Q8: Technics RS-858DUS Quadraphonic Q8 Recorder/Player

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Ah, thanks siwelk, maybe my memory isn't totally shot after all. That was the unit I totally wrecked several Q8 DSOTM from constant play. :)
Eventually I got divorced and my ex got the unit as well as all my Q8's, while I kept the rest of the quad equipment.
 
An old boyfriend had one branded Panasonic. I had one of these for a while and sold them to several clients back in the day. The motor was pretty weak compared to my Akai CR-80DSS. I still have an RX-847US, which is a Q8 player-only. I believe it has the same motor. Nicely designed deck!

Linda
 
What I'm wondering is (and I know there are sites out there) where can I get a service manual? I know there's places where they charge for a PDF copy but for this old quad equipment there's also sites that have manuals for free, in some cases even the maker still has them available, like Teac/Tascam. There is no copywrite infringement problems on stuff like this as far as I know and if I see one on ebay I'll buy it, but in the meantime it would be nice to have one for my deck.

Just wonderin'
 
What I'm wondering is (and I know there are sites out there) where can I get a service manual?

Just wonderin'

I have the owners manual + a sheet that has the wiring schematic diagram, I guess the manual wont be useful for your needs, but I could copy the schematic to the computer if you need it
 
I have the owners manual + a sheet that has the wiring schematic diagram, I guess the manual wont be useful for your needs, but I could copy the schematic to the computer if you need it

This is the machine I have. (Technics by Panasonic RS-858US) I had to feel my way along in restoring it as I found it in a GW store in the very early '90's. The speed will probably need to be recalibrated (mine was nearly a quarter tone fast/sharp) and once I realigned the heads (I used as broad a variety of tapes as I could find at the time using minimal cross talk and maximum HF as the navigational reference for azimuth) I was quite surprised. It still performs just fine. I had to improvise some new replacements for the motor mounts (the rubber had rotted) and now with the internet being what it is, I should probably try to find both a motor and new (Sorbothane?) "shock mounts" and do the restoration "first class" this time. I've had it for nearly twenty years and it still chugs right along. I use it to disabuse folks of how awful 8 tracks weren't, if they were weren't mistreated. At worst, they could (and did) compete with 3.5ips 1/4" qtr. track RTR's.

There might be a slight amount of "damning with faint praise" in that estimation, but mp3's are often nothing to write home about either.

This is my first post here. (My ID was just something off the top of my head, I was just barely too young to have gotten in on Quad at the ground floor. But I remember it well.)

Perhaps this belongs in a separate thread, but I thought I'd just throw it out there:

I've tried to restore a Pioneer QD-240 (I have the alignment records as well) and I'm having a pretty tough time with it. Everything appears to work, but I can't get the CD-4 pilot to register the carrier. I've used (with a new allegedly Shibata complimentary stylus) an L747S (I think that stood for Super Hedron), a 681EEE (new JICO stylus, I think replacing the D74) a Brand new AT-150ML, and Stanton 600/New Jico D61. No CD-4 pilot. I did change all the bulbs, so that's not the issue. I'm using a restored Pioneer PL-514, but I have a PL-L1000 in another system. (I read elsewhere here that tangential tracking 'tables worked better.....)

Thanks in advance for any assistance!
 
And now there are 5. As can be see from these 4 "US" versions and the original post of a "DUS" that make the total of versions to 5. The top picture of a Blue meter unit came from Google Images. The 3 stack are mine. Let's try to figure out the release order and then I will go into what may be the major design differences. I intend to go into the units to service them and I hope to find a date somewhere and then document the circuit differences. The only service manual I could find details the 5th unit: the "DUS" and what I believe is the 4th unit, the Top "US" unit, they both have the eject selector switch, AC outlet selector, voltage selector switch (which becomes a major issue) and DIN audio input/outputs outlined in the service manual. I will go into the differences between the 4th and 5th units later.

I believe that the 1st unit is the middle unit of the stack. You can it has no Pause switch or any kind of switch in center panel.

Next I believe that the 2nd unit is the bottom unit of the stack. It has 2 phone jacks, Noise reduction switch and clear meter bezels. This is important, my unit has green lighting. All of the other units have Green tinted bezels. I have been playing around with multi-color meter lighting for my Akai CR80 and Teac Reel to Reel decks in that I would use Green for playback, flashing Yellow for pause and Red for record. The only RS-858 that has clear meter bezels is the unit that has no pause switch! A transplant may be in order. Adding pause to the Akai is easy in that it is easy to stop the motor, but I have not overcome the rotation inertia of the capstan.

The 3rd unit I believe is the Blue metered units. Notice that the blue metered units have clear bezels and a noise reduction switch. This is interesting because it was always thought that the blue metered units came later, but as seen the blue metered came in the middle of the release schedule. If anyone has a deck with blue meters with a difference front panel layout, please post. Maybe we can get to the "Magnificent 7".

Note: All of this release order may be blown out the window if I or anyone else can come up with a date stamp somewhere in the unit and that date would have to be compared to date stamps in the other units. Maybe if some original purchase receipts were saved?, I know, A long shot.

Now the differences between the 4th and 5th units. From the front panel, it is mainly the phone jacks. Internally from the schematics in the service manual the most glaring difference is that the "DUS" uses a DC motor with it's voltage derived from a rectified DC from the secondary of the power transformer and the "US" units uses an AC motor with it's voltage taking directly from the line or the 115VAC tap. There are so many pros and cons to each method that would take a text book to explain. The advantage of using an AC motor on the primary side is that there is no or little interaction between the voltages on the secondary side being affected from the motor or vice-versa. And if the voltage is within design limits the speed of the motor is not line dependent. The speed of the motor is determined by the AC Line frequency and number of stator poles used. I believe that the fast forward is derived by applying the voltage to a tap in the stator poles so the rotor "thinks" it is getting say 240HZ instead of 60HZ thereby speeding up, a very stressful endeavor. The disadvantage is the same, frequency dependent. The "US" has no 50/60HZ select like the Akai does. This means although you can select 230V for Europe and unless you change the diameter of the motor drive pulley the unit will run slower in Europe. The service manual states 50/60HZ operation, a contradiction.
The advantage for the DC Motor is that as long as the transformer's taps for voltage select are designed properly it will make no difference if the frequency is 50 or 60 hertz. The fast forward on the "DUS" is accomplished by applying the DC voltage to a stator tap making the rotor think there is more DC voltage applied. Since the DC Motor speed is voltage dependent then a great mod would to put in a regulated and adjustable voltage to trim the speed. The disadvantage of the DC Motor is that if unregulated voltage is applied then any line difference can effect speed and and since it is on the secondary of the power transformer there can be interaction from all of the voltages causing say light diming, etc.
The Model Airplane industry has controllable DC motors that could rip the tape out of a dragging cartridge that may be a mod that could be done to put to rest any torque issue.

It has been said that the later units used a better motor, but I am not for sure. The manufacturers design to the limits. One unit may play a fully load tape cartridge easy while a unit in the same batch that is within tolerance may drag.
It would be interesting to correlate the units that drag to what is actually inside. It may be simply a tolerance issue. I will know more as I tear into my units. Any input from others would be great. This mystery may not rise to the Egyptian Kings, but it would be interesting to get the history straight on these units. More later as time goes by.
 

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Mine looks like yours, I just thought it was (analog brain that I am) color manipulation/skew. I assumed that filters or something had been used to maximize/alter the appearance.

No motor drag on mine in the '90's or now, but a new (correctly sized belt) will make all the difference. I had to pick it out of a lineup at MCM back before pre-made up kits and Ebay were established.

My Blue meter 858US -D?- (NR version) had to have the motor "rehabilitated". I did it in the very early '90's (I paid $10.00 for it and used up most of my thrift store luck apparently) and my motor rejuvenation skills weren't what they are now. (I've got a box full of motors that will probably replace it, if I can get one into the Panny "case" that was used to mount it.) The motor (compared to my usual brand Pioneer's custom encased Mabuchis) was easy to get apart and went together much easier. I had to fortify the rubber vibration isolation motor mounts. I haven't been into it for a decade or more but it still works as reliably as it did just post restoration. (New belts and new alignments, using the best pre-recordeds I had as a series of data points.) It's overdue to be gone into again. I'll probably have to make new mounts out of squares of Sorbothane or some such. The one thing (having no other with which to compare it) that I always wondered about was the "flutter" in the lights during fast wind. It's never affected anything adversely and it's done it from the day I got it. I assumed it did it brand new in stores. For an 8 track, it sounds terrific. Which is to say it sounds like a 3.75ips Open Reel. High praise that maybe isn't as high sounding as some might like it to be. I owned a player but no recorder because my beginnings (in all things, including audio) were modest. (They're still modest, which is why the $10.00 price of entry seemed like a "righteous" bargain.) I do okay now, but not okay enough to justify what these puppies bring on the 'bay these days. I keep it polished and play a Doobie Bros. or B,S&T tape on it several times a year to remind my old peers from college how not awful the format could be. Of course there's still the "Kuh-Klunk" of the track change between the next to the last and last note of "Symphony for the Devil" that inspires knowing grins from when we used to sit around and listen to it on my first (high fatality) stereo, but...it is...what it is.....thanks for the update!

P.S. I just secured a Pioneer SE-Q404 set of quad headphones to use on my quad tape machines (this one, a 1020L and a 2044) and with my (few) quad tapes. I've heard most of them two tracks at a time. But I would like to hear everything "all at once" using 100% technology of the time period. If anybody has any advice about them, I should be seeing them early next week. TIA.....
 
I never did get the QD-240 to respond to quad input. (I have all the Pioneer setup records that I'm aware exist.)

I know I should start a new thread. I've been busy with "health stuff"......I'll get to it soon.....
 
This thread is not closely/aggressively watched apparently. If you're good with tools and have ingenuity, I wouldn't be afraid to try the basics on your own. Changing the belt, etc. Even aligning it (on these machines) isn't difficult. Get the best (with the pads replaced in the underside of the tape) HF response while minimizing adjacent channel crosstalk. If I remember correctly, there's exactly one screw to adjust, so it's less "screw up-able" than RTR's or high end Cassette machines. Clean the heads using denatured alcohol or dedicated head cleaner. (Hard to find now though......not the denatured alcohol.....)

Deoxit in switches and sliders is a safe way to maximize peformance, just be sparing with it. It's NOT inexpensive and a little goes a long way. I'd do the internals of the motor as well, but I'd run it as soon as I applied it and I wouldn't "drown" it. Let it dry out from its own heat. Mine's still going strong.....

Good luck and let us know how it goes!
 
another forum newb here...i have one of these. clear bezels, no voltage switch, 'us' model. it sounds really good, a bit brighter than my akai, but not quite as high fidelity if that makes any sense...but it is problematic. tapes drag, tapes get eaten, channels drop out...i suspect dried out capacitors, among other issues. it could use a capstan roughening as well. who does these sorts of things? where can i get a belt? what is the meaning of life, the universe, and everything? 42. oh well...also, i can open mine up and look at numbers, stamping, etc. if that would help the hive mind any...thanks y'all!

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...For an 8 track, it sounds terrific. Which is to say it sounds like a 3.75ips Open Reel.

i think that is the ceiling for quad8s. which is a pretty good ceiling if you ask me. about 45 db s/n and 25 db channel separation is what i am seeing (hearing). the tape stock used makes a world of difference.
 
I'm the world's slowest person to run to the "dried out" cap excuse. I get why techs who rely on the interwebs to keep their queues filled like to make it thier first go to, but it's not been the case with my stuff. (And there's a LOT of it.) While it's possible (and not to be unexpected for gear this age) for caps to dry out and go out of spec, my personal experience is it almost NEVER happens. When I have seen it happen it happens in power amps or similar and in those cases, things like a lightning strike, poor storage environment or some such usually helps. YMMV.

Use acetone to revitalize all capstan pinch roller first. Clean it, clean it CLEAN IT. Clean it some more. Ditto the heads and replace the belt. If it still chews tapes (remember to replace the foam underneath the tape. ALL of the tapes, btw......) check the tape guide(s).

That screws more stuff up than caps ever thought about.....

Good luck....
 
thanks. i used deoxit on all the switches i could find; that helped the deck out quite a bit. i cleaned and demagnetized the tape path. i have some scotch pad thing mounted in an empty shell i use on capstans every now and then with a bit of tape head cleaner, and it seems to help. i will find some acetone and try that. can you point me to a source for a belt?
 
I apologize for the obscure non-audio reference. It's a Science-Fiction subculture reference to a (five book long-post modern irony was his wheelhouse, RIP) trilogy by Douglas Adams entitled "The Hitchhiker's Guide to the Galaxy". They build the biggest, baddest organic supercomputer ever conceived to solve the question of "Life, The Universe and Everything" (surprise, it turns out to be the Earth, which a race of stupid, knuckle dragging bureaucratic buffoons have just demolished) and after an eon or two, it spits out the answer: "42". (It's a sub reference in a ton of stuff that came after it, including the apartment number of the main character in the X-Files....)

The punch line is they have to tighten up the question ("junk in, junk out") and wait another unspecified number of eons for the answer. It's sort of a weird mix of Phillip K. Dick, Kurt Vonnegut and (maybe, though I've never been a huge fan) William Burroughs. Do not watch the movie if you're interested. It's a CF that nobody much cared for. It started life as a BBC radio series, then TV series, then the books and finally, the movie. No amount of editing could whittle five books down to a 2.5 hour movie. The story is so splintered between its various formats that it's created its own ecclesiastical infighting among fans. I don't get that serious, but it's influenced everything that followed it like few other things in Science Fiction had the ability to.......sorry for the disambiguation lecture. Please carry on with the Quadraphonic quality discourse.....
 
UPDATE: I just went back into my 858DUS and there are a couple of things I MISSED the first time I posted.

ONE: I HAVE the .pdf Service Manual. Somebody posted that they had the OM but needed the SM. I'm in the opposite boat. I have the SM (.pdf) and NEED the OM. So PLEASE PM me and we'll exchange emails (or I can post it here if it's helpful) if someone else will do likewise with the OM.

TWO: I just discovered that while the headphone jack is wired correctly with respect to F=Front and R=Rear, the LEFT and RIGHT Headphone outputs (both jacks) are BACKWARDS. It appears to have come that way from the Factory as I don't see anything remotely resembling "new" looking solder work. The connections will involve reversing a Green and White wire on one side and a Blue and White on the other. But FIRST, I'd like to hear from other owners if they have a machine with the same issue. It's not a complex thing to fix, but I'd be more likely to just leave it like it is (and flip my Pioneer SE-Q404's around on my head) if I knew it was a manufacturer oversight. Thanks in Advance for any feedback.....
 
I have an original OM for the one lever model. Also have SM for both one lever and two lever models. The lever(s) on the far left side when looking at the RS858

Richard
 
Hi Richard,

Do you have the OM in a .pdf? I'd like to get a copy if it's possible and not too much trouble.....I'll PM you...

Thanks!
 
Thanks to everyone who replied!

I have the Operating Instructions now, courtesy of jwb474. (Thank you!) Thanks also to everyone at the forum for their thoughts and assistance. It's a GREAT resource.

Update on my machine: (It's soon to be the first of TWO, I'm excited to have found a "backup" machine for this one.)
My re-restoration of my 858 is now complete. The motor is MUCH quieter and the alignment is spot on. While it's true that not every tape is, that's a foregone conclusion. Crosstalk is negligible and occurs very rarely. On those rare occasions, it appears to be the result of print through about half the time and is not related to Azimuth or Height adjustments. (What there is is so far below the tape hiss noise floor, it's really insignificant.)


I'm still curious about the reversed L/R channel issue (on all four channels) though. It shows at ALL outputs, but NOT on the meters. (It's past the Rec/PB head, that's for sure.) I had just forgotten about it. It's been in that system for about 20 years. In all that time it never complained once. (But then I don't use it every day.)

I just hook it up left on right and vice versa. (Which is how I had it before, but didn't notice it when I took it out.) I flip the quad phones around on my ears. I know there are fairly simple ways to internally correct it, but I haven't found the exact place where the point to point connections were reversed. I don't want to correct it in the wrong place and deviate from whatever was right on the schematic. (I.E., correcting it back by flipping it twice instead of undoing the first "flip", possibly made at the factory.) Maybe another day......but it sounds terrific (for that format) now. As long as nobody looks at the rear panel (which they can't get to anyway) all is well....lol....
 
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