Just acquired a Tascam MS16 and MSR16.....Woohoo!

altruistica

Member
Last weekend I went and collected two recent purchases, an MS16 and an MSR16. I was umming and erring about dipping my toe into the analog world again after the recent demise of tape suppliers, but after watching Ebay it seems there are some suppliers of 1" tape still, but the 1/2" seems a little harder to find. I did manage to come across a seller doing some Quantegy 406 1" so I bought three reels in anticipation of getting the machine. The reels are sealed in plastic bags and after using one reel (with the machine uncalibrated) the tape itself seems fine, with no shredding or deposits being left on the heads or rollers.....really clean. I only tried one reel, but the others seem to be in the same condition so I've gone and ordered another 10 reels. The 1/2" tape I've just bought from Ebay is 3m Scotch 996 supposedly from the mid nineties. The seller has offered a refund if any of it displays SSS (sticky shred syndrome). He reckons he sold some a few months ago and the buyer was happy so we'll see once it arrives. If I seem preoccupied with tape rather than machines, it seems to me the machines are useless these days without a decent supply of useable tape.

Well onto the machines. I've ordered a new capstan roller for the MSR as it feels very spongy and a new rubber for the tacho roller as this had gone to a tar-like substance. The seller had warned of this so I was able to bid accordingly. I cleaned tar from the tacho roller. The rest of the machine looks in really good condition, but the few reels of Ampex 456 that came with the machine won't be going anywhere near it as when I tried FF them it worked ok, but on REW the machine slowed to an almost stop.....I'm hoping this is because of the tape slipping on the tacho roller and not something wrong with the machine. Once the new rollers come and the new tape I'll know more.

The MS16 is a quirky old beast. It came with the mounting trolley and the two DX-80S, DBX noise reduction units. After a thorough clean (headstock and all surfaces) I tried the new reel of Quantegy 406 on it. I'm pleased to say the tape looks fine and is not exhibiting any signs of SSS. The whole machine needs calibrating which I've never done, but after watching a few videos on YouTube and reading the manual seems like something I could tackle. The MSR came with the extender card for mounting on the audio cards during setup. Unfortunately, the MS16 didn't. It seems like this card is necessary for getting to the rear adjusting pots. Is that right?

I'm unsure as to whether the capstan roller rubber needs replacing as it seems the tape is very near the repro head when FF or REW. I made a video of this but can't post a link here because I haven't yet made 10 posts. You'll find it on YouTube under the heading 'Tascam MS16 close to repro head, new capstan roller rubber needed?'

Another problem is the DBX on channel 8 seems to be malfunctioning. I don't know yet whether I'm going to run the machine using the DBX units, but since I don't have the 'bridging connections' (that's what the jumpers are called in the manual) I have to have the DBX units wired in to produce sound out of the recorder. The manual states that setup is done with the DBX units disengaged so I can plough on with this....well I can do when I decide which MRL tape to buy.

If I want to run the machine with the Quantegy 406 tape which MRL tape should I buy? Does that depend on whether I want to hit the tape hard (like a GP9 tape) without DBX engaged or will the tape not stand this kind of abuse? All this is pretty new to me (as in, I've read a lot but don't have the actual working experience of this) so anyone who's already doing this kind of thing please chine in.

Back to the problem on channel 8, I've documented that in this video, again which you'll find on YouTube titled 'Tascam MS16 problem with DBX on one channel'

Since I don't have a full service manual (I only have a PDF of the Operational Maintenence manual) I don't know the pinouts of the DBX so can't isolate which pins are channel 8. I have had the cover of the audio unit off, and looked at the main board on the bottom of the unit. It looks fine and I didn't want to delve too deeply as the wiring is very tight and tidy and I wouldn't know which bit might be knackered (if any).

Any help or advice much appreciated.

Al
 
Ok, just read the section in the MS16 'Operation and Maintenance' manual covering alignment. One thing puzzles me?

The desk I'm going to use both the MS16 and the MSR16 with is a Soundcraft Spirit Studio 16. I only plan on using either recorder at any one time. The desk is a 16 channel in-line console with direct outs and 8 groups. The groups can feed both the group outputs and the channel direct outputs simultaneously, with group 1 going to channel direct outs 1 and 9, group 2 going to channel direct outs 2 and 10 and so on.

The group outs and direct outs, output at different levels. I plan on using the desk's 8 group outputs to go to a patchbay, normalised through to the MS16's INPUTS 1-8, with INPUTS 9-16 available on the patchbay. The MS-16's outputs will come straight into the desk on its LINE inputs. I plan on using the desk's 16 channel direct outs to go to the MSR16's inputs. The MSR16 outputs will return to the 'monitor' section of the desk. I do have patchbays and mixers available if this doesn't work, but the plan is to keep the analogue stuff on one corner of the studio, and the digital stuff on the other corner. If more tracks are needed for a project then I'll probably utilise both desks (the digital stuff is served by a Spirit 24 desk) and move some stuff to digital of which there'll be 48 tracks going into the Spirit 24 if needed. So onto my question.

When the group outputs display 0VU (there is a built-in oscillator capable of 1Khz & 10Khz tones) the group outputs measure 0.775V. The direct outputs at this stage measure 0.198V, irrespective of whether a balanced cable is used or not. This equates to -12dBu and displays on the MSR16 as approximately -5VU. The MS16 as I've received it, without setup yet is connected to the group outs of the mixer via balanced jacks going to the MS16's XLR inputs (giving out 0.775V) and the INPUT meters all read approximately 0VU. This I've understood to mean that whichever mixer the previous user had, it was the same as mine, roughly speaking. To make the MSR16 read 0VU on its meters, I have to increase the mixer's group outputs to show approximately +4VU which equates to 0.315V coming out of the direct outputs. This all makes perfect sense apart from the fact that the MS16 manual states that setup should be referenced to 1.23V.....that's the bit I don't get. Well when I say I don't get it, I do get it. Is this reference level what was the standard +4dBu that pro mixers in the past all output? If so, surely I should be setting the MS16 to the level of my current mixer. ie to 0.775V?

If the answer to that is YES, then I think I just about have understood alignment. One last thing. Will the MRL tape I buy for use with the Quantegy 406 tape I'm going to use, reference 0VU as 1.23V or as 0.775V? I've just read about 'flux densities' and my head is truly spinning now.......

Cheers
Al
 
If the answer to that is YES, then I think I just about have understood alignment. One last thing. Will the MRL tape I buy for use with the Quantegy 406 tape I'm going to use, reference 0VU as 1.23V or as 0.775V? I've just read about 'flux densities' and my head is truly spinning now.......
Al

It's too late in the evening for me to think clearly about the reference levels especially since you seem to have three different ones in the system. Someone else will have to chip in with that, I think. My gut feeling from reading your description is that the MS-16 has been adjusted to line up to 0.775V instead of 1.228V which is what I would expected for balanced XLR gear.

However, this I can answer - the MRL tape by itself has little to do with the voltage the tape deck's I/O is configured to. You can play funny games with that by calibrating the deck to +3 above the reference level, but it's easier if you just buy a tape that matches your chosen operating level and calibrate the machine so that it plays back at zero.

The first thing you have to do in picking the right MRL tape is choose an operating level (or flux density). This will depend to some extent on the tape stock you're planning to use.

The old Ampex standard was 185nWb, which is considered to be 0. Most of the TASCAM decks were set up to use 250nWb (+3) including the MSR-24 and TSR-8 so I imagine the MSR-16 is the same.
I would double-check that the MS16 is the same since it's a more industrial deck than the others, but IMHO it's a pretty safe bet.
Quantegy 406 has a maximum operating level of +3 anyway - over that it is liable to saturate, which may cause artifacts if you're using DBX.

Quantegy 456 and RMGI SM911 have a maximum of about 370 nWb (+6?), which either means you have loads of headroom if you're running at 250, or you can line up the machine to use a hotter recording level (320 or 355) - assuming the machine can handle it. Most TASCAM multitracks are intended for +3 use only since they're using DBX and there's no need to run them hotter than that.

This might be useful, especially step 2:
Now I'm Really Confused. What MRL Tape Do I Need?
 
Are the Spirit 16 group outs balanced or unbalanced?

Is your audio level meter True RMS and is it a balanced meter or unbalanced?

Read the Sprit 16 manual regarding the nominal level of the direct and group outs. You need to pay attention to whether the nominal standard employed by Soundcraft was in dBV, dBv, or dBu.

I could look that up myself but it is too late, and I'm too lazy.

Bottom line is you've got to get a grip on what standard is being utilized on the mixer end, and we need to know what kind of level meter you are using. True RMS is a must, unbalanced is fine but then realize your observed levels on a balanced output will read half of the rated level because with an unbalanced meter on a balanced output you are only reading one leg.

Once we get some answers we can corroborate what you should see. I'm fairly certain you are close already.

On another note, if the group outs are balanced I'd skip using the patchbay and direct outs and get a splitter snake to take the group outs 1-8 and connect those to MS16 inputs 1-16 (group out 1 to inputs 1&9, group out 2 to inputs 2&10, etc.)

Also, basically ditto to what jpmorris said on the cal tape...you can technically use ANY cal tape (of the given tape width desired) to calibrate to ANY standard. There ARE a couple caviats to this, but they are relatively obscure so I'll avoid that here...and of course there are limitations particularly when you start using a tape of a certain speed standard to cal a machine running a different speed...BUT IT CAN BE DONE. To keep things simple for your MS16 you want a 15ips IEC tape. 250nWb/m is ideal, but you can use that tape to setup the machine at ANY level standard (i.e. +3 tape at 185nWb/m, etc.). It's simply all about what "0" on the tape deck's meters represent with respect to fluxivity.

So there's some stuff to chew on.
 
Thanks for the replies guys.......things are becoming clearer.

From the Soundcraft manual ' the mix, group and aux outputs are ground compensated and provide an effective way of optimising noise immunity, without the cost and complexity of balanced outputs.'......'All input Tape Sends are factory set to suit -10dBV equipment. If a level of +4dBu is required the output level may be changed by removing resistors R130 / 131 from the input PCB SC2970.'

The group outputs although sounding like they are balanced (ie...push a stereo jack into them and feel two notches) are in effect mono ground compensated....the tip is 0.775V, the ring and screen ZERO, when a 1Khz tone is showing 0VU on the mixer's group output. Using an 8-way stereo jack to XLR loom this signal shows 0VU on the MS16 when INPUT is selected.

I've just realised though, that as I bought this mixer secondhand someone could have tweaked the meter calibration pots. The 16 channel one I'm going to use was NOS...so should be as it left the factory. I've just gone back to the mixer to adjust the group outputs to read 1.23V when the fader is at max (unity marking) and then re-calibrated the group meters to read 0VU.....hey presto! The direct outs (called Tape Sends in the statement above) now output a signal of 0.323 which is near enough to -10dBV which should be ideal for the MSR16's inputs.

So now when I send the mixer's new 0VU setting (1.23V) to the MS16, the input meters show a reading of roughly +3VU. So things are becoming clearer. I now decide which MRL tape to get, probably a 250nWb one as the tape I'm going to be using is Quantegy 406, which if I've read correctly is a +3 tape. If I set everything to read 0VU, that would give me zero headroom before any tape saturation....is that correct?

Cheers
Al
 
I now decide which MRL tape to get, probably a 250nWb one as the tape I'm going to be using is Quantegy 406, which if I've read correctly is a +3 tape. If I set everything to read 0VU, that would give me zero headroom before any tape saturation....is that correct?

Cheers
Al

Yes. If you push 406 past 0 in that configuration it will probably start to saturate. This may cause tracking errors if you're using DBX, though I must admit to usually playing fast and loose with DBX and high signal levels myself anyway. I guess it's something you have to try yourself and see how it sounds.
 
Cool. Now that you've cleared that up why do I still feel like a complete ignoramus.?








:facepalm::D

Because...You read something I wrote, and what you write is what you are, and what you read is what you become.

I'm very sorry for spreading ignoramosity. :drunk:

Magnetic flux is a measure of magnetic energy. Nanowebers per meter is the measurement standard we use, represented as nWb/m. Your tape deck converts AC electrical audio signal to magnetic energy (flux) to imprint on magnetic tape. Your tape deck meters measure audio signal level right? What level of flux does "0VU" on your tape deck meter represent?

Good question, yah?

That's (one primary reason) why we calibrate the machine...so we have *some* idea what level of flux is hitting tape when the meter says "0VU". If the machine is setup so "0VU" represents 355nWb/m (which is the accepted standard for +9 tape) and we put 406 on the machine, "0VU" on the meter will already be 3VU *past* the saturation point of the tape.

Couldn't we just then tune our eyes to read -6VU as our "0"? Yep. There's no magic in it...setting the tape deck's meters so "0VU" represents something known is for no other purpose than a visual convenience...that "0" mark is easy to see...usually goes from black to red on the scale, etc.

Machine setup for "0VU" equals 250nWb/m and we're running 456 and we want to hit the tape harder and get some saturation/third-order harmonic distortion? Then we push levels so the meters are averaging around maybe +2 to +3VU. No need to recalibrate assuming the machine was already lined up and biased for the tape, etc. And YES jpmorris has a good point...doing the aforementioned would not be the best idea if using dbx. Best to set the machine up with "0VU" representing 3VU buffer before the Maximum Operating Level (MOL) of the tape being used, which in the example of 456, a "+6" tape, we set "0VU" to 250nWb/m flux level.
 
Thanks for the replies guys.......things are becoming clearer.

From the Soundcraft manual ' the mix, group and aux outputs are ground compensated and provide an effective way of optimising noise immunity, without the cost and complexity of balanced outputs.'......'All input Tape Sends are factory set to suit -10dBV equipment. If a level of +4dBu is required the output level may be changed by removing resistors R130 / 131 from the input PCB SC2970.'

Yeah, just looked over your manual. You need to look at page 31 where it talks about meter mods for peak or averaging, as well as subsequent pages that talk about output and input nominal mods to the channel cards. Who knows what has been done to the mixer. With that in mind you need to avoid getting tied up trying to reconcile what the mixer meters show (since they could be tweaked), and what the tape deck meters show (because they are also adjustable and ARE LIKELY set for a particular operating level), and rely on the reading of a good audio level meter measuring a 1K tone at the output of the mixer you are setting. You never told me what meter are using. It needs to be Tue RMS measuring and capable of accurate measurement across the audio spectrum. I use an old Fluke 87. It is unbalanced. If you have a meter like this or similar plug a mono TS to mono TS cable into the group output or direct output or whatever you are checking and increase the 1K tone until your level meter shows 0.316V (-10dBv) or 1.23V (+4dBu), THEN look at what the mixer meters and the tape deck meters show. Then you'll start to have an idea what you've got currently setup and then go from there.

The Soundcraft manual is not my favorite. NO clarity as to the the nominal level for the various inputs and outputs...there are SOME answers if you into some of the operating instructions for the various trim controls, but it isn't clear like other manuals I've read.

The group outputs although sounding like they are balanced (ie...push a stereo jack into them and feel two notches) are in effect mono ground compensated....the tip is 0.775V, the ring and screen ZERO, when a 1Khz tone is showing 0VU on the mixer's group output. Using an 8-way stereo jack to XLR loom this signal shows 0VU on the MS16 when INPUT is selected.

You say the "tip is 0.775V", measured with...what?

I've just realised though, that as I bought this mixer secondhand someone could have tweaked the meter calibration pots. The 16 channel one I'm going to use was NOS...so should be as it left the factory. I've just gone back to the mixer to adjust the group outputs to read 1.23V when the fader is at max (unity marking) and then re-calibrated the group meters to read 0VU.....hey presto! The direct outs (called Tape Sends in the statement above) now output a signal of 0.323 which is near enough to -10dBV which should be ideal for the MSR16's inputs.

Now we're getting somewhere. :)

So now when I send the mixer's new 0VU setting (1.23V) to the MS16, the input meters show a reading of roughly +3VU. So things are becoming clearer. I now decide which MRL tape to get, probably a 250nWb one as the tape I'm going to be using is Quantegy 406, which if I've read correctly is a +3 tape. If I set everything to read 0VU, that would give me zero headroom before any tape saturation....is that correct?

Yes, that is correct, but as jpmorris states, not a good idea if you are planning on using the dbx, and in general, depending on the source material not the best idea anyway. Note that the tape deck meters are averaging" meters. The meter might show "0VU" but that is the average signal level, not the peak. That's what the peak LED is for which IIRC pon an MS16 lights at +12VU. So your meter might peak at 0VU on a snare drum but the peak LED keeps lighting. The meter shows you are at the MOL for 406 and your peak LED is telling you you're hitting the tape with +12 over MOL for that tape with those snare hits...all those dynamics in your source material...that's why the general practice is to set "0VU" at a point that is actually 3VU *below* the MOL point for the tape. So if you get a 250nWb/m cal tape, then set the machine up so 250nWb/m reads +3VU on the meters.

Clear as oxide?
 
Because...You read something I wrote, and what you write is what you are, and what you read is what you become.

Ummm..I'm not sure what you are implying, but I hope it's meant to be funny. Yah?

Ok Cory, thanks for all the information. Having just moved from Oregon to Michigan, I might get a chance to use that info before I'm to old to read the meters...but at least I know it's here if and when.
 
Most certainly meant to be funny...and 100% poking fun at myself. ;)

If you are reading writings of the ignoramus (me), it's bound to suck out the brains of the reader (you). :D

Dang...one less tape-hound in Oregon. :(
 
Most certainly meant to be funny...and 100% poking fun at myself.

I thought so, but I haven't recovered my sense of humor yet. The trip here was..well, let's just call it..&%^&&%^(^@!&)!!!:facepalm::D


Dang...one less tape-hound in Oregon.

Yeah, I hated to leave Oregon, but ya do what ya gotta do. In this case, it was a matter of survival. I'd go back in a heartbeat if I could afford it.

You never told me what meter are using. It needs to be Tue RMS measuring and capable of accurate measurement across the audio spectrum. I use an old Fluke 87.

Cool. I'm in the market for a multimeter. Did an ebay search...lo and behold. Unbelievable what you find there......in this case..a Fluke EXPERT..

UPDATE!!! To every rule, there are one or more exceptions. There is at least one exception to this rule. One of E-bay's expert meter sellers has informed me that the Military version of the Fluke 27, the 27/FM is a true RMS meter. (The "non military" 27 does not have the True RMS feature.) This is such a rare case that the Fluke representative that answered my question did not know that the 27/FM was a true RMS meter! So, the 27/FM is better, because it has the "true RMS" feature. Please see my section "TRUE RMS" in my main guide (linked)
Fluke Meters - Models and Series, main | eBay

I knew there were some crazy doods out there..but man...a MULTIMETER EXPERT??:eek:
whudda thunk.:facepalm:

Hey Cory...keep on posting. I read your posts all the time. I haven't posted here in a long time because of my schedule in Oregon. Now...I don't nee no stinkin schedule.:D So HERE I AM!! Btw, since I still have two MSR's, and really want to get them going again...I'll be back with my own thread...soon. Just gotta settle in a bit first. Geeezus do I hate moving.:( Anyway, thanks for the clarification. Old fart syndrome sucks. Now, I need a beer. Later:drunk:
 
Thanks Guys....being able to toss things around has got it pretty clear now the situation.

So, I need to set the VU meters on the MS16 to read +3VU using a 250nWb MRL to provide +3dB of headroom when using the Quantegy 406 tape I have....that is clear now. I won't be in a hurry to but an MRL tape through the UK dealer though....it's on their website at £557....that's probably before 20%VAT (sales tax).............Anyone in the Manchester are UK want to hire theirs out....or even better still, want to give me a hand?

Any idea what might be wrong with the DBX on channel 8....the video is on YouTube:
Tascam MS16 problem with DBX on one channel

Cheers
Al
 
Chronicle, virtual beer mug *klank* atcha. :drunk:

Altrusitica, you got it, BUT DON'T FORGET YOU NEED TO CALIBRATE THE METERS FIRST. The procedure is in the manual. Follow it. One of the very first steps in the calibration process is to inject known tone into the tape machine and adjust the meters for "0VU" to that tone. I'm talking about the MS16 here. I assume its the same for the MSR16. The Tascam manuals do a nice step-by-step of the whole procedure.

What audio level meter are you using??

Have you checked on ordering the MRL tape from somewhere here in the states? Might even end up being cheaper? Check with Wayne Gunn at Audio Village. He sells tapes made for him by MRL. They're on eBay and you can order direct. Just Google Audio Village Wayne Gunn and you should get to his website and you can inquire from there but who knows...even with shipping and customs it might be a better deal?

Regarding the track 8 dbx issue: reseat all connections to and from the DX-8DS units if you haven't already, as well as where those connections terminate at the amplifier module and the transport. Any change? No? Try swapping the I/O cabling from dbx module 1 to module 2...does the problem move to track 16? Are there plugin channel cards in the DX-8DS units? If so re-seat the track 8 card. No change? Try swapping with a good card. Does the problem follow the card? Also try reseating the track 8 amp card in the amp cage. No change? Swap the card with another card. Does the problem follow the card? Make sure you do all these swaps/switches with the machine powered off.

As a total aside, I meant to comment on a question you asked early on about using +9 tape on the MS16: you cannot properly bias +9 tapes on the MS16 without executing a mod to allow higher output from the bias amps. It involves replacing a cap on the amp cards with one of a different value. The details are floating around this forum as far as the value and the specific part to replace. I can find it if needed.
 
Cheers Sweetbeats,

In my original post I tried to add some YouTube links but you have to post at least 10 times before you can add URLs. I have documented the DBX problem on YouTube......I've done everything you suggested (moved DBX multipins...the problem went to channel 16, so the problem must be on the audio interface side not the DBX units). I changed cards but the problem stayed on channel 8 meaning once again the problem is in the wiring or the circuitry of channel 8. I've doused the multipin connector with 'deoxit' and physically had a look at the DBX cable, but if it jumps to channel 16 that means the problem is either with the circuitry of channel 8 (which I think it is) or the backplate of the multipin. The problem is, the wiring is complex and I don't want to make things worse. Without the service manual it's impossible for me to know where to start.......with it, I probably wouldn't know, but if I have a tech look at it, they're going to have to have the service manual. Has anyone got a PDF? Probably impossible as I believe there are some very large sheets of schematics....Thanks for the link to the MRL....I'll investigate that route.
As for audio level meter, I've only got a general purpose multimeter at the moment....will that do? I bought a scope off Ebay a few years ago and I think it's a dual input scope so this could check the azimuth.

I'll keep reading around. That way when I finally get to do the alignment, I be more clued up than I am now.

Cheers,
Al
 
You can't trust the audio level measurements you are reading with a general purpose multimeter. It must be a "true RMS" measuring meter, and ideally accurate access the audio spectrum. A general purpose meter I had was only reasonably accurate up to about 400Hz...not good for measuring even 1K tones.

Do the dbx cables disconnect from both ends, or only from the DX-8DS units?
 
I'm just watching a few Fluke 114 meters....they're listed as True RMS.....will they be ok?

The leads from the DBX units only have multipins on one end....the other end is moulded into the units themselves. Because I don't know what happens at the audio interface multipin it's difficult to know where the signal is dying. The signal 'dies' when DBX is engaged on Channel 8....does that mean the switch or switching circuitry is to blame? Actually it can't be, because when the DBX multipin leads are switched, the problem jumps to channel16 and the DBX unit now receiving audio from track 16 is fine....so it must be somewhere in the audio units circuitry or the multipin backplate (I think?????).

Al
 
Fluke 114 is accurate within 1% from 45-500Hz, 2% up to 1kHz, unrated beyond 1kHz. It'll *work* for checking 1kHz tones but I wouldn't use it beyond that, particularly for anything in the HF audio band. Its not really intended for audio applications. If you don't intend to do anything with it audio level-wise beyond 1kHz tones its fine, but I like that my Fluke meter is rated out to 20kHz.

What is the make and model of your "general purpose" meter?

If the problem with channel 8 follows the cabling (and channel 16 craps out and channel 8 works when the looming is swapped), my first suspect is cabling.

If it was me I'd start with pulling the covers off the amp/meter module and checking for continuity from the pins on the Hirose connectors back to where the cabling terminates in the amp/meter module just to rule out cabling. This can be done with the meter you have and just set it to ohms/resistance and check for continuity.

So you DID switch amp cards (like swapped channel 8 with channel 9) and the problem stays with channel 8?
 
You can't trust the audio level measurements you are reading with a general purpose multimeter. It must be a "true RMS"

Correct... and now days its a lot easier to find a suitable meter at low cost. Back in the day in both recording and ham radio we had to lug around these boat anchors to have a quality meter, but now this is what I use and it is spot on accuracy wise.

RadioShack 42-Range Auto/Manual Multimeter with EFD, Catalog 22-075 (Formerly 22-811)

RadioShack 42-Range Auto/Manual Multimeter with EFD : Test & meter equipment | RadioShack.com

So we have a lot more quality options at reasonable cost than ever before. The small Flukes are nice as well if they are rated for the application.
 
Hi Guys,

I thought I'd have a fresh look at the DBX problem on channel 8. To rule out it being a card problem, I swopped cards 7 and 8. The problem remained on channel 8. So then I swopped the two DBX units over. After I did this I realise the assumption I made last time was incorrect. Because the problem was now swopped to channel 16 I thought the problem must be with the mainboard in the audio unit or the backplate.....BUT I suddenly realised, although the problem had been transferred to channel 16 (track 16), this is only because of the way the DBX units name the tracks. The upshot was that the same DBX unit was giving the problem.....which then ruled out the backplate (yippee, I didn't fancy having to de-solder and resolder 60 connections!). So I took the cover off the DBX unit concerned. The first thing I noticed was one of the power connections to one of the two transistors near the power indicator LED was almost hanging off. This connector doesn't have a locking plastic lug, so I gently prized apart the pins and re-fitted it. Then I had to work out which DBX channel on the board was channel 8....by following the front panel switch. I tried some Deoxit on the switch itself and two connectors dealing with the DECODE side of the signal. Still didn't work. Then I had an idea.....if it was component problem, possibly capacitor problem (there are about ten in and around the DECODE section, then if I gently heated them up with a hairdryer, would they work for a short period.

Watch the results here:

Tascam MS16, diagnosing DBX problem on Channel 8 - YouTube

Getting nearer.......has anyone a sheet of schematics for this bit? I don't know if they'll help though!

Al
 
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