Top or bottom, left or right?

sweetbeats said:
How does the reversing idler mount? The rotary guide on the Ampex 440-8 is held to the transport plate by a center bolt, but there are three fat set screws underneath also so the guide actually sits on a fully adjustable tripod. Good and bad but I wondered if there was any adjustability like that on your reversing idler...not that it should need it with a deck plate like that! :eek:
Click to expand...

It just uses a center bolt and the base mounts flush on the deck plate. No set screws, however. Once you get it almost tight, it starts to slip on the deck plate surface, so it's easy to just rotate the whole thing with the Allen wrench while watching where the tape goes on the idler. I've got it in a much better alignment, and the response is radically different, even without doing a proper alignment, which I will.

I also have some extra audio cards (#1 bias/erase and #4 record preamp) so I do have some options if those cards seem flaky on the machine. I did already pull the lower #1 card. It just wasn't doing the job biasing the machine. The annoying thing right now is that the left channel #4 (I think) works OK on playback, but I don't seem to get the input signal. I may swap that card out, too.

Cheers,

Otto
 
I don't suppose there's any chance of a picture of the linkage between the motor and the tape drive? I'm kind of struggling to figure it out :p
 
ofajen said:
More pictures...

The whole mix area:
IMG_7898.jpg
Click to expand...

Cool beans!

I gotta have that Charlie Brown garbage can. :)
 
jpmorris said:
I don't suppose there's any chance of a picture of the linkage between the motor and the tape drive? I'm kind of struggling to figure it out :p
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It's a rim drive. The capstan motor shaft points down. When it shifts into PLAY mode, the capstan motor shaft swings into contact with the rubber tire on the outside edge of the flywheel that is bolted onto the end of the capstan assembly. Here's an old picture when the transport was unmounted and I had it tipped up to work on the underside. You can see the big flywheel with the black rubber tire on the edge and the capstan motor shaft below the bottom of the flywheel....

IMG_5879.jpg


Cheers,

Otto
 
sweetbeats said:
:eek::eek::eek:

That flywheel looks big enough to go in my CAR...!

That capstan motor must spin pretty fast...:eek:
Click to expand...

I have a spare flywheel, unused, quite possibly the only one on the planet. It's hefty, probably at least five pounds. They really didn't mess around with this machine. The transport weighs 65 pounds, unmounted. The electronics racks are about 15 pounds each, so the eight track weighed about 300 pounds, including a bit over 100 pounds for the console.

I know the Ampex model 300 had a rim drive and was viewed as problematic, but so far I haven't seen much that concerns me. The flutter spec at 15 ips is .04% for flutter components 0.5-300Hz and .05% for flutter components 0.5-5000Hz, which is decent even today.

Cheers,

Otto
 
Last edited:
ofajen said:
It's a rim drive. The capstan motor shaft points down. When it shifts into PLAY mode, the capstan motor shaft swings into contact with the rubber tire on the outside edge of the flywheel that is bolted onto the end of the capstan assembly.
Click to expand...

Wow. I figured the distance between the motor and what appeared to be the capstan was too great and I must have been missing something. That explains everything. It can't be much fun if the rubber needs to be rebuilt.
 
jpmorris said:
Wow. I figured the distance between the motor and what appeared to be the capstan was too great and I must have been missing something. That explains everything. It can't be much fun if the rubber needs to be rebuilt.
Click to expand...

I haven't had to, but I know there are a few folks who still do such things. There's a fellow named Terry, I think, who does that.

The later M-65/M-64 units used a belt drive with the same geometry. The belt just ran around the capstan motor shaft and a part of the outer rim of the flywheel, which was about the same size and shape. That's why it's not a huge deal to upgrade the transport to belt drive. You just need a new motor, flywheel and a couple of electrical components, all of which I have.

Of course that would shift the thing to 30/15 ips and I would either need new record and playback amp cards or I'd have to mod them to produce the proper eq. I could probably just snag some M-56 cards at some point.

Cheers,

Otto
 
ofajen said:
I haven't had to, but I know there are a few folks who still do such things. There's a fellow named Terry, I think, who does that.
Click to expand...
Yeah, but they're generally used to getting a pinch roller in a jiffy-bag or something. That thing is the size of a dinner plate by the looks!
 
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