BUILD THREAD - A New Take on the Classic Pass Labs D1 with an ESS Dac - Page 50 - 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 28th January 2013, 05:40 PM   #491
glt is offline glt  United States
diyAudio Member
 
Join Date: Oct 2004
Thanks, qusp. The Edcor looks very reasonably priced...
__________________
www.hifiduino.wordpress.com
  Reply With Quote
Old 28th January 2013, 05:58 PM   #492
qusp is offline qusp  Australia
diyAudio Member
 
qusp's Avatar
 
Join Date: Oct 2009
Location: Brisbane, Australia
no problems, edcor have a lot of models, so you might need to do some searching for something appropriate, but the spec is reasonably good overall and very good for the money.

the O-netics I know more about, windings are tightly enough matched that they will cope no problems with direct connection to the dac, no caps needed to null AVCC DC current (they wont saturate) and the gandwidth is pretty good really, much better than some. nothing on a good solid state circuit such as this (for THD etc) but there is something to be said for the simplicity of the connection

something similar from Audio Note, Sowter, Lundahl, or heaven forbid the exotic Feastrex/Teramoto/Suzuki Finemet transformers will set you back MANY times more

Last edited by qusp; 28th January 2013 at 06:07 PM.
  Reply With Quote
Old 28th January 2013, 07:34 PM   #493
glt is offline glt  United States
diyAudio Member
 
Join Date: Oct 2004
I am talking $99 DAC to $99 Amp and likely a $99 full ranger :-)
__________________
www.hifiduino.wordpress.com
  Reply With Quote
Old 28th January 2013, 07:40 PM   #494
opc is offline opc  Canada
diyAudio Member
 
opc's Avatar
 
Join Date: Oct 2004
Location: Ottawa, Ontario, Canada
Are you targeting 99% perfection?

I like your concept... I would imagine with the right choices you could get a whole lot of bang for your $297.

hmmm... $99 would get you a pair of Fountek FR-89 drivers.

But I digress... It's OT.

If you're really looking for low price, Hammond also makes some 600 ohm telecom transformers that might fit the bill. I don't know the P/N off hand, but I'll check tonight. I ordered a few to see how they would work direct coupled to the output of the NTD1, but never got around to it.

Cheers,
Owen
  Reply With Quote
Old 28th January 2013, 08:39 PM   #495
glt is offline glt  United States
diyAudio Member
 
Join Date: Oct 2004
Thanks for the info on Hammond.
Have a pair of Wild Burro Betsy-Ks. Just need to build the cabinets
__________________
www.hifiduino.wordpress.com
  Reply With Quote
Old 28th January 2013, 10:06 PM   #496
diyAudio Member
 
Join Date: Jul 2009
Lot of discussion in just one day

I will try BAL-SE converter and compare it with direct connection with one phase and report the result. Transformer will not be considered at this stage.

Thanks for all the suggestion.
  Reply With Quote
Old 30th January 2013, 11:28 AM   #497
diyAudio Member
 
analog_sa's Avatar
 
Join Date: Aug 2002
Location: Sofia
Quote:
Originally Posted by glt View Post

But I agree, transformer is probably the simplest solution. Way, way back there were some recommendations for low cost (and good for audio) transformers. Anyone remembers?

Powered the monstrosity up and, no big surprise, direct connection of a summing transformer won't work. It is probably easy to trim most of the dc imbalance at the operating point by applying a parallel resistor to one of the source resistors, but that isn't the problem. As the circuit heats up the imbalance covers a range of 30-40mV, probably because the fets are only matched at the o.p.

I am certainly not an expert on cores but somewhere in the back of my mind there is some info that at least some of the more exotic cores do not take well to magnetization which can permanently alter them. So, any of the worthwhile transformers i can think of won't be too happy.

That leaves parafeed of course, for those who like it
  Reply With Quote
Old 8th February 2013, 05:47 PM   #498
diyAudio Member
 
analog_sa's Avatar
 
Join Date: Aug 2002
Location: Sofia
So, as promised i did compare the SE output to a bal to SE using a Lundahl 1676 connected as 1+1:2. In both cases no preamp was used and the following non-balanced power amp had 80k input impedance. Coupling caps were 3.3uF of Clarity MR. Due to unbalanced and unstable dc at the outputs, the transformer primary was fed through a cap as well.

In short, the SE cap only coupled output sounds much better than the transformer summed output, especially at the frequency extremes. Obviously i was biased towards this outcome and in any case it only proves that this particular Lundahl transformer is not so great in this application.

The I/V sounds very impressive - bass, dynamics and surprisingly - warmth. I am genuinely surprised that something powered from crappy 317/337 regs can sound so good. Btw, the regulators occasionally do not fire up on power-on - not sure if it's because of the large caps following them, or the high incoming DC voltage. Will replace them with 1085/1033 at fist opportunity.

Last edited by analog_sa; 8th February 2013 at 05:49 PM.
  Reply With Quote
Old 8th February 2013, 06:50 PM   #499
diyAudio Member
 
Join Date: Apr 2008
Quote:
Originally Posted by analog_sa View Post

...Btw, the regulators occasionally do not fire up on power-on...
That was a huge problem for me too, the only thing that wasn't expected... We can discuss what was done in my version, might save you some time.
  Reply With Quote
Old 8th February 2013, 07:22 PM   #500
opc is offline opc  Canada
diyAudio Member
 
opc's Avatar
 
Join Date: Oct 2004
Location: Ottawa, Ontario, Canada
Hi Guys,

I've never had this issue before with the regs. Can you elaborate on the conditions under which it is happening?

- What is the input DC voltage?
- What is the output DC voltage?
- What is the input capacitance?
- What is the output capacitance?
- What is the bypass capacitance?
- What 317/337 brand / type are you using?

Hopefully we can get to the bottom of it.

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 1760 29th December 2013 02:54 AM
Pass D1V3 DAC - build thread spzzzzkt Pass Labs 224 8th December 2012 03:40 AM
FS: Elektor Audioo DAC-2000 w/Pass labs D1 clone I/V sachi Swap Meet 4 26th November 2010 04:57 PM
IRF610 I/V convertion from Pass Labs D1 dac - single ended schiller Digital Line Level 5 15th October 2009 04:33 PM


New To Site? Need Help?

All times are GMT. The time now is 02:47 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