Go Back   Home > Forums > > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

AKSA Builders of market proven kits and modules at sound quality to rival the best in high end

Reply
 
Thread Tools Search this Thread
Old 26th September 2009, 01:41 AM   #111
Stuey is offline Stuey  Australia
diyAudio Member
 
Join Date: Mar 2006
Location: Perth, Western Australia
Quote:
Originally Posted by AKSA View Post
I will offer pcbs through Gareth on a group buy basis, but I would discourage smd because assembly is a higher level skill not normally associated with DIYers. P-A's outstanding work gives some idea of how lovely it can look! I like the idea, I really do, but leaded components are more practical for small runs and inexperienced assemblers.

Cheers,

Hugh
Firstly, thanks for doing this Hugh.

I agree with the above quote. While I need to get sorted on using SMD, if this were an SMD board I probably wouldn't bother. Through hole I may be interested.

Cheers

Stuey
  Reply With Quote
Old 26th September 2009, 01:59 AM   #112
keantoken is offline keantoken  United States
diyAudio Member
 
keantoken's Avatar
 
Join Date: Aug 2006
Location: Texas
Quote:
Originally Posted by Bigun View Post
Looks to me like the THD is too low, we don't want this to sound like an opamp do we !? - let's get that H2 up...
Your enthusiasm is admirable, but it's harder than it looks.

Tess - I replied to your Email address.

- keantoken
__________________
The Kmultiplier rail filter! -=- The Simple Kuartlotron Superbuffer!
Need something built, repaired or modded? PM me and ask what I can do!

Last edited by keantoken; 26th September 2009 at 02:02 AM.
  Reply With Quote
Old 26th September 2009, 02:00 AM   #113
MJL21193 is offline MJL21193  Canada
Account disabled at member's request
 
MJL21193's Avatar
 
Join Date: Mar 2007
Quote:
Originally Posted by Bigun View Post
Looks to me like the THD is too low, we don't want this to sound like an opamp do we !? - let's get that H2 up...
?
Quote:

A distortion is the alteration of the original shape (or other characteristic) of an object, image, sound, waveform or other form of information or representation. Distortion is usually unwanted.


H2 is higher than H3, higher order are below -125db...this is good!
  Reply With Quote
Old 26th September 2009, 02:07 AM   #114
keantoken is offline keantoken  United States
diyAudio Member
 
keantoken's Avatar
 
Join Date: Aug 2006
Location: Texas
Sometimes we want distortion in order to cover up the nastiness of the equipment that recorded/mixed the music, or whatever digital processing was made. 2nd harmonics seem to be most pleasant, so "higher H2" might not be so bad.

This circuit doesn't have a problem with H4 and above, so then any further "tweaks" would probably be to improve the ration of H2 to H3.

- keantoken
__________________
The Kmultiplier rail filter! -=- The Simple Kuartlotron Superbuffer!
Need something built, repaired or modded? PM me and ask what I can do!
  Reply With Quote
Old 26th September 2009, 02:12 AM   #115
Bigun is offline Bigun  Canada
diyAudio Member
 
Bigun's Avatar
 
Join Date: Jan 2009
Location: Waterloo, ON or Herefordshire UK
Aspen Headphone Amp
yes it is looking good, very little distortion. On the other hand, many things in life are more interesting if they aren't too pure...

I guess we'd better remember it's for headphones, -100dB is a noticeable signal, whereas for speakers it's already buried in the noise.

I'm wondering about the output cap still, 470uF looks OK but not great - again I have read headphones can have really good LF extension - what do you guys think ? Would we be better off at 1,000uF or 2,200uF ?
__________________
"The test of the machine is the satisfaction it gives you. There isn't any other test. If the machine produces tranquility it's right. If it disturbs you it's wrong until either the machine or your mind is changed." Robert M Pirsig.
  Reply With Quote
Old 26th September 2009, 02:12 AM   #116
MJL21193 is offline MJL21193  Canada
Account disabled at member's request
 
MJL21193's Avatar
 
Join Date: Mar 2007
Quote:
Originally Posted by keantoken View Post
Sometimes we want distortion in order to cover up the nastiness of the equipment that recorded/mixed the music,
I don't

I want to hear what was recorded faithfully.

My point is that the amp is exhibiting excellent qualities as is. I don't believe increasing distortion (even the "good" kind) will improve the sound.
  Reply With Quote
Old 26th September 2009, 02:13 AM   #117
keantoken is offline keantoken  United States
diyAudio Member
 
keantoken's Avatar
 
Join Date: Aug 2006
Location: Texas
Quote:
Originally Posted by Bigun View Post
For the cap multiplier, if we want to work that angle further, perhaps we should stick with the non compound version, keep it simple ?
This gets my vote. I don't see that a fancy regulator is needed, only to filter out mains noise.

- keantoken
__________________
The Kmultiplier rail filter! -=- The Simple Kuartlotron Superbuffer!
Need something built, repaired or modded? PM me and ask what I can do!
  Reply With Quote
Old 26th September 2009, 02:14 AM   #118
MJL21193 is offline MJL21193  Canada
Account disabled at member's request
 
MJL21193's Avatar
 
Join Date: Mar 2007
Quote:
Originally Posted by Bigun View Post
what do you guys think ? Would we be better off at 1,000uF or 2,200uF ?
I would use at least 1000uF - it's what I have in the sim.
  Reply With Quote
Old 26th September 2009, 02:19 AM   #119
keantoken is offline keantoken  United States
diyAudio Member
 
keantoken's Avatar
 
Join Date: Aug 2006
Location: Texas
Quote:
Originally Posted by Bigun View Post
yes it is looking good, very little distortion. On the other hand, many things in life are more interesting if they aren't too pure...

I guess we'd better remember it's for headphones, -100dB is a noticeable signal, whereas for speakers it's already buried in the noise.

I'm wondering about the output cap still, 470uF looks OK but not great - again I have read headphones can have really good LF extension - what do you guys think ? Would we be better off at 1,000uF or 2,200uF ?
Better yet, why don't we take feedback from the output side of the capacitor, with a 10k pot coming from the other side of the cap to keep offset under control? This would help cancel any capacitor distortions and it would also extend the bass even with small capacitors.

EDIT: oops, this would work with a dual supply, but it could be tough with single...

As far as the bootstrap - It would be super easy to just put two different tracks on the PCB for both options. This would also help in prototyping.

- keantoken
__________________
The Kmultiplier rail filter! -=- The Simple Kuartlotron Superbuffer!
Need something built, repaired or modded? PM me and ask what I can do!
  Reply With Quote
Old 26th September 2009, 02:26 AM   #120
keantoken is offline keantoken  United States
diyAudio Member
 
keantoken's Avatar
 
Join Date: Aug 2006
Location: Texas
Okay, here's my sim file. It's set up to run a response analysis - as you can see, the capacitor is compensated for (but because of single supply, I had to add another one..).

Downside to this is that the OPS has higher voltage swing at bass, so if the output cap is too small, we might actually clip.

- keantoken
Attached Files
File Type: txt Aspen_hdph_withCM_3.txt (10.5 KB, 34 views)
__________________
The Kmultiplier rail filter! -=- The Simple Kuartlotron Superbuffer!
Need something built, repaired or modded? PM me and ask what I can do!
  Reply With Quote

Reply


Aspen Headphone AmpHide 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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Another DAC + Headphone amp ghetto Digital Source 14 10th July 2008 04:02 PM
ESL Headphone X-former bjackson Planars & Exotics 5 19th September 2005 03:45 AM
Headphone amp audioPT Headphone Systems 5 28th September 2004 08:03 PM
Zen v4 headphone amp Rob M Headphone Systems 11 21st May 2003 12:58 AM
Aspen Amplifiers - the ASKA 100 WATT griff Solid State 25 13th April 2002 03:15 PM


New To Site? Need Help?

All times are GMT. The time now is 02:32 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©1999-2019 diyAudio
Wiki