Broadcast Audio limiter/compressor in audio chain for newbie

Discussion in 'Amplitude Modulation' started by KD6CXW, Jul 28, 2019.

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  1. KD6CXW

    KD6CXW Ham Member QRZ Page

    yes l'll be running the Bauer from central Michigan and thanks for the link. will post when shes home and up and running.
    sill getting thing around and have somethings like oscope ,station monitor,service monitor and looking at REA modulation monitor.
  2. KD6CXW

    KD6CXW Ham Member QRZ Page

    now this may be an option and may try . they have free trial and different ad on's the price is not bad as well .
  3. N2DTS

    N2DTS Ham Member QRZ Page

    Does the 528e have that?
    Does any non broadcast compressor have the delay?

  4. KA0HCP

    KA0HCP XML Subscriber QRZ Page

  5. K5UJ

    K5UJ Ham Member QRZ Page

    You'd think the 528E is the only box in the world of audio worth owning from the way it is being almost incessantly mentioned here. At around $900 new and $450 used, I'd explore other options, especially since what it does do can be accomplished in other ways or not bothered with. A de-esser isn't vitally important for example. Use a mic tailored for voice response and you can blow off the eq. The priority should be on a genuine tight peak limiter designed for AM broadcast and let everything else follow since the Symetrix box can't do that. Maybe it's fine for slopbucket who knows. I run an old Shure xtal mic that has a 10 dB rise from 100 cps to 5kc followed by a 20 dB roll off. I don't use an eq. It has enough output to drive a 6SC7 preamp stage which feeds a 60K to 500 ohm step down transformer to drive a Hnat-Hindes Tri-Maze, which is a broadcast processor/limiter I picked up at Dayton for $175. That drives the rest of the p.p. 6V6 speech amp via an isolation transformer on the output of the Tri-Maze, and the 6V6s drive the rig. You can run an Inovonics 222 or PMC to a minor amount of compression, say 6 dB gain reduction. If you want to get fancy you can find a CRL SEP400B 4 band compressor for multi-band compression. You probably already have a mic preamp I'm guessing but a Cloud Lifter is around $75. There are used graphic equalizers all over the place if you need one. Don't be in a big rush. A peak limiter will show up at some point. Try one processing chain element at a time.
    KM1H likes this.
  6. N1BCG

    N1BCG Ham Member QRZ Page

    How do you like that box? We bought a MicMaze and TriMaze to replace an Inovonics MAPII (yikes) and Steve Hnat himself brought and installed them.

    I wasn't thrilled with the three multiband outputs driving the wideband clipper without some kind of limiter in between (as the MAPII had). It was used on a full service music/talk station so the content was quite varied. The clipping level seemed inconsistent and highly dependent on content. The Hnat-Hindes line is super clean for sure, but it was eventually replaced with an Orban 9100B.

    Years later I was at another station with a TriMaze as a backup for their BTA-1AR. They're everywhere!
  7. K4KYV

    K4KYV Premium Subscriber Volunteer Moderator QRZ Page

    Especially for AM amateur use, and maybe even for AM broadcast. If anything, it would be counterproductive. Under normal less-than-perfect band conditions, given the i.f. passband and audio frequency response characteristics of the typical AM receiver, we more often than not need as much sibilance boost as we can get. Hence the built-in "presence rise" in the speech amp of many ham rigs and the 3 to 4 kc response bump in the D-104.
    KM1H likes this.
  8. K5UJ

    K5UJ Ham Member QRZ Page

    I've run the 222, and the CRL SEP400B and PMC450 and I think the Tri-Maze is my favorite of those. You get a preprocessor (compressor) to something they call TALE (triggered absolute level expander--the bogus mumbo jumbo in audio is amazing) followed by a three band compressor and then a limiter/clipper on the output. I think I have it set on 150 uS preemphasis. It has loudness without sounding "processed" to my ears. If it craps out it will kind of suck because the downside is I can't find a decent manual for it anywhere. It also has these green modules in it that must be proprietary crossover networks that are naturally unobtainium now, the one drawback to old processors.
    The fix for that from what I've heard is to put an Aphex Compellor or whatever the leveling Aphex unit is, ahead of the Tri-Maze. I'd like to try that myself but I'm the only program content there is at K5UJ.
    If you run across a manual for one please let me know. I'll pay for it. I have a really bad partial copy that's a copy of a fax. Schematics are no good.
  9. N1BCG

    N1BCG Ham Member QRZ Page

    I remember moving from it the studio (why there??) to a file cabinet at the xmtr site. I doubt it would be a big deal to scan it. The Hnat-Hindes manuals are only a few pages but Steve liked the full blue print size schematics. That will be the challenge.
  10. KD2ACO

    KD2ACO Platinum Subscriber Platinum Subscriber Life Member QRZ Page

    If you have a Kinko's office nearby, they have a nice E-sized scanner that's a couple bucks for the big sheets.

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