Going Mobile Project

[ecc83]

Well actually, since the pinch roller is a passive idler, it is actually better to have the pinch roller contact to the oxide side of the tape. The pinch roller does not drive the tape, it merely, under pressure, conforms or wraps the tape around a small portion of the circumference of the capstan shaft to increase the frictional coefficient between the capstan shaft and the tape, so the shaft can drive the tape. So the Philips compact cassette format transport is correct as far as the tape drive itself and the consideration of more gentle tape handling.

Never thought about that! Makes abundant sense.

Dave.

 

[bachelorb]

Two things that are unusual to me with the dropouts.

1. Most times when I hear dropouts they are momentary, like a second or so and usually on one channel. The fact that the volume drop lasts several seconds and occurs on both channels makes me wonder if the tape is somehow skewing off track and then recovering some time later. I couldn't really tell if the highs dropped off a lot, they seemed to, but it might be an illusion because of the volume drop.

My bad TR.... I transfer our churches messages to their website. I use Audacity and just dump it to a stereo track. The track I recorded was only one channel..... I really need to do better at this....

2. Is it possible that the head on the 234 is somehow been pitted on the surface? If it is significantly rougher than normal that could cause it to scrape oxide off the tape. It may need to be polished. If you have a really good magnifier, perhaps you could look at the surface to see if it is as smooth and shiny as the 134. I used to work with chrome plated printing cylinders and have seen cases where the surface has pitting which looks like the chrome is almost frosted in worst cases. Since the only things upstream of the playback head is the erase head and tape guides, you might look at those surfaces also. It almost sounds like something is rough and "sanding down" the oxide layer.

I will look at this!! It is a possibility. Looking at it with a magnifying glass, I can tell something is not the same. I'll try to get a picture of it.

 

[bachelorb]

So Today, I am waiting on parts..... I am really anxious to get the Tascam 134 together, but since I can't and I am going to have to pull the 234 out of my "rack", I decided to take a look at my whole desk.

For those who don't know I took a gigantic roll around TV out of a cabinet. Cut the cabinet down, and that serves as my Tascam 312B desk and rack for everything else.

The reason I do this is I have no friends and when its time to record, I roll the whole desk around so I can check levels while I'm sitting in the recording area. It really has worked out well except for a couple of small issues. #1-I have a separate amplifier for my monitors that I need to keep unhooking whenever I roll it around.....and #2- probably the biggest reason I figured I needed to do something was this

Seems like they don't make press board like they used to....... Since that area was cracked, I decided to cut out the middle shelf (which was the bottom of the tv cabinet and extend the space down as one rack into the old VCR area.

This would end up increasing my space the old 7U rack, to the new 9U rack. One slot is going to go for a power amplifier to power the monitors. The other slot I think I am going to use for a preamp for the mics...... well.... it sure didn't take me long to fill those two things up

So here's what I ended up with:

The beauty of this is I can remove the rack from the desk easily. If we decide to travel, I can take the rack along with my little 6 channel mixer into the motorhome. Everything will be self contained.

I do have a question though. When you are laying out your rack, do you tend to stagger things affected by heat (like an amplifier or tape player) with patchbays so you get more airspace, or is this not a concern

Thanks,
Brad

 

[bachelorb]

So Today's progress ....and question of course.....

Today after Easter festivities and a bit of construction cleanup, I finally got around to Starting to reassemble the desk. I've decided to put my insert patchbay on the bottom. It's the least used, and my power management strip goes in next. Everything would be ok putting the power distribution unit on the bottom except for all the dadblame adapters my effects and preamps need. Those definitely take up more than one rack slot, so instead of arraigning for convenience , I have to think about that. No big deal because the number of times I've used the insert patchbay in 3 plus years is exactly zero.
If I leave the spot blank though, its just a temptress, and my temptation has been working overtime lately.

So here's today's progress.

I also did my part to stimulate the economy today. I bought another compressor, a two channel amplifier, and a bluetube preamp. I'm excited about finishing this part of the project, but I'm not excited about the beating about the face and neck I'm gonna get when everything shows up Friday.....

Question of the Day: What do y'all do about cable management inside the rack?

Thanks, as always.......

Brad

 

[sweetbeats]

That looks much better, Brad.

I do a number of things for cable management at the back of the rack, though I often don't worry about it too much since its at the back, and hopefully I'm not needing to access it frequently. Some racks have braces at the sides you can run cables in between the brace and the outer panel of the rack. You can also install rack rails in the back of the rack and mount rack-mountable cable management panels. There are also self-adhesive or screw-mount plastic pads you can mount to the sides of the rack that accept zip-ties. Harbor Freight is a great place to get zip ties for cheap. I've also found rolls of 50 velcro straps for cheap at Home Depot. More often than not this is a huge help just bundling stuff together in logical groups with zip ties or velcro straps. A good place to get ideas on what is available for cable management is to go to an IT site like CDW and search cable management. The bigger the rack, the greater an issue it is...especially when its a rack with multiple 96-point TT patchbays. For smaller racks I often find simply using zip ties or velcro straps goes a long way to clean things up, and then if you want to support bundles over to the sides of the rack you can use any kind of screw-mount hook you can get at the hardware store or those plastic pads, or get fancy and rack up cable management panels at the back of the rack. Those are some ideas.

 

[bachelorb]

For smaller racks I often find simply using zip ties or velcro straps goes a long way to clean things up, and then if you want to support bundles over to the sides of the rack you can use any kind of screw-mount hook you can get at the hardware store or those plastic pads, or get fancy and rack up cable management panels at the back of the rack. Those are some ideas.

Thanks SB.... My crafty wife has just handed over some velcro loops she gets her twine in. They may do the trick.

Good Day Yesterday. Not a hardware day per se as I'm still waiting on parts, but more of a software day. I'm changing over to a hybrid system. Still have my outboard stuff, but I really want to learn a DAW. I decided on Cakewalk. Mostly because it was free, but also because I tried two others (Reaper, and N-Track) that I couldn't really wrap my head around......Anyway..... I pulled out my Tascam US800 I bought for the task a couple of years ago when I had a Linux system, downloaded the drivers, and hooked it up to my Portastudio.... and.....

The coolest thing (in my mind ) is this melodyne that came with Cakewalk. I am a very amateur guitar player and singer. This melodyne straightened my voice right on out. I couldn't believe it!!! Now I'm bumping up to 60 years old, and don't plan on taking voice lessons anytime soon, so for me..... This is a game changer!!! I've got a basic handle on the Cakewalk DAW, and managed to mix everything (....real basic here......) in the box.

Today, The goal is outputs from the Tascam US800 back to the desk. First I have to see what I've got. The US800 has two line outs, two headphone jacks, and a digital out that I had bought a D/A converter for a couple of years ago. I think I can use these outputs back out of the audio interface and to the desk....at least the manual says I can....

If anyone is keeping up..... three days until the packages arrive and the beatings begin.......

 

[bachelorb]

What could possibly keep me busy all day, but at the end of the day accomplishing nothing???

Three words HALF NORMALED PATCHBAY (and not realizing it was one)

 

[bachelorb]

I just can't figure it out. I'm about to take the tape deck out and see whats happening better. It happens on multiple channels, and at random places and it goes and comes.

Here's a youtube video of the drum track I was having problems with. The drum track was recorded directly off garageband from my iPad. You can hear how bad the fluctuations are throughout, but especially at around 50 seconds.

I wanted to close this one out. I haven't figured out an answer, but I have had the problem with three different tape decks, and three different tape manufacturers. I did an experiment where I recorded the same drum pattern directly onto three three different machines (Tascam 134, 234, and 424) and onto 3 different cassette tapes (National Audio (Type II), Delta Media (Type II), and Sony (Normal Bias). All 9 Tracks had dropouts on them. All the dropouts were random throughout the 9 tracks.

My setup is Iphone Garageband track -> Headphone out -> Recording device Line In. The Garageband track sounds fine when I listen to it on the iPhone. I'm really at a loss on this one. I haven't tried it, but I'm driving the recording levels pretty hard. Maybe back off on the recording levels???

This one has me buffaloed. I went back and listened to tracks where I recorded live instruments and there are no dropouts that I can tell by ear (including one last week). I'm thinking now the decks are fine.

Brad

 

[sr71rules]

Hmm. Try and rule out the tape machines. Can you record it back into a PC, or other mobile device? If that works, you know it's something between phone and tape machine?

Did you put your phone into Airplane mode and switch off Bluetooth and WiFi? Could be the system muting audio for notifications, etc...

It also could be RF noise demagnetizing the tape, or the head, while recording?

Very interesting.

 

[bachelorb]

I haven’t tried recording it directly to the PC. I’ll give that a try.

 

[sr71rules]

I'm very curious to see how this gets resolved. I am assembling a similar system too, though with a 238, and I'm hoping to avoid some strife on my end

 

[bachelorb]

I tried what you said and went directly to the DAW. There was no signal loss. Then I went through the tape player (Tascam 134) to the DAW ... again... no signal loss. I was kind of playing around with the drum track before to see if Garageband compression was causing any problems. So the soundtrack wasn't the same as the other day. Also I'm not sure that the recording levels weren't stronger the other day.

I might do some more testing in the next couple of weeks, but the taskmaster has decreed that I'm spending way too much time in my "studio". It'll take a week or so of annoying her before I can get any significant time back here.

 

[bachelorb]

THE last major piece to the puzzle is working!!!! .......I think........

I bought one of these that was a mouse house off from eBay (I didn't know it was a mouse house at the time). After we settled down in a permanent residence, I bought this one at a flea market for $10. This morning, I was hoping my Covid repair luck would hold out, and decided to work on it. Turns out all it needed was a new rewind reel belt and a fuse in the power supply. The mouse house donor had both of those, as long as some cosmetic things like knobs with covers, tape head covers etc.....

I don't know if it works because Uher used DIN 5 pin connectors for everything!! So.... I'm anxiously awaiting an Amazon order... If y'all would cool it on the toilet paper, it might actually get here before June!!

 

[ecc83]

I'm very curious to see how this gets resolved. I am assembling a similar system too, though with a 238, and I'm hoping to avoid some strife on my end

SOME people pay for that!

Dave.

 

[ecc83]

Hi Brad, Uher portables were the stock radio reporter's machine back in the day, not many stations would stump up for Nagras! I think they were pretty solid performers.

I don't know how familiar you are with the DIN electrical regime but you might find interfacing it with modern kit problematic? Main issue might be treble loss because the outputs are via high series resistances. Could be 47k even as high as 220k. DIN input circuitry is equally odd (but made sense in the valve era) so some work might be needed to get a good frequency response and low noise?

Dave.

 

[bachelorb]

Hi Brad, Uher portables were the stock radio reporter's machine back in the day, not many stations would stump up for Nagras! I think they were pretty solid performers.

I don't know how familiar you are with the DIN electrical regime but you might find interfacing it with modern kit problematic? Main issue might be treble loss because the outputs are via high series resistances. Could be 47k even as high as 220k. DIN input circuitry is equally odd (but made sense in the valve era) so some work might be needed to get a good frequency response and low noise?

Dave.

Thanks Dave. I am not familiar with the DIN electrical regime at all, but I have a feeling I'm about to be . I'll look into it, but yesterday I spent 2 minutes trying to hook a phono jack into an RCA plug..... this could be over my head.....

Last night, since there is nothing on manuals for this machine, I was watching some youTubes on it. One there was a guy fiddling with these controls.

you could really hear it changing the frequency response in "play" mode. I couldn't tell which ones on the video, but there were two positions he clicked to where the high frequency response was much better.

....on a side note, my mouse house donor came with an english face plate. The one I repaired had a lot of "fur'n" stuff on it. I decided to switch it out. I'm gettin older and remembering what Aufnahme and Pegel did may cause problems in the future....