Out board noise reduction

[clhboa]

Has anybody ever used one of these. How do they work? I was thinking about getting one and running my 8-tracks through it since they have so much hiss.

[retrokeeper]

I have a Concord Dolby unit that is an outboard type,it came with a 5" reel tape and a cassette that have test tones on them to calibrate the unit,but alas no 8-track tape.I need to test the unit to see if it even works,should be some way I can make a tape to do the 8-tracks....somehow?!? Rob

[TheReeler]

The noise reduction systems most time are encode/decode type, what means that you can't use the decode function with some piece that wasn't encoded previously, although it will reduce hiss, but also will reduce high frequences in the case of a Dolby A or B unit. If the unit is a dbx I or II, the decoded sound won't be "music".

There were some reduction systems to be used only in the playback, but never used one.

If I were you, I'd try to use a digital EQ to try to eliminate the hiss completly in the same way that a computer digital filter works.

[niklasthedolphin]

Before recommending digital processing of any kind, I think we should ask the starter of this thread what equipment he uses, what source and material he wants to record and what ambition he has.

Is it quality without compromise, digital processing interfering with analog recordings is not a good idea.

Is it tape hiss or LP clicks and pops that seems to be the problem?

It is correct that double ended NR systems are suffering from compatibility problems between machines (or units if external).

Single ended NR systems are more common in the recording line stage than in PB stage but are not available or at least scarce as external units.

On a cassettedeck, hiss can often be worked away by choosing another tape and do thorough calibration.
On R2R tape choise, speed, calibration are options.

"dolph"

[TheReeler]

I understood that he doesn't want to record, he wants to play 8 track tapes that have lot of hiss.

If he wants to record... the issue is different. I think taht nowadays, a second hand NR costs more or less the same that a second hand digital EQ and the result is really incredible because it also permits to solve some acoustic problems in our room.

[clhboa]

Yeah, The Reeler is right. I have no idea how these things work. I saw two DBX ones for sale and thought they be the answer to my 8-track tape hiss problem.

[TheReeler]

I don't remember the dbx model number of that unit, but if you find one at good price and you want a thing that is "plug and play", then that dbx is your best option.

On the other way, if you want to make measurement using a mike and correct some problems acoustics of your room, and reduce the hiss, then a digital EQ is the way.

[niklasthedolphin]

But if you use double ended NR in only one way, it works like frequenze correction/damping the treble?

You will loose a lot of treble this way.

I know nothing about 8-tracks.
They were never introduced for real in Europe.
But I assume they are generaly bad quality?

dbx and Dolby A, B, C and S are all double ended NR systems.
That means that they are supposed to used with the same allignments in playback as in recording.
Basicaly, they correct the frequenzee curve to enhance the treble comming in when recording so that treble will be reduced again when playing back.
At the same time tape hiss, which is high frequent, will also be reduced.

The Concord Dolby DBA-10 unit is also double ended NR system.
http://img.photobucket.com/albums/v500/dantiques/44000b/44011.jpg

So if 8-track is as I guess: It's not easy to turn a Lada into a Ferrari.

If you want to use dbx anyway, here (http://vintagedbx.free.fr/dbx.html) is a list of what dbx does what.
And here (http://vintagedbx.free.fr/forum/) is a forum to discuss the different dbx units in.

"dolph"

[TheReeler]

The dbx I was talking about is the 929. Take a llok at this:

http://www.dbxpro.com/discontinued/929.htm


Another good reference site:

http://audiotools.com/noise.html


Hope it helps.

[niklasthedolphin]

The dbx I was talking about is the 929. Take a llok at this:

http://www.dbxpro.com/discontinued/929.htm


Another good reference site:

http://audiotools.com/noise.html


Hope it helps.

Looks like a good suggestion.

"dolph"

[woutz99]

I also own a DBA-10 and suspect it is a Nakamichi OEM unit, just like some of their cassette decks at that time MK-6/7.
If you open it it looks like typical 70's Nak.
Anyone looked into this?