Thanks for your answer, Don. 2009/9/6 Donald Put <[email protected]>
> Jose, > >> >> I've just recently taken the maintenance of a Neotek Series II 16 channel >> console. I'm just opening it to see its state. For what I've been able to >> see, It was manufactured in the second half of 1980 or in 1981. I've asked >> Sytek about recommendations on its refurbishment, and was answered that they >> no longer support it. Later I knew of this list, and would like some advice >> on the task I've taken. >> > > Yes, Mike doesn't stock parts for this console anymore, but, luckily, there > are only a few captive items that aren't off-the-shelf. Most are available > from electronics suppliers. Unfortunately, a few of the potentiometers fall > into the category of unobtainium. > > Going to the point. I've seen that in the low-pass, low-mid band pass, mid >> high band pass and high pass filters for each channel, Neotek used 5 track >> potentiometers. I'm concerned about the wear on them, and, therefore, ways >> to replace them. Are there direct replacements of this kind of pots? If I >> need to use something else (the resistive element of another pot) to >> reburbish them, ¿what do you recommend?, linear?, log? >> > > The guy I bought my Series II from purchased all the remaining EQ pots for > these consoles from Sytek years ago, and I'm not sure if later styles from > the Elite or Elon will work or not. Maybe some of the other techs who have > more experience with these boards will chime in. > > There are five components to the original pots: two swiches and three > potentiometers. I have refurbished some of mine, but then went ahead and > bought all the new stock from the guy I bought my console from, so I ended > up just replacing all the EQ pots on the first 16 channels. This left me > with a few spares as needed in other areas. I figured that I will own this > console until I'm no longer recording, so I just went ahead and did the > replacement. I also like the newer pots because they have center detents. > > As for refurbishing the old pots, it can be done. The resistive elements > are 50K log, and I found that they cleaned up nicely and were OK and quiet > when I put them back in the circuit. I was a LOT of work, though, and I > think I'd only do this as needed. Check out the Caig products line for some > good stuff to use to clean them up and relube them. I think you can do a > pretty passable job without taking the pots apart (I disassembled mine), but > I think removing them from the PCB will make it a lot easier to get a good > shot of cleaner/lube in there. The pots are mounted with the openings > facing the PCB, which doesn't leave a lot of room to get the hose in there > to do a proper flush out. > > Well, I've done dismantling and cleaning of pots before, being these more complex than previous attempts will mean more time, but still there's the matter of the integrity of the resistive track. I've seen that previous maintenances included remotion from PCB, but they don't seem to ave been dismantled before. > Brian from Electric Audio was checking on some new pan pots, but I think > the supplier he was dealing with never really followed up. If Brian is > still reading this list perhaps he can give us any new info if he has any. > > I'm going to hand draw schematics of the wiring of this particular console, >> and since I'm seeing single layer PCB's, I have the intention of drawing the >> schematics of individual channels, ghost and master blocks. Are there >> available related drawings? >> > > Mike at Sytek will sell you a full set of schematics for your console, so > it might be worth contacting him. There were a few different designs so > you'll need the numbers off of your PCBs. I might have some that are > relevant to your console, and I'd be happy to share them if that's the > case. > I've already done the drawing for the power supply. It was modified at a maintenance almost 10 years ago. It may not keep "original" in shape, but the way it was done kept the supply noise very low. My main concern was a possible short due to a broken pin that I was notified about before seeing it the first time, but it looks in good shape. The channels PCB's are: Main: 480001-02, Aux: 480002-01 > > I'm going to recap where needed. Any brand you recommend? Any opposition to >> tantalum caps? >> > > I'd recap the whole console including the power supply if it hasn't been > done before. It's false economy to replace as needed in a console this > old. I recapped my whole board a few years back and have never had it go > down since. It's as solid as a rock and VERY quiet. > > As for brands, I used Nichinon UPW 105 degree C everywhere I could, and > other Nichinon models in places where bipolar caps were required. Panasonic > also make a nice electrolytic cap and some folks prefer them to the > Nichinon. Whichever product you decide to use, I'd make sure and get 105 > rated caps because they don't cost much more and they handle heat better. > > I also think on avoiding false economy, I was thinking more in the line of replacing those that were not replaced in earlier maintenances. I saw a bunch less than 10 years old in many places. On other non audio related projects I've used also Elna electrolytics. Once I got 125°C rated ones, for a circuit that had to stand a very tough environment. Surpassed easily UL and CSA standards. > As for tants, I can't recall running across any in my board. If I had, I > would've replaced them with newer versions of the same or did some > upgrading. I wouldn't use tants in place of any electrolytic. > > >> As for now I think these are the questions that cover most of the issues I >> already have, any more questions that arise, I will ask them at their time. >> Thanks in advance to all for your help. >> > > Good luck! These are amazing consoles when they're performing up to spec. > and they're really easy to work on. Neotek got it right all those years > ago, and I'm more than pleased with my Series II. > > Cheers, > -- > Don > > Thanks again for the response. I'm concentrating on the actual shape and broken wiring that I'm seeing. Juan José.
