Akai 747 w/DBX question


Hopefully there are still some reel to reel folks out there. So I currently have the 747 w/out DBX, and I have an opportunity to pick up the DBX version from a local person who owns a rather hi end audio store here in town. My question is: Is the Dynamic range extension worth the extra coin over the non DBX version? I don't record music from CD's to tape, and the added DBX if it works well should do wonders for recording from vinyl. I have owned reel to reels all my life but never this piece. Just curious if its worth the effort, and if you think it will it be an improvement.  
barnettk
I would take a pass on the dbx unit. If you really feel you need noise reduction would look at one of the pro units, dolby A 363, or a Dolby SR unit.

Other three options would be
1. get a set of half track heads for your 747
2. install a Vishay foil resistor at the loading position on the PCB where the signal from the head first goes to the board.
3. replace the wire from the head to the PCB with Mogami Console wire.

items 1-3 above will each reduce (increase S/N ratio) by a few db at 7.5 ips tape speed. 
@johnss

i have ave heard of the Doing the Vishay. Have not pushed it however. I’m not having a problem with much noise since I have been recording at 7.5. At the faster speed my recordings sound much much better. I was interested in the DBX mainly to get the bump on dynamic range which also by proxy reduces the noise however like I said the faster recording speed definitely improves things for sure. The Dolby A I think would improve the highs. The lower octaves are fine. I am also considering having re-capping the deck. It’s probably time since they have never been replaced or st least not since I have had the unit. I just feel that the highs have dropped off a bit. Not really a fan of demagnetization. There are two camps on that topic and it seems to be a little dangerous for me to try it myself even though I do have a demagnetislzer. Your thoughts on that.
barnettk
I was interested in the DBX mainly to get the bump on dynamic range which also by proxy reduces the noise however like I said the faster recording speed definitely improves things for sure. The Dolby A I think would improve the highs.
Dolby ’A’ will improve the highs and DR.

Not really a fan of demagnetization. There are two camps on that topic and it seems to be a little dangerous for me to try it myself even though I do have a demagnetislzer. Your thoughts on that.
I was not aware that there are two camps of thought about demagnetization. There’s no question that tape deck parts can become magnetized with use over time, which is obviously not good for the deck or any tape played on it. Demagnetization is actually part of routine tape deck maintenance. That it can be improperly done doesn’t mean that it should be avoided, imo.

@cleeds  

there are are some that think demagnetizing tape heads is not s good practice. Their words. Not mine. I was just curious to know how he felt about it. So you make a good point. I will never try it “myself” if it gets done it will be part of the bi annual service my deck gets. Good point tho. 
I would suggest demag'ing the heads every so often. Otherwise you will lose high freq response. Just make sure you use a demager with a protective tip and move the demager SLOWLY, you want remove magnetic fields from the heads not add them.

I demag the heads on my decks before doing any serious recording.

The stock load resistors on the 747 are carbon film. you may think the deck is quiet now at 7.5 ips, but wait til you listen to it with Vishays, you'll think you got 30% more musical detail coming through.

The other big benefit the 747 deserves is bypassing the audio stage coupling caps with film and foil caps.

Incidently the Vishays do wonders for MM and MC cart loading positions, but not trying to hi jack the thread.