diyAudio - Blog Entries
Go Back   Home > Forums > Blogs

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Old

HEC part II

Posted 17th June 2010 at 05:07 AM by abraxalito
Updated 8th September 2011 at 03:04 AM by abraxalito

Here's a pic of the underside of the DAC before I started hacking tracks. Bottom left area is where the digital circuits are, with ground plane. Top left are the analogue output filters. Right is the caps, rectifiers and regs of the power supplies - digital at the bottom and analogue at the top.

The AD1955 sits about the centre of this pic, and if you look closely you'll notice two small holes I drilled in the groundplane either side of it where I will later install the 10uF decouplers.

The second pic shows the component side, prior to any hacks - the 'virgin board' if you like, although sullied by the two small holes near the DAC chip. The analog supply is pin15, that's at top left.

Third, here's the meat of the digital circuitry and I've already added one decoupler to the AVDD (analogue positive supply). To the right of the 24.576 XTAL (not required) is the DIR9001 SPDIF receiver. The DIL chip is a multiplexer allowing both USB and SPDIF input...
Attached Thumbnails
Click image for larger version

Name:	P1010326.JPG
Views:	431
Size:	699.3 KB
ID:	165   Click image for larger version

Name:	P1010328.JPG
Views:	534
Size:	694.7 KB
ID:	166   Click image for larger version

Name:	P1010331.JPG
Views:	578
Size:	705.2 KB
ID:	167  
abraxalito's Avatar
diyAudio Member
Views 954 Comments 0 abraxalito is offline
Old
Rating: 3 votes, 5.00 average.

Don't be such a scientist!

Posted 15th June 2010 at 04:21 PM by jan.didden
Updated 15th June 2010 at 04:25 PM by jan.didden

I didn't get it. There are gifted design engineers on this forum. They get involved in threads. BUT, in most cases, eventually an 'issue' develops and the engineering guy gets binned or banned or asks to be banned. Why why why? Happened to me a few times. Not that I got banned, thank Ohm, but I got close to leaving because I too got enough of it.
Of what?
Let me explain. Most engineering types like to explain things, to tell others with less experience and knowledge what they are doing wrong and how they can do it better. They inundate you with facts, figures, links to engineering papers etc, and expect that the other guy flows over with gratitude. But, funny enough, it doesn't happen that way. The 'other guy' gets pissed off from being corrected all the time. Hell, he didn't come here for that, he came to have fun, discuss his hobby and his latest creation.

[flashback] At the time Al Gore's An inconvenient Truth came out, the same director (!) also made Too...
jan.didden's Avatar
diyAudio Member
Posted in Uncategorized
Views 5963 Comments 28 jan.didden is offline
Old
Rating: 3 votes, 5.00 average.

Salas HOT ROD DCB1

Posted 15th June 2010 at 03:56 PM by Tea-Bag
Updated 12th May 2014 at 03:29 PM by Tea-Bag (added BOM)

So I am going to write some details down about the DCB1 Hynotize Hot-Rod buffer. The current production board is black, 2 oz copper and 2mm thickness. (See below) The below blue pictures are prototype boards and are not representative of the product.

Here are some of the specifics to help understand ordering parts for it etc. This is not a detailed build guide, but there is a link to one below from another forum member.


Click the image to open in full size.

They can handle 10mm pitch snap-in capacitors 25mm width capacitors.

Click the image to open in full size.

There are positions for smaller MUR120 type diodes OR MUR820 style TO-220 style diodes. Not both!

The vRef LEDS can now be bypassed with a 25mm Film cap or a 100uf electrolytic. The film cap by consensus is best at .22uf.

Click the image to open in full size....
Attached Files
File Type: pdf Blue DCB1 v1.0.4.pdf (42.5 KB, 6444 views)
File Type: pdf SalasDCB1shuntreg build guide v4.1.pdf (50.7 KB, 6180 views)
File Type: pdf BOM DCB1 Oenboek.pdf (168.7 KB, 2834 views)
Tea-Bag's Avatar
diyAudio Member
Posted in Uncategorized
Views 21394 Comments 2 Tea-Bag is offline
Old

My project blog

Posted 14th June 2010 at 03:18 PM by taro2ss
Updated 14th June 2010 at 03:20 PM by taro2ss

Hello,

Click here is my project blog. There is some information about my headphone amplifier products.

Thank you.
diyAudio Member
Posted in Uncategorized
Views 511 Comments 0 taro2ss is offline
Old

Towards a better DAC - introducing the HEC

Posted 14th June 2010 at 04:16 AM by abraxalito
Updated 8th September 2011 at 03:05 AM by abraxalito

Doug Self's comprehensive work on power amplifiers has been an inspiration to me over a number of years. In it, he coined the notion of the 'blameless amp' as one which was beyond reproach, measurements-wise. So I pondered over running with the notion of 'blameless DAC' along the same lines. Initially this sounded attractive, even though not entirely original. Google found a reference to it already here on diyaudio but could not show me the actual posting.

I decided on reflection that the 'blameless DAC' would be not such a good idea. That's partly because for me, measurements are not the goal of audio design. Enjoyable sound is what does it for me, not vanishingly low THD figures. So a 'blameless DAC' could only be blameless if measurements are God, so to speak. For someone like me for whom auditory experience is all, I decided I'd need another term for my DAC project.

I've settled instead on the term 'highly evolved converter' or HEC for short. This recognises...
Attached Thumbnails
Click image for larger version

Name:	ad1955taobao.jpg
Views:	1467
Size:	455.0 KB
ID:	161  
Attached Files
abraxalito's Avatar
diyAudio Member
Views 2458 Comments 8 abraxalito is offline
Old

New scope...

Posted 2nd June 2010 at 04:59 AM by abraxalito
Updated 5th March 2012 at 02:52 AM by abraxalito

Click the image to open in full size.

Bought this (well not quite this one, mine has Chinese text on the panel) little puppy yesterday as my old UNI-T was just getting too frustrating to use. In particular its triggering ability is almost useless, giving way too much jitter. That added to the trig level encoder being majorly unreliable (its just over a year old) and lots of apparently self-induced noise on the trace meant I decided to bite the bullet. And boy I'm glad I did - its like getting a new pair of HD800s to replace my aged Sony CD3000s, everything is much clearer.... (and no, I haven't made that particular upgrade yet).

About six months ago I first noticed the younger sibling of this scope in a shop window in the local electronics market. I was blown away - a widescreen scope? That screen was drop dead gorgeous! This pic really doesn't do it justice so hopefully I'll post up one of my own pics soon.

Having been immediately...
abraxalito's Avatar
diyAudio Member
Views 2490 Comments 8 abraxalito is offline
Old

Salas Shunt v1.2 notes

Posted 27th May 2010 at 01:00 PM by klewis
Updated 27th May 2010 at 01:11 PM by klewis

The ones I posted as symmetric 1.2 in page# 190 can do for +/-24V. Those are the ones that Bill initially tested for supplying his OP AMPS. There is a Q2 2N5459 JFET which is 25V VDS max that will set a 30V absolute max Vin given that it sits on 1.85V and there is a Vgs and R1 drop above it. Respect that Vin max. That Q2 must have 7mA or more IDSS for the cascode to work efficiently for a 7-9mA 2SK170BL Q9 under it with the given R4 (220R). If you want to feel free from Vin restrictions or choosing JFETS, you can do the BJT cascode left side. See post #2432 for negative example.
Making an additional positive one like those for 5V, only needs R13 1k trimmer to be 5k trimmer so it can go that low.
R1 is changing current setting, by 0.6V/R1=CCS current. Steadily predictable because that 0.6V is Q7's Vbe. Does not vary significantly per part or batch as with Leds Vf.
As for Vref and output caps subjective preferences, as Andrew said.
Good luck!
...
klewis's Avatar
diyAudio Member
Posted in Uncategorized
Views 1521 Comments 0 klewis is offline
Old

Tweaking electronics sound quality in active speakers

Posted 24th May 2010 at 12:39 PM by abraxalito
Updated 25th May 2010 at 04:24 AM by abraxalito

My main listening system has been based on Fayou XPE active speakers for over six months now. I bought my first pair of Fayou speakers a year earlier than that, the lower-spec'd B2 models. The B2s are now my main PC speakers, connected to an Asus Essence ST. After getting the B2s, it was only a matter of hours before I had them open, poring over the implementation details. I noticed that the grounding to tweeter and bass/mid was shared so sliced into the board to give each unit its own dedicated ground path. I also tweaked the high current paths to the main PSU caps to ensure no impedances in common with the audio signal grounds. After these mods, the sound was highly enjoyable.

When I first heard the XPEs I considered them not to be quite as good sounding as my (tweaked) B2s, but given their superior amplification and bass/mid driver, figured they were ripe for hot-rodding. Their construction also suits tweaking much better as all the electronics is easily accessible on the...
abraxalito's Avatar
diyAudio Member
Posted in Uncategorized
Views 1398 Comments 4 abraxalito is offline
Old

A New Comer to Audio

Posted 17th May 2010 at 09:49 AM by borispm

Hi everyone. This is my very first post. I am not really new to audio but I am very new to DIY audio.

I have a pair of MB Quart standmounters with a cheapo Marantz receiver and they sounded great until I heard something high end, and that's why I've joined this DIYaudio, where I can explore more about audio (especially a very special group of fullrangers).
borispm's Avatar
diyAudio Member
Posted in Uncategorized
Views 874 Comments 1 borispm is offline
Old

Krell KSA150 - Low distorted output after heated up

Posted 16th May 2010 at 07:51 AM by wabun

my Krell sings well when turn on, but left channel has low distorted output after play for 3 songs..turn it off and let it cool down, turn on again it sings normal again ! but after play for 3 songs, the left channel has low output again...unable notice any damaged component, any good suggestion how could it happen and what is the cure ? Thanks..
diyAudio Member
Posted in Uncategorized
Views 708 Comments 0 wabun is offline
Hide this!Advertise here!

New To Site? Need Help?

All times are GMT. The time now is 10:24 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2