Teac VRDS-T1 Transport

[Qwin]

I find it strange that Ken replied some 7 years after Neil's original post, especially as the misconception was pointed out at the time.

Hi Barry, it was because I am looking at getting a VRDS transport, did a search on here and was surprised how many statements early on in the thread are just inaccurate.
Also, I don't think it was made clear, just how basic the build quality is on the CMK-4.X variants compared with all others.
Gaz
" what’s your take on the StreamUnlimited 8 drive and Blue Tiger CD-84 servo card, a new transport being used in higher end transports?
Curious how these stack up against the high end Teacs."

My knowledge is mostly around VRDS as I researched that mechanism recently.
But the StreamUnlimited/BlueTiger as used in the ProJect CD Box RS2 T and others, is very good.
Also worth noting is the Audio Note CDT TWO/II top loader, using Philips CDM Pro mechanism. Both fine machines.

The Wadia VRDS stuff is overpriced, what made them special wasn't VRDS, they didn't always use the best variant available, but their custom firmware.
Discounting the later and exotic NEO variants, there was not much difference between a TEAC VRDS 10 and an Esoteric P2, which was much more expensive.
The basic mechanism was the same, as was the hall effect brushless motor (same part numbers) The rigid metal bridge that supports the P2 mechanism is said to offer little over the heavily braced and rigid plastic version. It was the power supplies that were much much better. from memory the P2 had four separately regulated supplies on board.

I just pulled the trigger on an Esoteric P-700, but its in Perth, Australia, so I won't be seeing that for a while yet.

A re clock, improvements in the PSU and adding a better BNC 75ohm output board can elevate the old VRDS machines to a high level. But I'm talking about them as a Transport, the old DAC's they used can easily be improved on.

[Gazjam]

Cheers Ken.

[hifinutt]

ken what do you think of the new Teac 701t ?

https://teac.jp/int/product/vrds-701t/top

[Qwin]

ken what do you think of the new Teac 701t ?

https://teac.jp/int/product/vrds-701t/top

Hi Phil
Not a lot really.
I looked at it, as I'm in the market for a CD Transport and can't afford a hi end Esoteric.
With the old classic VRDS machines, the further you went up the model range, the heavier/Chunkier the bridge/bearing/shaft and clamp became, and the more attention they paid to the power supplies. An Esoteric model I looked at had four separate trannies with regulated outputs.

The 701/701T have a very light weight plastic bridge, with only a single locating screw a side and a cutaway (spoked) light metal clamp. Has TEAC's basic design philosophy suddenly taken a 180, or is it down to price? I'm not exactly sure which. They have paid attention to power supplies and make much of it in the blurb. I'm sure the servo board will be well designed and probably uses better parts, like the clock, than back in the day, but I worry about that basic VRDS engineering.

With that in mind, I personally made the decision to avoid the 701T and instead decided to buy an oldie but goodie VRDS transport and upgrade some of the internals.

I have an Esoteric P-700 Transport (same as TEAC P-700) on route from Australia, it uses a mid range VRDS mechanism.
I will fit the Tentlabs XO3.2 clock/PCB, with its on board SPIDIF output buffer and feed a new 75ohm BNC output socket direct from this. I'll leave the stock RCA and Toslink outputs in place, they will benefit from the clock upgrade and it allows some hook up flexibility, though I will only be using the newly created BNC output in my set up.
The XO3.2 will run off its own dedicated PSU, to keep the clock free from any artefacts in the main power rails.
I will look at the rectifiers and regulators on the main supply and possibly upgrade these.
The ultimate though, would be an external PSU and just feed clean DC into the Transport.
At first glance, looking at the Service Manual wiring diagram, there appears to be three requirements in the stock set up, +/-5Vdc +/-10Vdc both regulated and +/- 30Vdc unregulated. I would look at this in greater detail if changing anything.
It would be possible to externalise the fairly small stock Power PCB, but if I get that far, I may as well build a better power supply/s from scratch.
These mods, plus a total recap, which may be needed anyway, would leave me with a Transport of a high standard.
I chose the P-700 as the basis for my project, because I like the half width case format and it allows a separate PSU, up to half width, to fit on the same equipment shelf, should I go that route.

One thing to note about the old TEAC VRDS CD players, model VRDS 10/10SE/20/25 etc, is the digital and analogue circuits are on separate PCB's. So if you want to turn one into a Transport, you can very easily unplug and remove the DAC board and use the space for a better PSU etc.

Sorry to meander a bit from your question, it was my thought process, when deciding which direction to take on my own CD Transport quest and may be of general interest.

[Macca]

They probably didn't bother over-engineering the transport mech in the 701 as it makes bugger-all difference and would add a grand to the price.

I bought mine since I thought it was the best-looking new transport available, I didn't really have any other consideration.

I mean its a CD transport. It doesn't do much except read a disc. If I needed it to pull land rovers out of swamps I'd probably have considered the engineering side a bit more.

[Barry]

A well engineered laser mechanism can reduce jitter (typically from a few pico-seconds, down to tens of femto-seconds).

[Macca]

A well engineered laser mechanism can reduce jitter (typically from a few pico-seconds, down to tens of femto-seconds).

I take the view that jitter has never been audible even in the very first CD players.

[Qwin]

A well engineered laser mechanism can reduce jitter (typically from a few pico-seconds, down to tens of femto-seconds).

Yep, the Clock, its power supply and even the spindle/motor contribute to jitter.
If you break down the electronics involved in a CD Transport into processes, it is a very, very complicated piece of equipment.
I've just been trying to identify the SPDIF output on a 64 pin decoder chip and the Clock input on a 48 pin servo chip.
Turned out the clock crystal doesn't directly feed the Servo chip and goes through a data gate chip first.
Give me a record deck to work on any day.

[Qwin]

I take the view that jitter has never been audible even in the very first CD players.

The jitter itself is not audible, its many times beyond human hearing level. It's the result it has on bass definition, sound stage, transparency etc, which is audible.
A high level of jitter tends to sound muddy/smeared and can lack dynamics, makes a good CD sound like a badly mastered one.
This applies to anywhere in the chain, so DAC's and File based units are not immune.
Having said all that, even quite modest current production stuff is very good in this respect.
It tends to be models longer in the tooth that require attention.

[Macca]

vinyl and tape have magnitudes more jitter than even the worst CD player and those things are not an issue with those formats.

I'd suggest the worst problem you can have from CD is power supply noise bleeding into the signal, which you do see with some players (even expensive ones) which can be bad enough to cause the sort of effects you describe.

Really high levels of jitter just sound like tape wow, never an issue with CD.