Richard Kimber
pfm Member
Thanks Arthur, I'll give it a try. I've been mostly listening to the Abbado & Orchestra Mozart one.
- Richard.
MDAC first listen (part XXIII)
- Thread starter Richard Kimber
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Thanks Arthur, I'll give it a try. I've been mostly listening to the Abbado & Orchestra Mozart one.
- Richard.
iansr
pfm Member
No way I'm gonna let you pay for my bulk foils, and the only bad news is more work for you,
Well said that man. I'm not one of the people who has had his MDAC L2 modded with the original resistors, but if I was I'd be saying the same thing.
John: no one could reasonably expect you to pay for the Vishay upgrade. You fitted the original resistors in good faith and no one was to know that the Vishays might come along and turn out to be better. Where might this end? If in 6 months some other resistors get tried that are better still would you offer to pay those too? I certainly hope not. Your generosity is humbling but you need to be fair to yourself. I hope most if not all of the MDAC owners who are in for the upgrade would agree.
Akasha
pfm Member
OK I'm sorry for the bad news, but all those 13 units I've thus sent out will need to be return to me at sometime to be updated with the Bulk films x4... I'll pay for the x4 Bulk Films + return shipping as compensation for the inconvenience of having to ship them back to me...
It’s STUPIDLY good!!! I CANNOT believe how good even Johan’s unit now sounds (even with what ever is still “constraining” it) - I simply cannot! The amount of pure resolution these 4 resistors have brought to the table!
I can clearly hear this extra dimension and realism even though the “constraint” of Johan’s unit (indecently SimonOm units has the same constraint – so I’m now really suspecting the “Blue” 220R resistors as fitted to both units are at fault – otherwise its going to be really hard to find the cause).
I think I might a theory as to “How” these resistors are having such a dramatic effect on the sound quality– a logical explanation is that the "Quality” of the resistor is being “Magnified” by its function within the circuit – its part of an “inner feedback loop”.
As a theory I like to put forward that the forward gain of the amplifier “Magnifies” the quality effect of this resistor – there’s about 120dB forward gain, so I suggest that the “Quality” of the resistor is being “magnified” potentially by a factor of a million – hence it should no longer be such a surprise to anyone that this component position has proved to be so sensitive…
In “layman’s terms” think of a throttle control for a 1,000,000 HP engine – the throttle is going be extremely sensitive especially when driving a very light load – this is essentially what’s happening in this application. Any slight movement (or non linearity) of the throttle peddle is magnified by the MASSIVE power of the engine.
Thinking alone these lines and I can now better understand why others have reported improved sound quality with lower open-loop gain amplifiers (think lower power engines) – its not the Open Loop gain level that’s the problem, rather the linearity of the feedback components (the quality of the throttle control) being magnified by the open loop gain (Engine power)…
When you start to magnifying anything by a million times all kinds of odd effect are going to start coming into play... atleast I don't have to feel that I'm going mad... (just think "Magnified" by a Million times
No way I'm gonna let you pay for my bulk foils, and the only bad news is more work for you, I hope you will find a youngster with good eyes and a steady hand to do the upgrades and make some money for both of you. It seems the wizard needs an apprentice
The dedication and persistence you perform is admirable, and valuable learning for a lot of us.
The magnetism may not be the single biggest fault of the resistors, even though I used to learn to make resistors from the late great Steen Duelund, all magnetic and plastic where banned, silver connections where made and even resonance optimization where done on my own resistors.( 2 watts resistors are big enough to make for normal hands )
there must be someone out there to share experience and opinions regarding good sounding, nonmagnetic, reasonably priced SMD resistors ?
Searching the net I found out the late great Allen Wright (Waccum State Electronic) banned some "mini-MELF" resistors for the magnetic end caps already in 2004, unfortunately he did not give a favorite, seems he was still searching at that time:
(( Copy:
"Posted by Allen Wright (M) on December 26, 2004 at 12:34:29
In Reply to: Non-magnetic SMD resistors? posted by Henry Pasternack on December 26, 2004 at 11:15:12:
...is to test them yourself with a magnet!
I have no experience with the 1206 series, but went through several of the 0603 types for our attenuators to find one that wasn't. Many SMD chips (Caps & R's) seem use a nickel based sludge to make the terminations, and that's magnetic enough to be less than optimum.
>"audiophile approved"?<
Dunno -but be aware that quite a few of the1206 series are "metalglaze" and I'd expect these not to sound as good as the normal metal foil versions. I'd expect the bulk metalfoil VISHAY SMD's to sound really good, just like their regular bulk foil R's - and cost pretty much the same as well!
What I don't like are the tubular "mini-MELF" range that uses pressed on endcaps just like a normal wired R - that's SMD R's main advantage - IMO.
Seasons greetings, Allen"
))
Another opinion from the web:
(( "The winner?? The only SMT resistor worth listening to was the SMT version of the Roederstein through-hole parts. This is no surprise, because it is exactly the same part, but without the leads. It pretty much sounded exactly the same as the Roedersteins, which are still some of the best-sounding resistors around. They are in a MELF package, which is kind of a pain, and they have the steel endcaps, which I still don't get. How in the world they can sound good with steel endcaps is beyond me." ))
I don't get it either
I'm sure the bulk foil will sound beyond belief in places where it really matters, and no doubt John will know, (and listen to be sure), where it does, but it seems we might need suggestions, for good sounding, nonmagnetic, reasonably priced SMD resistors to be approved by John, for at least the 47R ?
.... Just to save around 250GBP each SuperLevel MDAC
and for "NotDarkSide" L2MDAC ? (all the SMD resistors)
......and for future.......LakeWest products ?
Anyone?
Even just www rumors...?
I hope Renata will feel better in the morning
mark.king
pfm Member
I seem to have missed a lot of what is going on here over the last week. Has there been a big revelation in SQ with some new resistors?
If so John could you send a picture of which ones were changed and what to order. I'm sure I could manage a swap out myself. I used to modify circuit boards for a living.If the debate is ongoing maybe when there is a conclusion you could let us know.
Cheers
If so John could you send a picture of which ones were changed and what to order. I'm sure I could manage a swap out myself. I used to modify circuit boards for a living.If the debate is ongoing maybe when there is a conclusion you could let us know.
Cheers
Igloo Audio
Registered User
Sorry, but why do the poor (no offence) ask so many questions?
The M-DAC is a great product, but 4 times its investment buys you perfection.
Peter
The M-DAC is a great product, but 4 times its investment buys you perfection.
Peter
JohnW
pfm member
John is mine included in the 13 returned so far
. Or are you talking about the 13 after the first batch.
Please pardon my confusion
Yes - Yours included, once the backlog is worked through you can send your unit back for upgrade to the lastest Spec.
JohnW
pfm member
Hi Mark,
Yes there been quite of lot of development since I've upgraded your unit, thus far:-
1. Output stage Emitter resistors reduced to 2R2 – increases ClassA operating area (benefits headphone users as output stage operates in pure classA for higher impedance loads) - lowers OPS native output impedance
2. Output stage protection modifications (Corrects a PCB design error)!
3. Output device Speed-up Capacitors replaced from Ceramic to Polypropylene type
4. 100pF Wima added to each output buffer circuit to enhance stability into capacitive loads – added protection for output stages with excessively high Hfe transistors (a couple of units had output devise with Hfe’s approaching x1000 – almost Darlington device territory)!
5. Option of using Vishay Bulk film’s in critical circuit position – atleast the x4 120R used in the internal feedback node.
I noted your unit sounded very good (yours has the NOS Tyco resistors) – it was Silver unit??? There’s been some variance in sound quality – for some reason certain black units sound worst then the Silver units – I’m still working on this issue.
JohnW
pfm member
Interesting information - I could give them a try, do you know which SMD devices he was referring too?
I'm sure the bulk foil will sound beyond belief in places where it really matters, and no doubt John will know, (and listen to be sure), where it does, but it seems we might need suggestions, for good sounding, nonmagnetic, reasonably priced SMD resistors to be approved by John, for at least the 47R? .... Just to save around 250GBP each SuperLevel MDAC
Yes agree, I'm not sure if its worth adding bulk foil 47R to the JFET's "Gate Stoppers" resistors, as there is no audio signal across these (So potentially we could reduce the bulk foils by x8)... But I would suggest using the 47R used on the JFET's source degeneration resistors - however I've yet to try this position with the bulk foils to confirm - currently I've replaced x4 120R's & the x16 main feedback loop resistors on JohanH's unit (so 20 bulk films in total).
JohnW
pfm member
Erh - ops! yes not quite what I meant (Sorry Plutox)!!! Renata and I plan to relocate to the mountains once we have built our house and LakeWest's European Offices etc
Sadly, it looks like it will not be for the next 5 years - as Renata's just got into university - studying Chinese... It would be too far for her to travel everyday.. with Winter snow and all...
JohnW
pfm member
Yes the L2 "Toy" upgrade replaces the Tyco / Dales with Vishay Bulk foils... these are included in your set of 36 resistors.
JohnW
pfm member
Sadly no, there's more then the resistors to the latest Spec.
JohnW
pfm member
Fwoor! He can upgrade my resistors any day...
Or buff off my flux off.
Or sync my master clock.
or... oh, I've run out of innuendo
On a different matter, I know things have quickly moved on now from the Dale v Tyco sound signature debate, but if a similar question comes up again, my take on this would be to use whatever is the best match for the MIMP as the default - as that's exactly where many of us are intending to go with our systems as soon as they're available. Or maybe it's not as simple as that?
For the MIMP's - Tyco / Vishay Bulks... but much is in a state of flux ATM.
JohnW
pfm member
JohnW
pfm member
JohnW
pfm member
That would be in my MDAC
Its quite amazing how these Bulk Film resistors effect the SQ... I've changed the "Suspect Blue resistors" - well in fact due to space restrictions I changed all 16 feedback resistors (so 20 Bulk Foils fitted ATM)... I'VE never heard such an improvement in SQ - yet I feel I'm still listening though what ever is "restraining" your units SQ... however, there's simply no escaping the fact that the Vishay Bulk Foils have reap a dramatic leap in performance - I REALLY mean dramatic! I sit here going GOSH and shaking my head all the time - and as you can imagine that does not happen to me often!
I must find out what's going on with your unit and holding it back...
I sincerely hope you do!
I'm afraid it will still take a lot of "debugging", despite our good luck wishes to you.(black unit owner)
Akasha
pfm Member
No more than he mentions, and from my own experience it will be best to avoid the magnetic end caps anyway, for a "standard reference" resistor
the net flows with contradictory information, therefore my call for good sounding reasonabley priced resistors, if a few interesting suggestions came up reccomended more times, They could be worth checking out
I have a friend who used to design Audio Note stuff, he now works in a company that mounts SMDs on PCBs for a Danish Very "high end" company,
I will ask him later today about his favorite resistors, and maybe get some 47, 220 and 1K for you to try.
Akasha
pfm Member
Hello John,
if the Bulk Foils are a big step up from the Tyco/Dale version, I have no problem paying for the extra costs of the resistors.
Then again, I can understand your wanting to investigate the restraining part.
Could you describe it further?
And then again I feel that at some point enough is enough.....
Earlier on I could hear differences in sound when switching through jitter reduction settings; also Coax 2 was better (regarding dropouts above 176kHz). Maybe this helps.
Cheers,
Johan
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