The Audiophoolery Thread.

[ms660]

Originally Posted by unitaudio

£3295? Or am I missing something? Regards,
Paul

From the page in the link, "Starting at $3,295"

Lawrence.

[Station X]

Originally Posted by ajgriff

Perhaps this should be merged with the long running audiophoolery thread?

Alan

Done.

[Craig Sawyers]

Originally Posted by Nickthedentist

https://symbolaudio.com/audio/modern-record-player/

Looks fun... if you've got very deep pockets! And I wonder how they avoid acoustic feedback.

I think I'll stick with my Pye Black Box

Well the core of that is a standard REGA 1 turntable, arm and "Carbon" cartridge, the combination sells for £275. https://www.analogueseduction.net/rega/REGAPLANAR.html. They have paid a bit extra for the transparent platter rather than the standard black one, but the is only about £50.

And they are retail prices. Negotiate and commit to volume and you can divide those numbers by two, or even three.

In fairness that is a well thought of basic deck combo, and has been going in various guises since Adam was a nipper.

Craig

[Valvepower]

In fairness that is a well thought of basic deck combo, and has been going in various guises since Adam was a nipper.

...well thought of basic deck combo Since 1973... now only 48 years short of 50 years and still privately owned by the chap who started it up

Terry

[Valvepower]

Hello,

To keep a balance...

Forgot to add... Rega does a complete system comprising of P1 Deck, amplifier and Speakers for around £1000 all made in the UK and Sunny Southend in Essex!

Terry

[Radio Wrangler]

So where did the Acos Rega turntable fit in?

David

I have just got three Toslink "cables" for a quid or so each, they work well. While looking for them I came across this https://www.directnine.uk/products/5-ft-premium-toslink-opti...le-with-net-jacket-manhattan-317924 at £9,044.40 each (40% off too), at least one doesn't need two for stereo!

[Craig Sawyers]

I thought I'd heard everything in this long and winding thread. But over £9k for a Toslink optical cable is ridiculous turned up to 11.

Craig

[Valvepower]

The Acos turntable came pretty much at the beginning of the life of Rega ahead of the Rega Planet and Px turntables, from memory it was a marketing collaboration between Cosmocord and Rega to make and sell turntables under the Rega Acos name. The early turntables used the Acos Lustre arm and that was also part of the deal. This didn’t last for long though, and the Acos collaboration was disbanded.

Terry.

Originally Posted by Radio Wrangler

So where did the Acos Rega turntable fit in?

David

[Radio Wrangler]

Ah, I had an Acos Rega with lustre arm for many years. My brother still has it. It was fully satisfactory.

Toslink £9k !

MM, you should now be regretting getting a cheaper one. If you had one of the £9k jobs, just think of the data coming out of the optical modules... the scintillating pinpoint 1's, the deep, velvety 0's. And as for the reassembled music, the adjectives you would have to deploy would strain anyone's vocabulary.

David

[Ted Kendall]

The universal version of the Lustre had a couple of weak points - the lock for the height adjust could crack the plastic lower moulding if overtightened (don't ask me how I know) and of course the toothed bias belts are starting to fail now after 40+ years. Not a bad old tool, though.

MM, you should now be regretting getting a cheaper one

I need four to do my silly optical switch to audio delay from two sources. I did note it is 5m long, all I need is a lot less than 1/2m so I have trimmed the 1m ones, I hope this will improve the "sound".

One day I may get a HiFi, meanwhile I just listen.

[Craig Sawyers]

Originally Posted by Radio Wrangler

Ah, I had an Acos Rega with lustre arm for many years. My brother still has it. It was fully satisfactory.

Toslink £9k !

MM, you should now be regretting getting a cheaper one. If you had one of the £9k jobs, just think of the data coming out of the optical modules... the scintillating pinpoint 1's, the deep, velvety 0's. And as for the reassembled music, the adjectives you would have to deploy would strain anyone's vocabulary.

David

Of course absolutely nothing you do with a TOSlink cable will compensate for the risible bandwidth of the transmitter and receiver modules. The main manufacturer is Toshiba (not surprisingly!) and the maximum specified bandwidth is 10MHz (the regular ones have a bandwidth of 500kHz!), with a pulse width distortion of +/-55ns for the 10MHz ones.

Absolutely nothing you can do with the bit of optical string that connects a TOSlink transmitter and receiver will compensate for the shortcomings of those modules. And that is before you factor in that the LED in the transmitter has a finite life, with the optical power reducing over time. Of course most audio nuts leave their gear on all the time, practically guaranteeing that the whole link will be below par.

The whole rationale between this optical link was back in the days of red-book 16bit 44.1kHz audio.

The joke used to be that TOSlink meant that you TOSSed the cable in the waste bin, or that only Tossers would use one. Having said that, I use TOSlink cables (cheapo ones) from each TV - but largely because that is practically the only way of getting an audio output from the things now.

The only real advantage is electrical isolation of this link.

You can do a whole lot better with coax with pulse transformers at send and receive to give galvanic isolation. Of course the devil is in the detail, because so called audio pulse transformers do not like working at 75 ohm send and receive impedances. But you can match them very nicely using resistive pads. It is pretty straightforward to get clean rise and fall of ~3.5ns.

Whether optical or coax in this context uses SPDIF (Sony Philips Digital Interface Format) signaling, which is in itself a historical peculiarity from the early days of red-book CD in the early/mid '80s.

Craig

[Valvepower]

Good to read a veteran Rega still doing sterling service. I recently helped Greg (BVWS) get a skip find early Rega up and going again and back to rude health.

I feel another reason for optical connections being popular is the optical transmitter is disregarded when it comes to EMC compliance testing whereas the Co-Axial, being a (wire) cable connection, will be more likely to radiate RFI thus making EMC compliance a little trickier.

The best optical transmitters and receivers are the Toshiba parts, the clones work OK, but the Toshiba are far better.

I think my optical connectors came from Farnell or CPC.

Terry

Originally Posted by Radio Wrangler

Ah, I had an Acos Rega with lustre arm for many years. My brother still has it. It was fully satisfactory.

David

risible bandwidth of the transmitter and receiver modules

More than enough for the stated 44.1kHz.

Of course absolutely nothing you do with a TOSlink cable will compensate for...

Try telling that to an audio, erum, "enthusiast", coax* analogue at audio frequencies too.

with a pulse width distortion of +/-55ns

Easily removed by a good clock recovery circuit.

*I made a scart to audio cable last night for my set top box radio feed to the "HiFi", the bit of "interconnnect" had a simple two core, non screened, inside. I feared not and it works (no audible hum).

Sorry folks, veering into the engineering...

[Craig Sawyers]

Originally Posted by merlinmaxwell

More than enough for the stated 44.1kHz.

Try telling that to an audio, erum, "enthusiast", coax* analogue at audio frequencies too.

Easily removed by a good clock recovery circuit.

Except that current equipment frequently uses greater bit depths (up to 24 bit) and sampling rates (up to 192kHz). You have real problems squeezing that down a TOSlink connection.

Of course this is all down to the standardisation of something from the early days of CD. Given a free hand now you would not come up with TOS. You'd use something with a decent bandwidth - there are lots to chose from right up to Terabits per second (not that there is any need for state of the art fiber backbone standards!).

But you take my point. Then you could do away with a PLL by separating data and clock, and just synchronise data either at the send or receive end. Job done.

But we've ended up with TOS, and rip off merchants selling foo optical bits of string for nine grand to people who have deep pockets and know no better.

Craig

[Radio Wrangler]

A lot depends on where the data came from. Some sources can be quite jittery, so as well as fixing corrupted bits from CRCs, you probably do want to re-sync to a good low-jitter clock.

This brings up the issue of the clocks being slightly different and eventually you wind up with either a sample too many, or a sample too few.

In the old Plesiochronous world, you had padding bits you could grow or sacrifice, but you still wanted a regular flow of samples to your DAC. The subsequent SDH world relies on everything being synchronised and no need for padding. I suppose the whole thing goes belly up if there is a GPS failure.

So with a need for regular feeding of the DAC, you need a clean clock oscillator, and you need a 2-port buffer. You can either manage the buffer by using a PLL to adjust the outgoing sample rate to prevent overflows and underflows, or else you make the buffer the size of a complete CD, read the whole lot in before starting playing. Hey, if the mechanism has stopped before the music starts, that's a wooden stake straight through the heart of all those audiophile arguments for separate decks and DACs or separate power supplies. Also if the file read is verified as properly corrected and error free (with any re-reads needed done), that's another sacred cow on the cattle truck.

Data is, well, just data.

Do you think we could sell them special, extra thick USB and CAT5 cables for their internet browsing, claiming that the concepts they read will be more favourable to their beliefs?

David

Do you think we could sell them special, extra thick

people.

[Craig Sawyers]

A creative alternative designed by an old friend (Steve Sells, chief engineer at Naim) is to use a FIFO. The data is clocked in using the recovered clock from a PLL. The data is clocked out using one of several closely spaced high stability oscillators, selected on the fly to maintain the data pointer to register half full.

It turns out that it matters not a jot that the precise rate at which the data is clocked out (and into the DAC), or that this has frequency discontinuities every now and again, provided the precision clocks always have low phase noise.

Craig

[jamesperrett]

There are modern high sample rate DAC's that use a sample rate convertor in front of the DAC so that it can be fed from a low jitter clock no matter how unstable the incoming data is.