Slamming meters and squealing sounds

[jortiz]

I've lurking for a while on this site. This is my first post. I've actually asked "Sweetbeats" a bunch of questions by PM since I got a Tascam 520 recently without the PS cable. I'm starting to have an issue with the 520 now that I haven't been able to figure out yet although I'm thinking I'm needing to get it serviced. Anyways, here is the issue.....when powering up the board (it's happened twice now) The meters are slamming and all I get is squelching/squealing sounds from the monitors. There is nothing engaged on the board, channels on, eq, trim, etc. The faders are all the way off, no input channels on. At times the meters will slam and then go down to nothing but the OL (overload) lights will come on and some will stay on and others will go off. I then turn the whole thing off and then try again. Like I said, this has only happened twice since I've had it for about 4-5 months. This morning is when it happened again. The other time I just unplugged it and waited and made sure nothing was going on with inputs, etc, and then it was back to normal until today. Is this board needing to be taken apart and looked at on the inside? What do I need to be looking for? The amp section? I know something sounds like it's going out but I'm not sure what to look for first. Any help would be appreciated. I'm sure sweet beats will chime in eventually. Thanks for any advice.

John

 

[sweetbeats]

*chime*

John, glad to see a post from ya!

I was thinking about you the other day and wondering about your power cable situation. My local Norvac Electronics shop does indeed still have a bunch of that 20-conductor non-shielded 22AWG multicore cable so if you need some let me know.

Are you direct-connecting the mixer to the power supply then?

Okay...sounds like something is feeding back on itself. I could get some really bad squeally sounds from the EQ section on a number of my mixer channels before cleaning the pots. Understand that cleaning meant removing the channel card and flushing the pots out with DeoxIT F5 through the holes in the pot body, exercising the pot and then another flush.

1. What jacks are your monitors plugged into?
2. Am I understanding correctly that the "MONITOR SELECT" switchrack (the row of switches in between the AUX faders and the STEREO A/B faders) all all in the up position?
3. Have you exercised all the pots and faders?

 

[jortiz]

*chime*

John, glad to see a post from ya!

I was thinking about you the other day and wondering about your power cable situation. My local Norvac Electronics shop does indeed still have a bunch of that 20-conductor non-shielded 22AWG multicore cable so if you need some let me know.

Are you direct-connecting the mixer to the power supply then?

Okay...sounds like something is feeding back on itself. I could get some really bad squeally sounds from the EQ section on a number of my mixer channels before cleaning the pots. Understand that cleaning meant removing the channel card and flushing the pots out with DeoxIT F5 through the holes in the pot body, exercising the pot and then another flush.

1. What jacks are your monitors plugged into?
2. Am I understanding correctly that the "MONITOR SELECT" switchrack (the row of switches in between the AUX faders and the STEREO A/B faders) all all in the up position?
3. Have you exercised all the pots and faders?

Hey Sweetbeats! Thanks for the reply. Yes I'm still direct connecting the PS straight to the board. I've gotten two female connectors from Canford (without the hoods) and that's it. I've just not gotten around to the other ideas you discussed with me. I could probably use the wire cable snake harness route though, so yes, I'd be interested in buying cable from you. You can PM me if you want.

1-my jacks outputs (ST Master A) from the console are going into a Mackie Big Knob. I just now tried going from the outputs straight to the monitors without any luck, thinking it might be the Mackie Big Knob.

2- The Monitor Select rack is not engaged but are in the "up" position. Nothing is on.

3- I haven't gotten to the point in taking deoxit to all the channels just yet, as I've been doing a bunch of recordings, (with no problems) but I have done a few because of some very scratchy pots. I've been waiting to finish recording this band and then I was going to disasemble the board for those type of things.

Thanks again for the reply. Good to hear from you! PS. I'm really envious of your monster Ampex 1000 reel to reel!!!!

 

[dodgeaspen]

Whatever you do listen to Sweet's advice, he's the man with a bunch of knowledge about this stuff. I had some issues with my mixer and NR units in the past few weeks and Sweet recommended the DeoxIT D5 and after trying it I was amazed at the difference in the way my gear works. Good luck.

 

[sweetbeats]

1. When you say you tried connecting the STEREO A jacks direct to the monitors "without any luck", do you mean there was no problem? Anything going from the Mackie unit to the M-520? Next time it is doing it (squealling), try using the STEREO B jacks...

3. When I said "exercised the pots and faders" I'm meaning without using cleaner...just turning them/sliding them back and forth. Make sure you use the DeoxIT "F5" Faderlube for pots and faders..."D5" is for metal contacts and is the proper thing to use for connectors.

Ampex MM-1000...you know its big when you have to strategize planning for how to move it. Its presently in my workshop/barn and soon needs to be moved to the garage where the studio booth lives. I'm dreading it. They are only about 100' apart but the ground surface is gravel and down a slight hill. Everything else I've been able to move in the car or hand-carry. Not so with Matilda. It is either try to get it back in the horse trailer or get some 3/4" plywood sheets and keep laying them end-to-end-to-end making a firm rolling surface as we go sort of like how the Egyptians moved pyramid blocks (albeit rolling on logs...fortunately Matilda has some hurky casters)...thought about trying to pull it with the tractor but I know something bad would happen through the gravel. It'd be funny though...I could take a picture of the MM-1000 with the garden tractor pulling it and caption it "Portastudio".

 

[jortiz]

1. When you say you tried connecting the STEREO A jacks direct to the monitors "without any luck", do you mean there was no problem? Anything going from the Mackie unit to the M-520? Next time it is doing it (squealling), try using the STEREO B jacks...

3. When I said "exercised the pots and faders" I'm meaning without using cleaner...just turning them/sliding them back and forth. Make sure you use the DeoxIT "F5" Faderlube for pots and faders..."D5" is for metal contacts and is the proper thing to use for connectors.

Ampex MM-1000...you know its big when you have to strategize planning for how to move it. Its presently in my workshop/barn and soon needs to be moved to the garage where the studio booth lives. I'm dreading it. They are only about 100' apart but the ground surface is gravel and down a slight hill. Everything else I've been able to move in the car or hand-carry. Not so with Matilda. It is either try to get it back in the horse trailer or get some 3/4" plywood sheets and keep laying them end-to-end-to-end making a firm rolling surface as we go sort of like how the Egyptians moved pyramid blocks (albeit rolling on logs...fortunately Matilda has some hurky casters)...thought about trying to pull it with the tractor but I know something bad would happen through the gravel. It'd be funny though...I could take a picture of the MM-1000 with the garden tractor pulling it and caption it "Portastudio".

I meant when I did connect from the Stereo A out directly to the monitors there was still the meters slamming and squealing. I just turned off the speakers now as not to damage them, but I still get the OL lights on. The meters will slam and then go down to the left although some meters will stay slammed. Other times the meters will go on and then all of them will go down but the peak lights will stay on (from the meter bridge) and the OL lights will go off. Then after about 30 seconds, they will slam again. Right now as I'm typing the meters are all down, but the peak lights are lit up. They have been like that for about 3 minutes. I just plugged in the speakers from Stereo B and am getting not a squeal but more like a mid frequency tone. I just tried the Mackie and the meters are not in the red but all the way up in the yellow. They were completely in the red that last time I hooked it up.

I have turned the knobs and exercised them left and right but that didn't change anything.

 

[sweetbeats]

Pull all the SEND/RCV jumpers on the channels and for the PGM groups...still wacky?

Confirm that the power supply connector is firmly and properly seated. Are the pins clean looking on the mixer connector for the power supply?

 

[jortiz]

Pull all the SEND/RCV jumpers on the channels and for the PGM groups...still wacky?

Confirm that the power supply connector is firmly and properly seated. Are the pins clean looking on the mixer connector for the power supply?

I pulled all the jumpers off and that seemed to do it. Then I got the slammed meters for a second and they went down with the peak meters lit. I then tried the PS connector and nothing really. Then I took the connector completely off, dusted off, etc. and reseated it. That worked! I've had it on for about half an hour now with nothing wacky going on. I've turned it on and off a couple times with it being normal. Thanks Sweet Beats. I guess that means I really need to look into the cable for the PS. I'll send you a PM about that. I got yours. I don't have time right now to answer. I got to get going. Thanks Sweetbeats! I guess I know what to look for if it happens again. Thanks again.

 

[sweetbeats]

Wierd stuff happens if certain supplies are not able to supply properly. I learned this when I was using a great little test light I built with instructions from member dementedchord. Well, and he was clear about this, and I was just thick-headed, but it only works up to a certain point. Once the current draw becomes too great it screws things up since the test light is basically a voltage divider which is fine for the device under test until the current left by the divide isn't enough for things to function...the device gets starved for power...so I had it hooked up to my M-520 to test for "trouble" after reinstalling some refurbished channel cards. The mixer went wacky and I freaked. Lights turning on and off, meters jumping, peak lights lit...sounds kind of like your symptoms. I thought I had cooked my M-520 but evm1024 kindly said words to the effect of "settle down, take the test light out of the power supply loop." All was fine. So that's why I thought maybe there was a bad connection.

Yes, a locking power supply umbilical would be good.

Get some DeoxIT D5 or other good-quality contact cleaner and spray it on the power supply connector, seat, reseat, make sure there is no strain on that unprotected connection and then power it up and see if it is smooth running consistently.

So the freaky meters and peak lamps are A-OK now...squealing gone too?

 

[jortiz]

Wierd stuff happens if certain supplies are not able to supply properly. I learned this when I was using a great little test light I built with instructions from member dementedchord. Well, and he was clear about this, and I was just thick-headed, but it only works up to a certain point. Once the current draw becomes too great it screws things up since the test light is basically a voltage divider which is fine for the device under test until the current left by the divide isn't enough for things to function...the device gets starved for power...so I had it hooked up to my M-520 to test for "trouble" after reinstalling some refurbished channel cards. The mixer went wacky and I freaked. Lights turning on and off, meters jumping, peak lights lit...sounds kind of like your symptoms. I thought I had cooked my M-520 but evm1024 kindly said words to the effect of "settle down, take the test light out of the power supply loop." All was fine. So that's why I thought maybe there was a bad connection.

Yes, a locking power supply umbilical would be good.

Get some DeoxIT D5 or other good-quality contact cleaner and spray it on the power supply connector, seat, reseat, make sure there is no strain on that unprotected connection and then power it up and see if it is smooth running consistently.

So the freaky meters and peak lamps are A-OK now...squealing gone too?

Yeah, it was okay after I reseated the PS cord (direct). I kept it on for a while. I just got back and powered it up again and it's still working without any problems. I did some monitoring on it and everything looks okay so far. So I guess I need to really work on getting a cable. I'll PM you about the cable. After this recording, I am still going to thoroughly go through it and DeoxIT and check all connections, etc. Thanks again.

 

[sweetbeats]

ONE MORE TASCAM MIXER SAVED ~ YAHOOOOOO!

 

[Muckelroy]

thought about trying to pull it with the tractor but I know something bad would happen through the gravel. It'd be funny though...I could take a picture of the MM-1000 with the garden tractor pulling it and caption it "Portastudio".

Cory, even if you choose to move Matilda with more practical means, you had better bust out your tractor halfway down the path, rig'er up, and take a picture. That would be f*ing hilarious!!