Anyone have a spare Technics CD-4 Test Record they want to sell?

[user 19847]

I purchased a Technics SH-400 CD-4 Demodulator recently without the test record. I am looking for someone who has an extra copy of the Technics CD-4 Test Record, shown in the attached photo, that has the Carrier Crosstalk Cancellor Adjustment track to properly setup the Demodulator. Thank you!

 

[Decoder Man]

Some years ago, I purchased an SH-400. The information I received with the unit specified the test record part number as being SPR-123. One came up on eBay for $125.00 but I could not bring myself to pay that much. On a brighter note. Someone, I think was Quad Bob, wrote an article about setting the unit up without the Carrier Crosstalk Canceller. I printed it out but am unable to find it. Now that I am about to sell my unit, I'm trying to find that post so I can provide it with the unit. If I am successful, I will let you know.

 

[J. PUPSTER]

Some years ago, I purchased an SH-400. The information I received with the unit specified the test record part number as being SPR-123. One came up on eBay for $125.00 but I could not bring myself to pay that much. On a brighter note. Someone, I think was Quad Bob, wrote an article about setting the unit up without the Carrier Crosstalk Canceller. I printed it out but am unable to find it. Now that I am about to sell my unit, I'm trying to find that post so I can provide it with the unit. If I am successful, I will let you know.

If you have a SH-400 you're selling I would be very interested in a purchase. Please PM me when you're ready - thanks!

 

[Doug G.]

Here is one thread dealing with the SH-400 and the CCC adjustment in which I participated. I don't know if it the same one referenced by Decoder Man (probably not since he says it was an article) but the thrust is that the CCC adjustment isn't all that critical. The circuit has to be some kind of comparator which looks at the carrier frequency (30kHz) output of both channels from the record and the pot adjusts the level of the channel of interest so it is minimum when the other channel is playing the carrier on its groove wall.

https://www.quadraphonicquad.com/forums/threads/technics-sh-400-and-the-ccc.30222/
Doug

 

[user 19847]

Some years ago, I purchased an SH-400. The information I received with the unit specified the test record part number as being SPR-123. One came up on eBay for $125.00 but I could not bring myself to pay that much. On a brighter note. Someone, I think was Quad Bob, wrote an article about setting the unit up without the Carrier Crosstalk Canceller. I printed it out but am unable to find it. Now that I am about to sell my unit, I'm trying to find that post so I can provide it with the unit. If I am successful, I will let you know.

Thank you!

 

[Doug G.]

Also, here is a post from Lou Dorren (I guess he's kind of an authority on the subject, huh. ), several years ago, about the (un)necessity of the CCC circuit:

"Hello Quad people,

Ress4278, Carrier crosstalk cancellation was an idea that I argued against with the Technics engineers. It is not needed and does run afoul the operations of the FM carrier limiters and the AM rejection of the QSI5022. The demodulators do not need this because the capture ratio of the QSI5022 and the new demodulator. Capture ratio is the ability of an FM system to capture the stronger of two signals on the same frequency and is measured as a dB ratio between the two signal strengths. The smaller the ratio the better the capture ratio. The QSI5022 had a capture ratio of 1.4dB, the new demodulator simulation comes in at .6 dB. How this works is that the separation of the cartridge in the sub-channel frequencies for good CD-4 cartridges is between 5 and 25 dB. With the low capture ratios of the QSI5022 and the new demodulator, they effectively reject the opposite groove wall 30KHz carrier which is 5 to 25 dB lower then the on groove wall carrier. The capture ratio of the QSI5022 is probably why some non CD-4 cartridges give some CD-4 performance.
So, no Carrier Cancellation Controls, but there will be 2 real time carrier level meters so you can see the actual carrier level of each channel.

Quadzilla, Does your Tate require phono level or line level? Does it have R.I.A.A eq built in?

Lou Dorren"

 

[user 19847]

Also, here is a post from Lou Dorren (I guess he's kind of an authority on the subject, huh. ), several years ago, about the (un)necessity of the CCC circuit:

"Hello Quad people,

Ress4278, Carrier crosstalk cancellation was an idea that I argued against with the Technics engineers. It is not needed and does run afoul the operations of the FM carrier limiters and the AM rejection of the QSI5022. The demodulators do not need this because the capture ratio of the QSI5022 and the new demodulator. Capture ratio is the ability of an FM system to capture the stronger of two signals on the same frequency and is measured as a dB ratio between the two signal strengths. The smaller the ratio the better the capture ratio. The QSI5022 had a capture ratio of 1.4dB, the new demodulator simulation comes in at .6 dB. How this works is that the separation of the cartridge in the sub-channel frequencies for good CD-4 cartridges is between 5 and 25 dB. With the low capture ratios of the QSI5022 and the new demodulator, they effectively reject the opposite groove wall 30KHz carrier which is 5 to 25 dB lower then the on groove wall carrier. The capture ratio of the QSI5022 is probably why some non CD-4 cartridges give some CD-4 performance.
So, no Carrier Cancellation Controls, but there will be 2 real time carrier level meters so you can see the actual carrier level of each channel.

Quadzilla, Does your Tate require phono level or line level? Does it have R.I.A.A eq built in?

Lou Dorren"

Thank you Doug.

 

[gvl_guy]

I have a question for SH-400 owners/users. (I have one, too.) I noticed that I pop out the adjustment controls, do whatever adjustments needed and it's all good. Then, I push in the control knobs and the meters go back down.

Do the adjustment knobs for carrier and separation need to remain out for it to work with the manual adjustments? I'm thinking when I push them back in it goes into some kind of "automatic adjustment" mode.

Any clarification would be very helpful. Thanks!

 

[user 19847]

I have a question for SH-400 owners/users. (I have one, too.) I noticed that I pop out the adjustment controls, do whatever adjustments needed and it's all good. Then, I push in the control knobs and the meters go back down.

Do the adjustment knobs for carrier and separation need to remain out for it to work with the manual adjustments? I'm thinking when I push them back in it goes into some kind of "automatic adjustment" mode.

Any clarification would be very helpful. Thanks!

Here is the operating manual for the SH-400, procedures call for pushing the knobs back in after making the adjustments to prevent the knobs from being turned after they are set.

 

[Doug G.]

The meter goes back down when the control(s) are pushed back in because the meter is disconnected from whatever control was being adjusted. The meter only indicates for the control that is extended. It will indicate for more than one control being extended at one time but it won't be correct. You only want one control out at a time.

I want to add that the SH-400 is, for me, the funnest/easiest demodulator to use because of the meter and all controls right on the front. When adjusting separation, you don't have to listen to the back channels. You can just adjust the separation controls and look at the meter for a minimum indication. The carrier level is just set so the meter pointer is within the thicker black line. No need to listen for the "cleanest' signal which doesn't really mean much, anyway.

You can adjust the carrier level "on the fly" while a record is playing by extending the appropriate control and adjusting even though, with this demodulator, the carrier level is pretty much automatically controlled by the QSI5022 chips, or, I should say, the chips accept a wide range of carrier levels and still function correctly. as Lou has explained in previous posts. I have found this to be true. This demodulator doesn't really need to have the carrier level set and was a point of contention between Lou and the Japanese engineers.

The only thing I wish the SH-400 had that it doesn't is discrete inputs and a setting for that. I have to use my SE-405 for my Blu-Ray player.

Doug