ShibaSoku Automatic Distortion Analyzer

David,

Now that is some very good work brother.
Nice documentation and pics so DIYers can follow along.

I'm surprised that this time of year the distortion
even rises...you must be doing a bunch of stuff
up there next to Santa Claus to get them hot.

Maybe in my next lifetime I can get me a 725.

Cheers,
 
Ok I put a copy on a USB memory stick. I will post mail it to you. Looking it over briefly, you need a scope and other basic test equipment to do the alignment by the book. email your address to me.

-Richard Marsh





sky2city said:
Richard,
Can you send the sch or service manual of VP-7722 to me now.
My VP-7722 have a problem need to be re-calibrated.
I have a SHIBAKOU AC-12B, Distortion calibrator. Feed the signal of AC-12B to VP-7722, got a large distortion result. such as -60dB Distortion + Noise, but the VP-7722 says -41.36dB.
compare to another one ,HP339 says ~-60.2dB.

I thing that the VP7722 need to be re-calirated. But I don't know how to do it. since much pos. and adjustment in VP-7722.


thanks.
sky2city@2104.11.17
my Email is sky2city@163.com.
Click to expand...
 
Richard:
Use Wetransfer: https://www.wetransfer.com/ Its free and they can handle very large files. No customs issues etc. either. I have been using it to pass around big files as well. Don't go "plus" unless you really need to move or share a lot of stuff.
 
RNMarsh said:
Ok I put a copy on a USB memory stick. I will post mail it to you. Looking it over briefly, you need a scope and other basic test equipment to do the alignment by the book. email your address to me.

-Richard Marsh
Click to expand...

Richard,
So much thanks for you help. I have scope, DVM, spectrum.....

And what's the file size of manual. I just mean, Demian's advice is good advice. Posting mail form USA to China will waste much time even the cost is acceptable.
Or if it's boring for register on Wetransfer, you can send mail and attended it. My mail box support 1G bits file, should base on that your mail box support large file too.

if posting mail is the best way for you, I will give address of my friend who live in USA, then he can transfer to me by internet Disk or other quick way.

looking forward you reply...

sky2city@2104-12-09
mail:sky2city@163.com
 
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sky2city said:
Pls give me your friends address.

-RNM


if posting mail is the best way for you, I will give address of my friend who live in USA, then he can transfer to me by internet Disk or other quick way.

looking forward you reply...

sky2city@2104-12-09
mail:sky2city@163.com
Click to expand...
 
1audio said:
1KHz Shibasoku 725 + Viktor 1 KHz.PNG
Click to expand...
According to your graph, why measurement centre frequencies of 97.14 Hz, 1.987 kHz, 2.996 kHz, and 4.969 kHz ( f3 not displayed? ) ?.

Dan.
 
Dan,

Not to put words in Davids mouth, but I'm guessing he did
put the marker on screen, unless ARTA didn't show it for
some reason. I noticed that too, I just figured it was a software
issue. I clearly see it on the plot. I have to be careful
or David will be editing my posts.

If you open it up full size you can see it there.
 
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The oscillator (a tweaked Viktor) is running at about 995 Hz so all the harmonics are a little off. The 97 Hz is an oddball. Probably the same component that drives the ratio circuit as in the later units except at a lower frequency in this one. Praxis only gives you 5 markers and F3 was pretty low so I skipped it.

I use Praxis because I know how to get it to do a lot of interesting things and I own it.
 
Holy Smokes,

That IS Demian. My Bad.

Well Demian and David both start with a D,
close but no cigar, now they'll both be pissed at me. 🙂
Sorry gents.

Anyway, as I was saying...Demian,
you didn't forget F3 in poast # 216.
If you click on the image and view it full
size, you CAN see the 3 in the grass.
it is right at the top where the Frequency
says it should be.

I was wondering about that. I just figured it was
some power supply artifact
 
SyncTronX said:
Dan,

Not to put words in Davids mouth, but I'm guessing he did
put the marker on screen, unless ARTA didn't show it for
some reason. I noticed that too, I just figured it was a software
issue. I clearly see it on the plot. I have to be careful
or David will be editing my posts.

If you open it up full size you can see it there.
Click to expand...

Yes I will edit your post. it's Demian's plot.
 
Thanks for the work put in by all you and for the upgrade suggestions. I should get around to appying them to my AD725C.
 
davada said:
I thought you sold yours.
Click to expand...
No one in the UK replied. I had one reply but I wasn't keen to ship it abroad with all the costs and hassle and it is old and mightn't withstand transit and I didn't want an unhappy buyer.
Unfortunately I am in full time employment which is good for pocket money but limits free time. I am also easily distracted onto other projects.
I have spent a little time messing about with a notch filter to go with the Quant Asylum QA400 that I have but it isn't progressing far at the moment.
 
davada said:
Yes I will edit your post. it's Demian's plot.
Click to expand...
Thanks David, it seems I can neither edit nor spell check my own posts.
And if I knew how to read, I would recognize names, even other country
Avatars. I don't smoke and drink rarely now so that's not an excuse either.

David, your in B.C., this Buds for you.

I even tasted the real thing in Chesky Budwiess.

Cheers, Don't keep too warm up there either
or distortion will be on the rise.
 
Cousins

One thing missing from the AD725 is an oscillator. They sell a seperate chassis model. It is spec'ed to be better than .0001% THD. However, there is a close cousin which Includes a very low THD oscillator all in one chassis. It is sold as a Panasonic VP-7722A.

I say cousins because they are both manufactured by the same company...... Matsushita Communications Industry - Japan. You see these more often on ebay et al than the ShibaSoku. Both built to high industrial standards.

Seperate units -- osc/analyzer from ShibaSoku or one chassis from Panasonic Industrial. Both excellent units.


VP-7722A.jpg [the other VP-7722A shows .00003% THD]



THx-RNMarsh
 
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