DBX 224 Disc/Vinyl Encoder/Decoder

[Karl C]

Cat Stevens; Tea for the Tillerman is another album on dbx which presents an amazingly rich tapestry in its presentation of the music.
The overall layering of instruments is very nice, and they are realistically  represented in space, with plenty of air around them.
Voices are also very clear with no hint of sibilance, with backing vocals sitting beautifully alongside leading vocals.
Acoustic guitars feature strongly on this album, and are not at all recessed.
Plucking of strings is easily heard, and the tone of the strings themselves are crystal clear, and well delineated from piano and drums.
Bass is clean and meaty also.
Absolutely superb rendition overall of this album on dbx!!

[Karl C]

Sarah Vaughan's Capacabana is a superb album. It's rendering on dbx is quite amazing.
Her voice is eerie and haunting, yet beautiful at the same time.
The layering of her voice comes across wonderfully on dbx.
With the palpable quiver in her throat echoing, almost lifelike, in between the speakers.
Syncopated rhythms and backing vocals themselves are surprisingly well layered, with percussion blending nicely into the mix.
The jazz guitar is melodic, and believable as its delicious tone dances in the air around the speakers.

[Christian Martens]

Just doing some listening to dbx discs.
Bought a copy of Oscar Peterson's, Action, a superb jazz album.

Sure, Action is a great album and "Exclusively for my friends" is a great set of records.
They all have been recorded in Villingen / Germany for MPS (Musik Produktion Schwarzwald is a German label, some translate it to most perfect sound  ).

AFAIK recording dates where in the 60s and are prior to the invention of dbx, so whatever that dbx-version did to this record, it is a kind of remix. Does the cover / booklet state they used the genuine tapes from MPS? The label is alive (again) and does reissues on vinyl.

enjoy the music,
Christian

[Karl C]

Sure, Action is a great album and "Exclusively for my friends" is a great set of records.
They all have been recorded in Villingen / Germany for MPS (Musik Produktion Schwarzwald is a German label, some translate it to most perfect sound  ).

AFAIK recording dates where in the 60s and are prior to the invention of dbx, so whatever that dbx-version did to this record, it is a kind of remix. Does the cover / booklet state they used the genuine tapes from MPS? The label is alive (again) and does reissues on vinyl.

enjoy the music,
Christian

[/quote

Hi Christian,

Interesting facts. I didn't know MPS was a German label.
However, this particular MPS version of Action was made by Nippon Columbia Co. Ltd. In Japan.

As for the dbx version there is nothing to indicate what tapes were used to press the vinyl. But whatever they did there is zero background noise (like a CD, LOL), and it is wonderfully dynamic.

Cheers, Karl.

[Karl C]

Another excellently recorded dbx disc is this Joan Armatrading self titled album.
It was recorded from a live concert appearance which is obvious from the raw sound of the performance.
However, it doesn't lack any of the dynamics I talked about previously with the dbx discs I have heard so far.
The clarity, stereo imaging, depth, and detail are all there.
While the cover is a little beaten up the disc is in mint condition, with a great lustre, shine, and not so much as a surface mark.

[Karl C]

Two more superlative discs on dbx are Captain and Tennille's, Song of Joy, and Rita Coolidge's Anytime Anywhere.
These are 80's classics, and were big on radio back in the day.
I don't ever recall hearing them with this much detail and nuance.

[analogadikt]

Looks like you have gone to the town hunting for DBX vinyl and have been enjoying yourself

Regards,

[Karl C]

Looks like you have gone to the town hunting for DBX vinyl and have been enjoying yourself

Regards,

Hi Anwesh,

Yes, I have been having a great time experimenting with this interesting part of the vinyl analog story.

So far I am really loving the full range, dynamic sound of these dbx discs. They really do sound amazing!

Mind you I have done a lot of modifications to the dbx unit, as I have outlined in this post.

What effect did that have on playback compared to the original unit?

Well, I can't tell you that because I never listened to it in its original form.

For example the original op amps LF 353N I removed and replaced with Burr Brown BB OPA2134PA. The 'BB's' are a modern equivalent of these old chips, and are much faster, and much better in every way. They are also a direct replacement, and do not require any other mods to install, such as a zener diode owing to differing voltages. Easy!!

 

I also have bought some original, unused dbx chips model 146221. Someone was selling these on eBay some time ago, and if one blows, no problem, I will be good to go after switching out the old one. I fully intend to keep the unit running indefinitely.

[swin]

Hello Karl C

I am most impressed with your upgrading of the 224. I acquired one awhile back, and one disc at the moment, I have downloaded the manual, the schematic is not very clear, how did you get on reading it, I am also convinced what is shown is not what is on the pcb layout, I am trying to find the play balance as mine is a little bit down on the right channel on play back, record levels are fine, it is a 117v and looking to convert to uk, any help would appreciate, I have search for a better copy of the schematic/manual without success as most peps have.

[Karl C]

Hello Karl C

I am most impressed with your upgrading of the 224. I acquired one awhile back, and one disc at the moment, I have downloaded the manual, the schematic is not very clear, how did you get on reading it, I am also convinced what is shown is not what is on the pcb layout, I am trying to find the play balance as mine is a little bit down on the right channel on play back, record levels are fine, it is a 117v and looking to convert to uk, any help would appreciate, I have search for a better copy of the schematic/manual without success as most peps have.

Hi,

Thanks for the kind words.

Sorry for not replying to your post sooner.

Indeed, I found the schematic to be rudimentary at best, nothing more than a basic reference.

Did you find out the problem with the channel  balance?

These units are some 40 odd years old, and could potentially have any number of issues. It doesn't hurt to rebuild them if you can find the time. When I first bought mine I didn't even bother to plug it in. I just replaced all the capacitors, and all the BJT's, which more often than not are the parts that wear out first, and that tend to give you issues over time. Also, solder joints themselves can dry out and cause issues like you are having, too. My unit was originally the 117v version, as well. I simply swapped out the old trafo with a 220v one, as pictured in this post. Using a step up/down external  transformer in line with the unit could also have caused your problems.

Anyhow, I hope you managed to sort out your issues, and get the unit up and running.

[Bacek]

Hi,

Hello Karl. Are you still using this DBX 224?

My first unit was 222 and I guess it was fine but I did not liked having step down voltage transformer as it was 110V unit, one I had was loud. So later I bought 224x with double power voltage support. It's slightly different than yours but set of features, inputs and buttons is the same. With this I have issue of playing normal records (not dbx encoded). With 222, pressing Bypass button was actually providing bypass functionality so it was passing turntable signal unmodified. With 224x seems that bypass works only for tape entries and disables tape encoding and decoding. How are you handling playing normal records with your decoder. I figured out that shorting tape in and out works with both bypass and dbx buttons pressed, which is not supported and trouble some to enable. Additionally there is possibility that enabling tape button (by accident) will blow thing out (as tape in and out are shorted/connected with rca cable)