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.

H2
H2
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 26th November 2019, 05:01 PM   #421
Antoinel is offline Antoinel  United States
diyAudio Member
 
Join Date: Jan 2012
Location: Pennsylvania
H2
Quote:
Originally Posted by plasnu View Post
I'm wondering you may find something interesting if you test H2 with M/S (mid/side) encoder/decoder.
Hi plasnu. Thanks for your note. I found on the web the operation of M/S encoder/decoder [MSED]. Its language is complex, but is interesting as it deals with processing of audio signals. Worthy of study and understanding.

Best
Anton
  Reply With Quote
Old 26th November 2019, 05:32 PM   #422
Nelson Pass is offline Nelson Pass  United States
The one and only
 
Nelson Pass's Avatar
 
Join Date: Mar 2001
H2
Quote:
Originally Posted by coolnose View Post
I have contacted Pa as requested, hopefully I am worthy . That said I will start a dedicated thread for the handout so no need to let me know here as it will be hard to keep trace of everyone...
Alas, the package was rejected by Customs.

I will try again.
  Reply With Quote
Old 2nd December 2019, 08:02 PM   #423
Antoinel is offline Antoinel  United States
diyAudio Member
 
Join Date: Jan 2012
Location: Pennsylvania
H2
Default Experimenting with H2. Part 1; the System

The three attached pictures show different views of the hardware which I'll be using to experiment with H2.

The middle picture shows:

1. Sony CD player as the music source. Its line level [R and L ]outputs are channeled via the the RCA Monster Cables under it.

2. Threshold S/150 power amp; 1982 or 1983 vintage. The orange cable [3 conductor] emanating from S/150 terminates in a bank of two 30,000uF capacitors; one per rail. This external bank augments the capacitance of the original and internal PSU capacitors. Makes a difference.

3. A scope to measure the Left output of H2. I need to correlate the value of this output with the graph on page 7 of the H2 article by Mr. Pass which is entitled Distortion% Vs Output Voltage. I must know the magnitude of %H2.

4. Up front is a Realistic device which reads the power output of the L channel across the Left speaker [Polk; 4 Ohms].

The right picture shows:

1. A top view of the H2 kit and other control electronics. The right-side proto board is a stereo buffer [to H2], and a volume level adjustment to S/150. Schematic to post.

2. The output of this stereo buffer/Volume adjument circuit feeds S/150 via 2 RCA Monster Cable cables on the right side of the view.

3. The left-side protoboard has

a. A voltage source of 2 LEDs and a Zener- connected BJT to reduce the output offset voltage of S/150 [ L ch = +45 mV, R ch = + 35 mV] to +/- 1 mV. Schematic to post.

b. An independent stereo input from SONY to the right-side proto-board [buffers/volume adjustment].

This setup will allow for an exhaustive study:

1. Direct connection from Sony to S/150. Will give me the impression of Music Fundamental [MF] plus impact [if any] of [+ DC] output offsets on S/150. Reverse the loudspeaker leads.

2. Indirect [independent] connection of SONY to S/150 via the buffer circuits. Will give me the impresion of [MF] without a DC offset at outputs of S/150. The right-side picture shows this inter-connection

3. The music impressions of the two phases of H2 with and without DC offset at the outputs of S/150.


Best
Anton
Attached Images
File Type: jpg System to study H2.jpg (235.4 KB, 430 views)
File Type: jpg System to study H2b.jpg (242.6 KB, 429 views)
File Type: jpg System to studyH2a.jpg (233.1 KB, 427 views)
  Reply With Quote
Old 3rd December 2019, 08:24 PM   #424
brian92fs is offline brian92fs  United States
diyAudio Member
 
Join Date: Jan 2017
Location: Northern California
H2
Default Question on output impedance

The original article for the H2 used a 100Ω output resistor (R4) for a stated output impedance of around 400Ω. The updated article now uses a 332Ω resistor (R5). Does this mean its output impedance is closer to 630Ω? The text from the updated article appears to still reference the original circuit. Also, what was the reason for the increase?
  Reply With Quote
Old 3rd December 2019, 09:47 PM   #425
Nelson Pass is offline Nelson Pass  United States
The one and only
 
Nelson Pass's Avatar
 
Join Date: Mar 2001
H2
I decided to make all resistors multiples of 332.

Use 100 if you like.

  Reply With Quote
Old 3rd December 2019, 10:09 PM   #426
brian92fs is offline brian92fs  United States
diyAudio Member
 
Join Date: Jan 2017
Location: Northern California
H2
That's what I suspected. Thanks for the confirmation and quick reply.
  Reply With Quote
Old 4th December 2019, 05:22 PM   #427
6L6 is offline 6L6  United States
diyAudio Moderator
 
6L6's Avatar
 
Join Date: Oct 2010
Location: Denver, Colorado
H2
If you would like a 2019 H2 generator kit, please look here -

The Christmas 2019 H2 giveaway! (and BAF fundraiser)
  Reply With Quote
Old 5th December 2019, 10:20 PM   #428
craigtone is offline craigtone  United States
diyAudio Member
 
craigtone's Avatar
 
Join Date: Apr 2006
Location: Holland, MI
Got the package from papa today! I’ll PM all those on the list tomorrow with postage cost.

Thanks papa! Bringing even harmonics to the masses ...
Attached Images
File Type: jpeg DED29129-2064-4999-8757-EB6A913ECA83.jpeg (351.0 KB, 218 views)
__________________
Craigtone Audio
Soundsmith Boheme, WT Classic, OPENAMP1, Apollo-R, Burson Swing Everest, Hafler 915, TSE 45, ALK Klipschorns
  Reply With Quote
Old 6th December 2019, 07:14 PM   #429
Antoinel is offline Antoinel  United States
diyAudio Member
 
Join Date: Jan 2012
Location: Pennsylvania
H2
Default Experimenting with H2; Part 2..Impressions

The attached is the schematic [L channel] for the audio system which I described in my previous post.

Most of this schematic is in post #390. The add-on is a circuit to reduce the power amp's output DC offset [L=+45 mV, R= +36 mV] to ~+/-1 mV. It is comprised of a string of the shown diodes plus the resistor [1 Meg] which is connected to the inverting input of the last OpAmp feeding Threshold S/150.
Essentially, the resultant H2 signal at the output of this last OpAmp is riding atop a~ [-15 to -18 mV] offset. The input of S/150 does not have a coupling cap to the preceeding stage. And thus readily allows this specific tweak. A wire shown on schematic from the proto board of the circuit can be readily connected to or disconnected [on the fly] from its destination [1 Meg] on the adjacent proto-board of the buffer/volume control OpAmp circuits.

Process conditions

1. The music output of the H2 generator was adjusted on the scope to a maximum of 1.5 Vp-p. This gave a a sweep of H2 up to ~ 1% H2 as read on the graph of page 7 in the article by Mr. Pass. Outliar peaks did emerge at ~2 Vp-p. This adjustment was done with the SONY remote commander/volume control. This adjustment was not altered when comparing H2 negative phase [H2np] with H2 positive phase [H2pp] while playing the same music/disk. It was tweaked up and/or down [counted the steps] to accomodate different disks which have variable output levels.

2. The power output of S/150 was adusted to read ~0.5 W peak on the Realistic power meter. The specific location on the schematic for this power output level adjustment is at the input of the last OpAmp; which I call Volume Control. Essentially by changing the value of the resistor which is connected to ground [82 Ohms].

Impressions.

Although my H2 generator is not calibrated per the suggestion of Mr. Pass, my impressions are commensurate with those he quoted; namely:

1. The sounds of H2np and H2pp [reverse the leads of loudspeaker] are unmistakenly different.
2. The description for the sound of [H2np] by Mr. Pass as "a deeper soundstage with improved localization than otherwise" is accurate. It is also a soothing and a calming event with each disk I listened to. Preferred

3. The description for the sound of [H2pp] by Mr. Pass as "in your face with enhanced detail" is also accurate. It was a bit louder than [H2np] to my hearing, hyper and aggressive. Its soundstage was a flat brick wall. Not preferred.

Effect of Output DC Offset of S/150 on the sounds of H2.

Maybe, I need to study more. Still, take note of the DC offset at the loudspeakers. If positive in value like S/150 has, it'll move out the cone of the DC-coupled woofer. But this same positive DC offset of S/150 will pull in the cone of the woofer when reversing the loudspeaker leads to compare the H2s. This is asymmetry in each situation and can synthesize its own H2. A DC offset of +/- 50 mV may seem trivial on paper; but its effects may not be.

Drive one loudspeaker with [H2np] and the other with [H2pp].

Gave a sound which was totally different from that of each of the H2s and the music fundamental [MF]. It was literally airy/fuzzy and floated like a wide fog above the loudspeakers. A great match in the H2 performance of the L and R channels in the H2 kit will be preferfed in this experiment. But note that this resultant sound from this test does suggest, and/or confirm that the sounds of [H2np] and [H2pp] can only be intrinsically different. Otherwise the resultant sound will default to that of [H2np] or that of [H2pp].

My studies will continue by using the same audio set up; using other loudspeakers. Fascinating, fun to me and easy to do.

Best
Anton
Attached Images
File Type: png H2PreampV1a.png (29.3 KB, 187 views)

Last edited by Antoinel; 6th December 2019 at 07:16 PM.
  Reply With Quote
Old 8th December 2019, 09:48 PM   #430
xhumari is offline xhumari  France
diyAudio Member
 
Join Date: Jan 2008
In the meanwhile I got another kit, so I'm leaving my slot to someone else who's interested.

1 - craigtone
2 - etinsley
3 - jims
4 - sampsonite
5 - cpcornell
6 - dBel84
7 - R.K. Rønningstad
8 - plasnu
9 - DIMDAS
10 -
  Reply With Quote

Reply


H2Hide 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


New To Site? Need Help?

All times are GMT. The time now is 12:04 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©1999-2019 diyAudio
Wiki