Anyone knows WHEN IT'S QUAD by using a Technics SH-3433 AUDIOSCOPE

Help Support QuadraphonicQuad:

scifi

500 Club - QQ All-Star
Joined
Apr 4, 2010
Messages
516
Location
US of A
The Radio Electronics article I posted is on an interface that works with a single channel oscilloscope. It connects to the vertical and horizontal inputs of the o-scope.
 

Sonik Wiz

2K Club - QQ Super Nova
QQ Supporter
Joined
May 30, 2005
Messages
2,664
Location
Kansas City
File den link doesn't work, and donpatten.com seems to be down. looking to make one of these boards, does anyone have the schematic?
Is the circuit you've been looking for?:

 

ButchDeal

Member
Joined
Sep 7, 2014
Messages
11
Is the circuit you've been looking for?:

Yes that is the one. Those should work. I thought the linked PDF from Don Patten would be a bit clear though.
Should that ADS1013D scope work?
 

Sonik Wiz

2K Club - QQ Super Nova
QQ Supporter
Joined
May 30, 2005
Messages
2,664
Location
Kansas City
Yes that is the one. Those should work. I thought the linked PDF from Don Patten would be a bit clear though.
Should that ADS1013D scope work?
Hard to say from the Amazon description. It is dual trace which doesn't hurt but you don't need. You do need X/Y input and not just a horizontal sweep. Dig a little deeper & see if it has X/Y input. Another clue is if the scope says it can display Lissajous patterns then it does have X/Y.
 

ButchDeal

Member
Joined
Sep 7, 2014
Messages
11
Hard to say from the Amazon description. It is dual trace which doesn't hurt but you don't need. You do need X/Y input and not just a horizontal sweep. Dig a little deeper & see if it has X/Y input. Another clue is if the scope says it can display Lissajous patterns then it does have X/Y.
Yes it does have Lissajous patterns capabilities.

It is pretty hard to make out the foil trace and wiring from the jpgs
 

Sonik Wiz

2K Club - QQ Super Nova
QQ Supporter
Joined
May 30, 2005
Messages
2,664
Location
Kansas City

ButchDeal

Member
Joined
Sep 7, 2014
Messages
11
Thank you that is much easier on my eyes.


I plan to do it on a perf board. Actually left over parts of a perf board I used to make an adapter to connect my Surround Master to my Marantz 4100 internal SQ decoder port.
 

Sonik Wiz

2K Club - QQ Super Nova
QQ Supporter
Joined
May 30, 2005
Messages
2,664
Location
Kansas City
Thank you that is much easier on my eyes.


I plan to do it on a perf board. Actually left over parts of a perf board I used to make an adapter to connect my Surround Master to my Marantz 4100 internal SQ decoder port.
There is a rather neglected thread here


about DIY projects. Sounds like you are pretty sharp with this stuff. If you have any cool projects, surround or not, please share!
 

doity

300 Club - QQ All-Star
Joined
Nov 29, 2014
Messages
327
This looks easy enough to make (Don’s original circuit) by someone who could make up a batch of them including the case. Maybe take pre-orders before buying some of the components to assure that it wouldn’t be a money losing proposition. Heck, at the very least they would be easy to unload on EBay with probably a tidy profit gained also.
 

Sonik Wiz

2K Club - QQ Super Nova
QQ Supporter
Joined
May 30, 2005
Messages
2,664
Location
Kansas City
This looks easy enough to make (Don’s original circuit) by someone who could make up a batch of them including the case. Maybe take pre-orders before buying some of the components to assure that it wouldn’t be a money losing proposition. Heck, at the very least they would be easy to unload on EBay with probably a tidy profit gained also.
Yuppers I've got the AES Big Blue Book of Quad with Don Patten's circuit in it. Pretty clever. If your using a CRT O'scope & can rotate the tube 45 deg than an even simpler circuit could be made.
 

Jim the Oldbie

My right elbow hurts.
Joined
Jun 6, 2015
Messages
1,080
Location
Midwest USA
Howdy Folks, Debbie Downer here with a minor caveat:

The Radio-Electronics Donald Patten circuit will only work with amplifier outputs that share a common "ground" on their minus (-) terminals. This is probably still the large majority of home AVRs and power amps being sold, but nowadays with all this newfangled Class-D etc. stuff, it's still worth checking. It's definitely NOT the case with nearly all of the car audio equipment currently sold - granted that's not a typical application, just an example that it's not unheard of in audio equipment, and this configuration may be migrating to the home market as well.

One quick way to check this is to use an ohmmeter to measure (with power turned off) between the minus (-) speaker terminals of 2 channels of your amplifier's outputs. If it measures near zero resistance, the above circuit should be OK. If you get a high resistance (or open circuit) reading, you could cause various problems (including damage) with your amp if you connect it to a common-ground circuit like the one in the article.

If you don't have access to an ohmmeter, maybe check the owner's manual for your gear. If there's any sort of bridged/floating output used, there will probably be a warning somewhere about not connecting any of the speaker wires together or something similar.

Sorry for not having any specific make/model examples of the above. Clearly I haven't been buying enough new gear lately. 😕

EDIT: This idea could be updated a bit, with differential inputs to eliminate the above issue, plus a bit more gain combined with a switchable -25 dB or so attenuator which would allow either line- or speaker-level inputs. At that point it wouldn't be difficult to add the half-wave rectification to the input buffer circuits for a bit more "precision" (and also to exchange the germanium diodes for dirt-common silicon types). Hmmm..... :unsure:
 
Last edited:

Sonik Wiz

2K Club - QQ Super Nova
QQ Supporter
Joined
May 30, 2005
Messages
2,664
Location
Kansas City
Howdy Folks, Debbie Downer here with a minor caveat:

The Radio-Electronics Donald Patten circuit will only work with amplifier outputs that share a common "ground" on their minus (-) terminals. This is probably still the large majority of home AVRs and power amps being sold, but nowadays with all this newfangled Class-D etc. stuff, it's still worth checking. It's definitely NOT the case with nearly all of the car audio equipment currently sold - granted that's not a typical application, just an example that it's not unheard of in audio equipment, and this configuration may be migrating to the home market as well.

One quick way to check this is to use an ohmmeter to measure (with power turned off) between the minus (-) speaker terminals of 2 channels of your amplifier's outputs. If it measures near zero resistance, the above circuit should be OK. If you get a high resistance (or open circuit) reading, you could cause various problems (including damage) with your amp if you connect it to a common-ground circuit like the one in the article.

If you don't have access to an ohmmeter, maybe check the owner's manual for your gear. If there's any sort of bridged/floating output used, there will probably be a warning somewhere about not connecting any of the speaker wires together or something similar.

Sorry for not having any specific make/model examples of the above. Clearly I haven't been buying enough new gear lately. :confused:
Per the original AES article:
" A simple circuit has been developed which permits an oscilloscope to be connected to the speaker lines or the 600 ohm program lines of a quadraphonic system" My emphasis. Using the 1N914 diode with only a .3V drop it would be quite suitable for line level monitoring, like the Panasonic or Heathkit.

I have thought about a circuit like this using full wave precision rectifiers that basically will have no voltage drop. The question I have never been able to suss out is does full wave show more amplitude precision than half wave ? But the latter shows better phase information?
 

Jim the Oldbie

My right elbow hurts.
Joined
Jun 6, 2015
Messages
1,080
Location
Midwest USA
Hey Mr. Wiz,

I was able to simulate the two different rectifier circuits back when I was messing around with this software thing. It looked to me as if the half-wave is still the better choice, likely for exactly the reason you mention above - it seems to retain more phase info.
 

Sonik Wiz

2K Club - QQ Super Nova
QQ Supporter
Joined
May 30, 2005
Messages
2,664
Location
Kansas City
Hey Mr. Wiz,

I was able to simulate the two different rectifier circuits back when I was messing around with this software thing. It looked to me as if the half-wave is still the better choice, likely for exactly the reason you mention above - it seems to retain more phase info.
I remember those posts! Insanely cool! I could never wade into that territory.
But I guess a take away with CRT Quad scope might be the best way is precision 1/2 wave rectification?
 

ButchDeal

Member
Joined
Sep 7, 2014
Messages
11
I like some of the other smaller scopes but few of them seem to specify that they handle Lissajous.
 

ButchDeal

Member
Joined
Sep 7, 2014
Messages
11
This looks easy enough to make (Don’s original circuit) by someone who could make up a batch of them including the case. Maybe take pre-orders before buying some of the components to assure that it wouldn’t be a money losing proposition. Heck, at the very least they would be easy to unload on EBay with probably a tidy profit gained also.
I would pay for one. Would be nice to put in a bypass switch to handle stereo and pair with recommendations on a nice scope.
 
Top