At last... (Audiolab) - part VI

[Steven Toy]

Nick is every bit as good an engineer as Anthony regarding valve amplifiers and ensuring that they are safe to use in the UK. Anthony has been very impressed with some of Nick's work and vice versa.

The advice I was giving was directed to those tempted by the Ebay ads.

I did not say that the grey imports are to be ruled out just that they be checked over by an engineer as you have done.

 

[Steven Toy]

Anyway, I would like to think that the hi-fi hobby/business will survive in the future thanks to talented engineers like Nick G, Anthony, John Westlake and Dominik.

 

[badgeratu]

This is my first post to this forum, but I've spent the last 3 hours reading this entire thread which has led to me joining and posting now.

First may I say how impressed I am with how John (and Dominik) interact with the users on this forum. It is rare, if encountered at all, that the actual designers or engineers of consumer products actively pursue feedback and provide responses on their products. I find it disappointing that AIG in China may not be providing the resources or relationship deserved of such people and their ambitious future plans, but remain hopeful they can move on from such constraints in the near future.

I have been looking to update my digital audio playback approach for some time. I currently have a Marantz SR7005 receiver with a pair of B&W 804S main speakers, and the B&W MT30 5.1 for surround duties. Digital music is fed into the system via an Apple TV 2 over optical via a Cambridge Audio DacMagic.

There are several points of limitation in this system. First, I hadn't realised that Apple TV 2 up samples to 48kHz for everything, but that doesn't surprise me - even through the DacMagic it hasn't been particularly impressive. All my music is ripped into Apple Lossless on iTunes, but I am currently in the process of re-ripping everything to FLAC using EAC with AccurateRip. I also have some hi-bitrate files obtained from the B&W Society of Sound which I would like to play, but again I've not been too impressed with the DacMagic (particularly over USB) in this regard.

Obviously the Marantz is also a relative weak point in terms of a quality source for 2-channel music. It's impressive as a home cinema receiver, but I think the 804S's deserve a better amplification source overall.

Which brings me to the Audiolab products, and this thread. I have an old Arcam FMJ DV27 which I've been using as a CD source (it has a reasonably stable transport) via coax, but was considering replacing it and the DacMagic with the Audiolab 8200CDQ. Over the course of the morning I have now revised that opinion and decided to go for the M-DAC instead - keeping the DV27 for CD transport duties only. This then gives me the future options to add a couple of 8200Ps for bi-amping the 804S's using the digital pre-amplification stage, but I will start with the source first.

So - John - if it's not too much trouble I will be PM'ing you shortly with an pre-order request for a silver M-DAC I work in London (Marble Arch) so can easily drop into Bartlett's if that's your preferred supplier.

Secondly - and this is for all forum members as much as John - there are some additional questions I have:

1) Many members seem to have taken up your suggestion of using a USB isolator between the PC and MDAC. Two have been mentioned - OLIMEX (http://uk.farnell.com/jsp/displayProduct.jsp?sku=1795095&CMP=e-2072-00001000) and another galvanically isolated model (http://www.electronics-shop.dk/galvanically_usb_isolation.htm?currency=EUR). Does anyone have any suggestions as to which of these may be the better choice?

2) You mentioned some posts back that you use the ESI Juli@ sound card in the lab for testing higher sample-rate under products using the Sabre chipset. I'd like to get the best possible audio source possible from my PC, but would you recommend this as an appropriate sound card source for consumer use for 24-bit/192kHz files over coax?

3) Following on from 2), which would you choose as the preferred source for 24-bit 96kHz files - a quality sound card via coax, or USB via isolator?

Finally let me conclude by saying that this purchase decision - made without having heard or seen the product - is based not just on a single review (What HiFi) but on the reputation and character I have observed of John and Dominik. I am essentially investing in them and their product.

And I am sure it will be worth the wait!

Simon

 

[badgeratu]

...or I would PM you John if your message box wasn't full again! Can you let me know what I need to do to secure a pre-order?

Also I'm both a Mac and PC user at home, so either option is viable as a sound source depending on which is the better quality option. I'll happily go out and buy a Mac Mini if the software & hardware support lends itself better to working with the MDAC than a PC solution. At least I'll have some £££ to put towards it by buying the MDAC rather than the 8200CD or 8200CDQ...

 

[arthur]

Hi Badg!

Welcome to this most remarkable of threads.

I'm sure John and others will be here sooner or later to answer the main questions, but I can offer some notions. I've had the cdq since January and it is quite superb, especially as I now have the new transformer and oled. the sound is always engaging. And as the Mdac is reputedly even better then we are voth goinfg to be happy!

I have only tried the Olimex isolator and it does exactly what it should dn the laptop the difference was considerable, an Utter bargain. Less so on the Macmini, but still worth the £30.

Good luck here.

 

[Brian]

I know, but that isn't what you said. You didn't qualify the comment, you generalised when you said " Chinese valve amps are barely safe at 220 Volts" so for anyone who doesn't already know something about Chinese valve amps they may well be worried by your comment, which is inaccurate.

By the way, I'm in no doubt at all about my valve amp. Whatever it says on the website the reality is it has multiple taps - 110v, 123v, 220v, 230v and 240v, plus my amp was built (with me watching and learning) by NickG, who was mentioned by yourself earlier on. I had previously heard Nick's WAD KT6550 in my own home and really wanted one of those but WAD were unable to supply at the time. I turned to Diy Hifi Supply and Nick knew which amp I was buying ahead of the purchase, I'm in no doubt he would have told me ahead of the purchase if he believed these amps were not safe for UK voltages, plus I doubt Nick would have been prepared to build something unsafe anyway.

Thanks for the concern but these particular amplifiers are not unsafe. You need to make sure what you're posting is correct before making these comments.

For example, take a look at this where you will see mention of :
Power: 105/115/120/210/220/230/240/250V AC

Nick is every bit as good an engineer as Anthony regarding valve amplifiers and ensuring that they are safe to use in the UK. Anthony has been very impressed with some of Nick's work and vice versa.

The advice I was giving was directed to those tempted by the Ebay ads.

I did not say that the grey imports are to be ruled out just that they be checked over by an engineer as you have done.

If you say so.

BTW my amp hasn't been "checked over" by an engineer.

 

[JohnW]

Hi John. I'm on the verge of pre-ordering an MDAC from Superfi. I intend to use it as my pre-amp, but would definitely need A/V pass through analogue input. If I understand correctly from previous posts, this will be possible via an upgraded external psu. Will I be able to buy the new psu on it's own at a later date? Any (ballpark) idea when this might be? Many thanks.

Hi Major Tom,

I think its a great idea to have the "AV" / Analougue system pass-though mode - I went to bad at 5am this morning after starting the design process for the PSU last night. Now that its not just a "Simple" PSU its a little more exciting.

I'm guessing I'll have the design completed by the end of October - which means around Febuary next year before the first units arrive in the UK - Ill try and speed the process up - but nothing's that plain or simple when working in China....

John

 

[major-tom]

Hi Major Tom,

I think its a great idea to have the "AV" / Analougue system pass-though mode - I went to bad at 5am this morning after starting the design process for the PSU last night. Now that its not just a "Simple" PSU its a little more exciting.

I'm guessing I'll have the design completed by the end of October - which means around Febuary next year before the first units arrive in the UK - Ill try and speed the process up - but nothing's that plain or simple when working in China....

John

That's great John many thanks, but will the upgrade be available separately to buy next year, or should I hold off on MDAC purchase until available?

 

[jamjar784]

I have only tried the Olimex isolator and it does exactly what it should dn the laptop the difference was considerable, an Utter bargain. Less so on the Macmini, but still worth the £30.

Hi Arthur,

I've had a look at the Olimex and it has a PSU connection. Did your comments above refer to using the adaptor on its own or with an external PSU? BTW Cost is £38, so cheaper than the Danish adaptor but you need a USB A to B cable (as for printer/scanner connection to PC), so another ~£5.

Thanks

 

[JohnW]

If it's not too much trouble I will be PM'ing you shortly with an pre-order request for a silver M-DAC I work in London (Marble Arch) so can easily drop into Bartlett's if that's your preferred supplier.

Hi Simon,

Welcome, thank you for your posting. I've added you to the Pre-order list, and I will PM you shortly.

1) Many members seem to have taken up your suggestion of using a USB isolator between the PC and MDAC. Two have been mentioned - OLIMEX (http://uk.farnell.com/jsp/displayProduct.jsp?sku=1795095&CMP=e-2072-00001000) and another galvanically isolated model (http://www.electronics-shop.dk/galvanically_usb_isolation.htm?currency=EUR). Does anyone have any suggestions as to which of these may be the better choice?

I don't have personal experience of either unit, But they appear to be built around the same Analogue Devices USB Isolator IC – and I’m sure pretty closely follow the AD application note.

For optimal performance for audio applications, there are a couple of areas that would need careful attention (Maximal RF isolation and careful decoupling of the isolated switching supply). Without having seen either unit, I cannot say which is better in these regards. One unit has a nicer external case...

If there’s enough interest Dominik and I could design an “Optimised” design – but this is not to say it would be any better then the existing two designs, as we have no idea of there “Ultimate” performance.

2) You mentioned some posts back that you use the ESI Juli@ sound card in the lab for testing higher sample-rate under products using the Sabre chipset. I'd like to get the best possible audio source possible from my PC, but would you recommend this as an appropriate sound card source for consumer use for 24-bit/192kHz files over coax?

Yes the ESI Juli@ is the best sound card we have encountered to date - and atleast we can also advise if you encounter any issues.

You should also consider using it via the Optical connection - this will achieve the very best isolation from your PC. MDAC will attenuate most (all?) Jitter effects. Although we have only specified the Optical on the MDAC for 96KHz - in fact its designed and tested to work at 192kHz via Optical on the production line (with the Juli@ in fact), but experience has thought us that most 192kHz optical sources are troublesome, so to avoid the hassles of having to explain to disgruntled customers that its there "treasured" source that is a fault - we sidestep the whole issue...

3) Following on from 2), which would you choose as the preferred source for 24-bit 96kHz files - a quality sound card via coax, or USB via isolator?

USB has the advantage of Async operation - thus the DAC is clock-locked to the “Source” which in this case is your PC, so theoretically the USB should perform the best. That said, with 3 levels of Jitter attenuation on the "Digital" inputs, one would hope the differences would be non existence - but then we are talking about Audio here...

John

 

[arthur]

Hi Arthur,

I've had a look at the Olimex and it has a PSU connection. Did your comments above refer to using the adaptor on its own or with an external PSU? BTW Cost is £38, so cheaper than the Danish adaptor but you need a USB A to B cable (as for printer/scanner connection to PC), so another ~£5.

Thanks

Hi JJ.

I use the adaptor on it's own. It is a bit of an irritation that it doesn't plug straight into the usb port on the laptop without an extra cable.

The Danish one does look better made in that it has a case that wont let in much dust.

 

[JohnW]

That's great John many thanks, but will the upgrade be available separately to buy next year, or should I hold off on MDAC purchase until available?

Its a "Plug and Play" external unit - just replaces the "in-Line" PSU supplied with the MDAC.

You can "Upgrade" at anytime - well atleast from when the unit is available

John

 

[Steven Toy]

. BTW my amp hasn't been "checked over" by an engineer

Brian,

We seem to be getting bogged down by semantics. Without quoting, I think I can conclude that it was assembled by an engineer (Nick) with you watching and learning.

Your amp was not exactly plug and play (and then bang!) straight off the slow boat.

 

[mark.king]

Hi john

Just checking I am on the pre order list as I never got a pm. It was for silver mdac atvsuperfi Leeds.

Also when designing the new psu what are your thoughts on the price point? What will the advantages be of the new psu? And last but not least do you intend it to be the same size as the mdac to match? I understand you may not have even though this far so far.

Cheers

 

[pwiles1968]

This is my first post to this forum, but I've spent the last 3 hours reading this entire thread which has led to me joining and posting now.

I have been looking to update my digital audio playback approach for some time. I currently have a Marantz SR7005 receiver with a pair of B&W 804S main speakers, and the B&W MT30 5.1 for surround duties. Digital music is fed into the system via an Apple TV 2 over optical via a Cambridge Audio DacMagic.

Obviously the Marantz is also a relative weak point in terms of a quality source for 2-channel music. It's impressive as a home cinema receiver, but I think the 804S's deserve a better amplification source overall.

Finally let me conclude by saying that this purchase decision - made without having heard or seen the product - is based not just on a single review (What HiFi) but on the reputation and character I have observed of John and Dominik. I am essentially investing in them and their product.

And I am sure it will be worth the wait!

Simon

I have recently Upgraded I was running an SR6005 with external power amplification from some Marantz MA6100s in to some B&W 805s

I now have the CDQ and a Bel Canto Evo II power amp, the difference is significant, the CDQ or the MDAC IMHO would be ideal I suggest you demo the amplification before you choose, I am finding that the B&Ws need really good amplification, Jhon's Audiolab products swing well above their price point and can be paired with high end power easily.

 

[JohnW]

Hi john

Just checking I am on the pre order list as I never got a pm. It was for silver mdac atvsuperfi Leeds.

Also when designing the new psu what are your thoughts on the price point? What will the advantages be of the new psu? And last but not least do you intend it to be the same size as the mdac to match? I understand you may not have even though this far so far.

Cheers

Hi Mark,

Yes your on the Pre-order list, I've not yet PM everyone who's on the list to confirm yet, But I believe I've added everyone who's either requested via this thread, PM or Emailed me.

Yes, the High Quality PSU will be in a matching case as the MDAC - and with the AV Bypass option.

Cost is targeted for between GBP 200 and at worst GBP250 - I'll try to keep the costs down.

At this time we don’t know how the MDAC will respond to a higher quality external PSU - if (any) sound quality improvement justifies the cost...

I'll post here as soon as we have built one and listened

John

 

[Interzone]

John, how large is the current MDAC supply?

 

[pwiles1968]

Yes, the High Quality PSU will be in a matching case as the MDAC - and with the AV Bypass option.

Cost is targeted for between GBP 200 and at worst GBP250 - I'll try to keep the costs down.


John

Would that be analogue bypass? Any way of having more than 1 input, AV and Turn Table , or would that be the QDAC.

 

[JohnW]

I suppose a way of reformulating my question is: would you prefer an MDAC -> 8200P or an MDAC -> 8200Q -> 8200P? Or an MDAC -> Rothwell -> 8200P?

Hi AndyU,

I'm not suggesting that the 8200P's are the best amps you can get at the price - its worth trying different combinations. However my responce would be the same for any poweramp:-

MDAC -> 8200P (Yes - Depenending if the Volume control during your normal listening level is somewhere above -30dB, closer to -20dB and above).

MDAC -> 8200Q -> 8200P, No

MDAC -> Rothwell -> 8200P (Yes - if the Volume control during your normal listening level is somewhere below say -30dB and lower).

Despite earlier recommending fitting the Rothwell Attenuators at the Power amplifier end (this normally results in the best Bass), by placing the attenuators at the Dac end, will result in the cable capacitance proving a slight RF filtering effect - which depending upon the system may result in a "smoother" sound (but with a softer Bass).

John

 

[ChrisPa]

The external "Passthough mode" built into the upgrade PSU module would select between the MDAC's outputs & an external analogue input (such as your AV reciever).

Yes, I'm planning the you can connect either Single-ended input (RCA) which then would be converted to Balanced (with also a balanced input) and then being able to select between these and the MDAC outputs - so ideal for your AV system.

John

So, an analogue buffer stage? Will this not 'get in the way' of the MDAC? It seems a shame to put an 'unnecessary' additional stage after the QDAC's CROSS output

Alternatively...

We have things in the works on the Pre-amp side...

Is this in addition to the 'Super MDAC PSU with analogue switching' or are they the same thing?

Is it that far from what you've described so far for the 'Super MDAC PSU' to an analogue preamp in the 'Super PSU'? - analogue switching plus gain control...

You'll note I'm still looking for the route to a QDAC...

(and I keep wondering what if any unused analogue layout is on the MDAC's circuit board and whether that can be utilised in any way?)