Guest Steven1963 Posted April 18, 2014 Share Posted April 18, 2014 Hello everyone! I recently picked up a pair of Lascalas and finally had a reason to dig out some old DBX gear I had when I was in the Military in Europe. I kept 2 pieces from a system I had from back in the 80's that included some pretty high end gear at the time (DBX amp and preamp, Nakamichi Dragon tape deck, etc..). Those pieces are a subharmonic synthesizer and a range expander (pictured). Well, the years have taken their toll and they've developed some quirks. Mainly, the subharmonic synthesizer has some issues at the RCA plugs. all things being perfect, it works flawless. BUT, sometimes the right speaker will cut out completely or have a low buzzing sound. If I touch (and mean touch lightly) on the cable at the plug, I can affect the buzz and/or bring the speaker back. So my question is (if anybody knows), is this something I can easily fix by cracking open the case and resoldering some old connections or is something more complicated in play here? I really, really am attached to these pieces. Emotionally even (weird, I know). And I don't want to exclude them from the loop if at all possible. So any input anyone might have is greatly appreciated! Steve Quote Link to comment Share on other sites More sharing options...
beeker Posted April 18, 2014 Share Posted April 18, 2014 call dbx. when you open a synthesizer it will actually look farely simple. thats why i recomend calling dbx directly. they may say oh my an oldie but the techs(tech support)will guide you and very likely help you so easily. if not report back and somebody may have experience with those particular units...maybe call 2 or 3 times to get a long lasting tech who has been there a while. nice units. no worries. they are well worth your time to get them operating properly. cheers 1 Quote Link to comment Share on other sites More sharing options...
Don Richard Posted April 18, 2014 Share Posted April 18, 2014 You probably have issues with dirty switches and potentiometers. Spray some contact cleaner on them and also the RCA jacks. Work the switches and pots, blow them dry, and see if the problem is still there. Quote Link to comment Share on other sites More sharing options...
garyrc Posted April 18, 2014 Share Posted April 18, 2014 ... the subharmonic synthesizer has some issues at the RCA plugs. all things being perfect, it works flawless. BUT, sometimes the right speaker will cut out completely or have a low buzzing sound. If I touch (and mean touch lightly) on the cable at the plug, I can affect the buzz and/or bring the speaker back. Careful! Keep a volume control that comes AFTER the subharmonic synthesizer turned way down (almost off) until you fix the RCA plug. As PWK once said, no fuse (including a fast blow) can operate fast enough to protect a speaker against the hammer blow of an RCA plug being disconnected or connected (if after the volume control, such as between a preamp and an amp). He hoped for the day that these plugs would no longer be on our equipment, but not much luck so far. Quote Link to comment Share on other sites More sharing options...
WMcD Posted April 18, 2014 Share Posted April 18, 2014 I would first look at the cable and RCA connector. These can be subject to corrosion and a loose fit. I don't know whether your RCA's are old or new. Either can have problems. A very competent buddy of mine went out and bought monster cable RCAs and there was a problem with his set up. It turned out that the sleeve connector on the RCA plug was so stiff that it was not fully engaging the collar because it could not be pushed in enough. (It is difficult to decide what gender to assign to these descriptions. Smile.) So much for the virtue of new "super wire". Only once did I have a problem with the innards of a unit. It was a Sony FM Walkman (about the size of a pack of cigarettes and a wonderful receiver). Wiggling the headphone mini-plug would solve a connection problem and it really seemed like the wires of the headphone leading to the mini-plug were broken / intermittent. But the headphones did not have the problem with other units. I opened up the Sony and upon close examination one of the solder joints leading to the headphone jack was cracked. It really still puzzles me how something as malleable as solder can crack. But it does. Note the design probably did subject it to fatigue. A quick touch of a soldering iron solved it. I throw out the episode to say that there is remote possibility there is an internal problem. But your units have probably not been the subject of such reversing stress. Again. I think you should take a very close look at the wire connector. Very nice units, BTW. WMcD Quote Link to comment Share on other sites More sharing options...
Guest Steven1963 Posted April 19, 2014 Share Posted April 19, 2014 After some additional troubleshooting, it's definitely the RCA connector on the back of the subharmonic synthesizer. I'll go to radio shack tomorrow and see if they've got one I can replace it with. Hopefully it's not too much hassle for me to pull out and solder back in. Thanks for the replies. Quote Link to comment Share on other sites More sharing options...
Frzninvt Posted April 21, 2014 Share Posted April 21, 2014 (edited) No need to replace the RCA jacks you just need to reflow the solder on the PCB. Common issue. Those DBX components were not built nor designed by the current DBX Pro company that is owned by Harman International they will not be of much help. They were made by the long defunct DBX consumer group that went under in 1990. The weak spots are the bypass, and pre & post buttons on the front. Remove the six screws from the sides and take the top cover off and spray some Caig's DeOxit into the switches and work them real good. Do this for the potentiometer controls as well. The PCB in the 120X-DS will have to come out or be tilted up to reflow the solder joints for the RCA's but it is not to tough a job to do. I have .pdf service manuals and user manuals for those units if you need them. If you have any questions on those DBX units you can ask me as I know the complete history of the company and have owned and worked on just about every piece of their gear. My favorites are the -DS (Digital Series) components. If you are daisy chaining them the 120X-DS should be first in the path followed by the 3BX-DS. When adjusted and used properly they make a world of difference. Today's recordings are so over saturated the 3BX-DS can work wonders in taming them. They 120X-DS can recover the bass that the recording engineers decided to rob from you. Especially like the older AC/DC and any recording that is bass shy. I even used a DBX 3BX-DS in my IASCA car audio competition days. Blew the judges away! No one knew what it was. Edited April 21, 2014 by Frzninvt Quote Link to comment Share on other sites More sharing options...
Guest Steven1963 Posted April 21, 2014 Share Posted April 21, 2014 (edited) Frzninvt: YOU are a god-send! Thank you so much for the information! I'll do this as soon as I get home from work. So nice to have such helpful people who are familiar with gear like this. I cannot thank you enough! And yes I agree when you say these items can bring out some very nice qualities in the music. I've already got the 120 torn apart on the kitchen table - I'll let you know how my re-solder efforts go. Also, are you familiar with their equalizer from the same time period? Sorry I cannot remember the model, but it was a kick *** EQ and I'd like to see if I can find one for sale. Thanks again! Steve EDIT: I just reviewed your gear list and I think you have that EQ listed...Man I miss that thing. Edited April 21, 2014 by Steven1963 Quote Link to comment Share on other sites More sharing options...
Frzninvt Posted April 21, 2014 Share Posted April 21, 2014 (edited) DBX made two equalizers that matched the other DS components the 2015G and the totally awesome 14/10 computerized equalizer. If you haven't already you need to slightly remove the uber sticky tape along the top end of the front fascia to get to the tiny allen screws that hold the adjustment dials on. Pay strict attention to their orientation when taking them off so you get them in the same spot when you put them back on. I see you have an EQ also you want that last in the chain. They will sound better if you use a DBX 200XG or 400XG signal router to connect them rather than daisy-chaining them. 14/10's do come through eBay but not that often and sell for $300 - $500 depending on condition & completeness. You want one with the original mic otherwise the RTA features will be useless. You cannot use any old mic because the equalizer sends voltage to the mic and the circuit can be easily damaged if the wrong mic is plugged in. There are also two versions of the DBX 14/10 the early version (1986 model) will illuminate a "64" in db field the display when powered up. The second and more desirable version (1987-1989) will illuminate a "---" specs were improved and it could read line voltage, then toggle to SPL level when the mic was plugged in. I have service and user manuals for them as well. There is also a website that a guy in France made and I provided 80% of the info he has posted. See here: http://vintagedbx.free.fr/dbx.html This site should have everything you might need for reference material including nice color cut sheets on the components. Edited April 21, 2014 by Frzninvt Quote Link to comment Share on other sites More sharing options...
Guest Steven1963 Posted April 21, 2014 Share Posted April 21, 2014 Great resource thanks! and for all of the information you've given me - you've been very helpful! Steve Quote Link to comment Share on other sites More sharing options...
babadono Posted April 21, 2014 Share Posted April 21, 2014 My DBX 3BX had cracked solder joints on the PCB where the RCA jacks soldered into it. I caught it in time as the foil had not yet broken. The way DBX attached the connectors on the back panel was cheesy, it is no wonder the solder got cracked. But hey we're talking a 30 year old piece of gear! I love what the dynamic range expander can do. Quiet the softer passages and open up the louder ones. It is a mystery to me why someone doesn't make a digital implementation of this type of gear in this day and age. 1 Quote Link to comment Share on other sites More sharing options...
Guest Steven1963 Posted April 22, 2014 Share Posted April 22, 2014 My problem is solved! Much thanks to Frzninvt for providing the solution. I re-soldered the old connections and it works like new. I will eventually pick up some of that Caig's DeOxit spray but right now I am not having issues with push buttons or knobs. I am so relieved and so happy to be part of a community that is so forthcoming with solutions. Thanks to all who contributed I very much appreciate all the input. But a special thanks, again, to Frzninvt. Steve Quote Link to comment Share on other sites More sharing options...
edriz Posted March 7, 2018 Share Posted March 7, 2018 I had the same issue with my 3BX-DS. Once I fixed the bad solder joint, since I was already in there, I gave it a nice Deoxit bath, then hit the contacts with fader Lube. Keeps them nice and shiny and lubed. I use a DBX 1231 EQ, 3BX-DS and the 120X-DS Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.