John Curl's Blowtorch preamplifier part II - Page 2303 - diyAudio
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 10th May 2012, 06:38 PM   #23021
1audio is offline 1audio  United States
diyAudio Member
 
Join Date: Mar 2004
Location: SF Bay Area
Blog Entries: 3
Quote:
Originally Posted by vacuphile View Post
Doesn't look like a relay to me, more like one of those flat opamps like JRC makes.
The reference designator is consistent with the other relay.

I finally recognized the three inductors next to the connector, lower right corner. I thought they were power supply isolation. That is really close to the big cap which is the output connection.

I can see maybe 1 MHz max with this layout. But what constitutes correct at 1 MHz for a phono transducer?
__________________
Demian Martin
Product Design Services
  Reply With Quote
Old 10th May 2012, 06:39 PM   #23022
diyAudio Member
 
vacuphile's Avatar
 
Join Date: Apr 2011
Location: Seaside
Quote:
Originally Posted by jacco vermeulen View Post
Out of curiosity, just how long have you been into audio electronics ?

Provided you can Reed : http://img.photobucket.com/albums/v5.../hr09-084b.jpg
Long enough to have bought some of those opamps I initially thought they were in Akihabara in the beginning of the eighties.

Since you want to learn about me, let me learn about you. Have you yourself done any original electronic designs in the field of consumer or other electronics?

Last edited by vacuphile; 10th May 2012 at 06:45 PM.
  Reply With Quote
Old 10th May 2012, 06:41 PM   #23023
diyAudio Member
 
john curl's Avatar
 
Join Date: Jul 2003
Location: berkeley ca
It would not matter at a $5K price point. It could be made in the USA for about $5000 retail. There just is NOT enough in the circuitry to justify the $25,000 cost.
We, for example, are bringing out a $19,000 phono stage that has 10 times the active parts, better caps, and includes a power supply. That is still very expensive, but at least there is a lot more inside the fancy chassis.
The Soul--- design looks like a Levinson LMP-2, well engineered with IC's and cost effective parts, primarily.
  Reply With Quote
Old 10th May 2012, 06:57 PM   #23024
hags is offline hags  United States
diyAudio Member
 
Join Date: Nov 2004
Location: Chain o' Lakes
Maybe they'll claim they're recoup'ing R&D costs, like many high end cable manufacturers do.
__________________
"Some lures are designed to catch fish, others are designed to catch fisherman."
  Reply With Quote
Old 10th May 2012, 07:53 PM   #23025
bcarso is offline bcarso  United States
diyAudio Member
 
Join Date: May 2005
Location: Canoga Park, California
Quote:
Originally Posted by hags View Post
Maybe they'll claim they're recoup'ing R&D costs, like many high end cable manufacturers do.
Yes, and for having the novel and completely unprecedented idea that broad bandwidth is good
  Reply With Quote
Old 10th May 2012, 09:48 PM   #23026
diyAudio Member
 
jacco vermeulen's Avatar
 
Join Date: Oct 2004
Location: At the sea front, Rotterdam or Curaçao
Send a message via Yahoo to jacco vermeulen
Quote:
Originally Posted by vacuphile View Post
electronic designs
In the '80s, i built circuits for testing whether Reed relays deteriorated small signal audio, due to their magnetic action.
Not very original.

A Reed relay in a SIL/SIP package is at least 2.5 times thicker than a JRC SIP8, the SIL also has a roof-shape top, hard to miss on a picture.

Amusing bit, a Hamlin HE3321 A/C series now roughly costs the same amount in € as it did in Dutch Marks back then.
(i still have lots of parts in SIL, SIP6 to SIP9. By Hamlin, Günther, CP-Clare, JRC parts, uPC1237, NEC UPA63/68A, other JFETs)
__________________
The buck stops Here

Last edited by jacco vermeulen; 10th May 2012 at 10:02 PM.
  Reply With Quote
Old 10th May 2012, 10:17 PM   #23027
diyAudio Member
 
Join Date: Sep 2004
Location: UK
I have thousands of those Hamlins left over from designing Automatic Test Systems.

With cold switching they last forever and can be tight stacked on a 0.1" grid.

What did you conclude from your magnetic/audio experiments? I never saw any effect on the lowest level analog signals, apart from thermal emf effects.

But that wasn't magic audio .....
  Reply With Quote
Old 10th May 2012, 11:14 PM   #23028
diyAudio Member
 
vacuphile's Avatar
 
Join Date: Apr 2011
Location: Seaside
Quote:
Originally Posted by jacco vermeulen View Post
In the '80s, i built circuits for testing whether Reed relays deteriorated small signal audio, due to their magnetic action.
Not very original.

A Reed relay in a SIL/SIP package is at least 2.5 times thicker than a JRC SIP8, the SIL also has a roof-shape top, hard to miss on a picture.

Amusing bit, a Hamlin HE3321 A/C series now roughly costs the same amount in € as it did in Dutch Marks back then.
(i still have lots of parts in SIL, SIP6 to SIP9. By Hamlin, Günther, CP-Clare, JRC parts, uPC1237, NEC UPA63/68A, other JFETs)
Jacco,

Your post reminds me of the fact that most present on this thread are known for their technical curriculum. I have to go on a pseudo for a while, but since I have some pertinent views on a number of issues, it may be good to post what I did in the beginning of the eighties of the last century to give you some measure.

The theme was robot arms, at a time when the fax machine was a rare novelty. Since the location of the tip of the robot arm is determined by the angular rotation at the joints, precission requires rigid arm segments, Any flex introduces errors. Because rigid=heavy, this introduces an arms race between the weight of the arm segments and the motors driving them. A lot of energy is wasted in the process, and it slows down things. So, the idea was to use light weight flexible arm segments, and measure the position of the arm tip to provide feedback to the control electronics.

What I designed is the electronics to measure the 3D position of an ultrasound conducer with a precision up to 1/10th of the wavelength. Interface between Apple II, break out box with quartz timers and devider cicuits, about a hundred LSxxx logic chips, analogue signal generation and capture, software, the whole shebang. Setup worked, but not at the speeds required to provide timely feedback, plus air is a rotten medium for accurate measurements of this nature.

Anyways, this was in the eighties, I couldn't halt evolution since, and my present pass time amongst others is to figure out the best possible power supply. May be posting on this shortly,

vac
  Reply With Quote
Old 11th May 2012, 04:52 AM   #23029
Bonsai is offline Bonsai  Taiwan
diyAudio Member
 
Bonsai's Avatar
 
Join Date: Jul 2003
Location: Taipei, Taiwan
Quote:
Originally Posted by jacco vermeulen View Post
Output stages are discrete Class A, rest is opamps (and coils)
Why am I not surprised?
__________________
bonsai
Amplifier Design and Construction for MUSIC! http://hifisonix.com/
  Reply With Quote
Old 11th May 2012, 05:08 AM   #23030
Bonsai is offline Bonsai  Taiwan
diyAudio Member
 
Bonsai's Avatar
 
Join Date: Jul 2003
Location: Taipei, Taiwan
"And LOOK at what you get with a JC-1, the quality of the components, (no IC's in the audio path) . . . "

The quality of the components on that PCB look pretty ok to me. WRT IC's, if you ever spent some time inside a modern semiconductor fab John you'd understand that your statement is pretty ill informed.

It seems to me the Solution folk are the first to cotton on to the fact that you can charge >$25k for an op-amp based phono amp, while you - a discrete FET proponent - can do no better than to say your effort is worth every penny of its $2.3k charging price.
__________________
bonsai
Amplifier Design and Construction for MUSIC! http://hifisonix.com/

Last edited by Bonsai; 11th May 2012 at 05:16 AM.
  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 10:43 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