Ampex MM1100 Variable Speed

[dawsonaudio]

I've been investigating hooking up a variable speed function to my Ampex MM1100/16 track.

Mainly, I'd like to throttle the speed down a little lower than 15ips. 7ips had a little too much high frequency roll off so I'm looking for something in between.

Would it be possible to send a signal from one of my DAW ouputs into the Ampex Variable Speed plug on the back of my machine. It looks like there is a dummy plug connected. 9600 hz is the frequency that the deck is currently using. I read in the Ampex manual that connecting to pin 2 (hot) and pin 3 (common) of the Variable Speed socket, I could add vso.

I'd create a track in my daw, insert a signal generator and feed that to the ampex deck. I'd wire pin 2 and pin 3 of the xlr out from my daw accordingly and float the ground lug at the input of the deck/variable speed socket. Would this work?

Thanks for any advice here.

Nate

 

[radardoug]

The signal on the input is single ended and relative to ground. You need a good level signal.
I would suggest a function generator would be better, as it is square wave out , and made for the job.

 

[dawsonaudio]

I'll try that out instead. Thanks for the advice.

Any recommendations on a entry level function generator? I've only ever used my DAW to generate tones for tape alignment, testing, etc...

 

[dawsonaudio]

I was able to get a good signal into the tape machine varispeed ref/in and adjust the tape speed via the DAW frequency generator, but the tape machine has a little flutter/ wobble to it like the tone generator isn't as precise and clean as the onboard reference 9600hz.

Any recommendations for a sub $200 dollar stand alone function generator that would work better than the output of my DAW?

Thanks,
Nate

 

[pucho812]

any reason why you want to varispeed?

 

[dawsonaudio]

I've been wanting to try out the 'in-between' speeds for a while now to see what the tape machine would sound like at say 22 1/2 IPS or at some arbitrary number like 12 IPS.

I don't have noise reduction for my deck so part of the reason I'd like to try speeds higher than 15 IPS would be to see if I can get a little less tape noise without going to 30 IPS which I don't really care for with the music I'm recording. Of course I can adjust eq to tape, but wanted to give the speed variation a try.

 

[gyraf]

..somebody should make a noise reduction system in-the-box-plugin for interfacing to tapes. Like dolbySR

(XR2206 is a decent function generator IC: https://www.aliexpress.com/item/1005006160600480.html )

 

[radardoug]

You already have the possibility to do the standard speeds. Tip, you can get more than two speeds out of an 1100.
And going in between would not be that different. It is already clear that your machine possibly has worn heads, since at 7 1/2 its not flat.
So is it really worth the effort? Of course you could use the varispeed for all sorts of musical experiments.

 

[dawsonaudio]

The heads are in great shape. Mostly I just wanted to test out the varispeed option on the deck and never really attempted to try to get it to work.

I've run all three speeds that the deck has to offer and have settled on 15 IPS. I like it the best of the three speeds.

I have been able to test it out again today and it's working like a champ with the signal generator from my DAW. I guess it was late the other night when I thought I was hearing a 'wobbly' sound. Of course, my alignment tape is only for 15 IPS so maybe I can compensate for the in between tape speeds without getting another alignment tape? I'm sure there's a crude way of doing it.

Thanks for the advice/help here. I really appreciate it.

 

[Brian Roth]

Once upon a decade, MCI floated the concept of a machine with up to 32 tracks using 3" tape. 20 IPS was one of the three speeds available on the transport. No mention of the EQ for 20 IPS.

Bri

 

[mg73]

Get a good signal generator and feed it to pin 2(Ref in) to the cinch jones connector.
Varispeed is the best tape efx

There is a mod for Ampex MM1100/1200 to get better low end at 30IPS,
will see if I can find the papers for it.
Mine has that mod and have great low end response