Ampex MM-1000 Story...

[sweetbeats]

Got the headblock plate modded and the guide installed.

Still need to put things back together but here's how it will look. The "new" guide is there right before the erase head. Chunky. Me likey.

 

[Muckelroy]

Will the roller resolve a wow/flutter/scrape-flutter issue that you were having already?

If so, was that issue within spec of the Ampex, or "out of spec" of the machine?

It's kind of amazing if this roller will actually move the spec scrape flutter numbers to a place better than the factory intended. Is that what you're going for?

 

[cjacek]

Will the roller resolve a wow/flutter/scrape-flutter issue that you were having already?

If so, was that issue within spec of the Ampex, or "out of spec" of the machine?

It's kind of amazing if this roller will actually move the spec scrape flutter numbers to a place better than the factory intended. Is that what you're going for?

Yeah, I'd like to know that too.

 

[sweetbeats]

I suspect that the speed/wow issues are related to the 996 I'm using as I have reason to believe that it is going sticky...that reason is mounting as I'm seeing more shed buildup in a couple places I didn't know about...and the other cause I suspect is that the capstan belt was wayyy off-spec in terms of tension. We'll see but I'm going to start using the 499 I have.

The new guide should reduce scrape flutter. I believe it is measurable, not thinking I would be able to hear the difference but that's never stopped me before. You'll find that the MM-1200 has a rolling guide in that position. No way to fit one on the 2" MM-1000...plus the 2" MM-1000 block only has one flutter filter...so the 1" format has better scrape flutter performance than the 2".

 

[cjacek]

You'll find that the MM-1200 has a rolling guide in that position.

Ah, I see. So that's basically a 1200 1" head-block now.

 

[sweetbeats]

Ah, I see. So that's basically a 1200 1" head-block now.

Welll...no.

The stock MM-1200 block whether 1" or 2" has two static guides just like the stock MM-1000 block...same with the MM-1100. Its a relatively common upgrade to put that rolling guide there in front of the erase head. The MM-1000 1" block has the advantage of having two scrape flutter idlers. That is unique to the MM-1000 amidst the 1" MM multitrack blocks. The MM-1100/1200 blocks whether 1" or 2" don't have room for the second flutter idler. The 2" MM-1000 block is like the MM-1100/1200 blocks in that there's not enough room for the second flutter idler.

So, in summary, no its not basically a 1" MM-1200 block now, its better (potentially).

There's another big difference between the MM-1000 heads and the MM-1100/1200...the MM-1000 heads are "old-school" where the head gaps are optimized for the purpose of the heads...the repro head gap is wider than the record head. Sync response suffers, but reproduce head response is good. The MM-1100/1200 heads are more contemporary where the head gaps are equal so you get the same response off the record and head and the playback head in reproduce. Does the MM-1000 perform better off the playback head in reproduce because the gap is optimized for that purpose? No, not really because the MM-1000 heads were made in the 440B era...the MM-1100/1200 heads were made in the 440C era and have about 3x the laminations so the have better HF response. So even though all three machines are based on the 440 heritage there are differences in transports (no viscous-damped reel idler on the MM-1100/1200), advanced heads on the MM-1100/1200...and certainly revisions and updates to the electronics along the way.

Bottom line: me likey the MM-1000.

Below are pics of the stock 2" MM-1000 headblock assembly, and then a picture of a stock MM-1200 2" assembly. Very similar.

 

[cjacek]

...the MM-1000 heads are "old-school" ....

Bottom line: me likey the MM-1000.

Me too!!

 

[sweetbeats]

Yah.

More thoughts...

See, the rolling guide right before the erase heads helps to prevent scrape flutter being developed at that guide, AND the erase head, and then notice on the 2" blocks the next thing the tape sees after the erase head is the record head. So with the rolling guide the only thing to produce scrape flutter prior to the record head on the headblock is the erase head. No way around that. On the 1" MM-1000 there's that secondary scrape flutter idler in between the erase and record heads...see it?

So on the 1" MM-1000, you get some scrape flutter damping at the reel idler (the one with the viscous flywheel) which comes right before that incoming guide to the headblock (before the erase head), and then the scrape flutter that is developed at the erase head gets diminished by that first scrape flutter idler, and then the scrape flutter that is developed at the record head gets diminished by the next scrape flutter idler. So there are really 3 scrape flutter damping devices on the MM-1000, and with the static guide replaced with a rolling guide there before the erase head the ONLY thing that can cause scrape flutter is the supply side brake arm which has a static post, and fortunately the wrap angle is really small there and there is very little pressure on the tape from that thing.

NOW...is it necessary to have a tape path filled with all sorts of rolling things? Well, not necessarily, and typically it is better to have less. Its not that simple. The more things there are in the tape path there more opportunity for either scrape flutter or mechanical vibrations or "noise" becoming a component. Scrape flutter is defined by the total wrap angle of static components in the tape path (which primarily effects the amplitude of the scrape flutter) prior to the capstan shaft, as well as the length of unsupported tape (which drives the frequency components of the scrape flutter...great length of unsupported tape means lower frequency components which means the scrape flutter may be more audible). My wrap angle sum is really low, the length of unsupported tape is relatively high. The bearings have to be good as does the surface of those rolling guides. All that stuff can put you back where you started if it is not right. And recall that Ampex went to the trouble of utilizing ruby bearings in their scrape flutter idlers...very very smooth with great wear characteristics. This is how Ampex addressed some of the compromises of adding all these rolling thingies to deal with the long tape path, which, again, is due to the fact that the MM-1000 is a converted quad VTR and the video heads are missing on the MM-1000, but the spaces are still there. Fun character. Now as you start looking at your own tape decks and analyzing "hey that's not a rolling thingy and the angle of that andandand..." just remember that I probably won't be able to hear the difference from installing that rolling guide there before the erase head. Why did I do it? Because...because I can, and it looks great, and it can't hurt, and I wanted to. Can't wait to see what the 440-8 rotary guide looks like out there before the head cover...have to find a 1/4"-28TPI x 1" flathead screw to mount it. Not easy. Probably have to get that up in Portland but I don't know when I can make it up there next.

By contrast here are a couple pictures below featuring (in order of appearance) the full MM-1000 tape path, the MM-1100 tape path (note that all three of those guides prior to the erase head can be rolling and one was rolling in stock trim on the MM-1200...no viscous-damped reel idler on the MM-1100/1200 but there was a basic constant tension system so wow was improved), as well as the 3M M-79, which was preceded by the M-56 and the M-23...just notice the different ideas of the tape path, wrap angles, static and rolling components...more than one way to tackle it for sure. I believe the 3M decks feature the shortest amount of unsupported tape which puts the flutter frequency components out of the audio band...flutter amplitude is less of a concern then and therefore so is the wrap angle around those incoming and outgoing static guides. The MM-1100 was notorius when it was introduced for its flutter producing tape path...no scrape flutter idler on the original MM-1100's either...a relatively large degree of unsupported tape, lots of wrap angle and nothing to mitigate the scrape flutter.

Enjoy...

 

[sweetbeats]

ANNNNND FURTHERmore...

I was pondering the whole "old-school" head thing too. It'll be interesting because I DO have a near-new set of 1" 8-track Ampex heads off of a 440C-8. I ALSO have a spare complete 1" MM-1000 headblock with so-so 440B-type heads in it. Maybe someday it'll be fun to load that spare block with the 440C heads (which have the 3x laminations but still have optimized gap widths...best of both worlds?), get it setup and then compare to the block presently on the machine with those IEM heads in it. The 440C heads will require different repro cards but...I have those. So I could have both blocks setup and ready to go and in minutes swap the blocks and cards out for a different flavor...might like the 440C heads better. Who knows, but its exciting to have these options, and its exciting to be blown away already by how it sounds in completely stock trim...I plan on replacing some key caps in the electronics and "going through" them at some point and some of those changes are reputed to "really open up the sound"..."like taking a blanket off". So I'm more than set. And soon the MM-1000 will have a permanent home in a proper sound room. Spoiled? Maybe, but I've been dreaming about this for over 20 years...so...oh well.

 

[ofajen]

By contrast here are a couple pictures below featuring (in order of appearance) the full MM-1000 tape path, the MM-1100 tape path (note that all three of those guides prior to the erase head can be rolling and one was rolling in stock trim on the MM-1200...no viscous-damped reel idler on the MM-1100/1200 but there was a basic constant tension system so wow was improved), as well as the 3M M-79, which was preceded by the M-56 and the M-23...just notice the different ideas of the tape path, wrap angles, static and rolling components...more than one way to tackle it for sure. I believe the 3M decks feature the shortest amount of unsupported tape which puts the flutter frequency components out of the audio band...flutter amplitude is less of a concern then and therefore so is the wrap angle around those incoming and outgoing static guides. The MM-1100 was notorius when it was introduced for its flutter producing tape path...no scrape flutter idler on the original MM-1100's either...a relatively large degree of unsupported tape, lots of wrap angle and nothing to mitigate the scrape flutter.

Enjoy...

Good point. Back when my little studio was the "land of many 3M machines" I had an M-56-8 and M-79-4 and M-79-2 along with an Ampex AG-440B 2-track (my M-23-2 was not working and lurking out of the way in several pieces at the time). The AG-440 was a solid performer, and perhaps better than the early MM machines, but the difference between the AG and the 3Ms in terms of audio band scrape flutter was one clear, audible difference.

John Stephens took the 3M transport a step further by eliminating the capstan, leaving just the guides, heads and reversing idler. The transport was driven by servo control of the reel motors. I assume he still had scrape flutter under control because Mitch Easter tells me that his Stephens machine sounded so steady and pure playing a 10K tone that you really couldn't tell if it was on input or repro except by looking at the controls.

Cheers,

Otto

 

[sweetbeats]

Good point. Back when my little studio was the "land of many 3M machines" I had an M-56-8 and M-79-4 and M-79-2 along with an Ampex AG-440B 2-track (my M-23-2 was not working and lurking out of the way in several pieces at the time). The AG-440 was a solid performer, and perhaps better than the early MM machines, but the difference between the AG and the 3Ms in terms of audio band scrape flutter was one clear, audible difference.

John Stephens took the 3M transport a step further by eliminating the capstan, leaving just the guides, heads and reversing idler. The transport was driven by servo control of the reel motors. I assume he still had scrape flutter under control because Mitch Easter tells me that his Stephens machine sounded so steady and pure playing a 10K tone that you really couldn't tell if it was on input or repro except by looking at the controls.

Cheers,

Otto

I had a feeling you'd chime in and I was hoping so...

The issue with the 440 becomes an even bigger concern in the 440-8 with those "biga** static guides" at the entry and exit of the headblock...plus the 440-8 takes that significant jog to the rotary guide first off of the supply reel before it goes to the reel idler so there is maybe another 12" of unsupported tape on the 440-8...

There was some dialog I'd read somewhere about a shootout between the M-79 and an early MM-1100...somebody that was involved at Ampex during the time or just prior to the development of the MM-1100, and I won't say the name because I'm not *positive* who said it but the comment basically centered around the nature of the team that assembled to develop the MM-1100 and that there were several oversights in the project and no flutter idler and all static guides and the design of the tape path was one of them...IIRC when they installed the flutter idler and rolling guides the MM-1100 came close to the M-79 in flutter performance but couldn't quite match it...I guess they had some issues with tape stretch on the M-79 so that was an element of the shootout too but there is only so much you can do with the MM tape path. It bears mentioning though that the people involved in the shootout couldn't *hear* the difference in flutter, but it was measurable. I must carry the Ampex flag here though as a fan with the MM-1200, which shares the same tape path design as the MM-1100 and certainly shares much with the MM-1000, and highlight that it is a VERY popular machine, arguably legendary, for its sound. It all comes back to the age old question (specs aside) "how does it sound?" The proverbial rubber meeting the proverbial road.

Otto, for crying out loud when are you going to quit talking about the Stephens and go get it??? Poop or get off the pot already.

And yes, that Stephens tape path must be noted...and ahead of its time

 

[ofajen]

Otto, for crying out loud when are you going to quit talking about the Stephens and go get it??? Poop or get off the pot already.

And yes, that Stephens tape path must be noted...and ahead of its time

Dale Manquen worked for 3M and made the first M-56 16 track machine, and then he went on to work for Ampex for a while. He did some work on the AG-440 C-series machine, but in our discussions he was quite clear about how far ahead he thought the 3M machines were of the Ampex machines in terms of audio performance until the ATR series came out.

As far as the 2" Stephens machine I've been interested in goes, yeah, it's a seriously cool machine, but in addition to a serious lack of money for the machine, calibration tape and tape stock, there're also the questions of whether I really want to bother with 16 tracks and whether I'm at all dissatisfied with my Otari 8-track. Not at all clear that either answer is yes.

My one purchase for this summer is a nifty little analog drum machine, the MFB-503 from Manfred Fricke in Berlin. I bought it to replace my old TR-606 that went insane. I've been using it just about every day since it got here and playing a lot and coming up with some new ideas, so it has been a very good thing!

Cheers,

Otto

 

[lonewhitefly]

does anyone know where one can find a Stephens deck? i've never seen on for sale anywhere. seems kind of like finding a chamberlin or something!

 

[sweetbeats]

Otto knows of a 2" 16-track...heheh...

No, they do seem to be pretty rare birds...hey Otto do you know how many were made?

I'd bet folks hold on to them as they are a pretty brilliant design, were relatively compact in size (I'm thinking of the 8-track) and are reputed to sound great.

 

[ofajen]

Otto knows of a 2" 16-track...heheh...

No, they do seem to be pretty rare birds...hey Otto do you know how many were made?

I'd bet folks hold on to them as they are a pretty brilliant design, were relatively compact in size (I'm thinking of the 8-track) and are reputed to sound great.

Almost all were multi-tracks. Very few small format 2 or 4-channel machines. I've read that he only made about 400 machines in total.

David Keane in Calgary has the Audities Foundation and he bought the last dozen or so machines John had on hand a short while before his death. David is now a key resource for those machines and my understanding is that he is remanufacturing the proprietary opamp modules needed for the machines. Brian Roth is a good person to contact as far as tech service. I believe he lives in Oklahoma City.

Keane was offering one 2" 24 track machine for $4K a few months ago. It was used formerly by the Grateful Dead as their remote recorder. Too rich for my blood and I don't wanna do 24-track, though my impression is that JRF has some 2" 16-track headstacks laying about for Stephens machines, so he might make someone a good deal on one.

I have been discussing a purchase of a 2" 16-track with someone else for a number of months. Obviously, neither the seller or I are in a hurry.

Cheers,

Otto

 

[cjacek]

David Keane in Calgary has the Audities Foundation and he bought the last dozen or so machines John had on hand a short while before his death.

Ooo... http://www.audities.org/audities/index.html

Enter the site and click on "Studio". Under "Equipment List" you can see several of those machines (you can click on the names to get photos with description). .....

Nice!

 

[sweetbeats]

Okay, so back to my rolling guide modifications for a sec...remember that I'm retrofitting a 440-8 rotary guide in place of the standard rolling guide right before the head cover, but I've been wigging out a bit over concern of finding the right screw to hold the guide to the guide block...I don't want to mod the guide and I don't want to have to mod the transport plate so the screw has to be a 1" flat-head machine screw...1/4" 28TPI...not realy common, and my ideal was to get it in stainless and in hex-socket drive...haven't found a thing on the internet...nothing local of course (small town)...out and about today and I stopped in at my favorite hardware store in the "big city"...wasn't expecting this...I go to the counter and tell the guy I need a 1/4" flat-head screw but in 28PI...he says "what length?" and I say "1 inch"...he says "no problem"...already I'm excited...I didn't care what finish it was in or what drive but I say "I don't know what finish you might have that in..." and he interrupts with "we'd only have it in blackened steel and stainless." Now I'm getting really excited and to cap it off he says "I hope hex socket drive is okay." $0.35. I'm freaking. Is it wrong to get so excited about finding the right fastener? That's what Ampex would have put on there. I'm just glad to have it as I can now mount the rotary guide...don't know when I'll get to that...the MM-1000 sits in the new garage all wrapped up until its new permanent home is finished...its a mess out there. Fortunately I think its pretty well protected but the cat keeps pissing on it...I don't know why she does that...like 6 times now. Can you imagine how crazy that's driving me??? Hopefully our windows get delivered tomorrow and I can get something permanent in the window opening in there to keep her out...

 

[Muckelroy]

Fortunately I think its pretty well protected but the cat keeps pissing on it...I don't know why she does that...like 6 times now. Can you imagine how crazy that's driving me??? Hopefully our windows get delivered tomorrow and I can get something permanent in the window opening in there to keep her out...

Well, on a few occasions our cat would pee in my dad's coffee.

 

[sweetbeats]

He ever drink the coffee before discovering it was "enhanced"?

When I was 14 my cat peed on ME as we were leaving on a 2 week family vacation...guess she didn't want me fooling around with other cats while I was away...she was rubbing my leg like cats do and then she backed up and...that was the only time she ever did that.

Hm...maybe our cat we have now is an Ampex enthusiast and is trying to lay her claim on my MM-1000...

 

[lo.fi.love]

He ever drink the coffee before discovering it was "enhanced"?

I once ate some cookies without knowing they were "enhanced". Who knew music tasted and looked so good!