Problem with ITC Delta Record Amp

[nleibo]

Hi Folks-:
I'm hoping someone with a considerable bit more knowledge than I, can help. I have an ITC Delta Record Amp (& associated Playback machine)--which I'm trying to Record onto. I have hooked up the Connector (to the Playback Unit), plugged in the A-C, hooked up appropriate Input & Output plugs. I tested the playback unit--Playback works--Play, FF, etc. Now I bulk erase a cart--insert it into the Record Amp--which is recording DIRECTLY from a MiniDisc (XLR outputs)--I set my meter to "REC", push the Record Button (RED)--see levels--I now push the Play button (listening to the cart playback on my mixer)--NOTHING--levels are still going--Nada, No Audio. Do I have a "lemon"--or am I missing some "adjustment". Keep in mind, I'm NOT an Engineer (& don't play one on TV, either --so I'm not arbitrarily messing with those circuit boards--although if someone thinks the problem is there, i would "take a shot" (given some specific details).
Thanks In Advance --especially for reading.

Neil Leibo

 

[LasVegasRadioJunky]

Could it be this simple? If the unit is as old as I suspect it is, the record head could just be really filthy. Try cleaning it with cue tips and denatured alcohol. As long as you still see residue on the cue tips, keep scrubbing.

 

[nleibo]

Thanks for your reply--so let me state what I've tried to do--so we can try & discover soem "UNcovered" ground. I've cleaned the HEADS "ad nauseum", I've RE-seated the circuit boards in the AMP unit. The PLAYBACK unit PLAYS--No problems in Playing, FF or Cueing. In attempting to record, I SEE the levels in the meter--but never HEAR anything recorded--AND the Cart just keeps recording--keep in mind it's a 40 second cart & keeps recording for MINUTES on end--so obviously no "signal" is getting thru. That's where we are--right now.

 

[RadeoEngineer]

If you have another machine which I assume you don't, then swap out the record card. Other than that, there may be some oxidation on the edge connector of the record card. You could try some deoxit on a cue tup to clean the connector and socket. If that doesn't do it it's scope time for some troubleshooting. Could be a power supply issue or a bad IC.

 

[nleibo]

I have another PLAYBACK Machine--same unit/model--ITC Delta--but I think you're referring to the Record Amp, which sadly I don't. I'll take a peek at all of the circuit cards (3)--as I'm not too sure which one the Record is--and see what I can see. On the subject of a "Power Supply" issue--then would the lights (REC, TER, SEC) NOT work--if it was a "Power Issue"?

 

[ChiefEngineer]

AHHH- If it keeps recording past the beginning then the stop tone isn't being recorded as well as program audio.

You get playback okay as well as tones so the problem is in the record side of things.

Make sure the jumper between the record amp and the playback unit are connected. You mentioned input and output but not the jumper. Without the jumper the record head is not engaged. The playback unit is also the record unit as far as the heads are concerned. make sure the playback unit has a record head and not just a blank to make sure it is record AND play. The playback only units had a place for the jumper and simply did not have record electronics.

Use a standard pencil eraser to clean gold contacts to a shiny new state.

I can't tell you how often i had to replace the capacitors in both record and playback units. Since itc hasn't been making these in 20 years? this might be an issue. And replacing just one never worked so all of them (electrolytic type) should be shotgunned. 6 or 8 and these were always cheap. Observe polarity.

 

[Tom Wells]

If the recording bias oscillator has died due to a failed cap no sound will be impressed ieven if the meters move in record mode.
Even if you can measure audio voltage at the record head.

If you have no scope to look for the recording bias signal, you may try holding a small AM radio near the recording circuit board.
A running oscillator should throw a whole lot of whistles and birdies into weak signals.

 

[nleibo]

Hi ,Chief Engineer--thanks for yuour response--that's one part I omitted--I HAVE the connector cable connected from AMP to PLayback--but what you've mentioned :>>"make sure the playback unit has a record head and not just a blank to make sure it is record AND play"<<--that COULD be the issue! How can i tell the Difference between a -">>record head and not just a blank "<<? I DO have another Playback Unit--for all I know it COULD have been part of a Record unit--so what to look for in differences between a Record head & "dummy" head? Very interesting!!!

 

[SFM-Ptgal]

A recording head is similar to a playback one. A stereo record unit will have 2 heads with 3 horizontal stripes each on their front. A playback unit will have a blank (dummy) and a striped one.

 

[nleibo]

Well, in comparing the Playback unit which came WITH the AMP unit, the "Recording" head looks very MUCH like the "Recording" head in a PLAYBACK ONLY unit I have--so I'm guessing it is a "dummy"--ergo not Recording--Hmmmm....Thanks, SFM -Ptgal, and to the rest who responded--I believe we have solved this "mystery".


NLeibo

 

[Lane_Lindstrom]

You should be able to just replace the "dummy" head with a record head. Those decks should have the wiring harness for the record head wrapped up inside. Let me know if you need one and stereo or mono.

Lane

 

[nleibo]

Thanks for the offer, Lane--will let you know--the seller has promised to "make good"--so we'll see--stay tuned

NLeibo

 

[XRQKFM]

I once bid for a Delta with record amp; despite the pictures on E-bay, the deck that arrived was a playback only without the record head. The seller refused to make good on the unit, and put the correct unit up for bid, forcing me to bid on it. Lucky for me, I won the bid and mate the proper units together! Always liking to having a back up, I got a second record amp and transport with a record head.

I have large photos showing the different between a play only and a unit with a record head, if you could use them, e-mail me: pd at xrqkfm.com include Delta Cart in the subject line and I will get them right out to you.

Update:
Going over to Engineering Tips, I see you solved the problem; I have the manual for the Delta's, If you need any information just email me

Beware of UPS and Fedx drivers: I have had both UPS and Fedx drivers toss heavy radio equipment over our 8ft security gate, rather than wait for the gate to open, despite signs warning against tossing boxes over. So far, they have killed a BE console, a couple Delta 99 cart machines and their record amps. I still don't understand what part of "Fragile DO NOT DROP" on the boxes they don't get, and the insurance never covers the loss: $16 paid out for a damaged Delta 99 record unit was an insult.


Steve
www.xrqkfm.com

 

[nleibo]

Hi XRQKFM--
You have described EXACTLY the situation I'm in--although the seller stated in an e-mail he "wants to make good" & is testing some units--being the Holiday, I'm inclined to give hima fe w days more, but I would be VERRRY interested in knowing the seller's name in YOUR transaction--and if this is perhaps the same person who tries to "pull" this sort of thing--!


NLeibo