With out pictures, it's not real- though it still may be unreal!

[JonMarsh]

The UPS guy did his thing today, though a bit later than I expected- still, who can complain.

:banana: :banana: :banana: :banana: :banana: arty:

This has got to be the most expensive loudspeaker impedance tester I've ever owned- and it's not actually complete, it's necessary to have a small power amplifier to use with it for that, in addition to the special fixture. (the little gray box that says AP that's roughly in the center).

Now, these days, you've got to figure you're getting something special when it actually comes with an inch and a half thick PAPER manual! (of course, it's available in PDF, but real manuals are SO convenient at times!)

The disk package not only has the system software, including in this case the optional Acoustics R&D software (Bye bye Fuzzmeasure?) but also test CD's for doing audio tests on CD and DVD players. CD players? Uh, yeah, I might have one of those around somewhere (actually, an SACD player or two).

Well, looking at the manual, I know there's going to be a learning curve, and some midnight and weekend oil involved. I expect a LOT of midnight and weekend oil!

[TEK]

Happy days for you Jon :-)
You mention loudspeaker impedance testing. Will you - in addition to measuring amplifiers - use this to do some measurements on the Ardents as well?
I remember that you mentioned doing a revision (a Mark II?) of the Ardent crossover - is that still on the table, and if so, will the AP be involved in that? And if doing a Mark II edition of the crossover, what would you try to archive compared to the current version
(sorry, got a bit carried away by curiosity about the notion of a Mark II crossover, even if it's mostly off-topic in this thread)

[dar47]

Better not be a Mark2, I think that was for the other 02 Woof's. That looks like a lot of fun! Maybe it time to get my Ncores over here, just got to clear room to get ready. What are you going to try first?

Okay what's the butter knife, epoxy and micro gauge for?

[JonMarsh]

Hey, this is our private clubhouse- nothing is off topic. As long as it's audio.

It is my intention to use this system for speaker as well as audio electronics measurements. that's why I popped for the extra software option, and the impedance tester. Now, the only thing "scheduled" in a Mark II is an official evaluation of how much to tweak levels if one builds a pair with the SW223BD02. IF I had more spare time, it might be interesting to go back and do complete fresh new measurements, but I don't think I desire to change the filter concepts at all- I certainly wouldn't go back to a Duelund approach like the first version Ardent- that crossover just winds up being too large and expensive, and with it's own tuning issues, as it really prefers to have time aligned drivers' whereas the special 3rd order concept in the Wavecor Ardent is designed specifically around using the time delay from driver offset to make a Quasi LR3 crossover work.

One must consider priorities, and there are many things I would like to do, but some of those will wind up on the backburner, until higher priority topics are taken care of (especially collaborative high priority topics!)

[JonMarsh]

Better not be a Mark2, I think that was for the other 02 Woof's. That looks like a lot of fun! Maybe it time to get my Ncores over here, just got to clear room to get ready. What are you going to try first?

Okay what's the butter knife, epoxy and micro gauge for?

That's a professional secret... :B

Actually, I've been gluing up toroidal cores for PFC inductors and winding them in my laboratory (use the English pronoun inaction, please... :W )

I'll probably run something simple first, like a Schitt headphone amp! Then the AURALiC preamp, then the NAD M22. I've got parts to build up an NC500 with SMPS1200A700, but need some connectors and other bits to mate to the OEM adapter; I've got two new mono chassis, as I sent my first set off to Steve Manning to play with.

I've got to put cable sets together, too, but I may just use some of my Hypex balanced cables as starting points. I need to read the setup booklet first. There are unbalanced inputs and outputs, but I know from working with other analyzes that floating balanced gives more reliable and consistent results- for example some power amps get really unhappy if you connect the input ground to the output binding post ground- this is because of poor internal grounding design, but it happens. With floating connections, no worries mate.

[JonMarsh]

Ordered cables and adapters for testing today, from several sources overall. Hope all will be in by the end of next week.

I also found an interesting PDF that was a PPT presentation about the APx555, so will take a closer look at that soon, in case there's some useful over view info.

Today was our V-Day dinner, as it won't be possible on the weekend due to the preparations and departure for her upcoming trip to New Zealand.

I want to have the M22 and the ABH2 measured by the beginning of March; my colleague from Munich will be over here then, and it would be easier (for me!) to have him take the amps to Munich, as he has a bigger weight allowance (Biz class, you know). I also hope to get setup to try doing the next round of acoustic measurements of the Minerva with this setup.

It's a little sad to think that the last time I was doing regular ampilifier measurements like this was in the 90's...

[TEK]

Looking forward to see what you figure out. Will be of great value in the coming design process to be able to do proper evaluation of the design!

[TEK]

Better not be a Mark2, I think that was for the other 02 Woof's.

One time in the future I'm playing with the idea of building new cabinets for the Ardents. If it comes to that I will probably reuse the drivers and crossover components in the new cabinet. But in that case a Mark2 would be interesting ;-)
Maybe in about 10-years time or so ;-)

This is the design that I'm looking at:

Image not available

Would need metal skills to build the stand, probably carbon or glass fiber for the back and real walnut wood for the baffle. I think it would be an exiting build that would require me to acquire a lot of new skills to pull it off. However, I do think that the driver and crossovers from the Ardents should be drop-in as the baffle in may ways have the same characteristics.
Or, it may never happen... or I might find a new home for the Ardent and build those as brand new constructions. Or - most likely I end up with those AND the Ardents, and no where to put them. Seems like that is Jon's strategy.
Jon - what do you do with all the speakers you build? Where did the Maxx that you build long time ago go? What about the Isiris? The M8at? :stupid:

Oh well - that will probably not happen before many years have passed :-)
Have some amp's to build first :dancenana:

[benthe8track]

I finally have a moment to check out whats going on over here (see price of oil).
Very sweet new tool Jon! I guess if you don't like it you can always trade it in for that new Tesla haha.

Tek, those outriggers are easy to make. Laser cut, tap, powder/anodize, done! If you wanted to get really fancy you just need a lathe to turn the spikes and knurled knobs.

[TEK]

He, he...
There are some different perspectives here.
Ben, are you in Oil? Here in Norway the oil priced have caused large number of layoffs. As you probably know Norway is quite large in the oil production section. Projects in thehundreds of billion (or is it called trillion? 9 zeros) class has been stopped because they no longer are echonomical substainable.

Easy is not a word that suite any of the following words from my perspective ;-)
Laser cut, tap, powder, anodize ;-)
I guess that it depends of your skillset and available toolset.

Powder coating is done by using a small electrical current, powder and then heat - right?
But what is the process for anodizing?

[benthe8track]

He, he...
There are some different perspectives here.
Ben, are you in Oil? Here in Norway the oil priced have caused large number of layoffs. As you probably know Norway is quite large in the oil production section. Projects in thehundreds of billion (or is it called trillion? 9 zeros) class has been stopped because they no longer are echonomical substainable.

Easy is not a word that suite any of the following words from my perspective ;-)
Laser cut, tap, powder, anodize ;-)
I guess that it depends of your skillset and available toolset.

Powder coating is done by using a small electrical current, powder and then heat - right?
But what is the process for anodizing?

Yeah I'm a project engineer for a company that operates in the oil sands of northern Alberta. It's a cyclical industry but this is a bad downturn.

I should have said, 'it's easy if you can find places that specializes in those processes'. You probably don't want tanks of sulfuric acid in your garage for anodizing haha. Basically you apply a DC current to your part (anode) releasing oxygen on the surface, this builds a tough porous surface (aluminum oxide is almost as hard as diamond) that dyes really well. Think the back of an ipod. A machine shop can probably help you find a local place.

[TEK]

thanks for the input ben.
I'll cross that bridge when/if I start this project :-)

[JonMarsh]

One time in the future I'm playing with the idea of building new cabinets for the Ardents. If it comes to that I will probably reuse the drivers and crossover components in the new cabinet. But in that case a Mark2 would be interesting ;-)
Maybe in about 10-years time or so ;-)

This is the design that I'm looking at:

Image not available

Would need metal skills to build the stand, probably carbon or glass fiber for the back and real walnut wood for the baffle. I think it would be an exiting build that would require me to acquire a lot of new skills to pull it off. However, I do think that the driver and crossovers from the Ardents should be drop-in as the baffle in may ways have the same characteristics.
Or, it may never happen... or I might find a new home for the Ardent and build those as brand new constructions. Or - most likely I end up with those AND the Ardents, and no where to put them. Seems like that is Jon's strategy.
Jon - what do you do with all the speakers you build? Where did the Maxx that you build long time ago go? What about the Isiris? The M8at? :stupid:

Oh well - that will probably not happen before many years have passed :-)
Have some amp's to build first :dancenana:

Kharma makes some nice speakers, and my colleague/friend in Munich used to have one of their models.

Everyone likes a different look- for example Steve Manning is really into the Wilson audio look.

Here’s his concept for a rebuilt Ardent, including adding PR’s tuned as in the Minerva:






They would be more of a challenge to build, but that’s quite in line with Steve’s skill set. I’ve only done one “clone” of a Wilson design, and that was back in the 90’s. But this look as he’s interpreted it might grow on one, if you don’t mind the many surface planes.

[dar47]

Sheesh. We keep topping designs, I feel sorry for the new guys looking in or guys on tight budgets. Like looking through the window of a Bentley dealership, haha.

Does Wilson make or have there own proprietary drivers made? One other I wondered a bought was what filters does Neal at Avalon use. I would think skimping on cross over parts is not an option at these price points? Tek you and Ben are still young I'm sure there will be another end game for you guys. Me I might just take the finish down and build up to hand rub the Ardents and maybe pretty external xover boxes, that would be it for me. Wondering what to change if I wanted to raise the tweet 1.5 db. as mine are down with with grills on? After trying the Ncore and going back to my amp I sure miss it. When I get that in the loop I should be good for a bit.

[JonMarsh]

Don't bashful about crossover tweak requests. I'll help you out on that tweeter level.

Yeah, one thing that has happened, is that for DIY, a few of us (you and Ben included) have really raised the bar for what might be expected, and we're doing some pretty cool things these days.

OTHO, it's still hard to beat some systems like the NatalieP for the bucks and simpler build, and even Curt and Jim Holtz have a nice approach to budget high end with the Statements and derivatives.

I still have my Isiris, and plan some updates for them, as well as getting the crossovers organized hopefully inside the enclosures.

I know a fair amount about the general techniques for crossovers in earlier Avalons (LR4) but have no knowledge about Neal's designs. I've seen some of those crossover builds, and I wouldn't say there's anything particularly special other than design for compactness. The internal cable wiring is paid more attention to, than most DIY guys.

I expect the Minerva's will be my last build for a while. Maybe we'll get around to some kind of version of the Owl, depending on how the the smaller Excel coax driver tests (someday- not likely this year) but I doubt the Mad Maxx/Jupiter will ever happen. But there could be a rough proto of it, basically just as a LF add on for the Minerva, and high passing the Minerva at 80 Hz or so.

Oh, and Wilson has used a lot of modified/proprietary ScanSpeak drivers, but I don't know if that's in their supply line these days.

[TEK]

When it comes to wilson, their design have never been on my favorite list. I think there is something about especially the lower bart that do not sit well in my taste. The Watt Putty for example.
The design above seems a bit better than most wilson design I have seen.

The Avalon design I have always liked a lot - but I have to say that after Maarten came onto the field with their design that design is my current favorite.

Me I might just take the finish down and build up to hand rub the Ardents and maybe pretty external xover boxes

Is there something about the current finish that you are not happy with as you arr wondering about doing this?
Onnly part I have to say that I'm not happy from a perfectionists point of view, however it's nothing that anyone watchimg them in their current location would ever think about (except if they were doing a critical check of them).

About projects - I still want that center that is not jet build - but I do not have the skillset to select the drivers and design the crossover on my own... And currently I do not have a box layout either...

[dar47]

Ya, mine were sprayed with I think 6 coats of conversion varnish but a little thin for my liking. Ben sanded his down and had a second round sprayed on his and his seems perfect. I got a little nic on one of the back edges that bothers me to. I don't know every time I walk buy the modula's I think those are perfect and of course I hand rub those. This would be something to do when I'm bored, if that ever happens. Tek I will probably ready in March for the NC500 build as the bathroom reno should be done this week. Cost me $800 just to do new water proofed walls and tile around a tube.

[TEK]

If/when you and Ben are ready, just give me a hint about what you want and I'll get you the info about the cost.

[JonMarsh]

As I keep making up test configurations to use, I keep adding cables and other bits to order- ordered about $250 MORE today than already... I should have realized this was going to nickel and dime me to death, too, after first gutting my bank account! :W

GF got off OK for New Zealand, first leg of trip, to Sidney. She won't get off that plane from last night until 1:30 PM PST this afternoon.... I've never been 15 hours on a plane at one go before, my personal worst was 12-12 hours on a flight to Hong Kong that had to divert around a Typhoon, on the way to Singapore.

BTW, sometimes I look at my Ardents and think about re-doign the finish on them, too... but not until I have a lot of spare time.

On the new project, I think I'm going to go with that General Finishes stuff that was recommended to me for GF's subwoofer. That should be find for 2nd level prototypes, right? :W

[TEK]

I hear a lot of good things about General Finish, and would like to try it out myself. However, I would (from what Inhave figured out until now) have to import it from UK, and that pop up the cost quite a bit. I also start to get some experience with the Glasurit auto paint and are not quite sure if I want to start learning another brand. At the same time the Glasurit stuff is insainly expensive.
Time will show...

Jon, what's up with your finish? Is it just a general lust for something else, or is there something that you are not happy with?

When it comes to long flights I'm a novice compared to you both. I think 10 hour trip from germany to south africa is my longest in one go. Long enough for me....

[JonMarsh]

The lacquer I used just has never really fully truly hardened, not even after many weeks- not compared to what I expect. It’s OK to get by, but I have to be real careful with the speakers. I probably should have used a catalyzing lacquer. OTOH, the General Finishes water based stuff has been quite nice, was eaiser to work with, etc.

Live and learn, like I say, I don’t claim to be a woodworker, more a wires and sparks kind of guy.

I’m going to use the general finishes stuff on my 2nd level Minerva acoutical prototypes. I almost have one completely glued up- just waiting for the top to finish it, it takes some steps, not really a design pracitical to put the box together all at once. Might get finished this evening, then I’ll post pictures. At 5 AM this moring it was 60 degrees F out, quite dry, very weird weather, but it’s forecast to rain later today.

[JonMarsh]

Quick update-

One more cable/parts order received yesterday, one still pending.

I did some initial check out, and I'm afraid that as AP says, the APx500 series is a software monster, and running Windows in a virtual machine may not really cut it for more advanced measurements or even two channels simultaneously, so this morning I bit the bullet and started looking seriously at what's at Costco online (I'm a long time Costco member- Executive card! . )

They had a lot of fairly good deals, much better than places like New Egg, Best Buy, etc, but what I settled on was a Dell XPS 15, 4 core, 4K display with display port output (can drive an external 4K monitor), and 512GB SSD. It was nearly a grand off the price those things went for when they were introduced in 2015- there's a newer, somewhat sexier looking model available from Dell, but a similar 2016 configuration would cost almost $1K more. That was ordered this morning, and at this point, I'm running out of juice for a little while! But it should handle the test tasks well, as well as some other test engineering things I might do with it at work. And if the topic comes up at work about using company Hardware, I'll just say, "Sure, just get me one of these!" (I currently have an old low end Lenovo which was "previously owned" by another employee before I got it in 2010- it was a cost constrained issue then. Just an email/web machine, a low end T420 Lenovo configuration. Total crap.

Image not available

Unfortunately it comes with Windows 8.1, but it's a free upgrade to 10.

OK, now that I've vented on that, back to my long to-do list for Sunday!

[benthe8track]

On finishes; I could still cut and polish mine and might do that before they go to their new home this summer. The conversion varnish seems to have held up well. In the 2 years or so the finish hasn't moved even with the huge humidity swings they see in a poorly ventilated basement.

[TEK]

On finishes; I could still cut and polish mine and might do that before they go to their new home this summer. The conversion varnish seems to have held up well. In the 2 years or so the finish hasn't moved even with the huge humidity swings they see in a poorly ventilated basement.

New home? Are you selling them? We are talking about the Ardents?
I must say that when it comes to the quality of the paint and drying as it should - that's absolutely no problem, neither with my Ardents or with the In-Kahn-Neatos I built for the living room. So - something good comes out of using good quality and very poisonous car-paint ;-)
For me the problem is more with the veneering. To much stress (where I used the iron-on method). Also probably did not use enough softener.

Jon - could you not dual boot your mac computer, so that you could boot it right into windows instead of running a virtual windows instance from the mac os?
Virtual OS usually have quite crappy performance - so I'm not very surprised that it was to slow.

Just have to comment on the nc500. They are a really good match to the Ardents :-)
Going to be interesting to see what a "Jon Mash" front end system board may do to the sound compared to the standard test board from hypex... ;-)

[benthe8track]

Oh no I'm keeping the Ardents forever. We're just moving downtown this summer, it will have actual natural light so I can take a decent picture finally.

[JonMarsh]

New home? Are you selling them? We are talking about the Ardents?
I must say that when it comes to the quality of the paint and drying as it should - that's absolutely no problem, neither with my Ardents or with the In-Kahn-Neatos I built for the living room. So - something good comes out of using good quality and very poisonous car-paint ;-)
For me the problem is more with the veneering. To much stress (where I used the iron-on method). Also probably did not use enough softener.

Jon - could you not dual boot your mac computer, so that you could boot it right into windows instead of running a virtual windows instance from the mac os?
Virtual OS usually have quite crappy performance - so I'm not very surprised that it was to slow.

Just have to comment on the nc500. They are a really good match to the Ardents :-)
Going to be interesting to see what a "Jon Mash" front end system board may do to the sound compared to the standard test board from hypex... ;-)

I have a Mac Pro setup for dual boot to Win10; works fine; using bootcamp. the problem is for the older Macbook Pro 17" notebook I wanted to use; it is not considered "compatible" with Win10 for Bootcamp, and you just can't get a normal WIN7 install disk anymore- all there are are OEM disks or refurb disks, and these don't work with Bootcamp setup- they use a different kind of boot process and installation tool. I have WIN10 running under Parallels, but this way it can only access 2 cores and about half the RAM. Even with 16GB installed, that's a bit marginal. I just figured I needed to go for something a bit more than marginal, and getting a $2500 Dell for $1600 seemed an OK deal.

[dar47]

Ah, that's my notebook. Lots of value with the XPS's and Dell tries to maintain their status as I thinks it's there best seller.

[JonMarsh]

This is a 2015 XPS with the 4K display built in, and some other high end doodads (that's the technical name for it, isn't it?)

CostCo didn't ever send a shipment notice, but they did send the laptop; it arrived yesterday evening, and after putting it on the charger and setting up and logging in, the next thing was starting the upgrade to Windows 10 (I'm not a fan of 8 or 8.1) (there are also a lot of things about 10 I'm not so happy with; a nice clean install of WIN7 would have been perfect, but you can't get that, and WIN7 does have pretty sucky HiDPI support, unless it's running under Parallels and their special drivers)

It finished downloading 10 overnight, and this AM I started the install process before heading out to Starbucks.

This XPS is interesting, the packaging is heavily influenced by what Apple has been doing for years, as well as the initial start up customized by Dell. The screen looks fine (4K) and the body is a nice combination of dark gray aluminum and carbon fiber reinforced plastic. The touchscreen makes it feel like something in between my iPad Pro and my Macbook Pro. But on normal Windows apps, I don't think it will be very practical. I've got a nice new Logitech mouse to deal with that. 16GB of RAM should get the job done; I'll install some of my CAD/SIMulation stuff on it too, such as SIMPLIS and Altium Designer. And of course, LspCAD! Oh, and the AudioPrecision software...

It will be a busy evening tonight.

[JonMarsh]

HiDPI on Windows 10 still is terrible :M

Well, Windows 10 doesn't handle HiDPI displays and applications worth warm spit either. I was tempted to use much, much stronger language than this, but after all, I am a moderator, and private forum or not, certain standards have to be met. :x

The problem likely lies in the underlying design of Windows API, and how developers have had to often hard code their own elements to get things done. And how the display settings are handled, I guess. So, the AP software, like several others I've just installed an run, come up with a mishmash of stuff hard coded at a certain resolution, with scaled elements at other resolutions. It looks ridiculous, and it isn't workable.

I recently bought a 25" 2560 X 1440 Dell display to use with my 4 channel scope; for now, that should work... but doesn't. It's keeping the HiDPI settings, and scaling down the graphical elements to stuff that's nearly unreadable. Probably due to the intrinsic settings of the XPS. This is even with the built in Dell 4K display turned off. That is not in mirrored mode, which I would expect this problem, but in extended desktop.

========================================

OK, found the fix... annoying. It installs and works fine on my Mac Pro running Windows 10.

It runs OK on the Dell, IF you setup for single monitor display on the external monitor, then REBOOT again to that monitor- then it forgets the HiDPI settings for scaling on the main display. Awkward, but at least there's a work around. Definitely not in the class of what I expect, based on how my Apple computers work- I can have a HiDPI display and standard display connected at the same time, and drag windows back and forth between the displays, and everything just works.

Sigh... well, at least I've got it working and can do some real stuff tonight. (Right now the Mac Pro is running a demo analysis of loopback testing).

[TEK]

It's really annoing when basic stuff that tou just expect to work actually does not work at all.
Happy to hear that you at least figured out a way to make it work!

When it comes to language, I'm from the nothern part of norway - we are well known to have a, lets call it "colorfull" language.
There is a actually a verdic from a norwegian court where a man was judged innocent for calling a policeman "hestkuk" (that's norwegian for the hourses co...k).
The judge ment that due to the tradition for "colorful" language the policeman should accept that kind of language :banana:

[benthe8track]

There is a actually a verdic from a norwegian court where a man was judged innocent for calling a policeman "hestkuk" (that's norwegian for the hourses co...k).
The judge ment that due to the tradition for "colorful" language the policeman should accept that kind of language :banana:

Hey thanks for the new word! I'm going to use that next time I get dragged to a dumb meeting.

Hey Jon, I wonder if those issues stem from the dell drivers? They love to put their stamp on everything.

[JonMarsh]

Hey thanks for the new word! I'm going to use that next time I get dragged to a dumb meeting.

Hey Jon, I wonder if those issues stem from the dell drivers? They love to put their stamp on everything.

I suppose it's possible... but doing a little research on other systems with 4K displays on Windows, there seems to be a pattern...

I could test the theory by plugging in a 4K Dell monitor I have to the 2010 Mac Pro, see what Windows does with it, and if it affects things the same way.

Boy, there is a lot of evil stuff that Dell's install of windows wants you to agree to if you go for the Express install, too- collects all kinds of information and sends it to Microsoft, the only thing they didn't ask for was a web cam in your bedroom.... :W

Well, here it is working...





I'm going to be barred from my favorite Mac web sites if I keep this up... :W

[JonMarsh]

Nickel and Dimed to death...

My friend and colleague who used to design commercial style clocked class D amps for the company he last worked for brought up the AP AUX00025 filter unit again- I have my own home brew balanced two channel filter, but as I joked with him, he's making me paranoid. Obviously, no one can argue with results if I'm using the AP filter.

(This is a special filter for testing class D amplifiers, provides a multi-pole low pass filter for the amplifier output to protect the AP's input stage and eliminate the carrier frequency from being detected as distortion in the overall process - keep in mind, my APx555 receiver has a bandwidth of 1MHz- it's the special version which is only an option on some of the other models, but which is standard on the APx555). And this filter is built to handle ludicrous levels of input voltage- we're talking up to +/-200V Pk to Pk (that's like filtering the input of the 115VAC power line)



I found one at an acceptable price on eBay, which means I get it right away and for less money- should ship today, from Sunnyvale CA.

[TEK]

As you add more equipment, will it not be harder and harder to know if any irregularity is from the tedt equipment or from the component beeing tested?

For example, if you are going to measure in the 0,001 range - will you be able to tell if noise is from the filter or the component beeing tested?

Anyway, I assume that it will be interesting to compare your filter with the AP filter

[JonMarsh]

That's why one does loop back testing first. This add on box is just passive RC filters and as you can see above, they spec the frequency response and residual distortion of the filter circuit (yes, even just RC filters can add distortion because of capacitor behavior). May be interesting to see if it's possible to come up with a test concept for crossover caps.

[benthe8track]

May be interesting to see if it's possible to come up with a test concept for crossover caps.

This would be really interesting.

[JonMarsh]

How to do it?

Two ways this might be possible-

• Four terminal measusrment, looking for discontinuities in impedance due to internal resonance (ties in with theories from Clarity Cap)
• Measure low level distortion, due to resonance and/or dielectric absorbtion

With an instrument this sensitive, a lot of possibilities are opened. Because it's all computer drive, there are ways to configure tests are very flexible.

Yesterday I spent a fair amount of time going through the PDF software manual picking out all the most useful parts (such as leaving out things specific to other models of hardware) and printing and setting up a binder with chapter printouts. The supplied printed manual is a soft cover printed in black and white. Not very useful if you want to open up something in the middle and go through a setup or procedure, as it won't stay open, and the screen shots are not nearly so legible in black and white!

[JonMarsh]

Finally got updated today by the eBay vendor; the Audio Precision AUX00025 shipped. Should be here by Friday. :T

[JonMarsh]

The AUX00025 filter arrived today; I got shipping notice for the HDO8038 eight channel scope; that shipped today, should be here next Wednesday.


;b>

[dar47]

So many toys, it going to make your head spin. i'm going to be pressing Ben to get my NC500 case designed, it's almost spring!

[TEK]

So many toys, it going to make your head spin. i'm going to be pressing Ben to get my NC500 case designed, it's almost spring!

Are you going for two monoblocks or a stereo amp?

[dar47]

Two mono's in one case, guess we should figure out what I need. Maybe take your route and change later when Jon does his thing.

[TEK]

The basic stuff is easy, it's just the power supply, the amp and Jons system board (or a hypex converter board if you go my route).
The converter board is 28euro ex tax. Two is 56euro - I'm thinking about that as rent cost for having something while waiting for "the real solution". Well worth it ;-)
What I find challenging was all the little stuff, plugs, cables, screws, resistors and leds, power switch and so on.
I started a writeup with quite detailed instructions - I might update that if you are interested.

[JonMarsh]

The basic stuff is easy....
What I find challenging was all the little stuff, plugs, cables, screws, resistors and leds, power switch and so on.
I started a writeup with quite detailed instructions - I might update that if you are interested.

THAT's why I went with that online sourced chasis and accessory kit of cables/connectors- just to save some time for a test build or two, and not having to much around with the little fiddle bits.

Speaking of fiddle bits, my score yesterday was picking up some stick on rubber feet from Radio Shack for the AUX00025 on the way home from my PLECS training in Menlo Park yesterday. Fiddly bits, in deed!

(The training was quite good- PLECS is a simulation program for power electronics, from a Swiss company that's a spin off of ETH Zurich, which I bought a personal copy back in 2011; it's been very useful, but this training and the extra collaterals and files with the handouts will substantially expand both my knowledge and skills with it and the range of application for me).

Steps large and small this week- another one was creating my own "improved" manual for the APx555 by printing out the PDF (which is in color, unlike the black/white soft bound manual received with the unit) and setting it up in a big binder with index dividers and a nice printed index list using the Avery template obtained online. Makes finding stuff and interpreting the screen shots MUCH easier.

I'll be running out to my storage units and picking up my high power amplifier test loads; plan to be doing actual preamp and amplifier testing this weekend, especially the Benchmark AHB2's, which have to be carried to Munich at the end of next week. I'm going to miss those, I think... May have to come up somehow with the loot to buy even just one to use as a sonic reference/target. Lot of respect for what they accomplished with that amp. At least I have a clear target what I want to aim for...

And the big scope is shipped on the way! Hot Damn!

[JonMarsh]

Going slow... testing some Schiit!

Got a lot of other tasks out of the way, including a long email updating my Munich friend, and a long replay to MEB46, who's been doing some interesting things in Munich like visiting Accuton. Unfortunately I can't talk about the interesting bits, but I can say there WERE some interesting bits which should have some impact on future developments. :W

Today I got the bench better arranged, got a few more test adapters locally, and actually tested something- my Schitt Magni (the original, not the newer Magni 2). I figured if I did something stupid, or if there was an issue with the gear, no harm, no foul, no major loss.

After noodling around a while with the at times obtuse user interface (like, having to click several buttons to completely activate the generator and see an output, even in fold back mode) I started getting the hang of things- watching some of the Videos I found on YouTube helped some also. Felt a lot more comfortable with things by the time I got done, AND, I didn't blow anything up!

So, for your entertainment and amusement, just two graphs I saved, one a level sweep of THD+N ratio from 10mV generator output to 2.5V generator output, showing variation in THD+NOISE with level for 1 kHz;



What this shows is that up to about 200mV input level, noise predominates, which is why there is a linear downward slope on THD+N; between three hundred and 500 mV input voltage, the THD is starting to rise, and just over 2VRMS (typical full scale on a CD player) the steep vertical rise is the onset of clipping. I could also plot this as a function of output level; was curious to see the input headroom though.

And the other a frequency sweep of distortion versus frequency, picking a level in the range near the fairly optimum distortion versus level, at 500mV input voltage. This is a fairly typical looking curve for a chip amp or opamp that has fairly high loop feedback below 1 kHz, but dropping off above that; THD rises more than I might have expected in the top end, climbing from about 0.00125 at low frequencies to almost 0.025% at 20kHz.

Gain maxed out in both cases, to optimize the relative noise performance.



Tomorrow I move on to Preamps and amplifiers!