mod to be able to record digitally with the internal microphones of a boombox
- Thread starter hansgauffin
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hansgauffin
New member
https://soundcloud.com/hitachi-trk5280e/trk-5280-mono1
I recorded the sound from the internal mics (bounced to mono) when in REC/PAUSE mode straight from the headphone amp into a minidisc.
Listen to the different noises, I want to get rid of them,! and I´m sure there must be some way to remove the "motor" sound? but I´m a little bit more worried about the static noise, (that sounds like an old vinyl)?
any help finding the origin of these sounds would be helpful!
thanxs
I recorded the sound from the internal mics (bounced to mono) when in REC/PAUSE mode straight from the headphone amp into a minidisc.
Listen to the different noises, I want to get rid of them,! and I´m sure there must be some way to remove the "motor" sound? but I´m a little bit more worried about the static noise, (that sounds like an old vinyl)?
any help finding the origin of these sounds would be helpful!
thanxs
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A Reel Person
It's Too Funky in Here!!!
...
The clicking noise (like vinyl) sounds to me like a static/grounding problem.
If it was coming from tape I'd recommend demagnetizing the heads.
The clicking noise (like vinyl) sounds to me like a static/grounding problem.
If it was coming from tape I'd recommend demagnetizing the heads.
hansgauffin
New member
Since the wav file I put up is recorded straight to minidisc I´m not sure if the record head would be involved in any way??
But I do have a head demagnetizer so I could try that!
But I do have a head demagnetizer so I could try that!
hansgauffin
New member
okey, I demagnetized the heads but the crackling is still there,, Next move is to try batteries,,and perhaps get the manual to find out where the headphone out is taking the signal from,,
miroslav
Cosmic Cowboy
hansgauffin
New member
haha!! I know it might seem wicked, but I actually like doing wicked things,, 
haha,,
haha,,
Lt. Bob
Spread the Daf!
actually I get the point and in the past I have argued for folks like you doing something like this just for the sake of doing it so let me withdraw my objection and express curiousity over how this will turn out.haha!! I know it might seem wicked, but I actually like doing wicked things,,
The easiest way is obviously gonna be if you can use the headphone out and simply monitor the mic's.
That's also gonna be the closest to the original sound you're liking as it will go thru much of the circuitry it normally goes thru.
If that doesn't work ...... seems to me if you open it up there's gonna be the usual 2 wires (or traces) that carry audio and then a wire that puts power to the mic. Seems like you could tap into them there.
hansgauffin
New member
Here is the schematic diagram, you can view it in a bigger version if you open it in a new window
can someone see if the headphone amp takes i´ts signal from the record head?
I marked the inner mic´s with a red square and the headphone out with a blue square, i cannot find the heads though??
can someone see if the headphone amp takes i´ts signal from the record head?
I marked the inner mic´s with a red square and the headphone out with a blue square, i cannot find the heads though??
A Reel Person
It's Too Funky in Here!!!
...
The headphone out does not come "off" or "thru" the head. The head is designated in the diagram with the little circle thing with the arrow, as R/P-H (record/play head), right and left, respectively.
From what I see in my minimally competent view of schematics, is that the R/P head gets a practially raw and unamplified signal from the internal mics, then the signal is split and amplifed to the Line Outs (DIN connector) and further amplified again to the Headphone Out.
Maybe you could tap the signal off the pins 2/3 (L) and 2/5 (R) of the DIN connector, which is off the LINE amp, and bypasses the Headphone amp entirely.
There are guys on this board who are way more savvy at reading schematics than I am. I'm sure they'll comment.
The headphone out does not come "off" or "thru" the head. The head is designated in the diagram with the little circle thing with the arrow, as R/P-H (record/play head), right and left, respectively.
From what I see in my minimally competent view of schematics, is that the R/P head gets a practially raw and unamplified signal from the internal mics, then the signal is split and amplifed to the Line Outs (DIN connector) and further amplified again to the Headphone Out.
Maybe you could tap the signal off the pins 2/3 (L) and 2/5 (R) of the DIN connector, which is off the LINE amp, and bypasses the Headphone amp entirely.
There are guys on this board who are way more savvy at reading schematics than I am. I'm sure they'll comment.
hansgauffin
New member
Thanks for taking your time, helping me out on this one!
So, from what I can tell by your reply I could aswell use the output (DIN) to monitor the internal mics?`
Thats good to know!
Can you see how I could turn of the mechanisms in the tape player (or whatever is causing the "steam engine" sound? and still be able to monitor the internal mics?
Preferable the easiest way?
So, from what I can tell by your reply I could aswell use the output (DIN) to monitor the internal mics?`
Thats good to know!
Can you see how I could turn of the mechanisms in the tape player (or whatever is causing the "steam engine" sound? and still be able to monitor the internal mics?
Preferable the easiest way?
A Reel Person
It's Too Funky in Here!!!
I love boomboxes. I have at least 5 of them & seek them out at Goodwill and SalvnArmy
Other than proceeding with your steadfastness to this desire, I have no recommendations.
I'd be more inclined to get a Tascam 488mkII and a couple low cost/batt op condenser mics and record in multitrack to tape. If I wanted more analog flavor I might step up to a 388, 34B or 38/M30 mixer. If I didn't care about multitracking more than 2 tracks, I might recommend a 124AV or Tascam 32. If I needed something to tweak the raw sound of this setup I'd consider a Fostex 3070 stereo compressor/limiter.
Oh wait,... I already have all that equipment.
Q: If the tape-play mechanism is broken, how did you determine that this boombox provides the "sound" you're looking for?
To answer you basic question,... in the turnaround,... have you considered just cutting the wires to the motor or finding a connector point to disconnect? I don't think there's any clear indication up front that the whooshing sound is coming from the motors at all, rather than from the amps. You will not know this for sure until you go in deep cutting and slashing, and if this boombox is nothing to you other than an expendable project box, then I'd do just that. You don't know what you'd get til you try.
Other than proceeding with your steadfastness to this desire, I have no recommendations.
I'd be more inclined to get a Tascam 488mkII and a couple low cost/batt op condenser mics and record in multitrack to tape. If I wanted more analog flavor I might step up to a 388, 34B or 38/M30 mixer. If I didn't care about multitracking more than 2 tracks, I might recommend a 124AV or Tascam 32. If I needed something to tweak the raw sound of this setup I'd consider a Fostex 3070 stereo compressor/limiter.
Oh wait,... I already have all that equipment.
Q: If the tape-play mechanism is broken, how did you determine that this boombox provides the "sound" you're looking for?
To answer you basic question,... in the turnaround,... have you considered just cutting the wires to the motor or finding a connector point to disconnect? I don't think there's any clear indication up front that the whooshing sound is coming from the motors at all, rather than from the amps. You will not know this for sure until you go in deep cutting and slashing, and if this boombox is nothing to you other than an expendable project box, then I'd do just that. You don't know what you'd get til you try.
Not quite. the r/p head gets record signal from the amp labeled "line" after passing through the record equalization network. The play back route is shown on the schematic.
Looks to me like you can monitor the mics after amplification at the DIN connector. Pin 5 line out R, pin 3 line out L, and rtn on pin 2.
Try that and dont engage any tape transport functions, that might eliminate some of the noise you are getting.
*EDIT: the machine will have to be set to record to monitor the internal mikes the way I described. Im with A REEL PERSON, open it up and disconnect the motor...
Looks to me like you can monitor the mics after amplification at the DIN connector. Pin 5 line out R, pin 3 line out L, and rtn on pin 2.
Try that and dont engage any tape transport functions, that might eliminate some of the noise you are getting.
*EDIT: the machine will have to be set to record to monitor the internal mikes the way I described. Im with A REEL PERSON, open it up and disconnect the motor...
A Reel Person
It's Too Funky in Here!!!
...
Thank you.
Ok, yeah I see that now, which I didn't recognize before. The switch that designates P or R, just before the head, changes the signal path considerably. When in R it taps of the line amp, when in P it feeds forward to the line amp. That would make sense.
Thank you.
Ok, yeah I see that now, which I didn't recognize before. The switch that designates P or R, just before the head, changes the signal path considerably. When in R it taps of the line amp, when in P it feeds forward to the line amp. That would make sense.
hansgauffin
New member
Other than proceeding with your steadfastness to this desire, I have no recommendations.
I'd be more inclined to get a Tascam 488mkII and a couple low cost/batt op condenser mics and record in multitrack to tape. If I wanted more analog flavor I might step up to a 388, 34B or 38/M30 mixer. If I didn't care about multitracking more than 2 tracks, I might recommend a 124AV or Tascam 32. If I needed something to tweak the raw sound of this setup I'd consider a Fostex 3070 stereo compressor/limiter.
Oh wait,... I already have all that equipment.
Q: If the tape-play mechanism is broken, how did you determine that this boombox provides the "sound" you're looking for?
To answer you basic question,... in the turnaround,... have you considered just cutting the wires to the motor or finding a connector point to disconnect? I don't think there's any clear indication up front that the whooshing sound is coming from the motors at all, rather than from the amps. You will not know this for sure until you go in deep cutting and slashing, and if this boombox is nothing to you other than an expendable project box, then I'd do just that. You don't know what you'd get til you try.
I also have a 388 and a fostex 3070!
1. I know from similar models, that I have grown up with. that the sound is always the same from those mics!, the tape player is functioning on this model, I were trying to get another one but bought this one instead,, this project is for the sake of nostalgia!
hansgauffin
New member
I really appreciate the time you guys put down in order to help me out, even though you find the whole idea pointless...
mdainst, do you think I can monitor the internal mics with the DIN connector? You see, there is also an option to connect an external microphone. Maybe its that signal that could be monitored without the tape transport functions going?
look at this picture of the back
Hitachi TRK-5280E - hitachi - BoomBox 70-80' Club / 70-80 -
I really think I should disconnect the motor! BUT will this not prevent the REC mode?
I think I can make this, but can you please let me know which connector-point I should disconnect, (if there is any), what´s its name on the schematic? I have never done anything like this before,, will the motor prevent all transport functions?
I´ll try this tomorrow and also try the batteries, If I succeed I´ll post another wav file of the sound, for comparison! THANKS!
Sorry guys! But I´m a real newbie when it comes to stuff like this!
mdainst, do you think I can monitor the internal mics with the DIN connector? You see, there is also an option to connect an external microphone. Maybe its that signal that could be monitored without the tape transport functions going?
look at this picture of the back
Hitachi TRK-5280E - hitachi - BoomBox 70-80' Club / 70-80 -
I really think I should disconnect the motor! BUT will this not prevent the REC mode?
I think I can make this, but can you please let me know which connector-point I should disconnect, (if there is any), what´s its name on the schematic? I have never done anything like this before,, will the motor prevent all transport functions?
I´ll try this tomorrow and also try the batteries, If I succeed I´ll post another wav file of the sound, for comparison! THANKS!
Sorry guys! But I´m a real newbie when it comes to stuff like this!
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hansgauffin
New member
I get it now! The DIN would give a cleaner sound since the headphone amp is bypassed,, but are you sure the inner mic will be monitored there?
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hansgauffin
New member
I get it now! The DIN would give a cleaner sound since the headphone amp is bypassed,, but are you sure the inner mic will be monitored there?