[greenhorn]

wrong link in the above post
Simple mixer
use this instead
Btw, one more clarification. line level out means low output impedance (actually all outputs should be low output impedance) and line level inputs mean high output impedance as mentioned previously. low output impedance and high input impedance are ideal characteristics of any device which gives voltage as input/output

And why oh why did you get a Z2300? I would have gotten the MX 5021 any day. much better SQ, remote , and you wouldn't be having this problem with it in the first place!

[DerAlte]

Rehaan-bhai, if you are in Noo Yok, even better - go to a store (Best Buy, Fry's, Radio Shack etc.) and get the stuff off-the-shelf, yaar:
1. One EP to RCA cable (one 3.5 jack, 2 RCA plugs marked Red and White)
2. One RCA to RCA cable (both ends 2 RCA plugs marked Red and White)
3. Two RCA Y-cables (One end an RCA plug, other ends 1 RCA socket each)

Make sure you connect both the Red RCA plugs to one Y cable, and Whites to the other.

And don't worry about the low-impedance, high-impedance business - that is meant for efficient power transfer! In your case, you only need very low power to be drawn by the amp. The amp'ed speakers that you have has a high impedance input - it will take only what it needs and amplify it based on the volume control setting.

[navin]

Originally Posted by Rehaan

So are the RCA & 3.5mm out both high impedance ?

Arey if you have RCA out use it. RCA out will be line level and has atleast 2 stages of processing less than 3.5/2.5mm out. 3.5/2.5mm out are for headphones (hence are low impedance). Line level is better.

Rat-Shack (Radio Shack) should have a stereo line level (RCA) switch box (like the ones should in the links earlier provided).

[greenhorn]

Originally Posted by DerAlte

Rehaan-bhai, if you are in Noo Yok, even better - go to a store (Best Buy, Fry's, Radio Shack etc.) and get the stuff off-the-shelf, yaar:
1. One EP to RCA cable (one 3.5 jack, 2 RCA plugs marked Red and White)
2. One RCA to RCA cable (both ends 2 RCA plugs marked Red and White)
3. Two RCA Y-cables (One end an RCA plug, other ends 1 RCA socket each)

Make sure you connect both the Red RCA plugs to one Y cable, and Whites to the other.

And don't worry about the low-impedance, high-impedance business - that is meant for efficient power transfer! In your case, you only need very low power to be drawn by the amp. The amp'ed speakers that you have has a high impedance input - it will take only what it needs and amplify it based on the volume control setting.

No , it is NOT about efficient power transfer, but about safe power transfer. Would any of you connect two amps in parallel? The same principle applies here. you might end up with a blown output (worst case) but hopefully output protection will kick in.
Either way, NOT recommended, and certainly not the right way to do things

Originally Posted by navin

Arey if you have RCA out use it. RCA out will be line level and has atleast 2 stages of processing less than 3.5/2.5mm out. 3.5/2.5mm out are for headphones (hence are low impedance). Line level is better.

navin, some portable/small equipment have 3.5 mm line outs because they simply dont have the space for full fledged RCA outputs

[DerAlte]

Originally Posted by greenhorn

No , it is NOT about efficient power transfer, but about safe power transfer. ... Either way, NOT recommended, and certainly not the right way to do things

@greenhorn-cheta, please understand the requirement stated in the first post by reading between lines (not very difficult) -
1. He wants to connect 2 sources very simbly, without any complications or switches, to one sink
2. One of the sources like (highly) likely to be off (electrically; high impedance state) while the other is playing
3. Even though both the outputs are coming from amps, these amps are not designed to feed low impedances; conversely, both are designed to deliver signal to high impedances
4. All conventional audio sinks (inputs) are very high impedance
5. Even if BOTH sources were to be ON, you should realize one of the sources (the cable box) is a relatively high-impedance output, so it will not create a problem for the laptop headphone amp

In the digital world, this is called WIRE-ORing.

Originally Posted by greenhorn

navin, ... dont have the space for full fledged RCA outputs

Oh, he should definitely know - he has been around audio for close to 30 years now!

[greenhorn]

Originally Posted by DerAlte

@greenhorn-cheta, please understand the requirement stated in the first post by reading between lines (not very difficult) -
1. He wants to connect 2 sources very simbly, without any complications or switches, to one sink
2. One of the sources like (highly) likely to be off (electrically; high impedance state) while the other is playing
3. Even though both the outputs are coming from amps, these amps are not designed to feed low impedances; conversely, both are designed to deliver signal to high impedances
4. All conventional audio sinks (inputs) are very high impedance
5. Even if BOTH sources were to be ON, you should realize one of the sources (the cable box) is a relatively high-impedance output, so it will not create a problem for the laptop headphone amp

In the digital world, this is called WIRE-ORing.

Oh, he should definitely know - he has been around audio for close to 30 years now!

agree with you upto the last point. If you mean by high impedance, that it is current limited , yes, but otherwise , it is low impedance. All voltage sources are ideally as low impedance as possible and no matter how relatively high impedance it is , it is certainly nowhere in the range of the resistance of a line level input.

I am aware of Wire ORing , but it is done only for open collector buffer outputs and tri state outputs , which are high impedance, virtually off. Try to Wire OR normal TTL /CMOS stuff , and they also will either go into protection, or blow their output stages.

outputs of analog devices arent wire ORed. you use resistors to buffer the outputs. Yes , it is essentially the same thing , all I'm asking is for a resistor in between to protect the outputs

BTW, i am aware of navin's knowlege and experience. just that

RCA out will be line level and has atleast 2 stages of processing less than 3.5/2.5mm out. 3.5/2.5mm out are for headphones (hence are low impedance)

made it sound like there were no line level outputs via 3.5 mm jacks when in fact there are. Just wanted to set the record straight

[DerAlte]

Originally Posted by greenhorn

agree with you upto the last point. ... Just wanted to set the record straight

Sorry sir, I can't boast of much high education. Just that I have done that simple mixing for the last 30 years and never blew any output stage, whether at milliwatt level or kilowatt level. I also wrote about keeping one of the sources off.

And, perhaps you did not understand what Navin had said originally!

By the way, do you teach in an engineering college? Your expression reflects high academic accomplishment.

[greenhorn]

Originally Posted by DerAlte

By the way, do you teach in an engineering college? Your expression reflects high academic accomplishment.

Oh DerAlte you flatter me . I barely scraped through my theory papers , but had an aptitude for practical stuff. unfortunately my weakness with theory ensured that i stayed on the wrong side of academia, and all this is limited to a weekend hobby :(

With both of the sources off, It wouldn't be a problem at all, as you said earlier , and i agreed.

If you've been getting away with shorting analog outputs together , you (and your equipment ) must be very lucky. Like i said , the output protection incorporated in most modern electronics should (hopefully) keep them safe.
However , I prefer to err on the side of caution, and would rather ensure that they are protected , than rely on the built in ones (which may, or may not exist, and i certainly don't want to find out the hard way!)

[navin]

Originally Posted by greenhorn

BTW, i am aware of navin's knowlege and experience. just that
made it sound like there were no line level outputs via 3.5 mm jacks when in fact there are. Just wanted to set the record straight

1. I am not above being corrected. Yes I have seen equipment that uses 3.5mm for high impedance but most of it is Pro (mixers, guitar synths, etc..) I was only refering to Rehaan's Music Bridge. Given that it has RCA and 3.5mm out I would assume that the 3.5mm out is for a headphone or wireless headhone base station etc..

Originally Posted by DerAlte

3. Even though both the outputs are coming from amps, these amps are not designed to feed low impedances; conversely, both are designed to deliver signal to high impedances
5. Even if BOTH sources were to be ON, you should realize one of the sources (the cable box) is a relatively high-impedance output, so it will not create a problem for the laptop headphone amp

Oh, he should definitely know - he has been around audio for close to 30 years now!

1. both outputs are high impedance (the laptop is being fed into a music bridge) the music brige outputs are RCA.
2. normally I dont think Rehaan would have a problem, it is just that given that we dotn want to blow anything it is nice to have a switch.

For those are counting the year was 1972 (chip amps were just becoming available). I was 9. The electronic dealers on Lamingtom Road knew me has "half pant". Boy I am OLD!

Originally Posted by greenhorn

If you've been getting away with shorting analog outputs together , you (and your equipment ) must be very lucky.

Der Alte must be refering to Mixers and othter such Pro/Studio equipment. Der Alte are you?

Most Pro equipment outputs are designed to be more rugged. I mean really rugged. I have taken the output of a Marshall and stuffed it into it's own input (positive feddback) and all I got what a howl (I did it just to show how rugged the equipment was). Try that with your home amp! No No No DONT try that with your home amp unless you want to fry it.

[DerAlte]

Originally Posted by navin

Der Alte must be refering to Mixers and othter such Pro/Studio equipment. Der Alte are you?

Hee hee hee! When there are too many sources, and one needs to finish one's work, taking chances builds character and experience!

Originally Posted by navin

Try that with your home amp! No No No DONT try that with your home amp unless you want to fry it.

NO NO NO, by all means go ahead, at least you will come to know whether your amp has protection or not! And a glass-cartridge tubular fuse costs only 5 bucks. (I am assuming that the experimenter has household and medical insurance - you just might get a shattered glass pane or ear drum)

[Rehaan]

Good day gentlemen,

Sorry for not getting back to you sooner - but i did not get the time to hook this up until yesterday and it didnt work well at all.

Originally Posted by greenhorn

... output impedance ...

^^ I feel like this might be causing an issue.

Due to the selection of cables i currently have at my disposal i had to use the RCA out on the TV Tuner and the 3.5mm out on the music bridge.

As i mentioned earlier, the music bridge will always be turned on and plugged in, but both devices will never be outputting audio at the same time.


The problem is that the audio from the cable box is now very very very very soft, & the music bridge audio is fine.

What can i do (anything short of soldering some resistors in there?)?
If i buy some more cables and use the RCA out on the music bridge as well, will it fix the issue?

cya
R

PS - greenhorn, to answer your question about why i bought the Z-2300 : Well, this was many years ago - it was THE best rated 2.1 system in its class on pretty much every review site (this, and some klipsch audio speakers).
When i received them, i was very dissapointed. The bass was boomy and not "tight" as everyone described and it was missing the mids a bit.
They were extremely powerful however, and did manage to host many 150-200people dance parties in the college days
Those parties took their toll, and the satellites evenually fried after being marinated in beer.
So to replace them i bought a pair of sony bookshelf SS-MB150H speakers on ebay, brand new, for $1 ($20 shipping, but still an awesome deal!).
I hooked those up to the Z-2300 sub & amp, a nice improvement.
However, the biggest improvement came when i moved to my new apartment and the room's acoustics just changed favourably. The combination sounds absolutely superb now - so i am happy.
Now i just want to be able to enjoy it without having to plug/unplug stuff in all the time - hence this thread!

[navin]

Originally Posted by Rehaan

but i did not get the time to hook this up until yesterday and it didnt work well at all.!

what is happening is that the music brige is a low impedance output (16-100 ohms meant for headphones) while the cable box is a high impedance output (10K-20K ohms). the music bridge hence shorts the output of the cable box and hence the cable box is really driving the music bridge and not the speaker system.

alas there are no such impednace equallisers that are commerically available today. Russound used to make one in the 80s but that was then. You will need to flip a switch. Other option is to make an L-pad to equallise impedance and level and run the headphone out through the Lpad.

[Rehaan]

Originally Posted by navin

.... low impedance..... high impedance......hence shorts the output of the cable box and hence the cable box is really driving the music bridge and not the speaker system.

Thans Navin. That makes sense.

However, as per my last question - If i use RCA on the music bridge as well, will that fix the problem ? (or atleast lessen it significantly?)

cya
R

[greenhorn]

Have i got a surprise for you

RadioShack.com - Home & Office: PA systems & power horns: 4-Channel Stereo Microphone Mixer

I think this will be all you need. its a 2 stereo input mixer. It's perfect!
check out its manual