[turbotr]

Hello everyone, TurboTR here in Texas- greetings. I've lurked a bit but thought I'd introduce myself finally.

By now I'm a senior electrical engineer in a PC related semiconductor company. Also did several years as an engine research engineer doing engine controls and programming for research projects for the US DOE, EPA and teh CARB for example. Also a long time high hp power adder drag race background, including selling and programming a popular aftermarket EFI control system And had an SCT tune dealership for awhile as well, on the side from the main engineering job.

I'm not expert on analog electronics by any means but always learning, and when in doubt I may just dive in. Some notable project lately, have done an extensive deep dive Naim amp improvements project which turned out fantastic really. Much learning was based on several great reference books and articles by Self, Cordell, Leach, Pass, etc. And then several hundred man hours (literally) changing, experimenting, etc. Also did a deep dive non-os DAC project with several interesting aspects including ultra low jitter, battery power, custom i/v, filtering and buffer sections, etc. Also learned a ton about the sound of passives, having tested a pile of high end resistors and caps and inductors in it. And many, many hours experimenting with speakers including open baffle in depth, full range, full range in open baffle (lol), MTM's, etc, etc..

Anyway, hope to continue to enjoy this site and maybe can make a contribution or two once in awhile too. Thanks for having me

Turbo

[JerryM]

Welcome to AudioCircle, Turbo! 

[Blackmore]

Glad you're here.

[FullRangeMan]

Welcome Turbotr;

[ArthurDent]

Greetings & Welcome to AC turbotr.    Nice pics, & system. Will look forward to your sharing of experience & knowledge.

[turbotr]

Aww thanks guys, you're making me feel very welcome 

Turbo


10KHz digital "sinewave" (lol) DAC out pre, post filter. Indeed Sony, "..perfect sound forever!" /s

[FullRangeMan]

Aww thanks guys, you're making me feel very welcome 

Turbo


10KHz digital "sinewave" (lol) DAC out pre, post filter. Indeed Sony, "..perfect sound forever!" /s

At the 1980/90 era audio press always praised CD.
Just after CD death many are beat on it.

[turbotr]

Why FR Man, if I didn't know better it would seem that somehow you may be implying that the digital 10KHz sine wave is imperfect?? /s

We don't even wanna see what 13, 15, 17KHz+ look like It would be hard to mangle it worse than it does. It's a horror show.. Well Halloween is not far off though..

However- what "saves" it somewhat is, the first distortion overtone by 10KHz is completely out of the audio band. And for my poor old ears in particular that's sadly true even by about the 5KHz fundamental lol

So in the end it basically modulates the amplitude of the fundamental (and that's bad too) but the horrendous distortion products are ~ out of band.

Turbo

At the 1980/90 era audio press always praised CD.
Just after CD death many are beat on it.

[charmerci]

Hello everyone, TurboTR here in Texas- greetings. I've lurked a bit but thought I'd introduce myself finally.


Anyway, hope to continue to enjoy this site and maybe can make a contribution or two once in awhile too. Thanks for having me

Turbo

Welcome aboard....


yeah, but what are the speakers???? 

[turbotr]

Thanks! There have been many, many through the system of course since the mid 80's (lol). I started out as a long time Linn Kan user in a classic Linn LP12/Naim system. But currently it's these now:

http://www.parts-express.com/project-gallery-speaker-project-dr-ks-mtm

And they do surprisingly well, especially now that the amp has been cleaned up substantially. Before that they were "pretty good" but "unrefined" and a bit grungy if you will. Now they're pretty darn stellar actually, especially all things considered.. Turns out the alum dome tweeter was basically just happily passing along ~ low levels of grunge from below. The alum 7" midbasses seem to do quite well IME. And the 2 of them are weighty enough to deliver the goods when required.

Another thing they do is fix the room boom problem I've had forever. An aspect not talked about alot with MTM's, but a godsend for my room anyway. I attribute it to the comb filtering of the bass/midband energy going on outside from the sweet spot (tg). My guess anyway. I think it helps focus the image too; they image awesome too. So the digital eq gets put away (yay!) and the LP12 with Akiva MC rocks out again (yay!) tg. Grand Funk's Red album is rendered in amazing fashion for example..

Anyway, the PE MTM trial has gone so well we'll be building these soon:

http://meniscusaudio.com/adelphos-pair-p-1387.html

Bagby's Adelphos with Satoris. MTM version of course. All the stuff is on hand waiting in the garage including all the xover upgrades, OFC wire, extra posts to make it passive bi-amplifiable, etc. We're swinging for the fences with this one.

Selling off a ton of stuff meanwhile. Much gone already but much still to go. Including a full blown Hawthorne OB experimenters setup in exc condition, a Linn Akurate 4200 (can use to drive it , etc. And Altmann has the Attraction DAC priced up so high lately thinking I'll even part with that now too Same for the Tera player I have too, #4 unit ever sold, hardly used.

Turbo

[turbotr]

PS I'd like to add that another tremendous upgrade for the speakers was finally moving to a good solid wooden stand. In this case built by Vapor Audio for their Stiff Breeze, which uses the same cabinets (and I auditioned them). It took them to another level vs the various metal stands I'd been using.

Here's another interesting scope shot too This is supposed to be 20Khz sine lol..





Purty huh

The Lecroy scope used here is an expensive Hi Res high speed model (12 bit) and it takes amazing pictures!

Turbo

[turbotr]

More interesting digi-pron.

This is a 15KHz 0dB 48KHz DAC chip output. Note the digital beats modulation too:





This was from a Tranquility DAC BTW, not the TK_DAC.


This shows a significant spray of bass distortion tones after a 100Hz 0dB 48Khz fundamental. I think this is at least partially why early digital became known for having "strong bass".





Yes, Super Scope does everything- faster than a speeding bullet.. more powerfuil than a locomotive.. able to leap tall buildinmgs in a single bound!

"..Perfect sound forevahh!" "Digital can nevah looose!"

Ok this is probably boring more people than it is entertaining I'll stop.

Turbo

[FullRangeMan]

I read in a old TAS a suporter from SACD saying DVD Audio also cant do a 10Khz square wave.

[turbotr]

Well much of the spectral content of a 10KHz square wave is outside the audio band, so technically any system that is audio band limited can't "do" a 10KHz square wave per se.

Meaning, if the system was hard band stop limited at 20KHz the only thing you'd see on your scope would be a 10KHz sine wave

[charmerci]

There's a section here called The Lab.


You'll get more responses there with your charts, I suppose.