ShibaSoku Automatic Distortion Analyzer - Page 19 - diyAudio
Go Back   Home > Forums > Design & Build > Equipment & Tools

Equipment & Tools From test equipment to hand tools

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 14th April 2014, 04:42 PM   #181
RNMarsh is offline RNMarsh  United States
diyAudio Member
 
RNMarsh's Avatar
 
Join Date: May 2012
Location: 2457 Cascade Trail; Cool, CA. 95614
[QUOTE=1audio;3891311

Richards unit does have a noise problem, that my much older unit does not have. I think it relates to the post filter gain circuitry since its not real obvious in the analog outputs but I'm not sure yet.

[/QUOTE]

Thanks Demian. I bought some lower noise opamps for the filters/post filters and found the pcb that has the filters.... followed the wire from the front panel output port back to a pcb.

Its a great instrument... super accurate at measuring low harmonic levels.

-Richard
  Reply With Quote
Old 1st June 2014, 11:53 PM   #182
alemi is offline alemi  Italy
diyAudio Member
 
Join Date: Jun 2014
Location: Milano
Hi, I'm Alemi from Milan, Italy ... I wanted to know if the ShibaSoku AD725C of PChi member is still available for sale, thank you!
  Reply With Quote
Old 7th June 2014, 05:40 AM   #183
RNMarsh is offline RNMarsh  United States
diyAudio Member
 
RNMarsh's Avatar
 
Join Date: May 2012
Location: 2457 Cascade Trail; Cool, CA. 95614
Demian.

Have you made any progress on lowering the noise etc of the 725D ??

THx-Richard
  Reply With Quote
Old 8th June 2014, 06:17 AM   #184
1audio is offline 1audio  United States
diyAudio Member
 
Join Date: Mar 2004
Location: SF Bay Area
Blog Entries: 3
Ricard:
The basic noise of the 725D is about the same as the 725 and quite low. The analyzer circuit is working well and swapping a few opamps here and there helped. Getting the 20 KHz filter working better is very important. Its between the input amp and the first notch filter, it responded to opamp upgrades as well.

The monitor output noise is very much in line with what it should be. The metering circuit however has a problem and I have not figured out yet where the key circuit is. Its post filters and post distortion analysis, probably in the meter amp itself. That it doesn't change when the meter response is switched suggests its in that circuit. The older unit does not have the response control circuit so I'm flying blind.

I think it would also benefit from a DC cal of the input amps but I need an extender board to do it.
__________________
Demian Martin
Product Design Services
  Reply With Quote
Old 9th June 2014, 03:17 AM   #185
RNMarsh is offline RNMarsh  United States
diyAudio Member
 
RNMarsh's Avatar
 
Join Date: May 2012
Location: 2457 Cascade Trail; Cool, CA. 95614
I think it is on this pcb ---->

The first pcb on the left of the near center pcb gap. from front top view..... Or, follow the wire from the monitor output port to that pcb.

There is a group of pcb on the left and a gap and a larger group of pcb on the right. The first pcb of that larger, right, group of pcb.

??

-RM
  Reply With Quote
Old 12th June 2014, 02:08 PM   #186
RNMarsh is offline RNMarsh  United States
diyAudio Member
 
RNMarsh's Avatar
 
Join Date: May 2012
Location: 2457 Cascade Trail; Cool, CA. 95614
Default Analyzers for sale -

There are a couple of nice analyzers - for a very reasonable price - for sale on ebay at this time:

A gen/analyzer combo from shibasoku - model AM57A. .003% Full Scale and 0-120dB range. About $1500.

Also, a Panasonic VP7723A about the same price; .0005%/ 0-130db range.

-RNMarsh

Last edited by RNMarsh; 12th June 2014 at 02:10 PM.
  Reply With Quote
Old 12th June 2014, 02:31 PM   #187
davada is offline davada  Canada
diyAudio Member
 
Join Date: Jul 2004
Location: Fort St John, BC Canada
Quote:
Originally Posted by RNMarsh View Post
There are a couple of nice analyzers - for a very reasonable price - for sale on ebay at this time:

A gen/analyzer combo from shibasoku - model AM57A. .003% Full Scale and 0-120dB range. About $1500.

Also, a Panasonic VP7723A about the same price; .0005%/ 0-130db range.

-RNMarsh
All very tempting. Is that THD or THD+N. I probably need something that goes lower for what I'm doing. Have you been able to extend the range using DM or notch?
__________________
David.
  Reply With Quote
Old 13th June 2014, 05:28 AM   #188
RNMarsh is offline RNMarsh  United States
diyAudio Member
 
RNMarsh's Avatar
 
Join Date: May 2012
Location: 2457 Cascade Trail; Cool, CA. 95614
Quote:
Originally Posted by davada View Post
All very tempting. Is that THD or THD+N. I probably need something that goes lower for what I'm doing. Have you been able to extend the range using DM or notch?
they each measure both. But its THD spec number.

I have not tried a notch with the Panasonic --- own one.... dont own the other. With the Panasonic - it is a copy of the ShibaSoku concept and will show on loop-thru test better than spec's minimum. A notch will drop that to nothing, I guess.


-RM

Last edited by RNMarsh; 13th June 2014 at 05:34 AM.
  Reply With Quote
Old 24th June 2014, 09:46 AM   #189
diyAudio Member
 
Join Date: Dec 2008
Quote:
Originally Posted by alemi View Post
Hi, I'm Alemi from Milan, Italy ... I wanted to know if the ShibaSoku AD725C of PChi member is still available for sale, thank you!
Hi, Alemi

There is the great VP-7722A for sale on ebay at this time
__________________
www.Levelfive-Audio.com
  Reply With Quote
Old 24th June 2014, 04:17 PM   #190
RNMarsh is offline RNMarsh  United States
diyAudio Member
 
RNMarsh's Avatar
 
Join Date: May 2012
Location: 2457 Cascade Trail; Cool, CA. 95614
Quote:
Originally Posted by levelfive View Post
Hi, Alemi

There is the great VP-7722A for sale on ebay at this time
That is their best model. the one I use a lot. Highly recommended.
0-130dB distortion range. With internal source: .0001% max.



THx-RNmarsh

Last edited by RNMarsh; 24th June 2014 at 04:24 PM.
  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
Meguro MAK-6571B Automatic Distortion Meter srh Equipment & Tools 8 19th January 2014 11:01 PM
Distortion Analyzer - Again Zero Cool Equipment & Tools 4 29th June 2013 11:14 PM
ADC SS-525X Automatic Spectrum Analyzer 503Timber Swap Meet 4 13th July 2011 10:05 PM
Shibasoku Distortion Meter, UK only dhaen Swap Meet 9 21st January 2011 03:53 PM
Recommendation on Distortion Analyzer Mark245 Solid State 2 19th December 2009 10:06 AM


New To Site? Need Help?

All times are GMT. The time now is 12:25 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