Return of the vacuum tube sonic hologram generator - diyAudio
Go Back   Home > Forums > Amplifiers > Tubes / Valves

Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum

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 April 2006, 07:54 AM   #1
diyAudio Member
 
Join Date: Nov 2003
Location: flyover country
Default Return of the vacuum tube sonic hologram generator

I recently resurrected my vacuum tube sonic hologram generator project after recently firing it up after several years and noting to my surprise that everything I had built in it still worked.

It uses inverted crossfed audio delayed much the same way as the Carver circuit does, but what I recently discovered is that when I had designed the delay to be 200uS, it was actually more delay than Carver used for his crossfed channels, which apparently varied from 60 - 140 uS depending on the particular design. I may actually reduce the crossfeed delay slightly, having learned this. The delay was accomplished, btw, with four cascaded 2nd order all pass filters. In the photograph, you can see the JW Miller air core chokes that I stacked to save space. If anybody has a C9 schematic, I'd be interested in getting hold of an electronic copy.

In the photo, you won't see any vacuum tubes, even though there are 12 of them in the 1U chassis. That's because I mounted them inside solid 1.5" pieces of aluminum (at left and right) which I had drilled out and tapped for tube sockets mounted on rubber grommets. The tubes can be accessed by removing the 'heatsink' covers. The two tube positions toward the front of the chassis on each side are HV vacuum tube regulator using a tube reference - one for each channel. I'm using solid state regulation for all tube filaments. One thing I must say for this type of construction, besides being a lot of trouble, is that it really cuts way down on microphonics.

I did some thinking about frequency shaping for the sonic hologram effect and realized that I probably had not been frequency shaping the right way when I had originally built it so I recently made some changes here that seem to have some promise. One problem is that I haven't been able to find good head masking response measurements - just a mathcad simulation that may be overly simplified, but does seem to have some validity. When I adapted the frequency shaping in accordance with these curves, the sense of depth layering is considerably accentuated and the mono or center image is more stable, both good things, at least so far.

I also had reserved a tube on each side to be sort of a phonograph tick and popdelay and analog switch for a future enhancement using a solid state tick and pop filter detector which I never built. Since I still enjoy LPs, I may yet try to get something together here since my LPs aren't getting any quieter
Attached Images
File Type: jpg sh3.jpg (95.1 KB, 357 views)
  Reply With Quote
Old 3rd April 2006, 05:50 AM   #2
diyAudio Member
 
Join Date: Nov 2003
Location: flyover country
Update: I pulled some data online including schematic for the Burwen TNE7000 (which data wasn't readily available when I built the tube sonic hologram generator) and I think there's a decent chance that I can adapt the control circuit to my design but using a dual triode as an analog switch instead of jfets. I have a little trick circuit to cancel charge injection also.

In case this might seem a bit confusing - the idea here is to do a tube sonic hologram generator AND a tick and pop remover in the same chassis. Either one can be disabled if desired by setting front panel controls appropriately.

Dont' think Richard Burwen would mind - not like I'm gonna cut into his sales at this point in time
  Reply With Quote
Old 9th November 2011, 08:41 PM   #3
4krow is offline 4krow  United States
diyAudio Member
 
Join Date: Nov 2011
Finally! someone who has built SH tube unit! I know that this was an old post, but I hope you can answer some questions. Thx, Greg
  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
Carver C-9 sonic hologram thingy Jimmy154 Swap Meet 7 4th October 2010 04:11 PM
WTB: Vacuum Tube Tester mrdon Swap Meet 0 22nd May 2009 04:01 AM
S3E Vacuum Tube angsuman Tubes / Valves 12 15th March 2008 05:12 AM
Vacuum Tube Pre O.C.L. gianmaria Tubes / Valves 13 16th February 2006 06:32 PM
DIY Vacuum tube amp turbo_h4 Tubes / Valves 2 1st July 2004 01:48 AM


New To Site? Need Help?

All times are GMT. The time now is 11:04 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