Go Back   Home > Forums > Source & Line > Digital Line Level

Digital Line Level DACs, Digital Crossovers, Equalizers, etc.

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
Reply
 
Thread Tools Search this Thread
Old 8th June 2011, 04:26 PM   #3701
brubeck is offline brubeck  Netherlands
diyAudio Member
 
Join Date: Sep 2009
Location: Netherlands
Quote:
Originally Posted by roger57 View Post
someone knows?
OF511JE Ohmite Carbon Composition Resistors
  Reply With Quote
Old 8th June 2011, 05:10 PM   #3702
roger57 is offline roger57  Canada
diyAudio Member
 
roger57's Avatar
 
Join Date: Sep 2006
Location: Edmonton, Alberta
brubeck -

My bad! In the last posting I made, I said CARBON, I meant GRAPHITE. Sorry about that! Graphite resistors aren't readily available (Dueland (Denmark) has some, but they are physically huge. They can be made, here's an interesting article:

GRAPHITE RESISTORS

In any case, by the time you get to 500 ohms, they'll be big!

Gary
  Reply With Quote
Old 9th June 2011, 11:27 AM   #3703
brubeck is offline brubeck  Netherlands
diyAudio Member
 
Join Date: Sep 2009
Location: Netherlands
Quote:
Originally Posted by roger57 View Post
brubeck -

My bad! In the last posting I made, I said CARBON, I meant GRAPHITE. Sorry about that! Graphite resistors aren't readily available (Dueland (Denmark) has some, but they are physically huge. They can be made, here's an interesting article:

GRAPHITE RESISTORS

In any case, by the time you get to 500 ohms, they'll be big!

Gary
What is the diffrence between graphite en carbon composite? As fas as i know it's both carbon mixed with clay?
  Reply With Quote
Old 9th June 2011, 02:09 PM   #3704
roger57 is offline roger57  Canada
diyAudio Member
 
roger57's Avatar
 
Join Date: Sep 2006
Location: Edmonton, Alberta
Have you ever tried writing with a resistor?

Seriously - the exact differences I do not know. I do know there are compositional differences in the balance of materials. It's know that CC resistors provide a more natural sound but can contribute more to noise. What I understand is that graphite has an open, airy sound with no noise artifacts.
You might want to check Duelunds website for more info. I may even take a stab a building some.
  Reply With Quote
Old 10th June 2011, 04:22 AM   #3705
diyAudio Member
 
Join Date: Sep 2010
Location: Oklahoma, Tornado Alley
Default MK7 module availability?

I am sorry if the question has been answered before.

ecdesigns, when will be the MK7 (or your final module) available to order form your website. I went on your website and it still says, MK4.
  Reply With Quote
Old 10th June 2011, 06:58 PM   #3706
diyAudio Member
 
Join Date: Apr 2010
I bought the analog metric board on eBay. I sourced all the parts and assembled the board. The static voltages all check out. I am using the CS8414. On page 11 a note says R25 should be 1k ohms and c33 should be 68nF, c35 should not be installed. On page 4 of the instructions, the following can be found:
Either uses 1K ohm for R25, 0.047uF for C33 for CS8412.
Do not assemble C35; R25 = 470ohm and C33 = 68nF for CS8414 Or Use 470 Ohm
for R25 and 0.22uF for C33, 3300pF for C35.

I get nothing on pin 26 of cs8414 whether or not a digital signal is present on the RCA input. Also what should the signal look like on pin 9 of cs8414. I'm getting no output. I don't see anything on the data and have no idea where the signal is being lost. This board is the biggest waste of time and money I have ever experienced. Has anybody ever been able to get this piece of junk working in either oversampling or non-oversampling mode?
  Reply With Quote
Old 14th June 2011, 08:06 PM   #3707
brubeck is offline brubeck  Netherlands
diyAudio Member
 
Join Date: Sep 2009
Location: Netherlands
Quote:
Originally Posted by roger57 View Post
Have you ever tried writing with a resistor?

Seriously - the exact differences I do not know. I do know there are compositional differences in the balance of materials. It's know that CC resistors provide a more natural sound but can contribute more to noise. What I understand is that graphite has an open, airy sound with no noise artifacts.
You might want to check Duelunds website for more info. I may even take a stab a building some.
I did some listening tests with MK7 DAC using different carbon composite resistors direct in serie with the DAC output signal. Tried 1 to 15 ohms and several watts (1/4, 1/2 and 1). If i can believe my ears the effect of more noise is significant. To much noise masks the sound immediately. In my setup i ended up with a 4,7 ohm 1/2watt. Just enough to add some sonic cream without causing masking effects.
  Reply With Quote
Old 15th June 2011, 08:45 PM   #3708
brubeck is offline brubeck  Netherlands
diyAudio Member
 
Join Date: Sep 2009
Location: Netherlands
Quote:
Originally Posted by brubeck View Post
I did some listening tests with MK7 DAC using different carbon composite resistors direct in serie with the DAC output signal. Tried 1 to 15 ohms and several watts (1/4, 1/2 and 1). If i can believe my ears the effect of more noise is significant. To much noise masks the sound immediately. In my setup i ended up with a 4,7 ohm 1/2watt. Just enough to add some sonic cream without causing masking effects.
A little rectification has to be made after further listening. With very good recordings, even 4,7 ohm gives little masking effects of the LSB's. (bravo for the resolution of the MK7 DAC!). With older recordings the resistor smoothens the sound in a gentle way. (i have to make a switch ;-)
  Reply With Quote
Old 15th June 2011, 09:35 PM   #3709
diyAudio Member
 
Join Date: Apr 2008
Location: Newcastle, Australia.
Quote:
Originally Posted by -ecdesigns- View Post
Here are the schematics of +5V, -5V and -15V LED-referenced series regulators with integrated capacitance multiplier for the TDA1541A. Exact output voltage can be set with R3, R8, and R12 (higher value increases output voltage, lower value decreases it).

The circuit works as follows (using +5V schematic as reference):

R1 and C1 form a low-pass filter that attenuates ripple voltage. R2 feeds the cleaned-up DC voltage to Darlington T1, driving it into saturation. C2 provides frequency compensation.

The output voltage is divided by R3 and R4, and connected to the base of T2. T2 emitter is connected to a green LED (approx. 2V).

As soon as the voltage across R4 exceeds 2V + 0.6V (V-BE), T2 starts conducting, reducing the current flow through T1. This way the regulator settles around the required output voltage.

If R4 was removed from the circuit, output voltage would settle around V LED (2V) + V-BE (0.6V) = 2.6V.

The circuit responds very fast (minimum delays), and noise levels are low enough for audio applications.

The LED could be replaced by suitable low-noise zener diodes, but do carefully check effects on sound quality.

Keep in mind that the noise produced by the reference diode is amplified by the attenuation factor of the voltage divider. With the 5V regulator, the LED noise is amplified approx. 1.9 times.

With the -15V regulator LED noise is amplified by approx. 2.7 times.

So try to find an optimum between reference diode noise and voltage divider properties.


The voltage drop across LEDs with different color are slightly different:

Current = 20mA.

Infra-Red LED, approx. 1.3V
Red / Orange LED, approx. 1.9V
Yellow LED, approx. 2V
Green LED, approx. 2.1V

Use plain LEDs (no low current LEDs) for lowest noise. Don't use blue or white LEDs.

I used green LEDs for these voltage regulators as they provide highest voltage drop (2V).
Hi,
Thankyou for the wonderful contributions here ecdesigns.
Just wanted some clarification with regards to your led ref supplies.with the -15 volt suppy r9 and r10 are 6k8 in one diagram and 2k2 in another...does matter which i use there?Also can c26 100uf be bigger..say 330uf?

thanks again
Paul
Attached Images
File Type: jpg ledregs.jpg (66.9 KB, 1062 views)
File Type: jpg regulators.jpg (101.8 KB, 1048 views)
File Type: jpg DSCF1054%20(2).jpg (14.9 KB, 1032 views)
__________________
" I love cats....but I couldn't eat a full one. "
  Reply With Quote
Old 15th June 2011, 10:05 PM   #3710
Sven257 is offline Sven257  United States
diyAudio Member
 
Join Date: Sep 2008
Location: Las Vegas, NV
Hi Brubeck,

So what carbon 'composite' resistor are you using?

Maybe you could try a carbon 'film' like a Riken-ohm or a Kiwame/KOA which will have less noise (masking) than a 'composite' resistor...

Peter
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



New To Site? Need Help?

All times are GMT. The time now is 08:29 AM.


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