This is a very powerful demo. I'm really floored how the voice and keys seem quite unaffected by the DBX II, yet hiss is completely gone. Amazing demo, thank you for doing this. I am blown away by this DBX 224 unit. 👍
Thanks Christopher. DBX II is indeed very very good. However, Toshiba AUREX, Nakamichi HighCOM II and Sanyo SUPER-D are equally good or even better in some regards. I'll be posting a comparison video hopefully this week.
I still have my dbx 221, 224, 3BX units. They're like new. I bought them here in Philly, PA from, the now "out of business," Radio 437 in the late 70's and early 80's along with a few other "Top of the Line" audio gear of that era.
I have one of these that I purchased around 1981-2. I wanted to use it with my Revox A77 and on discs. It does work, but the tantalum caps in circuit gave it a harsh sound. When you recapped yours, did you use bipolar electrolytics and Wima polypropylene caps? I don't remember if they used carbon film or metal film resistors. Matching parts to less than 1% is always helpful to increase common mode rejection. Tracking compression/expansion rates must be tough. About 4 years ago I paid $50 for a spare on Ebay. About 30 years ago, I rebuilt the A77 with better caps (no tantalum caps) and matched less than 0.5% Rhoderstein metal film resistors. CMRR increased by at least 20 db! Too bad I haven't used either unit for at least 25 years. 🎧
I only replaced the electrolytics in this unit. Have not yet gotten to the tantalums. DBX used metal oxide and cabon resistors in this unit. I'm actually in the process of reworking the rec and PB amplifiers of one of my tapedecks (A-7300rx) with metal film and PP caps for lower noise figures.
I could not believe that DBX made the noise totally disappear, wow, and the music sounded superb. I do have two questions for you Ralph. Would this work with three head cassette decks only or two as well? Secondly, what is the difference between the one you got and 224X? I would appreciate your reply to my query. Once gain, thank you for uploading a great DBX demo.
Hi, sure, it will work with any cassette deck. With a 3-header, you'll be able to listen "live" to the recording (with DBX encoded+decoded), with a 2-header deck, you'll have to record first, and than play back. Either way, the DBX II will work. It has a build in encoder and decoder for both channels, so no need to swap cables or anything. Just hook it up as per manual, set the levels correct, and it will work like a charm. DBX224X has the same DBXII NR system as the one in my video, but also has a visual indication with LED's.
@@ralphlauwaert2245 hi, would you know where to get the service manual for this particular DBX II: I’ve got one that I want to be fully checked before pairing a Nak 600 II with? Thanks for that, great vid, can’t wait power the noise canceler up!
@@farchmarch7043 Unfortunately, there is no service manual for the DBX224 available. I've been looking for one as well. What you can do is download the service manual from the DBX224X-DS, and from page 7 and onwards, check you unit against the Performance Tests section. I found that my DBX224, after a recap, still performed perfectly well without any adjustments.
@@ralphlauwaert2245 sweet I'm just getting into cassette tapes from vinyl. I have a Nakamichi as a starter and recently bought an ADC SS thirty equalizer, this will be the next addition for sure. Do you have a list of what is needed to get recapped? A video tutorial etc?
@@OGSAFUNKATEER1901 I recapped this quite some time ago, I didn't keep a list of caps that were replaced. there weren't that many if I remember correctly. Disassembly is easy, the main PCB comes right out, making recaping quite easy. It is advised to also calibrate the unit, as it might have drifted out of alignment.
Hi Dave, I do not have documentation for the 224. You can find a service manual on the 224X-DS, and check your unit against the performance tests described in that document to see if everything is still running in spec.
2 things : First , the original recording, while interesting musically , has a lot of hiss on its own Here it is czcams.com/video/Mflf6qw4Yo0/video.html Second , why it does not sound horrible when you switch off the DBX , it should be horribly bright , so, this tape was recorded using the encoder of you just used a recording you already had ? THANK YOU !
The original recording has indeed some hiss to it, but record it to cassette (type I, no noise reduction), and you'll find that the cassette hiss will be much more present than the hiss of the recording. As to your question about the sound not beeing bad when turning off the DBX : you can freely switch between DBX in or out during recording. Note that the audio you hear in the video is taken from the DBX line-out. NOT the cassette deck line-out. Just as a clarification , this is the audio chain (as you should use a DBX compander) : Line out of my PC -> to DBX line in - > to DBX "cassette-line-out" to the line-in of the cassettedeck ->to Line-out of the cassettedeck to DBX "cassette-line-in" ->to DBX line-out to my PC's line in. So you see, the DBX system sits between my PC and the cassette deck. Hence, when switching between the DBX in or out, the only difference is in the hiss. If I were to listen to the actual cassette recording from the cassette deck line-out, the sound would switch between OK (no DBX) to horrible (DBX on) and back.
@@ralphlauwaert2245 Yes , the DBX unit is connected just like an equalizer with tape monitoring switch . What I don't understand , DBX uses dynamic processing plus an Eq curve that boosts high frequencies and cuts low frequencies during recording , when you switch the decoder off during playback , the hiss comes back , but I can´t hear the dbx encoded sound , to my ears sounds the same but with the usual hiss. Anyway , I don't want to give both of us headache . Cheers !
@@rodrigobelinchon2982 Look closely at the cassette deck : it's in recording mode. So switching between DBX in or out will only affect the hiss. But you are correct in the way that if I play (not record) a cassette that is recorded with DBX on, and THEN turn the DBX off, than yes, it will sound horrible. For for the purose of the video, I set the deck in recording mode (Tape monitor), and then you can switch between DBX in and out without horrible audio.
@@rodrigobelinchon2982 Perhaps this helps : with the cassette deck in recording mode, and the monitor switch of the deck set to "tape" this is what happens : with DBX OFF : there is no DBX compressing and expansion. The audio is just recorded to the tape as it comes out of my PC. Switch DBX ON, and the audio will be recorded WITH DBX compression on the tape, and , at the same time, the DBX unit will expand the audio coming from the tape back to normal audio, so you can listen to it normally. So, switching between DBX on or off has no influence on the audio, with the exception of the tape hiss that is removed. Now, if I record a complete cassette with DBX ON, then playback that same cassette, but turn off the DBX system, then I will hear the horrible audio.
This is a very powerful demo. I'm really floored how the voice and keys seem quite unaffected by the DBX II, yet hiss is completely gone. Amazing demo, thank you for doing this. I am blown away by this DBX 224 unit. 👍
Thanks Christopher. DBX II is indeed very very good. However, Toshiba AUREX, Nakamichi HighCOM II and Sanyo SUPER-D are equally good or even better in some regards. I'll be posting a comparison video hopefully this week.
@@ralphlauwaert2245 thx! would any of those be good to get, or could you recommend the best 2 please?
@@raindaresmusic That would be Toshiba A.D.R.E.S. or Nakamichi HighCom II.
Perfect! Love my DBX 224... love my DBX 122... and my DBX NX-40... I use with reel to reel decks... good Job, excellent video. Thank you.
Thanks Johnny, much appreciated!
I still have my dbx 221, 224, 3BX units. They're like new. I bought them here in Philly, PA from, the now "out of business," Radio 437 in the late 70's and early 80's along with a few other "Top of the Line" audio gear of that era.
Excellent 👏👏👏
wow , what a difference , thanks for showing 👌👌😉😉👍👍
Increible😀
I have one of these that I purchased around 1981-2. I wanted to use it with my Revox A77 and on discs. It does work, but the tantalum caps in circuit gave it a harsh sound. When you recapped yours, did you use bipolar electrolytics and Wima polypropylene caps? I don't remember if they used carbon film or metal film resistors. Matching parts to less than 1% is always helpful to increase common mode rejection. Tracking compression/expansion rates must be tough. About 4 years ago I paid $50 for a spare on Ebay. About 30 years ago, I rebuilt the A77 with better caps (no tantalum caps) and matched less than 0.5% Rhoderstein metal film resistors. CMRR increased by at least 20 db! Too bad I haven't used either unit for at least 25 years. 🎧
I only replaced the electrolytics in this unit. Have not yet gotten to the tantalums. DBX used metal oxide and cabon resistors in this unit. I'm actually in the process of reworking the rec and PB amplifiers of one of my tapedecks (A-7300rx) with metal film and PP caps for lower noise figures.
I could not believe that DBX made the noise totally disappear, wow, and the music sounded superb. I do have two questions for you Ralph. Would this work with three head cassette decks only or two as well? Secondly, what is the difference between the one you got and 224X? I would appreciate your reply to my query. Once gain, thank you for uploading a great DBX demo.
Hi, sure, it will work with any cassette deck. With a 3-header, you'll be able to listen "live" to the recording (with DBX encoded+decoded), with a 2-header deck, you'll have to record first, and than play back. Either way, the DBX II will work. It has a build in encoder and decoder for both channels, so no need to swap cables or anything. Just hook it up as per manual, set the levels correct, and it will work like a charm. DBX224X has the same DBXII NR system as the one in my video, but also has a visual indication with LED's.
This is all on a type I cassette? That's amazing.
Yes, the cassette is type I. It's a Maxell SL-N90 that I bought in the mid '90s. DBX II works really well.
@@ralphlauwaert2245 hi, would you know where to get the service manual for this particular DBX II: I’ve got one that I want to be fully checked before pairing a Nak 600 II with? Thanks for that, great vid, can’t wait power the noise canceler up!
@@farchmarch7043 Unfortunately, there is no service manual for the DBX224 available. I've been looking for one as well. What you can do is download the service manual from the DBX224X-DS, and from page 7 and onwards, check you unit against the Performance Tests section. I found that my DBX224, after a recap, still performed perfectly well without any adjustments.
@@ralphlauwaert2245 thank you very much indeed for precious datas😉👌
Did you take it to get recapped or did you work on it on your own? This is an amazing device
I recapped it myself and also performed calibration .
@@ralphlauwaert2245 sweet I'm just getting into cassette tapes from vinyl. I have a Nakamichi as a starter and recently bought an ADC SS thirty equalizer, this will be the next addition for sure. Do you have a list of what is needed to get recapped? A video tutorial etc?
@@OGSAFUNKATEER1901 I recapped this quite some time ago, I didn't keep a list of caps that were replaced. there weren't that many if I remember correctly. Disassembly is easy, the main PCB comes right out, making recaping quite easy. It is advised to also calibrate the unit, as it might have drifted out of alignment.
By the way, I would love a manual or schematic of the 224, if you have one. 🎧
Hi Dave, I do not have documentation for the 224. You can find a service manual on the 224X-DS, and check your unit against the performance tests described in that document to see if everything is still running in spec.
Iono if im fooling myself but something sounds funny about the processed version
2 things :
First , the original recording, while interesting musically , has a lot of hiss on its own
Here it is czcams.com/video/Mflf6qw4Yo0/video.html
Second , why it does not sound horrible when you switch off the DBX , it should be horribly bright , so, this tape was recorded using the encoder of you just used a recording you already had ?
THANK YOU !
The original recording has indeed some hiss to it, but record it to cassette (type I, no noise reduction), and you'll find that the cassette hiss will be much more present than the hiss of the recording. As to your question about the sound not beeing bad when turning off the DBX : you can freely switch between DBX in or out during recording. Note that the audio you hear in the video is taken from the DBX line-out. NOT the cassette deck line-out. Just as a clarification , this is the audio chain (as you should use a DBX compander) : Line out of my PC -> to DBX line in - > to DBX "cassette-line-out" to the line-in of the cassettedeck ->to Line-out of the cassettedeck to DBX "cassette-line-in" ->to DBX line-out to my PC's line in. So you see, the DBX system sits between my PC and the cassette deck. Hence, when switching between the DBX in or out, the only difference is in the hiss. If I were to listen to the actual cassette recording from the cassette deck line-out, the sound would switch between OK (no DBX) to horrible (DBX on) and back.
@@ralphlauwaert2245 Yes , the DBX unit is connected just like an equalizer with tape monitoring switch .
What I don't understand , DBX uses dynamic processing plus an Eq curve that boosts high frequencies and cuts low frequencies during recording , when you switch the decoder off during playback , the hiss comes back , but I can´t hear the dbx encoded sound , to my ears sounds the same but with the usual hiss.
Anyway , I don't want to give both of us headache . Cheers !
@@rodrigobelinchon2982 Look closely at the cassette deck : it's in recording mode. So switching between DBX in or out will only affect the hiss. But you are correct in the way that if I play (not record) a cassette that is recorded with DBX on, and THEN turn the DBX off, than yes, it will sound horrible. For for the purose of the video, I set the deck in recording mode (Tape monitor), and then you can switch between DBX in and out without horrible audio.
@@ralphlauwaert2245 Right now I am confused , I'll come back later and watch it again . Thank you again !!
@@rodrigobelinchon2982 Perhaps this helps : with the cassette deck in recording mode, and the monitor switch of the deck set to "tape" this is what happens : with DBX OFF : there is no DBX compressing and expansion. The audio is just recorded to the tape as it comes out of my PC. Switch DBX ON, and the audio will be recorded WITH DBX compression on the tape, and , at the same time, the DBX unit will expand the audio coming from the tape back to normal audio, so you can listen to it normally. So, switching between DBX on or off has no influence on the audio, with the exception of the tape hiss that is removed. Now, if I record a complete cassette with DBX ON, then playback that same cassette, but turn off the DBX system, then I will hear the horrible audio.