Tape sync questions

[Brian Roth]

@RoadrunnerOZ Wow, a 36 input 5106! I used to maintain one of those but the owner gave up on it because every #^^$# Dialistat pushbutton was failing....broken latches and/or glitchy contacts. At one point, he bought 100's of replacements before the switches were discontinued but I eventually ran out. Owner was also getting "grumpy" <g> paying me for the constant maintenance. He replaced the desk with a Neotek Elan.

Bri

 

[RoadrunnerOZ]

@RoadrunnerOZ Wow, a 36 input 5106! I used to maintain one of those but the owner gave up on it because every #^^$# Dialistat pushbutton was failing....broken latches and/or glitchy contacts. At one point, he bought 100's of replacements before the switches were discontinued but I eventually ran out. Owner was also getting "grumpy" <g> paying me for the constant maintenance. He replaced the desk with a Neotek Elan.

Bri

I found a way to repair the Dialistat switches - we got new latches made from Delrin - the latch tips break off or deform causing the switch to fail. The switches don’t need to be removed on the channel card to repair - just remove the cap, circlip, spring and U cover - pull out the latch bits and put in a new one. Also the sliding contacts never seem to fail, they just need a good clean with Deoxit D5 or for extreme clean D100 and then flush with CO Contact cleaner - but I have a bag full of spare switch parts if they do fail.
Going in on Friday to replace some more latches. I also found a way of repairing the rotary switch pots by drilling the rivet tops, dismantling the switch cleaning the contact areas and increasing the tension on the spring contact elements.
Picture of a new latch and a dismantled rotary switch-pot:

 

[Brian Roth]

OMG...I forgot about the Jean Renaud (?) rotaries! Those were becoming a disaster as well. Bottom line, the studio owner was completely tired of paying me to constantly repair/replace switches, and then having other ones soon fail in the middle of a session after the latest round of repairs.

Box of toothpicks sat on the desk to "latch" the Dialistat switch failure du jour. <g>

Bri

 

[Brian Roth]

Forgot to mention....the desk sat idle most of the year. It was primarily used for recording an annual two day live blues show to a pair of 1/2" 2 track ATR-100's. The studio/venue was (is) in an old gothic-style church. Yes, the control room had (has) a totally modern HVAC system.

Bri

 

[RoadrunnerOZ]

yes, i will listen to your advice and look for a synchronizer which might be able to connect with my machine. Maybe that's my best bet. Would have been much easier if the machine had a built in microprocessor that could read SMPTE, like those from my (perhaps not universally true) experience very unreliable half inch 16 track fostex's.

Oh, you had a 90-16? Cool! Agreeing about the Ampex likeness. The round buttons and all. Also bears some visual similarity with the MCI machines. The electronics is also quite silent – lower noise floor than my 85-16.

Off topic, but I'm posting a pic of my buddies:

I notice you have 2 tape machines in the photo - are you intending to sync them both?

 

[RoadrunnerOZ]

OMG...I forgot about the Jean Renaud (?) rotaries! Those were becoming a disaster as well. Bottom line, the studio owner was completely tired of paying me to constantly repair/replace switches, and then having other ones soon fail in the middle of a session after the latest round of repairs.

Box of toothpicks sat on the desk to "latch" the Dialistat switch failure du jour. <g>

Bri

We use cable tie ends to hold down dodgy switches - we kept all the ends from when I made new power supplies for the Neve (the old linear supplies were noisy, hot and failing). I put all the new supplies in 2 rack drawers with switch on the front and a Super quiet 6dBA fan in the back.

 

[Brian Roth]

Oh well, I don't have that desk "under my care" any more <g>. It had been purchased as used (I recall from perhaps the ESPN TV network??) in the late 1990's. I became involved with it circa 2006, a month or so prior to the annual Blues Masters live show when I was hired to make it function as well as possible. Every year afterwards, I was again hired just before the annual show and fought with it again.

Internal heat was another part of its eventual downfall. It had been recapped a year or three before I was involved. Even those 105C Panasonic lytics were dying by the end of the 2000 decade.

Whatever....it was an interesting desk with many good attributes. I always thought the "orange pumpkin" toroid audio transformers down in the audio cards in the belly looked cool! <g>

Bri

 

[RoadrunnerOZ]

Yeah we took some of the spare transformers and put them in the rack for general purpose use - cabled with XLR I/O - about 8 IIRC.

 

[RoadrunnerOZ]

We’ve also noticed the desk runs cooler and sounds better since replacing the power supplies and recapping all the channel cards and supply rails in the desk

 

[EmilFrid]

I notice you have 2 tape machines in the photo - are you intending to sync them both?

No i don't intend to do that. I don't understand the need for more than 16 channels. The other machine is there in case of a catastrophic breakdown.

 

[Michael Tibes]

I'm not sure if the concept of synchronisation has been broken down in all the replies yet, so here is my take on it, hoping to make things clearer:
You want one system to follow another system as exact as possible. Follow means constantly regulating the slaved system (which may be a DAW or tape machine or Videoplayer or...) or have both systems follow the same reference (typically a video sync pulse).

It is important to understand the difference between full and start synchronisation. Start synchronisation will only be exact at one moment: when the slave is started in sync. The slave could typically be a DAW reading timecode from a tape machine and starting at a certain time. It will start fine, but it won't follow the slight variations in speed the tape machine will have. How big these variations are will depend on luck. I believe this is what reaper might be able to do without additional hardware.

In order to really be in sync the DAW can use a synchroniser which creates a wordclock from the incoming timecode, following the inconsistencies. There were several devices on the market for that, I remember something like the digidesign smpte slave driver or C-Lab time machine. If you get lucky those can be found second hand for little money. None of the units I know worked perfectly though.
One could also use the DAW as master and have the tape machine follow, though that is way more difficult for several reasons. One is that the synchronizer units from back in the day were very complicated to program, then they were made to sync tape based machines which do not only read timecode but also tacho and directional information from the machines in order to locate the slave. A DAW won't provide these informations, so the tape won't wind back when you jump to the song start on your DAW. These units are also pretty old and I have seen only very few on the market over the past decades.

The topic is very complicated, so my question would be what the real use case is? Record drums to tape, then dump them into the DAW to edit? No need for synchrosation ;-) Otherwise I would use he tape machine as master, locate with it's locator and use a synchroniser like the timemachine to have the DAW follow the tape. It should work flawless in theory, practical problems are word clock jitter and how exact the time transmission works. If I recall correct the smpte slave driver used MIDI to transmit the time information, which is obviously not ideal. A later version of the timemachine which was built for Steinberg used timecode embedded in a digital audio signal, which is as exact as it can be.

 

[RoadrunnerOZ]

The OP already has sync working with the DAW chasing SMPTE now, originally using MTC but that had issues, Reaper is configured to either sync to MTC or SMPTE without the need for a synchroniser. The idea was to possibly sync a tape machine using Reaper as a master - but Reaper doesn’t issue play, record, stop, rewind, fast forward or any capstan pulse information so a synchroniser would be needed that can issue those intelligently from a simple SMPTE code read from Reaper. Problem here is when you mouse click a DAW to a new location it doesn’t issue any new SMPTE position until you start play. Sync using DAW as master is nice in theory but unless the DAW is written to provide all the needed info it ends up being fraught with problems. All these issues have been discussed throughout this thread.

 

[aurt]

The OP already has sync working with the DAW chasing SMPTE now, originally using MTC but that had issues, Reaper is configured to either sync to MTC or SMPTE without the need for a synchroniser. The idea was to possibly sync a tape machine using Reaper as a master - but Reaper doesn’t issue play, record, stop, rewind, fast forward or any capstan pulse information so a synchroniser would be needed that can issue those intelligently from a simple SMPTE code read from Reaper. Problem here is when you mouse click a DAW to a new location it doesn’t issue any new SMPTE position until you start play. Sync using DAW as master is nice in theory but unless the DAW is written to provide all the needed info it ends up being fraught with problems. All these issues have been discussed throughout this thread.

This was the joy of the MicroLynx back in the day. It would see and control Pro Tools as the TC generator in its heirarchy. It sent WC via BNC and, I believe translated MTC and control signals through the old Apple printer cable, to Tools. All you had to do was set the master machine to Gen, and Bob's your uncle. Using other synchronizers, I quickly found that locating in Tools required a quick burst in play to get the tape machine to locate. Not the end of the world, but not as nice as just having a box that would tell the machine where to go as soon as.

 

[aurt]

I found a way to repair the Dialistat switches - we got new latches made from Delrin - the latch tips break off or deform causing the switch to fail. The switches don’t need to be removed on the channel card to repair - just remove the cap, circlip, spring and U cover - pull out the latch bits and put in a new one. Also the sliding contacts never seem to fail, they just need a good clean with Deoxit D5 or for extreme clean D100 and then flush with CO Contact cleaner - but I have a bag full of spare switch parts if they do fail.
Going in on Friday to replace some more latches. I also found a way of repairing the rotary switch pots by drilling the rivet tops, dismantling the switch cleaning the contact areas and increasing the tension on the spring contact elements.
Picture of a new latch and a dismantled rotary switch-pot:

I used to swipe the latches from the SSL routing cards that had one broken one out of the four, back when I had a VR (and an SSL) to look after. Then I found out that Neve actually had the latches remade, much as you did, and I could order from them. Helps to grease them when you put them in, too. Just a touch of something thick.

 

[RoadrunnerOZ]

I used to swipe the latches from the SSL routing cards that had one broken one out of the four, back when I had a VR (and an SSL) to look after. Then I found out that Neve actually had the latches remade, much as you did, and I could order from them. Helps to grease them when you put them in, too. Just a touch of something thick.

Unfortunately the latches have a limited life. We got some that were injection moulded but they’ve started to deteriorate so now the new ones are CNC machined from Delrin. They’re only 5mm long and 2mm tip to back and the pin about 1mm dia and fiddly to work with - I’ve refined a system to get them replaced in less than 20min - the double PCBs have to be removed from the card chassis and split and the other board lifted to access the switches to dismantle.

 

[aurt]

Unfortunately the latches have a limited life. We got some that were injection moulded but they’ve started to deteriorate so now the new ones are CNC machined from Delrin. They’re only 5mm long and 2mm tip to back and the pin about 1mm dia and fiddly to work with - I’ve refined a system to get them replaced in less than 20min - the double PCBs have to be removed from the card chassis and split and the other board lifted to access the switches to dismantle.

On the VR, iirc, only one half of the cards were able to be fixed without pulling the switches. I don't remember which side was which, but all down the channel the left or right of the butterfly cards you could finagle the chassis off and get to the latch, but the other side was mounted latch side to the board, so, nah. #$^*%$$#^$#.

 

[RoadrunnerOZ]

Only 1 switch on the Neve I’m working on now in one of the channels I found had been soldered in latch side down - all the rest latch up so repairable without removing the switch. You have to be careful not to pull out the carrier too far or bye-bye spring slide contacts - did that one or two times but with a bag full of spares, who cares.

 

[RoadrunnerOZ]

I wonder what inspired the colour scheme on these - battleship grey paintwork and knob top coloured inserts reminiscent of military parts, aircraft type recessed countersunk bolts and nuts to hold the buckets together.

 

[Brian Roth]

Speaking of those old Neves....

When I was servicing the one here, another (apparently) heat related failure (besides the lytics) were....for lack of a better name....were the multiple "ribbon cables" that interconnected various PC boards stacked inside the modules.

I call them ribbons but they had a wide spacing between conductors, which were wide/flat metal strips. They were encased in a sandwich of clear plastic material. The "glue" holding them together failed. If you had to fold back the PC boards for servicing, the clear plastic fell off.

Those modules were like little toaster ovens internally! 10000000 NE5534 opamps per module <g>.

Bri

 

[RoadrunnerOZ]

I’ve been using thick double sided tape - removing the plastic insulation sheets that fall off, using the clean outer surface of the insulators (too hard to clean off the crumbly old adhesive) to tape to and swapping front sheet for rear and sticking them back on over the flat wires - the tape adhesive grabs well to itself through the gaps in the flat conductors.