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  DBX Expander
I have recently acquired a Teac reel to reel and although it's a great machine, soundwise, it just doesn't measure up to CD or LP's in my system. I have a chance to purchase a DBX sound expander that I'm told greatly enhances the sound of the tape. I have no experience with this box at all. Does anyone have any knowledge of what this does?
Markus1299  (Threads | Answers | This Thread)

  Responses (1-28 of 28)
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10-11-08   The purpose of the expander is to attempt to undo some of th ...   Ghostrider45

10-11-08   I agree as well. the dbx does to much pumping of the signal. ...   76doublebass

10-11-08   Well, i totally disagree with the 2 comments above. i have d ...   Opalchip

10-12-08   I think opalchip has a great point, first spend the money to ...   Buconero117

10-12-08   Dbx is no substitute for properly functioning equipment. a ...   Mapman

10-12-08   I've not heard the dbx, but agree with an r2r tuneup. i rece ...   Jb0194

10-12-08   Thanks for all of your responses!! this is a wonderful site ...   Markus1299

10-12-08   $700 is a lot. i paid between 2-3 hundred for mine on ebay. ...   Mapman

10-13-08   First - $700 is ridiculously high for a 3bx. the best 3bx, w ...   Opalchip

10-13-08   Markus, the first this i would do is have the reel to reel ...   Normansizemore

10-15-08   Dbx nr (type i or type ii) pretty much requires good equipme ...   Bdymek

10-17-08   Fyi, a 5bx just sold on ebay tonight for $1100 which was act ...   Opalchip

10-17-08   Opalchip, nice read about the dbx gear. thanks. the compr ...   Mapman

10-18-08   What a great thread! i have a perfect 3bx-ds sitting in my ...   Emailists

10-18-08   If you dial it in properly, i doubt you will want to sell it ...   Opalchip

10-19-08   Would you be willing to sell your unit???? i'm curious to ex ...   Markus1299

10-19-08   I certainly don't want to sell mine, but the 3bx-ds is very ...   Opalchip

10-19-08: Crem1
DBX'ers : I own a mint DBX 117 that's been in storage for many, many years. Do you feel its worth re-installing in my rig ?
Crem1  (Threads | Answers | This Thread)

10-19-08: Mapman

I had a similar single band 118 at one time and did not like it in general for expansion in my system...too much pumping and breathing introduced with only a single band.

I did use it on occasion for compression in order to listen to recordings more effectively late at night at lower volumes.

I do use the 3 band 3bx for expansion in my system currently and would find it hard to live without on many recordings, particularly on vinyl.

Yesterday I played a vinyl copy of "Thick As A Brick" by Jethro Tull that I recently picked up for the first time. It sounded fantastic right off save that the dynamics were noticeably compressed. I switched in the 3BX and things took off without reservation from there. It was sweet indeed!

Mapman  (Reviews | Threads | Answers | This Thread)

10-21-08: Frzninvt
Just so that you guys know the 5BX offers NO upward expansion! All the expansion the 5BX offers in downward. the only upward expansion you perceive is the 5 bands of indepdently adjustable impact restoration. The 5BX is more of a compressor than it is an expander. The the crap quality of CD recordings these days the 5BX is an invaluable tool to compress the way oversaturated & distorting CD's being spewed out by the music industries these days.

The 3BX-DS on the other hand does provide upward expansion and does have 3 bands of impact restoration. If you are using vinyl, tape, RTR, or MP3's the unit you may want to use is the 3BX-III it's processing style is more aggressive than that of the 3BX-DS and geared toward analog sources. It offers 12db of impact restoration vs. the 10db provided by the DS unit. That said the 3BX-III can be made to sound bad if you are too aggressive with the transition level and expansion controls so keep them moderate. The 4BX uses the same processing style as tne Series III but comes in a bigger box and is remote controllable if the owner hasn't lost it over the years.

Another kick ass thing to try is to run dual 3BX-DS units, one for each channel. The VCA's in these units are mono-triggered so you can use some quality "Y" adapters and use one for left and one for right. Make sure that the transition level potentiometers on the rear of the units are in the same positions. The difference and performance will astound you. Better defined image, tighter response, and stunning impact. I have run this configuration with dual 5BX's, 4BX, and the 3BX-DS units are my favorite combo.

It has been said that Pioneer got the expansion thing right using stereo VCA's so try a EX-9000 expander as well. It is a three band unit, the bands are independently adjustable and it has two processing styles based on the music you are putting through it. The choices are "hard" and "soft."

Another unit that operates similarly is the BBE 1002 or ARS these units focus on high level detail and also provide a "lo contour" to boost the bottom end. Alpine and many other companies offer scaled down versions of the BBE process in thier units. A stand alone version for the home is much better and will make more than a subtle difference. The Pioneer and BBE units will usually cost you less that $100.

I have used these units extensively for over twenty years and never noticed any pumping or artifacts with them. I run an all Klipsch Heritage system so dynamics are off the scale, and the level of realism achieved has to be heard to be believed. Even at levels in the 125db to 130db range in the living room. I still use a DBX DX5 CD player that has built in processing and can play any CD-R out there.

Frzninvt  (Answers | This Thread)

10-21-08: Mapman

Great information. Thanks!

I have a 3BX series II I picked up for a couple hundred about a year back on Ebay that I think is worth its weight in gold when a particular recording needs it. How is that similar or different from the others?

Mapman  (Reviews | Threads | Answers | This Thread)

10-21-08: Frzninvt
The 3BX series II was shrunk down by the use of IC's vs. the all discrete circuits found in the original wooden side 3BX unit. This is actually the least favored unit of all for whatever reason (some say it exhibited the pumping effect), not sure if the Series II still used Stereo or Mono VCA's but the stereo VCA's in the original 3BX caused the image to wander.

I owned one for a short period of time and found no issues with it. I prefer the later models because of the addition of the "impact restoration" function which really increases the realism of the percussion attacks. As with all range expander wise use of the transition and expansion levels provide the best results.

Frzninvt  (Answers | This Thread)

10-21-08: Mapman
I don't hear those issues with it either. Impact restoration would be an interesting enhancement to try, though impact of percussion is certainly improved significantly just through expansion as is with the 3bx S2. Percussion has startled me and made me jump on several recent occasions with the 3bx switched in.
Mapman  (Reviews | Threads | Answers | This Thread)

10-21-08: Opalchip
I use my unit primarily for the Impact Restoration. The effect of the IR is to really open up the leading edge of sounds that already have a fast attack. High hats, cymbals, plucked strings, bass thumps really sound much more like live music. Until you A/B back and forth, you don't realize what you've been missing - once you do, there's no going back.
Opalchip  (Threads | Answers | This Thread)

10-21-08: Frzninvt
I totally agree when it comes to dial it in by frequency range, and adjustable independent impact level, and overall output level the 5BX has no equal. The Impact Restoration function is worth the price of the 5BX alone. The other features certainly have their place as well it is a great sounding musical piece of equipment. It also has a very elegant look to it. It's rarity certainly makes it a conversation piece.

I have heard of people using the Quantum or Quantum II to perform similar functions and over larger frequency ranges but I have never tried one myself.

Frzninvt  (Answers | This Thread)

10-21-08: Markus1299
Thanks guys for all the very valuable responses. I have had my A4010 reel to reel completely refurbed and my 3BX series 111 is on it's way so it should be an interesting experience through my Cary Slp05. I'll let ya know what I hear or don't hear

Markus1299  (Threads | Answers | This Thread)

10-22-08: Emailists
Since my system is balanced, and I'd like to keep it that way, could I just use one 3BX-DS for each channel? Meaning left is inverting - right is non inverting, then combine them back to XLR? I already use gear (Strain Gauge) that puts out balanced signals over 2 RCA's, and have a custom adaptor that goes from 2 RCA's to XLR.

Frzninvt - is this what you are referring to, or did you mean the signal goes through expansion twice? Please elaborate.

Emailists  (System | Threads | Answers | This Thread)

10-22-08: Frzninvt
The VCA's in the 3BX-DS are mono triggered so dedicating one each to each channel (L & R) improves imaging, staging and definition. It also gives you the flexibility to adjust the channel expansion independent of one another.

I used 2 male RCA to a single female "Y" adapters (two per unit) giving me a single "mono" input on each unit. One for the left channel and one for the right channel. Not daisy chained. I suppose you could do it with XLR to RCA adapters.

Make sure the rear mounted trim pots for HF & LF transition are set equally on the units. You can tweak them as necessary by watching the front displays so you are getting the same level of expansion out of each unit. Having units close in manufacture dates helps too.

The 3BX-DS can be calibrated and adjusted using the Service Manual. Better capacitors in the power supply improve performance as well.

Frzninvt  (Answers | This Thread)

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