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Tape Machines => Tape Project Machines => Topic started by: docb on March 13, 2007, 11:38:05 PM

Title: RS1500 rework developments
Post by: docb on March 13, 2007, 11:38:05 PM
I've spent the last week or two working up a rational procedure for refurbing and (hopefully) improving the performance of the RS 1500.

A couple of areas that seem to be most critical for best performance are the coplanar positioning of the tape path components and subsequent head alignment, and the proper spool brake tension in both winding directions.

The tape path is quite critical in these machines. Unfortunately it is also easily misaligned from bumps and dings. A careful visual alignment using some established reference points is a starting point for static alignment, and the bulk of the alignment adjustment is made with shims. Once the visual alignment is complete the travel of the tape over the rollers, guides and heads and the tape pack position need to be observed. Any necessary final adjustments will show themselves more clearly as the tape moves. I have found that if the tape path aligment is done with enough care some sources of friction in the tape path can be removed and some guide surfaces can be replaced with lower friction materials. This seems to bring out a subtle improvement in dynamics.

Following this the head block can be removed and a careful visual positioning of the heads can be done. From there the headblock is replaced and alignment with a calibration tape is usually pretty easy.

Before any of this is done, however, the brake tension must be adjusted. I have worked with several different machines now, ranging from minty low hours units to beat up old dogs. One thing is consistent with the machines I have worked with - it seems you can't set the tension to the spec in the manual, regardless of how new the stock felt brake pads look. I spent quite a few hours testing different brake lining materials and I can happily say that I have found a material that seems to hit the tension spec in both directions, dead on. I have worked up a procedure for rebuilding stock brakes with this material. It's remarkable how much better an RS1500 works with the proper brake tension. The tension rollers never pop up at stop (which is critical for being able to stay seated on your lazy butt when you're using the IR remote) and the reels stop very quickly at runout. With the tape kept in good tension the pack seems to come out better when you stop and start a lot too.

Now that I'm finally getting a blow by blow listing of the steps of the refurb process together and I should be able to start developing pricing.
Title: Re: RS1500 rework developments
Post by: mstcraig on March 14, 2007, 08:25:20 PM
Again, forgive me if this has been addressed. Can I assume that you will, at some point in the future, be offering Technics machines for sale that are all modified and "turn-key"? I would be very interested to see what you are asking for these. Or, can someone send you a machine they own already and have you do your magic to them? Lastly, any more news on what rooms The Tape Project will be demonstrating in for the upcoming Stereophile show? Craig
Title: Re: RS1500 rework developments
Post by: docb on March 14, 2007, 11:12:45 PM
Yes to both. We will offer machines for sale when we can find them (we have small stockpile now) and we will also do refurbs and upgrades on customer machines. I will have some shipping crates made that can be used by customers to ship a machine to us and return it. The customer will have the option of purchasing the shipping crate or returning it.

I'll try to come up with a list of things to look for when checking the condition of a machine that one is thinking about purchasing. Some things that commonly need work like brakes are an easy and relatively inexpensive repair/upgrade, while bent and broken guides, arms and motors are not necessarily easy to replace. Other commonly or broken worn parts shouldn't be too expensive to fix and I will try to find reasonable current production replacements for them - the head selector switch comes to mind. And of course head wear makes a big difference in the value of a machine. I hope that folks will be patient in their search and get a fair deal. I've seen a few folks pretty frustrated by "mint" machines that were a wreck, "new in the box" headblocks with completely shot heads, and more than one machine that was shipped cross country with only a little popcorn thrown in the box.

We should have copies of the first four albums for demo at the Sterophile show, and possibly a few other treats...
Title: Re: RS1500 rework developments
Post by: docb on March 27, 2007, 05:40:01 PM
Here's the latest update -

I have just wrapped up the design of the remote control receiver cabinet. For me cabinets are one of the PITA jobs in this business, but I think I came up with a pretty functional setup. The remote box will be 1U tall (1.75") rack style, and will sit above the RS1500. There will be a row of cutouts in the faceplate, of the symbols for Rew, Stop, Pause, Play, FF. These will be centered between the two reels, and light when you hit the corresponding button. There will be no Record button on the remote. You will have to use the Record button on the machine, as we don't want anyone yelling at us for accidentally recording over a Tape Project tape.

I have also been casting about for improved tension roller arm return springs. I have some off the shelf stock to try. So far so they seem to be great, but if they don't pan out in the long run I will have some custom ones made.

This afternoon I am working up a new power entry panel for the back of the RS1500. The plan is to loose the silly battery jack and whimpy power cord, and put in a new panel with an IEC connector and two NEMA three prong outlets, so you can plug the tube preamp and the remote wall wart into them and have just one $27K 1-1/4" diameter yak fur lined neutronium power cord coming off the cabinet if you like.

Lew Hardy is making us some dovetailed walnut rack cabinets to house the RS1500, IR remote receiver, tube repro amp and VU meter cabinet. I'm trying to make this as modular as possible so folks can add things as they wish. Meantime you can use blanking panels where the future upgrades will fit.

Oh yeah, about that VU meter. PJ got a bee in his bonnet and we will be making a truly useful, accurate standalone VU meter setup that can be used with the RS1500 project or in your studio.

OK, I gotta start pulling my stuff together for the trip south to test the duplicating setup. I'll be here sporadically for a few days.
Title: Re: RS1500 rework developments
Post by: scully280 on March 27, 2007, 09:32:09 PM
Doc,
Will the VU meters be buffered?  Old school VU meters have a lousy sound and I had a pet peeve in past days to buffer them where they were put across outputs.  Also I like the power cord re-work, I think I'll start brushing the fur on my spare cord for correct magnetic orientation.
Title: Re: RS1500 rework developments
Post by: docb on March 27, 2007, 09:37:51 PM
Yes, they will be buffered and use precision op amps. PJ looked at the circuits that were around and said "shoot, we can do way better than that." We will also have switching so that one can sum and difference the two for phase and level adjustments.
Title: Eureka! Tape path mods
Post by: docb on April 01, 2007, 11:04:39 AM
I'm in San Francisco with Paul and Michael this week. One of the cool things about this (besides dinner at Original Joes) is that I get the opportunity to try new product developments on Paul's mastering system, which has been dubbed the Big Magnifying Glass. The combo of that system and Paul's and Michael's super acute hearing gives me just about the best double check possible for mods that seemd to produce an improvement on my own system.

To cut to the chase, we did quite a bit of comparision of the stock tape guide setup and my modified setup. The modded setup is designed to make the tape path setup more like the original isolated loop design of the 3M M59 and M79 machines. On Paul's system this was an easily discernable improvement. More stable sounding, cleaner, more focused, all the things one would hope to hear if the tape is traveling with as little friction as possible.We all signed off on this mod as part of the RS1500 modfication we will offer.

It's rather a tweaky mod to do, starting with a very systematic adjust and check, adjust and check, over and over kind of process to get all of the tape path guides, rollers and heads in dead on alignment. It's time consuming, but well worth it. Once the tape path has been made as true as possible and the tape is packing as flat and well centered as possible I make some changes to the fixed guides in terms of the number of them and the materials that the tape rides over. Once it's all dialed in the sound is cleaner, the tape packs great in both play and fast wind, and in fast wind it spools like a mother.

We tried a few other things including A/Bing the stock head vs. the Flux Magnetics extended response head with this new tape path setup. The stock head is very good, but the extended response head is like "Ahhhhh..." Bass is certainly more extended sounding, but I also perceive the same kind of sonic improvement that one gets from going to premium audio transformers, sweeter but not slower, blacker background but without losing any resolution.

Another experiment was to try Athan urethane pinch rollers. Sorry to say this was not successful. The rollers are very soft compared to the originals, and the sound with them in place was not focused, lacking in articulation - muddy is a good word. So one might guess that the tape is not being as well controlled as it passes through the dual pinch rollers and capstan. Luckily the stock pinch rollers seem to hold up quite well. I will be looking for some alternative replacement rollers, and perhaps experimenting with the roller pressure with the Athan rollers to see if I can get any improvement.

Later yesterday Paul got the 1" machines set up and today we will be making the running masters for the first albums. Monday is slated for our first whack at duping with the new duping line. We are getting so close!
Title: bit by bit
Post by: docb on April 11, 2007, 01:54:05 PM
Lew Hardy of Vivaldi Audio just dropped off the prototype dovetailed walnut rack case today. Beautimous! It's 16U tall and 8" deep, so it will accomodate from top to bottom-

the 1U high IR remote receiver - which I have received the custom front panel for, in bronze with gold engraved lettering to complement the look of the RS1500

the 10U tall RS1500

a 1U ventilated panel to allow for air circulation for

the 2U tube repro amp

the future 2U tall VU meter box

Parts are still pouring in (and man, is the mullah ever pouring out) as I am working to get three prototype machines together for the Stereophile show. I have some great looking Studer/Revox style hub adapters on the way from Europe, a prototype bronze w/ gold engraved lettering repro amp front panel, parts for more repro amps, custom power entry panels, etc., etc.

I'll post pics as things come together.
 
Title: Re: RS1500 rework developments
Post by: xcortes on April 12, 2007, 09:37:40 AM
Any idea of prices yet?

xavier
Title: Re: RS1500 rework developments
Post by: docb on April 12, 2007, 11:38:19 AM
I'm in the process of sourcing and ordering all sorts parts right now for three prototype mchines that will go to the Stereophile show [insert sound of big vacuum cleaner sucking up Bottlehead's bank account ;^)>] and the picture is beginning to take shape. I promise to put up some pricing as soon as I have a clear picture of the costs involved. It would probably be counterproductive to throw out a premature figure that is too far off from what we end up with as the final price.

 
Title: Re: RS1500 rework developments
Post by: classicrecordings on April 12, 2007, 01:20:37 PM
Will these machines be limited to playback at 15ips, or will they also be able to playback at 7.5ips?

David
Title: Re: RS1500 rework developments
Post by: docb on April 12, 2007, 02:39:59 PM
They will play 3-3/4, 7-1/2 and 15 ips, 1/4 track and 1/2 track, just like a stock RS1500. The only real difference in function will be that the extended response 1/2 track head is optimized for 15 ips rather than 7.5 ips that the stock 1/2 track head is optimized for. The 1/4 track head will remain stock and works great with prerecorded 7-1/2 ips 1/4 track tapes. The outboard repro amp will do NAB and IEC eq, and I'm looking into adding one other custom eq to order, like AES or Nagramaster.
Title: Re: RS1500 rework developments
Post by: xcortes on April 12, 2007, 04:22:20 PM
I assume that the machines will keep their recording capabilities?

Also that you can buy only the machine and use a different amp (have you heard about the "Seduction")?

Title: Re: RS1500 rework developments
Post by: docb on April 12, 2007, 06:07:31 PM
I will not be altering the record circuit at all (as I have no interest in doing this) so it will remain stock in it's functionality. And you can plug anything you want into the tape head output - our repro amp, a modded Seduction, a vintage preamp with tape eq input, a repro amp from Tim, whatever. I will see if I can work out a switching arrangement that would let a person switch between the internal playback electronics and external playback electronics. I suspect that folks won't be going back once they hear a good external repro amp, and I haven't bothered with such a switch in our demo machines because it might add noise.
Title: Re: RS1500 rework developments
Post by: ironbut on April 14, 2007, 11:45:41 PM
This is related to my post in the Service Resource forum. As I said there, my RS1500 is working fantastic now but during my visit to Paul's studio, Doc showed me the tape path mods and tweaks he'd been working on. It involved reducing scrape flutter by eliminating friction causing guides that can be done without "if" the rest of the tape path is darn near perfect. He and Michael showed me how it also results in a " tape pack " that, after rewind, looks more like one from playback. Of course now I look at every " un-perfect tape pack " with horror!
Title: Re: RS1500 rework developments
Post by: docb on April 15, 2007, 01:32:06 PM
Do bear in mind that some of your old prerecorded tapes may not ever pack that well. When I check a machine I use one of our new tapes to check the pack, and then some old ones that I know are problem children, just so I don't fool myself into thinking every tape will always come out perfect. But all that said, I have been able to get problem machines to pack any tape a lot better than when I first fire them up on the bench, and new tapes can be pretty consistently tight and smooth even at fast wind. I think the reel you saw packing actually had a couple different types of tape spliced together and it still packs really well.

I started on a new one yesterday. Found one thing that seems to be fairly common, which is that the tension rollers are sitting at different distances from the deck plate. That's a good place to start if you're sorting out packing issues. Keeping guides clean makes a big difference too. Any gunk buildup can tilt the tape, and that is guaranteed to throw off the pack.

This is a good time to to mention that if you see a tape that is flange packing, stop. Flange packing is when the tape sits up against one flange, rather than being centered on the reel with some space between the tape pack and each flange. This can curl the edge of the tape and that can permanently screw it up. If it's just one tape that is the problem, experiment with running it onto a different reel, or experiment with applying or removing the silly ass rubber shim for the reel turntable, depending upon which way the tape is shifted on the reel.
Title: Re: RS1500 rework developments
Post by: heideana on April 17, 2007, 11:09:35 AM
Wow!!!  I can't say that I totally understand all of the technical details, but its' really, really, really exciting time (and major paradigm shift!!!!) for RTR right now!  Thanks again to all for breaking the inertia!
Title: spy photo
Post by: docb on April 18, 2007, 09:53:03 PM
This is a closeup of the prototype walnut cabinet, to show the dovetail, and the not quite finished faceplate of the remote receiver. When the receiver is complete the icons will light up as you push the corresponding button on the remote. I'll show more complete pictures as I complete the rest of the components.
Title: Re: RS1500 rework developments
Post by: Danny Kaey on April 19, 2007, 09:14:03 AM
nice!!!
Title: Re: RS1500 rework developments
Post by: classicrecordings on May 14, 2007, 09:43:53 AM
Where would the machines that are getting the "Plan B" update need to be sent?

David
Title: Re: RS1500 rework developments
Post by: docb on May 14, 2007, 10:42:16 AM
Hi David,

I'm working to get set up to start receiving machines this week. We already have quite a few folks asking about sending machines to me for work. We had a slight mishap with one machine we shipped to NY. I think it may call for a modification of the shock handling capabilites of our crates, that I need to work out before I can have crates made for Plan B machines. I'll keep everyone posted as to my progress this week, and hopefully by next week we can begin scheduling mod work for our clients.
Title: Re: RS1500 rework developments
Post by: mstcraig on May 14, 2007, 11:28:32 AM
Did I miss something? Could you explain what a "Plan B" update" is please?
Title: Re: RS1500 rework developments
Post by: docb on May 14, 2007, 12:51:18 PM
While you guys were off galavanting in NY I was hard at work getting the website updated.  ;^)>

http://www.tapeproject.com/machines/machines.htm (http://www.tapeproject.com/machines/machines.htm)
Title: Re: RS1500 rework developments
Post by: classicrecordings on May 15, 2007, 12:25:22 PM
Would there be any problems sending a RS-1506, as compared to an RS-1500? Is there any diiference other than the recording heads?

David
Title: Re: RS1500 rework developments
Post by: docb on May 15, 2007, 02:04:37 PM
A 1506 is just fine, they are the same in the aspects which we work on. I am just back from the crate maker, where I dropped off a 1506 for them to use for fitment. I hope to have crates ready for shipping machines by early next week.
Title: Re: RS1500 rework developments
Post by: ironbut on May 22, 2007, 06:17:46 PM
Hey Doc, on the tape path mods have you noticed how worn the tape lifters get. I noticed a flat spot on both of mine. I would think that after a while, this flat spot would become a groove that could damage tape edges on rewind and ff. I was thinking that a replaceable sleeve might be a way to improve the wear of the lifters. When you depress the rollers the lifters get well out of the tape path so I doubt that increasing the OD of the lifter would effect playback/record. I don't think that they are detachable from the lever/arm that moves them because I was hoping to rotate them to an unworn side.
Title: Re: RS1500 rework developments
Post by: docb on May 22, 2007, 07:00:12 PM
It is something I have thought about. I have a couple or three sizes of Teflon tubing. I'll see if I have some that will fit.

FWIW the report from the field is that the machines we sent to Stereophile packed tape very nicely all weekend. I don't recall the amount of wear on the lifters and the machines haven't made it home yet for me to check, but I think maybe one had at least a fair amount of lifter wear.
Title: Re: RS1500 rework developments
Post by: classicrecordings on May 30, 2007, 02:56:29 PM
Hi David,

I'm working to get set up to start receiving machines this week. We already have quite a few folks asking about sending machines to me for work. We had a slight mishap with one machine we shipped to NY. I think it may call for a modification of the shock handling capabilites of our crates, that I need to work out before I can have crates made for Plan B machines. I'll keep everyone posted as to my progress this week, and hopefully by next week we can begin scheduling mod work for our clients.

Are there any updates as to when you will start taking machines in for tape path updating and head replacement? I am trying to decide whether to ship my machine from Canada, or buy one in the US, and have them ship it directly to you.

Also, where would the machine need to be shipped to? Knowing this may be helpful deciding what to do based on the shipping costs.

TIA, David
Title: Re: RS1500 rework developments
Post by: docb on May 30, 2007, 04:16:29 PM
One of the things on my list this week is to check on the status of the custom shipping crates. I haven't heard from the crate maker, but I imagine they will be ready soon. I will be installing some foam padding once I get the crates here and then testing them to be sure they protect the machines properly. So it will be a few days after I get them before they are ready to send out. Machines sent in for mod work will ship to my lab here in Poulsbo, Washington 98370.
Title: Re: RS1500 rework developments
Post by: classicrecordings on August 10, 2007, 06:57:35 AM
Are you able to take in machines for the "Plan A" update yet?

David
Title: Re: RS1500 rework developments
Post by: docb on August 10, 2007, 10:18:37 AM
I must apologize for falling behind on the hardware end of things while we've been concentrating on getting the details of getting first year's tapes together. I still owe a couple of repro amps to clients (they are moving along, with some good progress made earlier this week) before I dive in to more work. What with Bottlehead, Tape Project and now VSAC involved, sometimes I feel like one of those old time one man bands, and cymbal on my left knee keeps sliding down to my ankle while I'm trying to do a Sousa march. Now that we are so close to spooling albums I will put a concerted effort into working out the last of the shipping bugs and get the upgrade program rolling. Bear with me for a couple more weeks while I get the shipping crates reworked and devise a schedule for efficiently moving through what appears to be a pretty good sized group of subscriber machines coming in for mod work.
Title: Re: RS1500 rework developments
Post by: classicrecordings on September 14, 2007, 08:23:41 AM
Would it be possible to just send in a 1500's tape head stack to have the heads replaced? Or is it necessary for the head stack to be on the machine for proper set up?

David
Title: Re: RS1500 rework developments
Post by: docb on September 14, 2007, 11:40:06 AM
Hi David,

If you are comfortable doing your own alignment just send your headblock straight to Greg Orton at Flux Magnetics. He will install the new on the block and give is a visual alignment. That makes a pretty easy starting point from which the align the heads once the headblock is back on the machine.

http://www.fluxmagnetics.com/ (http://www.fluxmagnetics.com/)