8mm Forum: How Do I Use The Preamp Out On An ST-1200?

This is topic How Do I Use The Preamp Out On An ST-1200? in forum 8mm Forum at 8mm Forum.

To visit this topic, use this URL:
https://8mmforum.film-tech.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=001015

Posted by Dan Lail (Member # 18) on January 27, 2005, 01:26 AM:

I have an ST-1200HD Mag/Optical projector. I have the projector in a sound proof booth. I run the sound out through the aux and into a small mixing board that is preamp only and from there into a 50w per channel stereo amp. This sounds okay on most prints. But when running the sound out of the preamps out, what is the best piece of gear to have inline between the projector and the stereo amp?
Also, mag sound prints sound better through the preamp out than the optical prints do. The opticals have very weak sound through the preamp outs. Why? [Confused]

Posted by John Clancy (Member # 49) on January 27, 2005, 01:52 AM:

Agnello Guarracino uses a car audio thingy which converts ordinary speaker outputs into normal hifi line outs. Cost him £10 and should be available anywhere that does in-car audio hardware. It was designed for older in-car equipment which don't have hifi outs.

Posted by Tim Christian (Member # 48) on January 27, 2005, 06:56 AM:

Something like this?

Posted by Kevin Faulkner (Member # 6) on January 27, 2005, 07:43 AM:

You really need to lift the output from the 2 moni sockets on the rear of the machine. This will allow you to playback stereo sounctracks through a stereo amp. The only problem is that the level out from these sockets is not that high so you need to have an amp with a fairly sensitive input.
Optical sountracks tend to have a lower output than the mag tracks. On my GS I have altered a couple of resistors to bring the average level up to the same as the mag output level. This is also possible to do on the ST1200.

Kev.

Posted by Dan Lail (Member # 18) on January 27, 2005, 01:40 PM:

Thanks Tim & John, I'll look into these devices also. [Smile]

Kev, I would really rather use the two moni preamp outs because it would eliminate light noise from the final power amp creeping into the audio and allow stereo play back. This sensitive amp that I should place on line between the two monis and the stereo amp, I guess it would be a stereo preamp, right? [Confused]

As far as optical sound tracks, can they be reproduced in stereo? If not I could just use the device Tim & John suggested, right? [Confused]

Posted by Paul Adsett (Member # 25) on January 27, 2005, 03:09 PM:

Dan, I would strongly recommend that you feed the output from the projector first into a 10 band graphic equalizer, and then into the stereo amplifier. The equalizer can be used to filter out low frequency hum, and to boost high frequency response. It can dramatically improve the quality of both mono and stereo sound tracks.

Posted by Chip Gelmini (Member # 44) on January 31, 2005, 08:28 PM:

Attention KMart Shoppers

AUX OUT: Mini from the projector to RCA male (mono. Next connect female single RCA to Female double RCA splitter. Connect standard left/right stereo RCA audio cable between female double RCA splitter and the stereo receiver input. This will promise you get the sound out of all channels used. NOTE: This works as a pre-amp meaning the projector volume must be turned up in addition to the receiver volume control turned up for sound to be heard.

MONI1 / MONI 2: Purchase one pair of MINI to RCA female adapters (about 1 inch long) and connect standard stereo RCA left/right male cable between adapters and stereo receiver input. This will promise that stereo sound will be true coming from the ST1200HD. Note these plugs are fixed output. Volume adjust will be ONLY with the receiver volume control.

Optional Accessories:

Radio Shack audio video switcher. Use this for audio only connections and give the ST1200HD what it really needs: a mono/stereo switch (that the GS1200 has). You can use this with only one input on the receiver amplifier. No more swapping cables. Recommended that this device be electrical to have it's own power, and to promise that no sonic BOOM will be heard if you switch modes while playing film at the same time.

Dan, this should really help you quite abit. I invited Ernie to Cape Cod, you're welcome to visit too, although you have further to go. I'll be cruising down I-95 in April on my way to Florida for a vacation, if you're not too far out of the way I could stop by and show you how to do this only takes a few seconds assuming you have all the right stuff.

CG

UBB.classic^TM 6.3.1.2