Go Back   Home > Forums > Member Areas > The Lounge

The Lounge A place to talk about almost anything but politics and religion.

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 3rd October 2012, 04:32 PM   #27951
diyAudio Member
 
john curl's Avatar
 
Join Date: Jul 2003
Location: berkeley ca
I find that a middle of the road design philosophy works best with Parasound. That is: A good balanced topology (if possible) running as hot as is prudent, even if it requires extra heat sinks, however, not truly all Class A, with power amps, but in A-B with as much current as possible in the output devices, without overheating the heatsink. Everything else all the way back to the input runs in truly Class A in operation. This is because I want to minimize any higher order nonlinearities, as much as possible, open loop. Class A in the driver circuits is important in this quest. For my preamps, ALL Class A, including the output. NO, Class AB, or Class B. My preamps run relatively hot, if I can make it that way. Works for me, gives me Class A reviews and appreciation for my efforts by serious listeners.
Feedback is an added 'compromise'. IF I could, I would use less negative feedback, but the distortion numbers start to rise, and look bad, on paper. Only Ayre, at this time, to my knowledge, does it in a more ideal way, BUT their distortion specs are necessarily worse. However their sonic success, often, is better than mine.
  Reply With Quote
Old 3rd October 2012, 08:12 PM   #27952
PMA is offline PMA  Europe
diyAudio Member
 
PMA's Avatar
 
Join Date: Apr 2002
Location: Prague
Audio Research - REF 5 preamp.
__________________
Pavel Macura
http://web.telecom.cz/macura/audiopage.html
  Reply With Quote
Old 3rd October 2012, 11:02 PM   #27953
diyAudio Member
 
Johnloudb's Avatar
 
Join Date: Feb 2008
"The REF5 is only the second Reference preamplifier to have its main board laid out horizontally, after the REF Phono2, with its transformers off the board and mounted on the sides of the chassis. The new audio circuit is fully balanced, pure Class-A triode, with zero feedback. The tube complement includes four 6H30s in the analog stage, with a 6550 and a 6H30 in the power supply. Massive energy storage, the most of any Reference preamplifier, provides tremendous dynamic capability. Total gain is 12dB via the balanced outputs and 6dB via the single-ended outputs."

Audio Research REFERENCE 5 Vacuum Tube Line-Stage Preamplifier

But tubes don't count!
__________________
My Website: Hyperacusis, Tinnitus, My Story
  Reply With Quote
Old 4th October 2012, 12:00 AM   #27954
bcarso is offline bcarso  United States
diyAudio Member
 
Join Date: May 2005
Location: Canoga Park, California
Quote:
Originally Posted by Johnloudb View Post
"The REF5 is only the second Reference preamplifier to have its main board laid out horizontally, after the REF Phono2, with its transformers off the board and mounted on the sides of the chassis. The new audio circuit is fully balanced, pure Class-A triode, with zero feedback. The tube complement includes four 6H30s in the analog stage, with a 6550 and a 6H30 in the power supply. Massive energy storage, the most of any Reference preamplifier, provides tremendous dynamic capability. Total gain is 12dB via the balanced outputs and 6dB via the single-ended outputs."

Audio Research REFERENCE 5 Vacuum Tube Line-Stage Preamplifier

But tubes don't count!
Well, 6H30s can be pretty quiet, especially if one is weighting things to reduce low frequency noise contributions, running at modest gains, and not making anything worse otherwise. And running balanced at once reduces even order distortions to the extent devices are matched.

Massive energy storage in the power supply. That would be one to be able to discriminate aurally. Or not
  Reply With Quote
Old 4th October 2012, 12:16 AM   #27955
fas42 is offline fas42  Australia
diyAudio Member
 
fas42's Avatar
 
Join Date: Jun 2012
Location: NSW, Australia
Blog Entries: 9
One of the "everything matters" is making the power supply as perfect as possible, to be an ideal, Spice type of voltage source. So massive overkill there is one approach to getting there, a sledgehammer technique ...

Frank
  Reply With Quote
Old 4th October 2012, 02:28 AM   #27956
diyAudio Member
 
john curl's Avatar
 
Join Date: Jul 2003
Location: berkeley ca
I consider the Ref 5 a serious contender in hi end hi fi. Gee Wiz! They actually prefer an open loop design like the CTC Blowtorch, the Ayre, or even the Audible Illusions line amp.
  Reply With Quote
Old 4th October 2012, 03:14 AM   #27957
diyAudio Member
 
Join Date: May 2005
Location: toronto
How do 4 tubes in the audio path and 2 in the regulator circuit end up costing $12,000? Must be the 4 of $2,900 teflon caps................
  Reply With Quote
Old 4th October 2012, 03:31 AM   #27958
diyAudio Member
 
john curl's Avatar
 
Join Date: Jul 2003
Location: berkeley ca
You should try building something of that quality, sometime. It gets expensive.
  Reply With Quote
Old 4th October 2012, 06:08 AM   #27959
fas42 is offline fas42  Australia
diyAudio Member
 
fas42's Avatar
 
Join Date: Jun 2012
Location: NSW, Australia
Blog Entries: 9
I was doing some surfing of YouTube, to find an example of what the end goal is in audio, and this is the best sample I found so far, by Kenrick Sound: Manfrotto FIG RIG 595B test video - REY AUDIO RM-7V in KENRICK SOUND showroom - YouTube. This is worth watching through to the end, to see how the sound fills the room even when the recorder is completely unaligned, in the extreme sense, to the sweet spot.

This is a group of people who "get it", who understand what's possible, which is why they keep moving the video POV throughout the shoot -- apart from demo'ing the steadycam ...

Frank

Last edited by fas42; 4th October 2012 at 06:27 AM.
  Reply With Quote
Old 4th October 2012, 09:22 AM   #27960
diyAudio Member
 
Join Date: Nov 2011
Quote:
Originally Posted by ticknpop View Post
How do 4 tubes in the audio path and 2 in the regulator circuit end up costing $12,000? Must be the 4 of $2,900 teflon caps................
This is what I usually tell my customers when they start asking similar questions - when you go dining to the 5-star restaurant you don't expect to be charged basic prices for the raw "materials" (water, salt, meat, vegetables etc.). Why should it be different in audio?
  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



New To Site? Need Help?

All times are GMT. The time now is 02:22 PM.


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