MDAC First Listen (part 00101110)

[BigDog]

Exactly.

+1 Have not even finished my first cup o' joe and already my head hurts!

 

[Rune]

+1 Have not even finished my first cup o' joe and already my head hurts!

If you run LMS on a NAS or something else and the FDAC is just seen as a squeezebox or Roon endpoint then you don't really need to worry about any thing Linux or mounting shares.

Just ignore any post that include the word Linux

 

[Boozyuzi]

Anyone happen to know if Apple's 10.11.4 update to El Capitain released yesterday fixes issues that may affect the MDAC over USB? ....so far I'm still running 10.10 to avoid any issues, but if they were fixed it would be nice to upgrade. I've just given it a try with another Mac runing 10.11.4 and so far it "seems" OK. Can someone remind me exactly what the issue was before?

My Mac Mini appears to have lost the distortion & clicks that have been there since I upgraded to El Capitan. Running the lastest update..

I had to go over to connecting with optical as it was driving me crazy but back to USB now, see how it goes..

Definately sounded a bit rougher over optical.

 

[BigDog]

These arrived yesterday £ 5.99 inc. delivery from China !
Highly recommended, the light is now fit for purpose (LED +push button switch) even removable to use as a separate light source.

11 levels of magnification, can be worn over spectacles.

No brainer.

I have no affiliation with Laozong Gou.

http://rover.ebay.com/rover/1/710-5...0001&campid=5338728743&icep_item=252254461326

Just received my pair today. Have not tried them yet but they are effen amazing for the price! WAY

 

[scubaboy]

JohanH, efski, Rune, thank you for the replies.

Up until recently i was using a netbook with an external hard drive via usb to my Mdac using Foobar with really good results. Not the slickest set up in terms of usability but, sounded really good. Well, the netbook took a tumble and is no more so, i'm left with just my CD player as a transport. My Chromebook can't be used and my wifes Mac is exclusively for University work at the moment, i dare not touch that.
In anticipation of getting the Fdac, i had been looking for a far better solution to digital replay anyway, the demise of the netbook just brought that forward a little. My system is simple, Valve amp/DAC/Speakers, purely for stereo. My idea is to have a storage device that the children can stream their programmes from, my wife can back up important work to and i can have my music collection saved to and added to when i want to rip a cd. I had narrowed the search down to either a Synology or Qnap NAS or a Vortexbox, the latter also offering the ability to rip cd's in a 1 box solution. From recent posts it appears that the Fdac will be recognised by the NAS with appropriate soft ware installed,which is great news and has answered my initial question of whether something would need to be in the chain to allow playback. This is looking like a great solution paired with a nice audio player controlled by a tablet it should be a joy to use, giving me access to my own music stored on the hard drive and opening up a whole new listening experience through a streaming service. My only concern is what the replay quality will be like over wj fi? I suppose i can site the NAS near the system and connect via usb but cooling fans are always audible and annoying. It would have to be a long cable to have it in another room. The Vortexbox would be another box in the rack but, no fans( at least i think not) plus it has the benefit of a cd drive. Speaking of cd drive, if JW is able to fit one in the Fdac chassis would that be able to rip and transfer the digital file through a network to storage or would it be just for replay?

 

[misterdog]

Just received my pair today. Have not tried them yet but they are effen amazing for the price! WAY

Laozong Gou being the Chinese for mister dog but as no one noticed....

 

[davidjt]

Bob L & misterdog

Thanks again for saving me the hard (brain) work. It's never straightforward when two similar cables have different colour codes.

Having lashed up a twin Calex supply, first impressions are very positive. As usual, incremental improvements are at first most noticeable in the percussion on Jazz and R & B tracks: I haven't needed to tweak the subs down this time, but bass is tighter, cymbals better defined and the overall improvement in separation, 'presence' and drive will obviously be carried over into classical music. (From what I've read lately, it's all about transients.)

So now I have to take it apart, get a case, IEC plug, socket and fuses and build the thing properly. Just as soon as I can bring myself to switch off the music.

 

[BigDog]

Laozong Gou being the Chinese for mister dog but as no one noticed....

So much for comedy as a second career!

Dà zhǐ de gǒu

 

[Bob L]

Bob L & misterdog

Thanks again for saving me the hard (brain) work. It's never straightforward when two similar cables have different colour codes.

Having lashed up a twin Calex supply, first impressions are very positive. As usual, incremental improvements are at first most noticeable in the percussion on Jazz and R & B tracks: I haven't needed to tweak the subs down this time, but bass is tighter, cymbals better defined and the overall improvement in separation, 'presence' and drive will obviously be carried over into classical music. (From what I've read lately, it's all about transients.)

So now I have to take it apart, get a case, IEC plug, socket and fuses and build the thing properly. Just as soon as I can bring myself to switch off the music.

You're welcome, as they say. I'm very glad to have another recruit to the 3-rail community (of so, far as I know, one) . I know that feeling of not wanting to switch it off! For the record, I am abandoning my idea of the cannibalised Humax case- too difficult to come up with a permanent fixing down of the Calexes, which are quite heavy in a rather flimsy box. I he found it quite dofficult to sort out a vented case- there are lots on the web, but all too small by a few mm. or more. The only one which hs any prospect of working looks like Maplin's "2-part large ABS box", and I have just ordered one.

One useful point which came out of the prototype was the effect of changing 2-rail to 3-rail. Organising his was trickier yhan had I expected. The only way I could sort out to do the changeover with an SPDT switch meant using different halves of one PS ifor the 3- and 2- configurations (try it and see, and let me know if there is a better solution...). Nevertheless, the sound was clearly much better in the 3-rail configuration, confirmed by an independent pair of ears. Essentially the differences were just that there is more of what davdjt reports
in the 3- configuration.

 

[misterdog]

You're welcome, as they say. I'm very glad to have another recruit to the 3-rail community (of so, far as I know, one)
One useful point which came out of the prototype was the effect of changing 2-rail to 3-rail. Organising his was trickier yhan had I expected. The only way I could sort out to do the changeover with an SPDT switch meant using different halves of one PS ifor the 3- and 2- configurations (try it and see, and let me know if there is a better solution...). Nevertheless, the sound was clearly much better in the 3-rail configuration, confirmed by an independent pair of ears. Essentially the differences were just that there is more of what davdjt reports
in the 3- configuration.

+1 joining this weekend.

Though I have PM'd you for clarity about the above.

 

[JemHayward]

Sorry to veer off topic, but we are rarely completely on topic here, so I hope I will be forgiven! Mainly a question for JohnW though others may well know the answer:
I'm thinking of getting a Quad 306 as a "spare" power amp, and it may get used on the output of the MDAC. The quad input isn't balanced. Should I:
1. Used single ended outputs on the MDAC
2. Use the balanced outputs wired into RCAs at the amp end
3. Use a balun transformer - I think this is how the balanced inputs are configured on my EAR890
4. Is there a way to modify the input stage of the 306 to give a real balanced input, as Quad did make amps for pro use based on a similar circuit.

 

[davidjt]

I haven't compared single vs twin supplies I'm afraid: as soon as you mentioned it, two seemed the obvious way to go. 300+GBP to power a s/h MDAC always seemed daft, but 40 + hardware was proportionate and likely to be (almost) as good. I have a slightly over-size metal case, picked up for a song ages ago, so in the absence of anything better at Maplins, I'll do some gbh to that and then respray it.
I know all about expectation bias, having fooled myself in the past, but it's very satisfying to put together something that works, and a delight to hear new things in familiar music. I can hardly wait to hear it with the Detox removing/defeating jitter upstream.

 

[Bob L]

I haven't compared single vs twin supplies I'm afraid: as soon as you mentioned it, two seemed the obvious way to go. 300+GBP to power a s/h MDAC always seemed daft, but 40 + hardware was proportionate and likely to be (almost) as good. I have a slightly over-size metal case, picked up for a song ages ago, so in the absence of anything better at Maplins, I'll do some gbh to that and then respray it.
I know all about expectation bias, having fooled myself in the past, but it's very satisfying to put together something that works, and a delight to hear new things in familiar music. I can hardly wait to hear it with the Detox removing/defeating jitter upstream.

I wouldn't bother with the comparison; I was only curious, since I had suggested this, to see if the second supply really made a difference. It does, and I'm happy!

 

[timola]

Mainly a question for JohnW Should I:
1. Used single ended outputs on the MDAC

As far as I know, if the signal cable is fairly short (upto 2M) then there is very little difference if any. I don't run my MDAC balanced and it sounds brilliant to me....still, let's see what John says.

 

[JohnW]

I'm thinking of getting a Quad 306 as a "spare" power amp, and it may get used on the output of the MDAC. The quad input isn't balanced.

The Quad 306 is an "Honest" amplifier design which shares its circuit design with the Quad 240, 520, 606, 707, 909 etc. It has 1 pair of output devices and a rather small heatsink so its not really up to driving your ML ESL's with there Arch Welder current requirements!

For a small box speaker, the 306 is a great Amp.

Should I:
1. Used single ended outputs on the MDAC

4. Is there a way to modify the input stage of the 306 to give a real balanced input, as Quad did make amps for pro use based on a similar circuit.

The Quad "606" style circuit does not lend itself to be modified to be truly balanced (unlike most amplifier designs) - not only is the front end circuit rather "rudimentary" and non symmetrical, but the bridge circuit itself presents a varying complex impedance that cannot be accurately simulated on the opposite input phase.

2. Use the balanced outputs wired into RCAs at the amp end

This gains you nothing but the use of different connectors (XLR's over RCA's)...

3. Use a balun transformer - I think this is how the balanced inputs are configured on my EAR890

This would work, but decent Balanced transformers are expensive, magnetics are a black art - I'm scared by transformers!... personally I'd be inclined to just use the SE inputs...

However:-

I have a few Quad 240's these are basically the 306 with larger heatsinks and PSU + balanced inputs + level controls...

After my recent experiences with the amplifiers we use in the listening system - I've designed a "simple" Amplifier that is a production "forerunner" to the Reference VFET amplifiers.

Due to lack of time, I've designed the circuit but we have a third-party designer working on the PCB - it is being designed to fit the Lecson AP1/AP3 style Tower heatsink

The prototypes will be built into cannibalised Lecson AP3's and when I visit China next month for Detox production meetings I'll work with the mechanical designer for "our" version of the towers... with the electronics being completed. I have a few "cool" ideas for our heatsink profile extrusion tooling.

These amplifiers will be Monoblock towers - with a truly balanced ClassA current dumping 150W+ (with plenty of Current) - they will be the best practical designs without the VFETs' Tube + VFET devices.... Obviously as Reference designs the VFETs will be better, but these "towers" will be full production designs and designed to achieve the best results with the MDAC / FDAC.

I can get you a QUAD240 shipped out when I send you the DETOX prototype .. you can play with these and save your funds for the Towers or VFET balance

 

[JemHayward]

The Quad 306 is an "Honest" amplifier design which shares its circuit design with the Quad 240, 520, 606, 707, 909 etc. It has 1 pair of output devices and a rather small heatsink so its not really up to driving your ML ESL's with there Arch Welder current requirements!

For a small box speaker, the 306 is a great Amp.



The Quad "606" style circuit does not lend itself to be modified to be truly balanced (unlike most amplifier designs) - not only is the front end circuit rather "rudimentary" and non symmetrical, but the bridge circuit itself presents a varying complex impedance that cannot be accurately simulated on the opposite input phase.



This gains you nothing but the use of different connectors (XLR's over RCA's)...



This would work, but decent Balanced transformers are expensive, magnetics are a black art - I'm scared by transformers!... personally I'd be inclined to just use the SE inputs...

However:-

I have a few Quad 240's these are basically the 306 with larger heatsinks and PSU + balanced inputs + level controls...

After my recent experiences with the amplifiers we use in the listening system - I've designed a "simple" Amplifier that is a production "forerunner" to the Reference VFET amplifiers.

Due to lack of time, I've designed the circuit but we have a third-party designer working on the PCB - it is being designed to fit the Lecson AP1/AP3 style Tower heatsink

The prototypes will be built into cannibalised Lecson AP3's and when I visit China next month for Detox production meetings I'll work with the mechanical designer for "our" version of the towers... with the electronics being completed. I have a few "cool" ideas for our heatsink profile extrusion tooling.

These amplifiers will be Monoblock towers - with a truly balanced ClassA current dumping 150W+ (with plenty of Current) - they will be the best practical designs without the VFETs' Tube + VFET devices.... Obviously as Reference designs the VFETs will be better, but these "towers" will be full production designs and designed to achieve the best results with the MDAC / FDAC.

I can get you a QUAD240 shipped out when I send you the DETOX prototype .. you can play with these and save your funds for the Towers or VFET balance

That would be great! Now I'm in a dilemma... I'm a fully signed up, and paid up member of the VFET club, but the idea of a Lecson styled power amp to drive my MLs would be just way beyond cool, and the realisation of a dream of many years.

Would the 240/306 actually work with the punishing impedance of the Summits at moderate volumes?

 

[MartinDurham]

Oh for 100% sure the Detox will solve the switch PSU noise from being injected into your system amongst other benefits

This is exactly what I was hoping for from the detox.

 

[misterdog]

.
Now a fully paid up member of the dual Calex owners club, or DCOC.

As someone once said, every little helps..

 

[Nick1881]

Hi John, don't forget, I still have your Quad 520f amp here if you need it.

 

[BigDog]

Having never heard of the Lecson amps, I HAD to google them. For those unfamiliar like myself, nice summary here...

http://lecsonaudio.com/?page_id=62

and source attributed to the design...

http://lecsonaudio.com/?page_id=56

Pun intended, design!

My Class A Pass amps are space heaters also but not as pretty as these!