Cardas Frequency Sweep and Burn-In Record

[Gene C 1,748]

Just picked up a test record from Needle Doctor for $28.00 with intent on testing the TT with an O-Scope. Want to make sure both channels are square even though everything sounds perfect, just wont know for sure unless I see it.  So, anyone here do that before? Going to do some research but was hoping I could pick a few brains here while I do that. Thanks.

[dennismiller55 4,809]

Which test record did you get?  I have a brand new HIFI News Test LP.  Side 2 has a couple of tracks that are 400hz at 15 db on both channels.

 

I am sure your test lp has some similar tracks.  Just look for a track with steady tone with equal recorded levels on both channels.  Connect your oscope to your tape out (or external processor out) on the pre.  You don't want to use any of the preamps outputs after the line amps and tone controls.  Sync both channels on the scope with the same level and display.  Also make sure the channels level controls are in the Cal position.  While observing both channels move trace b up and over trace a.  If they are in phase and of the same level the display should completely hide the other and look like one trace.  

[danowood 2,167]

What a fantastic idea, Wish you were state farm (like a good neighbor) we'd have fun on this block LOL

[Gene C 1,748]

Thanks Dennis. Here's the link Cardas Frequency Sweep and Burn-In Record, couldn't see myself spending more than that. Saw one on there for $100.00 with no reviews.  

 

BTW Dennis, do I have to come off the Sunfire to test? There's a pre-stage in between the Sunfire. So wouldn't it be better to come off the pre-stage or just the TT itself?

[dennismiller55 4,809]

I forgot you use an external TT preamp.  Yes just connect your scope to these outputs.  If your TT preamp has RCA output jacks you will need 2 BNC to RCA adaptors.  That way you can use two RCA to RCA interconnects to hook up to the scope inputs.

 

 

 

 

 

I found a track list for your test lp at DisCogs .  

 

It looks like track A8 (1 kHz Triangle Wave -14 db, Both Channels, In Phase) could tell you a lot about your setup.  When viewing this track on the scope the sides of the triangle (saw tooth) should be flat on both sides.  If they are not it might indicate a problem with your cartridge, interconnects, or your TT preamp.  I would suspect a problem if the trace has shark fin shape.

 

Track A9 (1 kHz, -14 db, Both Channels, In Phase) could also be used to verify the right and left levels.

 

The other tracks are interesting.  I would have to read the instructions on the lp cover to understand how to use them.  Looks like a great test lp. 

 

 

 

 

Hope this helps. 

[danowood 2,167]

epay has them for about 26.00 too   http://www.ebay.com/itm/cardas-frequency-sweep-and-burn-in-RECORD-33-1-3-RPM-/141134030536?pt=Music_on_Vinyl&hash=item20dc3e66c8#ht_1522wt_1362

 

Would like to see what tests results look like.  I may have to find a occiliscope and do some simular testing.... one of these days lOL

[Gene C 1,748]

The test record showed up an hour ago so just got around to checking the 1khz test tone with the scope to see how everything lined up. Looks good but the other tests on the record will have to wait, some butthole at the office fucked up so now I have to go back in for an hour and fix a mistake.

 

How'd I do? sorry for the blurry picts, didn't want flash on.

 

 

 

[dennismiller55 4,809]

It looks like your scope also gives you an empirical value of both channels in addition to the sweep.  Mine does not.  Both signals are equal and in phase with each other.  It looks good to me.

 

[Gene C 1,748]

Thanks Dennis. The ADS1102 is a good digital scope for my novice needs. Did not get a chance to pick my dad's brain when he was out here last summer so its been slow learning with this scope. But for what little I know it works great.

 

Here's the display during a full signal sweep, was around 1 or 2 kHz when the photo was taken. Think my ears cut out at 18khz.

 

In all I'm impressed with this test record. It told me what I knew but just wanted to make sure, ya know.