A Look Inside a Realistic 32-1100A Stereo Mixer

A "Realistic" brand portable Stereo Mixer is opened just to see what might be expected from it. I couldn't find the schematic for model no. 32-1100A online, but the schematic for the 1200 seems close.
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[@Sonic-Boom]

I had one of these. Brought back some memories!

[@Bitshitter]

I got one of these brand new back in the day, and still have it today! I used it to mix some dance music tapes for me and my girlfriend during the late 80s-early 90s. I do not remember that the 6v supply coming with the unit, although it has the jack for it. I seem to remember that it was a "buy separately" type thing.....

[@miguelsalami]

I think your right none come with it even NOS.

[@aderftard]

Same here, I bought it out of necessity (had to DJ unexpectedly and lacked funds). I also remember buying the power adapter separately. I still have mine in a box somewhere - now I'm going to have to dig it out.

[@miguelsalami]

I just bought one of these on eBay in like new condition can't wait to try it out❗You better use your before another 20 years goes by🎶🎵👍👍💛

[@trevortjes]

Nice video! I bought almost the same mixer at a thriftshop but it says stereo disco mixer instead of stereo mixer but its the exact same mixer as far as I can see. That metal part in the corner of which u thought was a filter for the power seems to be a step up converter. When u listen closely u can hear the squarewave buzzing. The red cable that comes out of there has about 24 volt on it. Also the fader knobs came off very easely on mine so I might make a video on it soon so U can see the insides a bit. I must say that it made me very happy seeing all the analog circuitry. I also already added a little backlight mod for the VU meters so it looks a lil more 'premium' vintage.

[@harrytaylor1887]

The whine is really irritating! I tried increasing the value of the capacitors on the power supply, but it didn't seem to help. Any ideas on how to improve it?

[@MichaelBeeny]

I had something similar as a kid, but mine was under the EAGLE label, common in the UK at that time. Mine also was mains powered. Always had a slight buzz and quite a bit of hiss. Not really HiFi even in it's day but did not cost much. I guess you get what you pay for.

[@heggy_69]

I'm actually interested in some of these as guitar effects, and I think for that purpose it's a good thing that they're not hifi lol

[@sonofabeach71]

I had one of these. Me and my brother used to make rap demos with them 30 years ago. I used to actually scratch on one of these.

[@tonepilot]

"She wasted her life" Lol, kinda harsh :)

[@paulrydzinski9995]

right! Thought that was pretty rude. Some people take other directions in life

[@DynamicOwl13]

I thought that too. What if she watched the video lol

[@danielpeterson2702]

Most people that took "radio" in college were finding a way to extend high school and drugs/alcohol were a part of it. I am sure he had evidence for his conclusions and it is always kind of sad.

[@JohnAudioTech]

Interesting with only six volt supply. Not a lot of headroom for output signal especially as batteries age. Single element output stages can sound nice but won't put up "hifi" figures on test equipment. If you build the opamp preamp I made, use 100 ohm output series resistors if it is to drive signals into shielded cable. It is a stability issue. I didn't use them on my amp because it is meant for the bench only.

[@hiddenobserver8447]

And the condition of the multitude of coupling / decoupling electrolytic capacitors is very iffy after decades.

[@Ralphofficial_]

I just bought me one from trade it for my hood recording studio I don't know how to connect it to my laptop

[@DynamicOwl13]

It's been awhile since I seen it but I know there's a video on how to set them up with a laptop

[@HillsWorkbench]

Sorry, I missed replying to this, you probably figured it out by now. You should be able to drive any line-level input, such as tape in. Just get a cable with RCA connectors at one end and a stereo earphone jack on the other to match the computer.

[@midmodaudio6576]

Thanks for the video. The woman who gave the mixer decided not to be a broadcaster and for that reason, she wasted her life?

[@HillsWorkbench]

No, because she left me! And a teaching career that was probably her main effort. I think she might have had potential as a radio DJ. But a lot of DJ jobs vanished as more networked satellite programming took over.

[@diymariuselectro]

I found pic o power supply and shows + in the middle and - external.you said the other way.

[@DoctorRazzArea4]

Hello! I use one of these for djing. I'm trying to figure out WHEN the batteries are low enough to effect the sound negatively. When I started, the battery tester indicated in the red, but now it is just between the red and the black. I'm wondering WHERE the needle on the battery tester should indicate when it's time for new batteries. Any help would be greatly appreciated, thank you! I supposed I will take out the batteries and check them individually, but if I only I had the manual I could see what the manufacturer recommends.

[@HillsWorkbench]

They should stay in the red or nearly so if they are alkaline. If it shows significantly lower than when new then you are at the discharge knee.

[@DoctorRazzArea4]

@@HillsWorkbench Thanks, yes I DJed last night and it starting becoming distorted. Seems the battery life is not particularly long.

[@HillsWorkbench]

@@DoctorRazzArea4 You should find a DC power pack for it.

[@stanpatterson5033]

I had a 1200B, which had a built-in power supply so you just plugged it into 120v AC. Mine had a cross-fader to fade between two line sources, and the VU meters were at the top left instead of top center. I believe the VU meters were lighted, but I haven't pulled out the board in years. I lent it out to a friend once, and it came back screwed up, so since it was still under warranty, I took it in to the local RS service center, and they straightened it out quickly, they told me it looked like "I" had been plugging and unplugging live devices and ended up zapping something. Never lent it out again, and never had another problem with it since then. I still own it, it's in storage, still in the original carton and packaging, saw it last about 4 years ago.

[@DynamicOwl13]

That would piss me off enough to never borrow equipment to idiots. That's one of my pet peeves when ppl just plug n unplug things that are powered on

[@jamesgarvey8279]

Hi! loved the video. Would it do any harm if i were to use a 9v battery instead of the 4 AAs ? Thanks!

[@HillsWorkbench]

It would be risky, that's 9V instead of 6V. And the battery voltage gets boosted in this circuit so Voltages throughout would be increased. Likely the 9V would cave under the load and maybe save things but I wouldn't count on it. Battery life would likely be pretty short also. You could look at NiMH 9V replacements that actually do 7.2V (as opposed to ones that do 8.4V), but why, 'AA' cells are about the best buy in alkalines.

[@jamesgarvey8279]

I was just curious, thanks for your thoughtful answer. I appreciate it !

[@synthmalicious7541]

Do you know how the Battery Test works? Like what its even supposed to respond with if the batteries are okay?

[@HillsWorkbench]

Sorry for the slow reply. I tried to find the unit to check but couldn't locate it, I may have given it away. But I'm pretty sure on mine there is a red mark below the usual scales on one of the meters...

[@HillsWorkbench]

Yeah, rewatched to be sure, there is a scale for the battery on the right meter just below the main scale.

[@synthmalicious7541]

@@HillsWorkbench No need to apologize. Thank you!

[@hughjanus6975]

So I just picked one up, put batteries in it and they started melting the battery case! I couldn't understand why, batteries test good, but it gets very hot. Burned me. I tested the terminal and the DC jack and it shorts the positive and negative terminals when in the "off" position. What the hell is wrong?

[@davidjamesfishkin4148]

Does this mixer have a fuse in it? I can't remember what I did but mine has no power with batteries or using a 6v adapter. Can anyone help me out on how I use a multimeter to test why I have no power? Thanks in advance.

[@HillsWorkbench]

Read back in the comments. Turns out there is a little DC to DC booster in the one little sheilded box in the corner. You need to see if the 6v gets to that point and if the higher Voltage is being made.

[@HillsWorkbench]

I don't believe there is a fuse but it's bee a while...

[@davidjamesfishkin4148]

@@HillsWorkbench Thank you for the info. I will have to learn how to use my multimeter to detect the problem. I would like to get it to work again.

[@HillsWorkbench]

@@davidjamesfishkin4148 Just set it to Volt DC. Experiment measuring whatever batteries you have around. Most newer meters auto-range but on many you will have to select a range. Start at the highest range you might need and then work down if needed.

[@HillsWorkbench]

@@davidjamesfishkin4148 I will try and dig mine up and see if I can think of more suggestions.