!

Initial fitting of drivers onto the cabinet

Ohm reading after insertion of speaker connectors and cabling of all internals

Close-up of one of the cabinets during initial usage

Initial usage was jaw dropping! Really sweet with bass to match ... no wonder the ProAc 2.5 is hardly available in the resale market.

It is a suprisingly power hungry speaker though. Will dig out my 200watt's power amplifiers once I have a chance to cleanup the room.

Shall update again once I have a chance to burn them in...

Saturday, September 24, 2016

Rhodium plated connectors

I had been pondering on a purchase of Rhodium plated connectors for a quite a while. Finally decided not to proceed.

A brief intro to Rhodium for those not familiar. Rhodium is a rare earth element in the same group as platinum, gold, silver, etc. Quote from Wikipedia - "Being a noble metal, pure rhodium is inert. However, chemical complexes of rhodium can be reactive." 

Rhodium plated items are not cheap. They are normally available as high end automobile spark plugs as well as high end hifi connectors.


Decided not to purchase any Rhodium plated connectors after someone on a hifi forum who was touting the benefits of using an high end contact cleaning fluid on their own Cardas Rhodium speaker connectors. He show a pix of the contaminants after using the high end contact cleaning fluid on a cotton bud afterwards, as well as reporting audioble reproduction improvement.

One has to ask - is the Rhodium plating of the Cardas Rhodium connector pure??? 

Based on the chemical properties of the element Rhodium, it should be inert. In theory, when he cleaned the Cardas Rhodium connectors, there should be no noticable residue to the naked eye - not the proportionally largish dark patch on the cotton bud, as shown ... unless it was not pure Rhodium but a chemical complex based on Rhodium.

Hence my personal logic is why pay extra for this Rhodium plating when one still has to clean the connector vs a normal gold plated version ... unless you have plenty of extra cash to spare

Thursday, September 1, 2016

DIY PROAC 2.5 Clone (Part-2)

Updates

The cabinets have been completed and the provider have requested for additional curing time before putting the finishing touches. Looks like I can only complete the DIY after another month or so. The pix the provider sent over did look ok but were very low resolution.

Will be purchasing the specified drivers from overseas, as the local agent pricing was not that convincing (prices are before GST). In addition, delivery costs are extra from the agent.  In the past, I have bought quite a number of drivers from overseas without issues - hence no brainer for myself. It's my choice and am comfortable with it - hey I have even Fedex a 29kg power amplifier from overseas before!

In the meantime, most of the PRC Ebay items arrived about 2-3 weeks after payment - as per below.

Speaker driver terminal connectors 
Speaker terminals with long lugs



Managed to locate a ready made bass port with the required specs - would have preferred a all plastic component though.
Correct spec ready made bass port for the cabinet


The following cutout was made in preparation for drilling the holes to place the speaker lugs with provision for a bi-wire layout (since I was at it). Will position the bottom of the cutout just above the bass port opening of the cabinet. Then will drill the designated 1st set only.
Cardboard skeleton for drilling speaker terminator lugs

Bought these from a local hardware store. S&P within PRC was not viable.
For cable termination from crossover to speaker lugs


The following pix shows the clone crossover schematic at the top, and, the PCB circuit diagram for the crossover board purchased at the bottom. You can see my scribbles over the PCB schematic.
Reference circuit diagram at top with the modifications for the PCB layout

The main reason to buy the crossover PCB was to simplify the crossover component layout and permit a compact PCB vs a DIY crossover board. In addition, the compact PCB can be positioned thru the woofer driver port and will fit neatly between the woofer and the bracing within the enclosure, in a vertical position with the back of the PCB against the wall (using the internal bracing to hold the weight of the crossover). If you refer to Part-1 for the enclosure specs, you will then understand why.

I decided to not separate the tweeter and woofer access points as I do not see any real advantage doing so. Anyway, it is relatively simple to convert the PCB connections to support a bi-wire configuration (separate and hook-up 3 GND connections on the tweeter circuitry), since the connectivity on the PCB has been separated into INPUT and GND for inputs with HF OUT, LF OUT and GND for outputs. Another reason for choosing this particular PCB.
Completed crossover


For the curious, the inductors are constructed from 1.5mm copper and hence weights quite a bit. I did find it necessary to cut the original straps on the inductors, to reposition the termination point for better connectivity to the PCB. Had to re-drill the PCB holes for the inductors as the original on the PCB were just too small.  The green caps are 1uF Russian PIO (Paper-In-Oil) capacitors. The black caps are ERSE Audio. The PIO(s) were combined in-parallel to create the custom values as per specified on the clone schematics. The PIO in the middle of the PCB was mounted on a daughter DIY board (space restrictions). The ceramic resistors were purchased from Malaysia as they cost about SGD$2 (each!!) locally  and are much cheaper in Malaysia (roughly SGD1->MYR2.98). A friend help acquire them on a family trip.


Internal cables will be as per my DIY LS 3/5A. Had to re-drill the PCB to accommodate these cables as well.

Am awaiting for delivery of black hex screws for securing the drivers to the cabinet.

Monday, August 1, 2016

DIY Quad PRE/POWER DIN-RCA interface

While awaiting parts for the Proac clone to arrive, I finally had the need to make the following for myself (after making a few for clients).

It's a simple interface converter to enable old Quad models to be connected to other equipment. Pin-outs are at http://myoldvintagehifi.blogspot.sg/2012/02/bi-amping-quad-303.html

Plastic case from EBay
4-pin DIN for Quad pre/power amp connectivity to RCA
RCA from Ebay
Decided to try using a solid copper core for transporting the LHS and RHS signals, as the previous units were completed using normal cables. Earth connectivity remain unchanged.
Solid core copper cable used for connectivity
Been using it everyday for the past week ... so far, so good 

Saturday, July 2, 2016

DIY - PROAC 2.5 Clone (Part-1)

I decided to initiate a DIY clone of the infamous PROAC 2.5 as have given up trying to purchase one in the used market after searching for years. A hifi dealer I frequently dealt with, informed he has never came across one for sale yet.

Searching the internet for information, the most promising clone seem to be the one at http://www.justblair.co.uk/blog/137-diy-proac-response-25.html as there were positive feedback from previous owners of the actual unit who long for another chance of ownership, and, made the clone using the information from the link as reference.

From past experience, my main hurdle was the enclosure. I am not capable nor have the equipment/facilities necessary to fabricate them. Fabricating them locally would cost "an arm and a leg".

My previous EBay contact (REF: DIY LS 3/5A) quoted an expensive cost for the cabinets only (with S&P)!!!

Fortunately during my exploration of the Chinese version of EBay, I stumble across a vendor who fabricates speaker enclosures. Hence I provided the above link for reference and the vendor says NO PROBLEMO. Total cost would be much lower. Naturally I placed the order and now praying for the best ...

In the meantime, I am going thru the parts list and buying most of the necessary parts from the Chinese EBay site. After all why pay a 3rd party who would purchase from China and resell to you for a profit, right?

We have to face the facts, most items are nowadays manufactured in China - there is really no choice.

I will only be buying the capacitors and actual drivers from non-China sources.

Hope to update next month, once I receive the items.


Monday, June 6, 2016

DIY - Experimental Open Baffle speakers (Part3)

Apologies as I have been busy with my (discounted) shopping spree on China's version  of eBay ... kept feeling I had not done something recently!!! Finally remembered what it was...

After much searching, found what seem to be the proper replacement for the original crossover board on the Pioneer S-D77 (now DIY Open Baffle) speakers - see pix(s) below.

Original crossover from the Pioneer S-D77
Replacement crossover from China

The replacement was a ready made 2nd order 3-way crossover with 2dB boost on the HF.

How does it sound vs the original crossover?

Initially the PRC crossover sounded as if it someone had place a thick floor mat over it - even with the 2dB boost! After a couple of days, it began to remove the "thick floor mat" - details was then neither here or there, but reproduction was beginning to open-up. After a few more days, it sounded close to the original crossover. About a week later, bass details started leaping out.

A few of my visitors were pleasently surprise by the quality of audio reproduction from the DIY Open Baffle, when driven by my Audiolab 8000A.

Hmmm ... how much did I pay for my pair of production speakers from the shops??? Bloody hxxx ...

Sunday, May 1, 2016

Internet streaming using PC via USB DAC

Finally had the time to hooking up my DIY TDA1541 DAC to the PC via USB to the hifi set.

The PC is an older laptop which I have since redeployed for live streaming for songs (Spotify, etc) and sports event(s), etc. Since the USB DAC was Plug&Play compatible, setup was a breeze after making sure all the necessary cables are in-place, and, flicking the toggle switch on the back of the DAC chassis.

Initial setup for testing

As  this is the 1st time using the DAC components, initial reproduction was a tad bassy when compared to the output from my Sony ES tuner, for the same FM station. Otherwise the details were all present. Will update once it has been run-in.
The DIY USB DAC with TDA1541
Connections on the rear

Friday, April 1, 2016

Philips CD-880

The Philips CD-880 was my 1st proper CD player. I actually had my heart set on the Philips CD-650 but was informed it was no longer in production, and, the CD-880 was it's successor when I had save enough to buy one in 1989. Paid $1250 for the CD-880.


Philips CD-880 pix from the net

Don't think I need to go over the specifications etc for the unit as it is quite a well known unit and there are many sources of such information on the net. 

What I will do is provide information regarding what's not well known about the CD-880. I owned one for 13 years before deciding to sell it.

The unit was mainly plastic and thus quite light. If memory serves, was about 6kg. The laser does not read from the old blue dye CD-R which were available at the time.  The tray mechanism was not as solid as the Sony ES series but did an adequately job; had a built-in adapter for the smaller single version of CD.

The remote was well design and pleasant to use.

Variable output from the CD-880 had too much HF for my taste. At that time, I tested the results by connecting the CD-880 directly to a Carver power amp with a pair of Celestion SL-6s. Fixed output was much better but still a little lean on the bass. Extremely fluid and rich mids thanks to the TDA1541A.

Another plus was the shock absorption capability of the attached feet to the base of the unit - the CD-880 would play non-disruptively unless you gave it a hard knock squarely on it's chassis!

Personally I think the display presentation of the CD-880 was the best of the lot ... looks cool, even after more than two decades!!!

Do I have any regrets selling my CD-880? No, as I still prefer the sonic signature of it's predecessor.

Tuesday, March 1, 2016

DIY - Experimental Open Baffle speakers (Part 2)

(continuation from Part 1)

After some plastic surgery, the ugly duckling was transformed to the below. Woofers were salvaged from the original Pioneer S-D77. Replacement midrange are AIWA and tweeters Celestion.

The resultant open baffle
Initial layout after hooking up the misc components

Frontal view
How does it sound?

In short - blew my socks off (... can't find them)!!! I NEVER expected such promising results. The resultant open baffle (aka OB) sounds extremely open and natural. Using the setup in the living room, I could hear additional details from my favourite CD(s) I never realised were in the recordings ... till now! Even so, bass reproduction seem to change drastically between CD(s) which could be due to the resulting impedence or matching of the make to do components. Nevertheless this seem to be the common sore point for the many OB(s) on the net.

Was originally planning to dispose of these cabinets after some mucking around ... I now intend to order some decent components for further exploration. Much followup would be necessary before I can finalise the replacement crossover for the OB ... guess will require a Part-3 for the OB in the near future.

In the meantime, I started performing "trial and error" tests using the many components in my collection. Changing the DAC in the above setup produces large differences in the quality of reproduction.

Monday, February 1, 2016

DIY - Experimental Open Baffle speakers (Part 1)

Since I now have a crippled pair of Pioneer S-D77 speakers at my disposal, I went thru my inventory of spare drivers to determine if any could be attached to the cabinets to get them going again.

Unfortunately none of the available drivers could not be mounted onto the cabinets as per original as the baffle cutouts were (again) just too small.

As the cabinets were glued together (no screws), it is very troublesome to attempt fitting the available parts from internally. Fitting them externally onto the cabinets would create a Frankenstein ... the boss will not approve!

I was considering salvaging the usable parts before disposing of the cabinets. It was then the idea hit me - why not convert them into an experimental Open Baffle speaker?? Always wondered how a pair of open baffle speakers would sound in my living room after hearing a pair of Gradient Helsinki at a local AV show couple years ago. LOVELY ... until they told me how much a pair costs!!!

Anyway... back to reality.

Planned steps of action are:-

1. Investigate available DIY open baffle (OB) designs on the net
    - Most the OB implementations on the net seem to be ground up implementations eg from scratch
    - These implementations have several common characteristics
      - baffle to house the drivers
      - some with, others without a base for bracing the baffle
      - wide unrestricted rear to maximise sound dispersion
      - OB kits seem to cost an arm and leg, even before shipping
      - minimal information on the crossovers deployed on most projects
        - need to test before we will know if a different crossover will be required for an OB?

2. Draw the desired outlines onto the existing cabinets
    - Since I have a jigsaw and sander handy, decided on a simple straight line cut-out of cabinets
    - Will retain only the baffle and the speaker connectors on the base

Cutting outlines for the cabinets on masking tape. LHS cabinet shows the rear, RHS cabinet shows the side
3. Remove all drivers and misc components from the internals. Ensure the misc cabling out of harm's way when jigsaw bites

Stock crossover on cabinet before the jigsaw bites
4. Jigsaw away the undesired portions of the cabinets*
    - Extract the stock crossover afterwards since originally fastened to the side of the cabinet
      - Tried unsuccessfully to remove the crossover before jigsawing
        - The enclosed cabinet makes for difficult DIY-ing

5. Sand away any sharp edges after the jigsaw is done*

*For those not living in Singapore, I need to explain the reason for delaying the metamorphosis. As I am one of the many Joe's residing in a government flat (just about 90% of the population), I can only create the mess in the external areas (with the all the accompanying din) during limited hours of the day and must cleanup afterwards. Would be an effort to do so after jigsawing and sanding the cabinets. Since the authorities do perform a wash-up of these external areas on a certain day of month, I should take advantage of this scheduled activity! Heh heh heh ....


6. Install the available pairs of tweeter and midrange units (same Ohms) onto the inside of the baffle
7. Reuse the original woofers
8. Reconnect all components to the correct wiring and polarity to the original crossover
9. Test the resultant OB


Friday, January 1, 2016

DIY - possible simple solution to deteriorating sound from a Quad 33 channel

Over the years I discovered it is necessary to clean the copper contacts on the add-on boards on some vintage hifi components every so often. This is especially true for my Quad 33 since I am now residing in the tropics. The Leaks seem to be trouble free at the moment ... touch wood

Some of the symptoms I have experience are the following, and, these occurred even after I use contact cleaner on the potentiometers and push-buttons:-

- one channel cutout and remain silent after some initial low level crackling upon powerup
- crackling sound on one channel which seem to get louder and occur more often as time goes by
- volume on one channel which seem to get lower and lower over time

One option is to use contact cleaners. Spray some onto a cotton-type cloth of sorts and use it to rub against the contacts. Unfortunately I find the results does not last long. You would need to repeat the procedure about every 3-4weeks due to the effects of the hot and humid climate.

After some experimentation I now use a different procedure. A good quality pencil eraser is recommended. Give these copper contacts a good rubbing with the eraser. I normally hold the board in one hand and ensure only the contact end of the board are say 1cm are inside the edge of a table. Then use the other hand to deploy the eraser. This will ensure minimising the possibility of damaging the board, Once completed, please ensure no eraser leftovers are on the contacts before reinsertion into the unit,

My Quad 33 boards seem to require such maintenance every  few months. One of my clients with a Quad 33 has the same issue and was quite surprise by the effectiveness of such a simple solution.

So save yourself a costly trip to the shop by giving the above a go before that.

Tuesday, December 1, 2015

Pioneer S-D77

A friend asked for assistance with his Pioneer speakers, which seem "unwell".

When the pair of speakers arrived at my door step, they look "tired" as the cabinets were in average condition (6.5-7 out of 10). Initial inspection indicated the tweeters on both speakers have been damaged with one woofer look worn. Both mid-range drivers look to be in reasonable condition. Specification on the cabinets are 180W 6Ohms and are not bi-wireable. My guess is each cabinet weight about 12kg.
Frontal view

View from the rear with bass port "covered"

Once hookup, it was immediately evident both of the tweeters were not operational. When checking the drivers individually, I discovered one of the mid-range was not operational as well. Even so, the presentation was decent, actually quite pleasing to the ear. The stock crossover is simplistic with a single inductor with two bipolar capacitors and a single semi-conductor current breaker - no resistors.

Hence the 1st option was to replace the damaged drivers. Unfortunately we then discovered the original replacement units are quite pricey (in USD), especially after shipping from overseas.

Second option was to source for 3rd party alternatives. This was when we realised the baffle cutouts were unique, customised for original parts only. As my friend and I do not have a portable router, it was not worth purchasing one for a "1-off" task, in addition to the 3rd party alternatives.

Thus my friend decided to dispose of the speakers. It was mine to recycle. Now what should I do with this pair of crippled speakers? Or rather what can I do to it???

Sunday, November 1, 2015

DIY - ferrite isolator on tuner antenna cable

In the recent weeks, I would hear some unnatural clicking sounds from the tuner in the hall every so often. 

Initially though the tuner require maintenance. Thus I connected that tuner to my 2nd set for verification - no such issue?

Hence the issue was specific to my main setup. I have been adding more electrical components to that locality. Guess some of the newer components were not as well constructed with less than proper shielding.

Solution? 

Most cost effective solution I could think of was to use some spare ferrite isolator (plastic assembly with two pieces of ferrite core) from my "junk box". 

1st attempt using a single ferrite core produce good results with much reduce clicking. Since I had a few, added another for better effect. That seems to have done the job - see pix below.


Was getting carried away and started putting the ferrite isolators on the TV antenna cables as well. Adding the 1st was effective as it did clear up the pix somewhat. Adding the 2nd was disasterous as the TV pictures were pretty blurry!!! Hence removed the 2nd ferrite core from the the TV antenna cabling.

Oh well ... you won't know till you try it

Thursday, October 1, 2015

Technics RS-M45

The RS-M45 was the 1st cassette deck I own. Bought it as part of the "808-series" of slim profile components from Technics with IR remote capability, in 1980.

Do not have the actual pix as the RS-M45 was sold many years ago - hence will refer to one from the internet. I actually kept the RS-M45 for another decade after selling off the "808-series" components before letting it go. Should have kept it... (***regrets***)

Technics RS-M45 from TheHifiEngine database
Specs are available at http://www.hifiengine.com/manual_library/technics/rs-m45.shtml

In those days, Technics was one of the more affordable brands which produce decent turntables and cassette decks (Nakamichi cassette decks were "King of the Hill" then).

The RS-M45 shared the many of the important core electronics with other high-end Technics units of its time eg RS-M02/65/85, except it does not have all the "bells and whistles" available on the front panel. Nevertheless it was a great cassette deck for the price eg "best bang for the buck" back then.

One GREAT feature was the electronics ability to compensate for dropouts. When I play certain cassette on other cassette players, you would hear the dropouts eg sudden loss of volume on certain positions of a song. These dropouts can be rather annoying ... especially when listening to one of your favourite tracks. On the RS-M45, it would proceed as if nothing was wrong!

Tuesday, September 1, 2015

DIY Better indoor FM antenna

I encountered FM reception issues when setting up my 2nd set comprising of the Quad FM3/33/303 in the spare room.

The  setup in the main hall had access to the radio antenna for the building. However there was no such access point in the spare room.

I initially experimented using a bare wire antenna (pix below). 
Bare wire antenna and the removed SMA connector from the other antenna experiment

While the Quad FM3 could receive stereo broadcast, the signal strength would waver eg LHS and RHS indicators would dim and brighten every so often. You would hear distortion(s) every now and then.

Checking the shops in the neighbourhood reveal the available indoor antennas were either too cumbersome, expensive or look like something from Dr.Frankenstein's basement!!

Hence I then search thru my recyclable items (aka junk pile) and came across a WIFI antenna scavenged from a dead router eg 2.4Ghz 54Mbps. As the WIFI antenna required a SMA connector, I had to procure a suitable mounting interface online (see pix below) as the local DIY or electronic part stores does not carry such a component(???).
SMA base with 3m cable and SMA connector

WIFI antenna and the SMA base with cable
WIFI antenna mounted onto the SMA base

Once the SMA base arrived, I cut off the SMA connector at the end of the cable (Ref: 1st pix) and strip the coax cable to enable connectivity to the olden-type TV antenna connector (see below).

Old TV-type connector with the stripped cable from the SMA base
Old TV type antenna connector inserted into Quad FM3

Connecting the above setup to the FM3 produce a solid unwavering signal. The STEREO, LHS and RHS signal indicators on the FM3 now remain lit brightly all the time!

Solid tuning lights and Stereo indicators on the FM3 after using the WIFI antenna
Location of the SMA base with WIFI antenna respective to the FM3