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

Pass Labs This forum is dedicated to Pass Labs discussion.

Pass HPA-1, what do we know?
Pass HPA-1, what do we know?
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 2nd December 2016, 10:33 AM   #11
xrk971 is offline xrk971  United States
Got Foam?
diyAudio Member
 
xrk971's Avatar
 
Join Date: Oct 2012
Location: Metro DC area
Pass HPA-1, what do we know?
Thanks, Juma.
Component values? I assume sk170/sj74 and BC550/560's then IRF610 and IRF9610 are good?

Can TL431 and a pot and resistor be used for bias circuit?
  Reply With Quote
Old 5th December 2016, 06:17 PM   #12
jam is offline jam  United States
diyAudio Member
 
jam's Avatar
 
Join Date: May 2001
Location: Auburn, CA, USA
In is a current feedback design, the IC is used as a servo and Juma is on the right track.

Circuit design aside part of the key is the custom transformer, which surprised me in the design phase on how much transformers affect the final sound.

Jam

Last edited by jam; 5th December 2016 at 06:38 PM.
  Reply With Quote
Old 5th December 2016, 06:51 PM   #13
2 picoDumbs is offline 2 picoDumbs  Australia
diyAudio Member
 
2 picoDumbs's Avatar
 
Join Date: Sep 2013
Quote:
Originally Posted by jam View Post
part of the key is the custom transformer, which surprised me in the design phase on how much transformers affect the final sound.

Jam
Due to conducted and radiated noise or other properties?
__________________
"If you leave this point unattached to some circuitry, an ideal constant current source will emit a small lightning bolt which will travel until it connects to something." Nelson Pass
  Reply With Quote
Old 5th December 2016, 08:00 PM   #14
jam is offline jam  United States
diyAudio Member
 
jam's Avatar
 
Join Date: May 2001
Location: Auburn, CA, USA
To some degree. I went through about seven prototypes before I decided. The construction was important as well.
  Reply With Quote
Old 5th December 2016, 08:12 PM   #15
mlloyd1 is offline mlloyd1  United States
diyAudio Member
 
mlloyd1's Avatar
 
Join Date: Feb 2001
Location: Northern Iliinois
Pass HPA-1, what do we know?
Hi Jam:

Did you evaluate any R-Cores?


mlloyd1
  Reply With Quote
Old 5th December 2016, 08:20 PM   #16
2 picoDumbs is offline 2 picoDumbs  Australia
diyAudio Member
 
2 picoDumbs's Avatar
 
Join Date: Sep 2013
Quote:
Originally Posted by jam View Post
To some degree. I went through about seven prototypes before I decided. The construction was important as well.
So you're saying if you tell me you'd have to kill me?
Hahahaha
__________________
"If you leave this point unattached to some circuitry, an ideal constant current source will emit a small lightning bolt which will travel until it connects to something." Nelson Pass
  Reply With Quote
Old 5th December 2016, 08:43 PM   #17
jam is offline jam  United States
diyAudio Member
 
jam's Avatar
 
Join Date: May 2001
Location: Auburn, CA, USA
Micheal,

I have tried some R-cores before and they are quite good but I have found that a properly designed toroid is as good and has some advantages.

Last edited by jam; 5th December 2016 at 08:47 PM.
  Reply With Quote
Old 5th December 2016, 08:50 PM   #18
jam is offline jam  United States
diyAudio Member
 
jam's Avatar
 
Join Date: May 2001
Location: Auburn, CA, USA
Yeah Pico,

.........it would be Pico on the barbie!
  Reply With Quote
Old 5th December 2016, 09:33 PM   #19
Zen Mod is offline Zen Mod  Serbia
Official Court Jester
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
Pass HPA-1, what do we know?
I'm finding when I go overkill with shunt reg , I can use whatever type xformer I want
__________________
my Papa is smarter than your Nelson !
clean thread; Cook Book;PSM LS Cook Book;Baby DiyA ;Mighty ZM's Bloggg;Papatreasure;Papa... by Mighty ZM
  Reply With Quote
Old 5th December 2016, 09:47 PM   #20
jam is offline jam  United States
diyAudio Member
 
jam's Avatar
 
Join Date: May 2001
Location: Auburn, CA, USA
Hi Zen Mod,

I agree with you completely, but with the HPA-1 heat would have been an issue. I have a pre-amp prototype that I am working on that uses a shunt. I run about 1.5 time more current through the shunt than through the circuit for best sound.

A pic
Attached Images
File Type: jpg IMG_0549.JPG (169.8 KB, 721 views)

Last edited by jam; 5th December 2016 at 09:51 PM.
  Reply With Quote

Reply


Pass HPA-1, what do we know?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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
My first Desktop HPA The Coolest Headphone Systems 19 26th November 2015 05:04 PM
HPA-nxV300 & HPA-nxV300se what's the difference? pcsl999 Holton Precision Audio 14 3rd September 2013 10:24 PM
HPA-nxV101 Signature sonnya Holton Precision Audio 10 28th July 2012 08:10 AM
MI-HPA banginon Music 0 10th February 2011 04:40 AM
HPA-nxV201 Released Soon! The Saint Holton Precision Audio 5 23rd September 2009 05:33 AM


New To Site? Need Help?

All times are GMT. The time now is 02:53 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki