Questions about the Magnavox D8443

[Lasonic TRC-920]

Cool. Looks pretty good. Not too bad to work on, a little clumsy but not bad.

I'm not a big fan of the wire connector things, but at least you don't have to desolder it all.

You'll have a good time with it though. The way your projects have been turning out, I'm sure it'll be a sign of hope for these beautiful but sad machines.

Thanks bro, it looks about as simple as it can get. The only goal I really have, is I would like to save the tuner. Of course this will get Blue Tooth, but the tuner (to me) is still the heart of a Boombox. When the west coast guys and I get together, we always try to find a station for a group blast, just like back in the day. I think it's still important. But if not F'n GONE!

 

[jimmyjimmy19702010]

You will find that trying to utilise the old tuner will be difficult. An easier solution might be building an FM tuner board like this: https://www.ebay.com.au/ulk/itm/272143769723 and have it connected to an input selector switch that will allow you a three way selection: FM tuner, wired line in and BT.

It would be cool too if you could adapt the existing tuner dial and cord etc to the new tuner board keeping the tuner dial and antenna ntact and usable!!

James....

 

[Lasonic TRC-920]

You will find that trying to utilise the old tuner will be difficult. An easier solution might be building an FM tuner board like this: https://www.ebay.com.au/ulk/itm/272143769723 and have it connected to an input selector switch that will allow you a three way selection: FM tuner, wired line in and BT.

It would be cool too if you could adapt the existing tuner dial and cord etc to the new tuner board keeping the tuner dial and antenna ntact and usable!!

James....

I know it's very hard if not impossible to intercept the radio signal and redirect it to the new amp. But since the radio is on it's own pc board I'm going to have a look to see if I can locate its route.

There are amp / bluetooth / digital FM receiver packages that I can buy, but the nostalgia in me really would like to keep the ol' dial, knob and antenna working.

One thing for sure, I'm glad I won't get any shiat from the boomboxery crew for cutting it up

 

[trippy1313]

Yeah, tuner is essential, I 100% agree. Even though radio today is half commercials, dialing in a station is what it's all about.

It's kinda what at least I grew up playing with on the radio, the tuner dial.

 

[trippy1313]

Do you think if a real sub doesn't work, you might end up with a Lasonic in there instead of that Philips?

 

[jimmyjimmy19702010]

This might be a new trend in Boombox upgrades - non grail boxes of course!

I'm planning a similar deal with an empty Sanyo M9998K shell I've had lying around here for years. All internals gutted, running a pair of 6 inch 4 ohm car speakers and matching tweeters. The large Sanyo casing should give plenty of internal volume for 2 mid sized drivers to produce solid bass.

James....

 

[Lasonic TRC-920]

Do you think if a real sub doesn't work, you might end up with a Lasonic in there instead of that Philips?

I honestly don't know what will happen.

I little off subject but...

Over the last few years I have been playing around with micro sub-woofers. First for my car using 3 inch Tang Band subs I found on Parts-Express.com. I made tiny enclosures that were the absolute minimum recommended sealed space. I learned that the smaller the enclosure, the more dead on you need to be with your enclosure size. It took some time, but I finally managed to tune the little boxes by gluing small wooden cubes 1/2"x1/2" until they were perfect. In the end, I got them to hit down in the the 20hz area, and they sounded great for that application.

Next I used a 4 inch cardboard shipping tube, again, the goal being tiny. Using the same sub at one end and a 4 inch passive radiator at the other. In my first tests, instead of the radiator I used a port tube. The recommended length was 38 inches long, 1 inch diameter. In this form, it hit like a beast. I was able to tune it to use the radiator and got it down into the low 30's, but with out enough over all volume. When I hooked it up along side my J1, you couldn't hear it at all.

So here we are....Back to the Maggi.

Is it possible to use enough of the boombox it's self sealed up to make it thump?

Scrap the 8" speaker, use it as a radiator and put one of those Tang Band 3 inch subs on the rear of the case?

Find a shallow profile 8 inch sub, build a sealed box using 50% of the interior and then use twin ports inside each side behind the stereo woofers, folding them back and forth in the confined area (think Bose wave radio) and port them out the bottom?

I have actually had success with this last option when it comes to small spaces. If I can get it sealed and ported correctly, then it's just a matter of pushing the 8" like JVCFloyd was driving!

It might be a combination of some of these things...Real 8" sub in seal up box, passive radiator on rear case, and dual folding ports.

 

[Reli]

I have a pair of Lasonic / Lucky 4 ohm speakers out of a 918 that I think will fit. These have a nice long excursion and in the 918, tons of bass. I think they would be great as the full range driver replacements if they fit. They are smaller than the 920 woofers. Plus they have a really nice chrome center cap.

20160301_145527.jpg

Those are 4 ohm speakers, right? Good replacement for the shitty 8 ohm ones that are restricting power.

According to the service manual, that box has a Unisonic TDA2004 class B amp pushing 2 watts per channel to the left and right speakers, and a TDA2003 amp that pushes 3.2 watts to the "sub". So, not exactly a powerhouse.

But Unisonic says the first amp is safe up to 10 watts per channel, and the sub amp is safe up to 10, so you could get a decent bump by lowering the Ohms on those speakers.

BTW there is no third amp, unless they're talking about the preamp chip.

 

[check tha bass]

Yes i also had this box,the looks are nice but the sound is of something your dog does on your neighbours lawn when they are not looking,awwful !! and not having a Vu Meter fitted was a crime,the designer of that box should have a big foot shoved up his ass for not including one..

i wouldn't mind buying another one just to experiment with,i normally would never dare touch a box,i like them as original as possible !

Myself,I would get a small 12v digital amp board,and i would take the wiring and piggy solder onto the headphone board.

Advice is,if you want a 8443 to modify,yes get one if its cheap,but if you want one,to listen to then i wouldn't bother,you will be very dissapointed,there is many many better quality boxes out there thats worth spending your money on.

 

[Lasonic TRC-920]

Well, the radio showed up safe and sound, not bad packing and it looked like the postal service handled it with white gloves on. ONE IN A ROW!

I have to say, it's in better condition than I thought. And I have heard worse radio's.

Those are 4 ohm speakers, right? Good replacement for the shitty 8 ohm ones that are restricting power.

According to the service manual, that box has a Unisonic TDA2004 class B amp pushing 2 watts per channel to the left and right speakers, and a TDA2003 amp that pushes 3.2 watts to the "sub". So, not exactly a powerhouse.

But Unisonic says the first amp is safe up to 10 watts per channel, and the sub amp is safe up to 10, so you could get a decent bump by lowering the Ohms on those speakers.

BTW there is no third amp, unless they're talking about the preamp chip.

Some good information there.

So, how can I bump the power chips?
4 ohm stereo woofers and a 4 ohm sub for sure.

Yes i also had this box,the looks are nice but the sound is of something your dog does on your neighbours lawn when they are not looking,awwful !! and not having a Vu Meter fitted was a crime,the designer of that box should have a big foot shoved up his ass for not including one..

i wouldn't mind buying another one just to experiment with,i normally would never dare touch a box,i like them as original as possible !

Myself,I would get a small 12v digital amp board,and i would take the wiring and piggy solder onto the headphone board.

Advice is,if you want a 8443 to modify,yes get one if its cheap,but if you want one,to listen to then i wouldn't bother,you will be very dissapointed,there is many many better quality boxes out there thats worth spending your money on.

Not too much love around here for these Maggi's

Here's another question, I know that the decks are always broken due to a bad gear, but this one will turn the wheels if I push play. Maybe just belts?

 

[Northerner]

Well I've had 3 and there are, as you say, definitely worse sounding radios. I chucked new main speakers in (no idea of the ohms they were just modern ones I had lying around) and it improved the sound markedly. All 3 have had working decks which is a bit lucky

 

[jimmyjimmy19702010]

Lower ohm speakers will pull more power out of the amp. Keep in mind through that the original speakers are probably super sensitive so unless your new speakers are equally as sensitive, they won't sound any louder.

New quality speakers will definately sound better though, if not louder. Those original speakers do look like crap.

If you want to keep everything stock but want more power, why don't you just grab one of those $5 PAM amps hardmen demoed and hook it up to the headphone circuit then to the speakers. Hook up some power and you should be able to finally give those speakers some real power!!

James.....

 

[Reli]

Lower ohm speakers will pull more power out of the amp. Keep in mind through that the original speakers are probably super sensitive so unless your new speakers are equally as sensitive, they won't sound any louder.

New quality speakers will definately sound better though, if not louder. Those original speakers do look like crap.

If you want to keep everything stock but want more power, why don't you just grab one of those $5 PAM amps hardmen demoed and hook it up to the headphone circuit then to the speakers. Hook up some power and you should be able to finally give those speakers some real power!!

James.....

Good point about speaker sensitivity......It's a shame most speakers don't tell you what it is.

Chris, I would go even lower than 4 ohms if you can find it. That is, if you're keeping the stock amps.

Wonder if a brand new Lasonic speaker could fit for the sub? Aren't those 8 inches?

 

[Lasonic TRC-920]

Well I've had 3 and there are, as you say, definitely worse sounding radios. I chucked new main speakers in (no idea of the ohms they were just modern ones I had lying around) and it improved the sound markedly. All 3 have had working decks which is a bit lucky

To be honest, with all the radio tinkering I have done, I have only swapped out speakers once or twice. So I don't have much experience on the subject. Norm did explain to me in detail how to pick a good replacement and why regarding sensitivity and ohms when I was working on the Louder Blaster Project.

Lower ohm speakers will pull more power out of the amp. Keep in mind through that the original speakers are probably super sensitive so unless your new speakers are equally as sensitive, they won't sound any louder.

New quality speakers will definately sound better though, if not louder. Those original speakers do look like crap.

If you want to keep everything stock but want more power, why don't you just grab one of those $5 PAM amps hardmen demoed and hook it up to the headphone circuit then to the speakers. Hook up some power and you should be able to finally give those speakers some real power!!

James.....

I had thought of doing that and seeing how good of shape this thing is, that is an option especially if the deck might just need a rebelt.

But I think this project requires an over the top, full custom, never before attempted SUPER HACK! Also, there are just so many of these, it's not like I'm wrecking a grail or something

Good point about speaker sensitivity......It's a shame most speakers don't tell you what it is.

Chris, I would go even lower than 4 ohms if you can find it. That is, if you're keeping the stock amps.

Wonder if a brand new Lasonic speaker could fit for the sub? Aren't those 8 inches?

That was another question I had, The 5.25" White TRC-918 speakers I have would look SWEET with a White Lasonic 8" in place of the factory center sub. But the Lasonic speaker is not a true "Subwoofer". I wonder how that would sound? If I do replace the amp's, I was going to run an amp that I have that has a Subwoofer Mono option, so it would only get 100hz and below (or whatever the signal output is).

I think it would look SWEET with all white woofers., all with MASSIVE center chrome dust covers!

Anyone got a single Lasonic 8" collecting dust?

 

[Reli]

That was another question I had, The 5.25" White TRC-918 speakers I have would look SWEET with a White Lasonic 8" in place of the factory center sub. But the Lasonic speaker is not a true "Subwoofer". I wonder how that would sound? If I do replace the amp's, I was going to run an amp that I have that has a Subwoofer Mono option, so it would only get 100hz and below (or whatever the signal output is).

I think it would look SWEET with all white woofers., all with MASSIVE center chrome dust covers!

Anyone got a single Lasonic 8" collecting dust?

People were buying those Lasonic speakers last year, so maybe they're still selling them. They aren't true subs, but neither is that POS in there now, lol

 

[Lasonic TRC-920]

People were buying those Lasonic speakers last year, so maybe they're still selling them. They aren't true subs, but neither is that POS in there now, lol

I have now managed to source an 8" Lasonic woofer via our good member SLO, he has a used one, so it will be as faded at the 918 speakers

And you're right, how could the Lasonic speaker be worse that the factory one. Some time ago I spoke with Albert at Lasonic and he told me, the new Lasonic speakers are IDENTICAL to the classic's in all the specs. They are all the same from the 931, 935, 951, 975 and i931 series. The 975 with LBS hits so hard, that if they can survive that, they should make a good Sub.

Only one way to find out, if it doesn't work, I will buy a proper subwoofer.

 

[Reli]

Dude that will look fresh, 10 times better than what's in there now.

I bet that sub amp is connected to a filter that weeds out the high frequencies, so even though it's not a real sub, it will at least be focused on the lower half of the sound spectrum.

 

[Lasonic TRC-920]

Dude that will look fresh, 10 times better than what's in there now.

I bet that sub amp is connected to a filter that weeds out the high frequencies, so even though it's not a real sub, it will at least be focused on the lower half of the sound spectrum.

Yep, I think you're right...we will see

 

[check tha bass]

yes,do it man,i want to see this done asap,can you not like hurry yo ass up lol,all it needs is a good amp,good speakers,and a vu meter,the first 2 is possible,but with the 3rd option couldn't you cut in to the tuner back plate and fit your own ? needle meters ? just a thought.you could turn this mush in to a masterpiece,well,you got me excited

 

[Lasonic TRC-920]

yes,do it man,i want to see this done asap,can you not like hurry yo ass up lol,all it needs is a good amp,good speakers,and a vu meter,the first 2 is possible,but with the 3rd option couldn't you cut in to the tuner back plate and fit your own ? needle meters ? just a thought.you could turn this mush in to a masterpiece,well,you got me excited

Ha Ha Ha!

Lovin' the enthusiasm brother...I am in parts collection, brainstorming and information gathering mode right now. The radio is now here, member SLO has generously offered up a Lasonic 8" to be used for the sub replacement, I have 1 of the amp's I need (will buy a second) to do the amp replacement, will need a bluetooth module.

I think this might go in a few stages.

1) Swap all the speakers for Lasonic's. See if there is any improvement. Report back
2) Replace tweeters. See if there is any improvement. Report back
3) Gut the inside and build a subwoofer enclosure and seal off the 8" and power it with it's own mono amp. Power 5.25" speakers with own stereo amp. Install all other needed components to make work.

Lots of work to go.

Once I open this up and start working, I will be moving this thread over to the "Customization" section of the forum! Stay tuned!