Crown SX722 ideas.

[70salesguy]

This is a big and I means big reel to reel machine. It is 85lbs. IT'S. Like the monolith from 2001 space Odyssey.

As you have found out, pictures don't convey how massive these units are.

 

[Satcom123]

Well, with the move and all. I finally got around to at least taking a picture of the unit. Yesterday I took the lower electronics unit out, (which was easy) and took it to work. I took all the pots and dissasembled them. Cleaned all the carbons and wiper arms. Lubed them. I cleaned all the ckt board potentiometers by spray contact cleaner and exersizing them, noting to put them back in their set positions. Cleaned up the face and installed it. Sounds pretty good but I don't have any half track prerecoded stuff.

 

[Satcom123]

Well I finally got around to fabricating some cables to test recording. Hooked them up as per manual but no indicated input on the VU meters or out of the headphone jacks.

I do have a burnt out light bulb inside the unit right behind the power panel. It's a W304 lamp. I just wonder if this lamp is a path for the recording ckts? There are two of them side by side. One of them is broke.

I wonder if I can jumper them?

Can anyone enlighten me on this?

 

[Satcom123]

Well I did some testing and I found out that it was the amp. I put it in FM mode and got the input VI meters to respond to an input. I then set up recording levels and recorded. I played back and only the right channel recorded.
So it looks like I need to inject a 1khz tone into the affected channel and do some probing. I cleaned all the pots on the boards. I even switched inputs but the left Chanel does not play when in playback. These are where I'm at right now.'

 

[BANDWIDTH]

Good luck with your new machine!

 

[Satcom123]

Fresh. So Im on my own. Well just as well. I just thought that some that owned one would chime in. I will at least try to document some of the things I do for helpful posterity sakes.

 

[eddisc]

give it time, Satcom: plenty of pro's here; only 24hr in a day & we sometimes need to PLAY w/our own stuff:thmbsp::yes:
(like right now for me: dubbing Edie Brickell from web to RtR to CD and surfing...HEY: WATCH THOSE LEVELS!!!!!):nono:

 

[Satcom123]

Thanks Eddisk. I posted over there at Tapeheads.

 

[Satcom123]

Here is a pic of the bulb that's broke.

 

[Satcom123]

I got some bulbs that were 28v ones. I installed them and at first I thought they worked but didn't. These bulbs do not light up like the original ones did. The tape deck does seem to brake good in fwd and rev.

Now as far as the right channel being out during playback. I found out it was a bad RCA cable I was using. I took a pair of dykes and chopped it. All that time and it was a stupid cable. :sigh:

It now records and plays back good.

Now back to the breaking bulbs. I remember when I first got the rtr, those lamps were on. They were pretty dusty so when I tried to take one of them out it broke. Does any of you that have a Crown know if these lights should be on all the time or what?

 

[Satcom123]

Well, sometimes things don't work out as is with the problem with this deck. It still exhibits problems in the right channel. I took the amp section out and inspected the left and right amp boards. Bad news. Leaky caps all over the place. They are odd caps too. 6.8uf 35v ones. I am hopping for some help in identifying these and other caps. Here are some pics. One thing I noticed was on the right amp board it has these capacitors like the one in the second pic. While on the left amp board, there are the dipped type that is shown in pic 3. And they appear to be polarized. Anyone got any ideas which type to use?

 

[Satcom123]

Here are some more pics.

 

[notsofast]

AE techron does alot vintage Crown stuff. Terry Dewickt is a very trusted audio guy. The Lansing Heritage forum has some very helpful people on it. If you get stuck on something maybe these recommendations could help.

 

[Satcom123]

Thanks for the link. I browsed it on my phone at work. Lots of stuff on there. :thmbsp: