MDAC First Listen (part 00100011)

[JohnW]

Hi John,

That's great, I do think it sounds great, very interested in how you mod for av bypass, pics would be great. Thanks again

Nick,

Sorry, too late for internal pictures as your units already been closed up - I intended to post Pics of the extra rear panel AV bypass RCA's.

Lets just say that somethings are better kept hidden - I "stand-up" the Output Mute relays Vertically above the PCB and then hardwire the AV bypass signals.

It works effectively (does not result in sonic degradation to the MDACs output as no extra components are in the signal path), but lets say its a little Mickey Mouse... I'm always glad to be of service

I also added a couple of small Modification to improve SQ - and replaced a couple of distressed Caps.

 

[Nick1881]

Hi John, that sounds good. I'm flying to Belfast today but back in a couple of day, can't wait to have a listen. Thank you so much, I owe you a few drinks now.

 

[EIffel]

The chassis will come in either Black or Black Chassis with Silver front panel*

*That said I'll perform thermal tests to measure the thermal efficiency of the Silver heatsinks - if the thermal dissipation is not degraded too much, then we can have complete Silver (Silver Chassis + Silver front panel).

How would you (and other Silver VFET owners) feel if we had to use a Black Chassis / Silver front panel for the "Silver" units?

As my MDAC(s) are the only components that don't have a silver font panel and a black chassis, I certainly have no objection to what is being proposed. Furthermore, as the amps will not be near my other components, an all black design would also work (with the side benefit of improved thermal dissipation)

 

[iansr]

First choice would be all silver but happy enough with a black chassis if needs be.

 

[PhilCTTE]

And raised up 25cm ! so the centre of the delay rings are at ear level.

1600 by 700 mm.

Be interesting to see pics , if you have any ?

I'm really astounded just how good these summit x panels are.
Dont think I'll go back to box speakers again !
I,ve just seen some CLX Arts at a good price .... must resist
Really looking forward to Johns VFETS

 

[banjoman]

John, is there any chance of getting onto the list for the VFET amps - additional ones you may build? Assume current quota is well filled up!
I am already paid up for MDAC2 L3.

 

[davidjt]

First choice would be all silver but happy enough with a black chassis if needs be.

*+1

 

[Ekranoplan]

I have your PM, give me a day to reply as you asked many questions and I'd like to complete a PCB section I'm working on (Close to completing the ESS Analogue PSU section) - then lastly the ESS's Digital section PSU then the Right hand channel is completed

Thanks John, look fwd to reply.

 

[ti33er]

Mr Westlake

Just curious but do you think the VFET amplifiers will run quite hot!?

I am contemplating selling a lung to get a pair, but have a little one and all my stuff is inside a cabinet - its open back, but even my Tag McLaren Monoblocks get about as warm as I can tolerate any of my kit getting, and they operate fairly cool in reality)!

Many thanks

 

[JohnW]

Hi John, that sounds good. I'm flying to Belfast today but back in a couple of day, can't wait to have a listen. Thank you so much, I owe you a few drinks now.

Nick,

Shipped yesterday - I'll forward the tracking number.

I had a slight issue with the unit on final test random "sharp" clicking, first on the Left speaker, then on the Right, never both at the same time - this was viv USB?

I opened the unit and checked the PSU voltages, Clock & Audio output and everything appeared OK - I could not recreate the issue.

I rolled back the software to V0.90 - I the clicking was present while the unit was loaded with A.10 so I'm not sure if it was a software issue - as I've never really used A.10 with my PC.

Its shipped back to you with V0.90 you can reload A.10 and your customised setting will still be stored.

 

[JohnW]

John: about TDAC - at what point do we get the chance to commit to a TDAC (as well as or instead of MDAC2)? I'm certainly still keen, but it'd be nice to have a rough idea as to when to be ready

I'll be asking for the L2 payment for the MDAC2 as soon as I've issued the PCB... If you decide, then this will be your first installment for the MDAC2 project.

You can always swap your order for the MDAC2 to TDAC if you decide before sending the funds for the MDAC2 PCB "at cost".

 

[JohnW]

As my MDAC(s) are the only components that don't have a silver font panel and a black chassis, I certainly have no objection to what is being proposed. Furthermore, as the amps will not be near my other components, an all black design would also work (with the side benefit of improved thermal dissipation)

I should clarify that the VFET Amps will be available in 2 versions:-

1. Black (Black front panel / Black Chassis)

2. Silver - hopefully Silver Chassis / Silver front panel, but if its found that the radiant heat dissipation of the silver heatsinks is too badly effected then we will be required to uses a Black Chassis / Silver front panel – however cosmetically I’d prefer a 100% silver unit.

 

[JohnW]

I'm really astounded just how good these summit x panels are.

Yep, thats Martin Logan ESL's for you!

Dont think I'll go back to box speakers again !

Once turned there's no way to go back, you would just spend your time thinking how you miss the SQ of the ESL's!

I,ve just seen some CLX Arts at a good price .... must resist

Says the man who needs to move home next year!!! Guess you could always fashion a home out of the CLX's shipping containers!

Really looking forward to Johns VFETS

And I get to hear them first on my CLS's!!!

 

[JohnW]

John, is there any chance of getting onto the list for the VFET amps - additional ones you may build? Assume current quota is well filled up!
I am already paid up for MDAC2 L3.

I've sent you PM with the full details, please forgive my poor writing style, my heads so full of the MDAC2 PCB design and "perfecting" the VFET circuit that I just have no mental capacity left to concentrate on my written form... writing & communications does not come naturally to me.

Its fascinating to me that I can see and design complex electronics circuit straight out of my head, any yet with something as "basic" as the written language and I'm no better then a 5 year old child! I admire those who have the skill of communication - I'm sure they don't realise how lucky they are.

 

[JohnW]

Mr Westlake

Just curious but do you think the VFET amplifiers will run quite hot!?

I am contemplating selling a lung to get a pair, but have a little one and all my stuff is inside a cabinet - its open back, but even my Tag McLaren Monoblocks get about as warm as I can tolerate any of my kit getting, and they operate fairly cool in reality)!

Many thanks

ti33er,

They will not run as hot as full Class A amplifiers - but the VFET's will be operated in Class A - about 10W per heatsink (plus the standing current though the Dumper stages) - so its not going to operate 100% cool.

Lets say the heatsink will be idling at a Max. of around 50DegC, it will not really heat up much beyond that point even when playing music - unless your planning a party.

I forwarded you the VFET details via PM, please forgive my terrible writing style.

 

[Nick1881]

Nick,

Shipped yesterday - I'll forward the tracking number.

I had a slight issue with the unit on final test random "sharp" clicking, first on the Left speaker, then on the Right, never both at the same time - this was viv USB?

I opened the unit and checked the PSU voltages, Clock & Audio output and everything appeared OK - I could not recreate the issue.

I rolled back the software to V0.90 - I the clicking was present while the unit was loaded with A.10 so I'm not sure if it was a software issue - as I've never really used A.10 with my PC.

Its shipped back to you with V0.90 you can reload A.10 and your customised setting will still be stored.

Hi John, that's great. I'm using a usb to coax so I get 192khz so it should be fine, haven't used the mdac usb input in a few months.

Thanks again

 

[JTC]

You can always swap your order for the MDAC2 to TDAC if you decide before sending the funds for the MDAC2 PCB "at cost".

Forgive my ignorance, but what would the difference in...

1) timescale
2) performance
3) cost

...be between MDAC2 and TDAC? Assume fusion loveliness, use the supplied graph paper to illustrate your answer and show all working

 

[JohnW]

John,

1. My ONLY priority for 2015 is the MDAC2 and VFET Amps - its the nature of the beast that I'll spend a significant time supporting the MDAC2 upgrades and bug fixes etc. by Comparison the VFET Amps will be a delight

2. Measured performance slightly worst the MDAC2 - but MDAC2 with be State of the art, Sonically I suspect the TDAC will outperform the MDAC2, but by how big a margin is impossible to say at this point.

3. TDAC cost is projected between GBP1500 to GBP2000 - as a Toy / Fusioned MDAC owner you have a GBP300 credit.

 

[TimR]

I should clarify that the VFET Amps will be available in 2 versions:-

1. Black (Black front panel / Black Chassis)

2. Silver - hopefully Silver Chassis / Silver front panel, but if its found that the radiant heat dissipation of the silver heatsinks is too badly effected then we will be required to uses a Black Chassis / Silver front panel – however cosmetically I’d prefer a 100% silver unit.

Hi John, I was originally down for the silver 8200MB chassis, but started thinking black might be easier to hide if I were to locate the amps on the floor somewhere near the speakers (I believe the advice is to use longer XLRs and shorter speaker cables, right?)

However, if these bespoke cases are going to look uber smart, then maybe I won't want to hide them

Is the silver version going to be a painted front panel, or bare milled metal?

Hard to believe that your planned design has improved beyond the incredible spec we originally signed up for, this seems to have become the norm with you though! Thanks so much for all your effort and the attention to detail you're putting into it, as ever. I'm feeling quite bad that you might be lumbered with the extra task of selling off the unwanted 8200MBs though. As per what others have said, I'm happy to absorb any extra costs this might incur, I'm just glad to be onboard with the project.

 

[JemHayward]

I'm not on the VFET amp list, as I'm really happy with my EAR 890, and really don't want to change it, but...

It would be interesting to know the dimensions of the new VFET chassis, just in case a place on the waiting list became available.

Trying not to be tempted!