BUILD THREAD - A New Take on the Classic Pass Labs D1 with an ESS Dac - Page 54 - diyAudio
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 11th March 2013, 04:01 PM   #531
qusp is offline qusp  Australia
diyAudio Member
 
qusp's Avatar
 
Join Date: Oct 2009
Location: Brisbane, Australia
hey also guys, this might be useful for some of you

its from the last round, but everything is in the same places. those are M3 size dots, so 3.5mm diameter, but the numbers for the coordinates are noted in imperial. alternatively just use the cordinates in a drawing package as they are to scale.

red text is the device mounting, purple are the ackodac AKD12/8 holes in the PCB the rest are other various mounting holes on the board you can use to screw it down and pinch the fets in place
Attached Files
File Type: pdf heatsink drilling pattern.pdf (440.5 KB, 48 views)
  Reply With Quote
Old 11th March 2013, 04:14 PM   #532
diyAudio Member
 
Join Date: Jul 2009
Thanks Owen and Jeremy, delay on the Internet made Jeremy's reply a little later!
  Reply With Quote
Old 11th March 2013, 04:58 PM   #533
qusp is offline qusp  Australia
diyAudio Member
 
qusp's Avatar
 
Join Date: Oct 2009
Location: Brisbane, Australia
no worries, indeed the internet is slow over here =) it takes quite a while for the signals to reach there because of the world spinning the other way in Au...

dont just set to 1.65vdc, actually measure your AVCC regulator, its usually set to around 3.5v these days for the buff I think. I use 3.6v, mine is set to 1.8vdc source->ground

Last edited by qusp; 11th March 2013 at 05:24 PM.
  Reply With Quote
Old 11th March 2013, 05:11 PM   #534
qusp is offline qusp  Australia
diyAudio Member
 
qusp's Avatar
 
Join Date: Oct 2009
Location: Brisbane, Australia
crap, I attached the wrong pdf. sorry heres the right one, the first one above is accurate, but is the simplified version. sorry about that, it saved to another folder of the same name on my backup drive.
Attached Files
File Type: pdf NTD1 drilling pattern for forum 2 .pdf (457.6 KB, 55 views)
  Reply With Quote
Old 11th March 2013, 05:25 PM   #535
Just DIY!
diyAudio Member
 
pinnocchio's Avatar
 
Join Date: Sep 2010
Location: Montreal
Qusp, those resistors that we ordered are they the same thickness as the Mosfets? Do they have a tab? I just wanted to know how they would be fastened under the PCB.

Thanks
Do
__________________
PREAMPs : AMB α10 + JC-80 clone | Balanced DCB1 | LDR3x | AMPs: AMB β24 | Aleph 5 | FirstOne | ML-2 | TSSA | Telos 390 Clone | My_Ref FE
DACs : TPA Buffalo II + OPC's NTD1 I/V | TPA OPUS + IVY III | Moon 380D DSD Speakers : Jim Holtz Statements | Astasia SD | Tubasson Mark 2
  Reply With Quote
Old 11th March 2013, 05:39 PM   #536
qusp is offline qusp  Australia
diyAudio Member
 
qusp's Avatar
 
Join Date: Oct 2009
Location: Brisbane, Australia
no they arent, no to220 is the same as a to247, caddocks arent either. yes they do have a tab, check the datasheet for approx dimensions

you have 2 choices. drill holes for them as well and screw all the fets and resistors to the heatsink through the holes in the PCB, then and only then, solder in place (this is what I do as it assures all have good and even contact).

be careful of the zfoil legs, as they are tinned copper only, dont bend too sharp a right angle in the legs with the pliers and dont spend a lifetime wiggling the PCB to get all the fets and resistors legs through.

alternatively you can use a small piece of PCB to place between the resistor body and the heatsink to make up the gap and then use the PCB to pinch them all down, bolting the PCB down and pinching everything down at once; again dont solder till after this, otherwise you can get different heights due to tolerances.

you havent read these instructions here?
  Reply With Quote
Old 11th March 2013, 05:41 PM   #537
qusp is offline qusp  Australia
diyAudio Member
 
qusp's Avatar
 
Join Date: Oct 2009
Location: Brisbane, Australia
Owen, since first post editing is retrospective, maybe you could add these things to the first post?
  Reply With Quote
Old 11th March 2013, 08:18 PM   #538
Just DIY!
diyAudio Member
 
pinnocchio's Avatar
 
Join Date: Sep 2010
Location: Montreal
Quote:
Originally Posted by qusp View Post
Owen, since first post editing is retrospective, maybe you could add these things to the first post?
Good idea! Since it is the build thread it would be nice to have the adjustment procedure on the first thread as well. I know you just posted them above but imagine if you have to search through 54 pages and more. Just makes life a lot more easier.

Thanks
Do
__________________
PREAMPs : AMB α10 + JC-80 clone | Balanced DCB1 | LDR3x | AMPs: AMB β24 | Aleph 5 | FirstOne | ML-2 | TSSA | Telos 390 Clone | My_Ref FE
DACs : TPA Buffalo II + OPC's NTD1 I/V | TPA OPUS + IVY III | Moon 380D DSD Speakers : Jim Holtz Statements | Astasia SD | Tubasson Mark 2

Last edited by pinnocchio; 11th March 2013 at 08:21 PM.
  Reply With Quote
Old 6th April 2013, 09:38 AM   #539
diyAudio Member
 
Join Date: Jul 2009
Quote:
Originally Posted by opc View Post
Hi bigpandahk,

All of that seems about right. Or at least, mine runs at those temps.

The temp of the fets depends entirely on the heatsink size, and it sounds like yours might be a little on the small side.

The regulator temps depend a lot on the voltage on the unregulated side and the voltage of the rails. They dissipate the dropped voltage.

For setup:

1. Set the output of each supply rail to the desired DC value (I use 45VDC)
2. Use the other pots to set the voltage at each DAC output node (with reference to GND) to 1.65VDC.

Allow to stabilize and re-adjust.

Once it's all stable, connect up the DAC and fire it up. Let it settle in again and adjust one last time, then you're good to go.

Cheers,
Owen
Although I can adjust all the voltage according to the procedures, but I found that the Gate voltage for both channels are different. One channel is around 1.55V while the other is over 3.8V. I don't think it's normal. Can anyone advise what is the possible problem?
  Reply With Quote
Old 6th April 2013, 01:42 PM   #540
opc is offline opc  Canada
diyAudio Member
 
opc's Avatar
 
Join Date: Oct 2004
Location: Ottawa, Ontario, Canada
bphk:

Are you measuring directly on the gate of the fet, or before the 220 ohm gate stop resistor? If you're measuring directly on the fet gate, then you're probing a very sensitive node and could be inducing some oscillation.

Try measuring prior to the resistor.

If all the other voltages are alright, then you should be fine, but you are correct, the gate voltage should be nearly identical for all four fets given how closely everything was matched.

Other possibilities / things to check:

-Are all your insulators to the heatsinks alright? Any shorts from the fets to the sink?

-Do you have the correct gate resistors soldered in? Are they all 220 ohm?

-Did one of the fets suffer an ESD event? This could damage but not destroy the gate and cause what you're seeing.

- Are all other voltages exactly the same between the other channels, and the good fet in the same channel?

Regards,
Owen
  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


Similar Threads
Thread Thread Starter Forum Replies Last Post
A New Take on the Classic Pass Labs D1 with an ESS Dac opc Digital Line Level 1762 6th September 2014 05:49 PM
Pass D1V3 DAC - build thread spzzzzkt Pass Labs 224 8th December 2012 04:40 AM
FS: Elektor Audioo DAC-2000 w/Pass labs D1 clone I/V sachi Swap Meet 4 26th November 2010 05:57 PM
IRF610 I/V convertion from Pass Labs D1 dac - single ended schiller Digital Line Level 5 15th October 2009 05:33 PM


New To Site? Need Help?

All times are GMT. The time now is 10:58 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