RIAA Preamplifiers on a Budget

Pre-amp Circuits for turntable MM or MC reproduction

Apologies for the lack of updates over the last few weeks, our scribe has been off ill for a few weeks. Here’s to a new session of articles and hopefully a little bit of invigoration to our framework.

The true value of Vinyl

It’s amazing how times change – I was recently given a treasure chest of CDs, DVDs and records (vinyl) from my brother whom has left our shores for the UK and guess which media carries the most value?

In line with this and the comparative interest from local folk to listen to vinyl (read: huge interest) we thought it relevant to add some words on the subject. Continue reading “RIAA Preamplifiers on a Budget”

Parts for Vintage Equipment

Where to get vintage gear spares?

Over the last 6 months I have received quite a few mails from desperate individuals wishing to restore their old radios, tube and semiconductor, integrated amplifiers, turntables and tape decks.

Honest Sam's Top Notch Sales - Cars in Unbelievable Condition
Honest Sam’s Top Notch Sales – Cars in Unbelievable Condition

Belts and power supplies and many semiconductors have equivalents but we get stuck with Germanium, decals, knobs and switches with most gear and then the mechanical parts to decks and turntables. In South Africa we have to turn to eBay where often shipping charges become exorbitant. Continue reading “Parts for Vintage Equipment”

More about DACs – the A/D Converter

M-Audio Fast Track Duo

The A/D Converter – pushing vinyl to digital

The common and garden DAC can be picked up cheaply at most electronic stores, ready to run straight from your CD player through optical (Toslink) or coax and used to drive your analogue only system.

Although these little units are cheap by comparison to high end products being portable they can be used in most cases where a device does not have an analogue output so you really don’t have to trash your vintage equipment.

Going higher end there are literally hundreds of different brands to choose from, most having bidirectional data lines through USB which allows one to input binary and output analogue or vice versa through ADAT (Toslink) usually.

Behringer U-Phoria UMC20
Behringer U-Phoria UMC20 – Audio Mart and Sound Select

For anyone wishing to record vinyl to their computer one would need a RIAA spec preamplifier. For tape or cassette deck the line outputs would suffice but in most cases non-professional decks would need further amplification. Why? Continue reading “More about DACs – the A/D Converter”

Vintage Audio Vs Modern Technology

Is vintage audio better than modern releases?  (post 2000)

This reminds me of the first argument I had regarding the merits of mechanical VU meters over LED.

Yeah, we like vintage stuff, especially with those big VU meters. Hell, I was looking at the specs of the Pioneer SX-1980 the other evening and thought  what a beast this must have been in the 1980s. At 270W this is certainly by no stretch of the imagination much in modern times thanks to PWM, Class D and mounted on a one inch square heatsink.

McIntosh_MA6800
McIntosh MA6800

en:McIntosh Labs MA6800 amplifier. *Source:  *Credit: [http://www.flickr.com/people/ux/ Akira Kamikura] *License: cc-by-2.0 {{cc-by-2.0}}

Continue reading “Vintage Audio Vs Modern Technology”

The importance of RIAA

Trichord Dino+

Why do we use RIAA?

To kick off, and this is a response to forum user “Roggies” request for a schematic for a budget quality tube pre-amp for MC cartridges.

Unfortunately MC never has a cheap solution and that’s the bottom line.  MM may be getting better but phono die-hards are still going to have to dig deep if they want to belong to the elite.

We won’t get into a debate about which is better, tube or SS but on a spec level there are some incredible op-amps around which do an incredible job to amplify low level signal from vinyl but of course we have the tube purists.   Continue reading “The importance of RIAA”

Changing the argument in modern audio – the digital sound

Asus Xonar U7

The DAC and digital sound – big quality at half the expense

Coming from an analog website it may sound as if we are doing a 180 here but the truth remains, we still have the analog versus digital argument.  Something which will never quite be put to bed, the digital war continues.

My first CD player was the Sony CDP1, a small, heavyweight, state of the art digital ‘icon’ to the audio world. In fact at the time I was not even aware that it was first commercial release, rather just wanting to get my hands on a CD player, a Sony, to impress my friends.

The vinyl years

Two things stood out at the time, one without doubt the easy way to play the media – damn but vinyl was finicky, and then you had the problem of friends playing disks which were so bad that it would damage the stylus (was I the only guy that had a freakin’ sound system) and the big one,  no crackles, pops, buzzing, clicks, jumping, feedback and of course,  the big one – lifting the arm to change tracks.

As time went by CD players dropped in price, had more functions and became quite a part of our lives. Everyone had one by the 1990s. Turntables were packed away or trashed, vinyl was dead. Or was it?

The CD years

I stopped listening to vinyl for about fifteen years, it was always cassette tape or CD and then DVD.  I gave away both my Sony turntables which I DJ’d with in the early 80s. The marketing machine was fine tuning us for the silver disk and they did a remarkable job except for one thing – multimedia computers came on the scene in the mid-90s.  (PCs and Windows, Apple was always the front-runner).  We suddenly could compress our 40MB file to 4MB in the form of MP3s. We became used to this,  piracy was no longer something we found on the high seas, it was in everyone’s home.  iTunes suddenly kicked in and we could buy individual tracks not the whole CD where the artist possibly had only one good track. CD prices started falling and before we knew it the audiophiles started reminded us of a couple of things that we had forgotten about.  CD quality is 20 to 20, vinyl is so much more.  In the last decade suddenly we found vinyl on the shelves again.

The shortest route between two points is the straight wire

The digital versus analogue argument is all about the shortest path, sampling frequency and DAC quality. Vinyl has two paths, de-emphasis at the RIAA amplifier (where disk cutting excursions on the lower registers uses a lot of space the engineers de-emphasise these excursions and boost the treble). On playback the reverse is applied. The second path is the amplifier itself.  Simply put, cut out the unnecessary and only amplify the necessary.  Add tone controls if you wish but make sure the amplification is flat, as close to dammit from 0Hz to 100kHz. Wishful thinking but yes, technology can allow this.  Makes one think how the NAD 3020 became so popular with an output stage using transistors from the Ark.   But let it be said that these amplifiers were very popular and indeed, more because of vinyl than anything else.

Vinyl supposedly reduces fatigue, is non-sterile, not compressed to hell and back and also, importantly, does not have the 20 to 20 limitation.  A guru even went so far as to say that music is something we also sense outside the audio spectrum.  He is a very good musician, who am I to argue. So what has made that incredible CD player now near redundant?  The DAC and the internet of course.  Breaking up an analog signal into parts and then re-assembling  these parts or as in a CD, taking 1s and 0s and then re-assembling to get a ‘resemblance’ of analog is just not on.

Technology has allowed us to push the clocking of a digital circuit into the hundreds of Megahertz, the Digital to audio converter now even runs at 384kHz or higher.  CD players, or rather the media is sampled at 44.1 kHz. Using the Nyquist–Shannon thereom, sampling frequency must be a minimum double the sample rate – 44.1kHz also encompasses anti-aliasing filters which reduce the bandwidth.  Lots more of that on wiki.  Bottom line is that all CD players run at 44.1kHz – man decided that our uppermost frequnecy limit is 20kHz so let it be. But DACs have improved in leaps and bounds over the years, high end DACs costing upwards of R30 000.00.  Ouch. But here’s the thing.

We take an analog signal, slice and dice so it can fit nicely onto your computer and then rebuild this signal through the DAC to reproduce a nice sliced and diced analog signal. Why not just copy your vinyl onto a high end tape recorder, preferably an R2R where the media can sit for 10 to 20 years and hopefully not be subject to degrading.  Oh, yes this happens.  The Audio Technica AT-LP120-USB Turntable sells for about R 7 500.00, throw in a RTR for about R 10 000.00 and Bob’s your uncle, or aunt.

Asus Xonar U7
Asus Xonar U7 – 192kHz A-weighted 114dB front at 24bit/96kHz freq response 10Hz to 46kHz

But no, not to be, not to be.  Just have a look at how long it takes to set up your reel to reel – your computer boots up in 20 seconds and then you have the Xonar U7 as I have. Exceptional quality and in only 60 seconds you have YouTube, access to free downloads, very good quality audio. And that’s the thing – if you want a no frills, high quality audio setup go the digital route. If you are looking at the pseudo-acoustic route go analog. Real analogue. In the real world a high quality setup of either can be expensive. For Sunday afternoon listening pleasure I opt for the analogue.  Day to day listening, digital. It’s all in the head any way.

The Internet of Everything

We have all heard this phrase and it’s not one which will go away quickly – the IoT or Internet of Things is going to change the way we react with the net and the universe.  At home you will have a menu listing trillions of songs and movies. You won’t need to keep a library – you will need to pay royalties but as the companies supplying this service become more popular these royalties will be measured in terms of cents.  It’s happening now already.  We live in a quick fix world – digital streaming media is the way things are happening.

 

Technics SL-1200 MKII Refurb

Changing the buttons on an SL1200

New buttons for the Technics SL-1200

The Technics SL-1200 MK2 turntable is still very much in demand. So much so that when manufacture stopped in 2010 an army of DJs got together and requested Matsushita – Panasonic to continue with the model. Yes, it was relaunched tail end of last year for a staggering amount – have seen them here going for between R 28 000 and R 45 000 per turntable. For a turntable that many audiophiles claim to be mediocre this is surprising. But is it that?

Technics SL-1200 MK2
Technics SL-1200 MK2 – about to have a refit of knobs and decals

The first 1200s were made for the Hi-Fi market in the 1970s and not DJs as what is suggested.  They were also by no means mediocre, if that were the case DJs the world over would not be seeing these as the be all and all of turntables. But it’s not in the sound quality alone, moreover in the build quality. Built like a tank, quartz locked, heavy – no frills, no fancy controls and definitely nothing exuberant.

The 1200 MK2 especially was the DJs favourite.  “Pitch perfect” as the saying goes. Although the weight should be a giveaway as to where Technics were heading it must never be forgotten that what made these TTs so popular was the high torque motors, near instantaneous start up to controlled frequency. How many DJs dropped these heavy machines only to find that after a bit of panel beating here and there they would still work flawlessly.

Although most of us in the audio world get on our high horse when the gurus come out to play and make comparisons of these decks to others, usually the more expensive units we need to also be careful. The Technics was and still is a very capable machine.  It is also a direct drive – this is what makes them attractive in the world of beat.  The gurus scoff this off, real turntables are belt driven. To be sure I have had cheapy belt driven even idler turntables which performed marvellously well – none of them are still in my cupboard though.  A turntable which has been running for the last 4 decades is nothing to be sneezed at – and there are plenty of them. First and foremost we need to look at the mechanics of these turntables. This may also have gotten Technics into trouble in the first place because as far as high end turntables go these were actually quite cheap.

Not to repeat what a thousand other forums and blogs have to report, we will only go so far as to say show us the longevity of hard working turn tables and then how much money they have made for the owner? Unfortunately DJ controllers have killed the turntable market, audio modeling software is frighteningly accurate, MP3s and other media are highly portable – in other words there is NO way out for the turntable except into the hi-fidelity space of your home. The Technics may have it’s haters but one thing is for sure, to make a comeback after 6 years is going to breathe new life into your home audio.

Against all promises to myself I purchased two of these turntables off a DJ recently (yes, I know, I know – try to buy them off anyone else?). They had not been well looked after but in hindsight what are we supposed to expect – these are workhorses, not showpieces. The plastic buttons really looked horrific, the heads and cartridges were Stanton,  setup definitely for slip.  Changed these two first off for Audio Technica 95s, head shells were generic, changed mat, ordered in from KAB USA buttons, oils, greases and a overhang tool.

SL-1200 Pitch control 1
SL-1200 Pitch control – looks pretty shot (after 25 years).
SL-1200 Pitch control 2
SL-1200 Pitch control – nice and new from KAB USA
Technics SL-1200 button replacement
Some more buttons to go – all from KAB USA

Note that both turntables were sprayed black – this reflects the plinth of the 1210 and not the 1200 which was silver. Tell a DJ not to change the colours of his deck. I am pedantic about this but forget that these were not show pieces.

Anyway, I was impressed with the service of KAB USA and will use them again. It’s not just the service though, their pricing is better than most on eBay. From picked, invoiced to shipment outside USA waters took 4 days. They sell all spares for the 1200 and 1210.

In order to refurb completely is going to be a month long exercise. Although the previous owner said that these turntables had been recently serviced it must have been done by someone who used a feather duster.  Servicing a turntable such as this properly is going to take more than an hour or two. This includes changing the stereo output leads, fine tuning weight and tracking and lubricating the moving parts.

The New Vinyl – magnetic tape

And the final outcome: Magnetic tape beats vinyl.

Well we don’t really know about this one but based on our research this seems to be the case.  But let us be realistic.

A good turntable is going to put us back about R7 000 to R8 000 and then we are only just starting up our engines.  A good professional series tape recorder, which you don’t really need is going to be upwards of R20 000.  But here’s the crunch: the tests get done on a master tape copy or at least as damned near to a master reproduction. These cost upwards of R4 500 per tape.

Magnetic Tape beats Vinyl
The cat “eMotion” enjoying some analog Part I Act II

If we take the vinyl and record to a professional series reel to reel deck the reproduction can never be better. Likewise tape recorder to vinyl unless you have the master copy vinyl already. We won’t bicker here – most people will understand this but here’s the crunch.  Just what amount, what value do we put on this reproduction which is so outstanding, so good, that the hairs stand up on your arms? What came first, the chicken or the egg?

Value wise digital lies top of the list.  I will argue the point that the Zoom H6 hand held recorder from record to reproduction at under R7 000.00 cannot be beaten by any analog system.  The audiophile community understand the rationale about having an excellent DAC and of course, ADC. Your digital CD player output frequency range varies between 20 Hertz and 20 kHz.  Those engineers behind CD format weren’t on Opium when they devised that 44.1kHz was the optimum sampling frequency. It’s twice the maximum frequency we can hear after all.  What then makes vinyl then second best and tape, the ultimate in audio luxury? Well these are analog pages after all, right?

Magnetic Tape beats Vinyl
The cat “eMotion” enjoying some analog Part II Act II

To put things in perspective one needs to be the right age, that age which brought us through analog into our digital world.  The first listenings to digital after twenty years of vinyl, R2R and cassette tapes. Crystal clear, frighteningly clear in fact. Great dynamic range and when played loud, no feedback. No skipping, jumping, popping and cracking. Just beautiful sound. Picture this in your mind for thirty seconds and now jump to 2010.  Invited into a friend’s home to undergo a blind listening test. No reason given – just blindfolded, ears open and listen.  Dark Side of the Moon.  Different, very, very different.  Ambience, colour, warmth.  No new amplifier, no new speakers just a Linn Sondeck and a brand new vinyl reproduction. This was the same freaky feeling I had when listening to my brother’s vinyl reproduction of The Wall after years of listening to the digital format.

What do you think?

Next:  Part II – start your engines folks and open your wallets – here comes the 1950s and 1960s Reel to Reel….

 

 

Akai M8 test – Turntable reproduction

turntable reproduction - castle knight 1s and the LT-1200

Akai M8 test – Turntable reproduction

Obviously the final test will be the recording of and playback of material but at this stage 7″ reel tapes are in scarce supply but have ordered through eBay from Netherlands 🙂 so will do a quick recording of the actual analog signal on a digital recorder, the Zoom H6. Hey how smart is that? Or should this be, hey this is an analog site you dumb schmuck!  I don’t really care personally – I also have the original PCM file which is 122MB.

 

Akai M8 turntable reproduction
Analog player – digital recorder (Akai M8 vs H6)

Excuse the makeshift connections, didn’t cause too much noise though.

turntable reproduction - castle knight 1s and the LT-1200
TT Reproduction through Tube Amplifier – Technics 1200 in the background..

Fleetwood Mac – Go your own Way (mp3)

A few things to remember here:

  • The turntable to Akai to recorder was via microphone, not through a line source.
  • I used alligator or croc clips to connect the TT to the preamplifier – I didn’t want to cut wires, so there will be some noise present.
  • The amplifier definitely lacks grunt into these speakers but then again these speakers need a minimum of 25W to make them sing.  Class AB EL34 35W would be ideal.
  • I tested the playback with monitor headphones and there was little bass. I deliberately had the tone control set at half way. The EL84 amplifier has very beautiful highs.
  • The speakers are definitely not designed for just a low power rating but they are fairly new – need to be run in for a while yet.

Overall I was impressed.