Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

PA Systems A forum for discussion of all parts of a sound reinforcement or DJ system: loudspeakers, mixers (desks) etc.

What are ways I can distribute signal to multiple amps over 50 feet
What are ways I can distribute signal to multiple amps over 50 feet
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 17th September 2019, 08:34 PM   #1
HavanaWoody is offline HavanaWoody  United States
Stiguini Slayer
diyAudio Member
 
HavanaWoody's Avatar
 
Join Date: Sep 2019
Location: North East Florida
What are ways I can distribute signal to multiple amps over 50 feet
Lightbulb What are ways I can distribute signal to multiple amps over 50 feet

I would like to synchronize several amps I have used in an outdoor system at my home. What I don't know is what issues I will encounter or the results I should expect. I have 3 6 channel Class D amps that are less than 75 feet from a central area I would like to be able to control the signal. All of these outdoor amps have 6 analogue RCA connectors. I have previously installed (many years ago) direct buried data cable that contains 6 awg 24 twisted pair and 4 awg 22 that are shielded with foil and a braided ground. A total of 12 24 gauge conductors and 4 22 gauge with a braided ground that I am unsure of the total gauge.

I want to be able to tap the signal from my Dennon AVR3200 or Technics SA-AX720 to feed these satellite amps. OR just use a mixer to send 3 left and 3 right if DAC is going to lose the extra channels when its not encoded for more than 2 channels. I'll also be looking to seperatly get signal to 4 self powered Sub woofers in strategic locations that are not as distant.

I would like to be able to plug in a guitar and a Microphone at the central location or by RF or Bluetooth wireless.

Can I send a digital signal over this distance and extract it at multiple points? would analogue pre-amp out be strong enough or should I expect to need a speaker level signal.

I am not seeking to have perfect reproduction or bragging rights on how much I spend on equipment, This is simply so we can sing along and play amplified instruments whether in the man cave, at the fire pit or in the den. and I am using equipment I have accumulated over many years and willing and capable of using a soldering iron and components as needed.

Why has no one developed a bluetooth router or opensource wi-fi that can do this?
  Reply With Quote
Old 17th September 2019, 10:26 PM   #2
indianajo is offline indianajo  United States
diyAudio Member
 
indianajo's Avatar
 
Join Date: Jan 2010
Location: Jeffersonville, Indiana USA
This has been done before. Look at Peavey loudspeaker management systems. VSX26e, VSX48e Page 111 of the catalog. There are other PA equipment vendors. There are much cheaper long distance line level interfaces over Cat 5 wire, or radio link, or toslink. These are single channel or stereo only. Newark.com (farnell US) sells them, but the parts-express.com catalog is more user friendly. The newark database, you have to know the exact name of what you are looking for. Parts-express is US Ohio based, farnell operates worldwide. A "mixer" generally has at least 4 outputs, a master send, a monitor send, a effects/tape send, and a headphone send. If you can limit your outputs to four stereo channels, one of those is much cheaper. Some of them have differential outputs for hundreds of feet of hum free transmission, most of them are single ended only. The three Peavey mixers I own are single wire drive only, good maybe for 100' with twisted pair to the amps on the stage.
__________________
Dynakit ST70, ST120, PAS2,Hammond H182(2 ea),H112,A100,10-82TC,Peavey CS800S,1.3K, SP2-XT's, T-300 HF Proj's, Steinway console, Herald RA88a mixer, Wurlitzer 4500, 4300

Last edited by indianajo; 17th September 2019 at 10:29 PM.
  Reply With Quote
Old 18th September 2019, 12:14 AM   #3
HavanaWoody is offline HavanaWoody  United States
Stiguini Slayer
diyAudio Member
 
HavanaWoody's Avatar
 
Join Date: Sep 2019
Location: North East Florida
What are ways I can distribute signal to multiple amps over 50 feet
Exactly the road signs I was seeking. indianajo Thank you I have never tried sending a low level signal over a distance or with twisted pairs so I had no idea it was even a real thing. I added all that buried cable when I put in my Irrigation drainage and lighting, I had lots of materials I wasn't willing to toss and figured Id find a way to use them for audio video or something with a cool factor eventually. That was 15 years ago LOL. And boy am I glad I put all that copper in the ground, including 100s of feet of 10 gauge for speakers. the cost would be crazy today.

With that direction I can move forward to soldering up some terminal blocks and figure out how much resistance I have on the lines and how much signal voltage will be needed. Ill give it a go with my old amps and mixers first.

I can't justify buying the Peavey loudspeaker management system new at this time but I know what to look for at the pawn shops.
  Reply With Quote
Old 18th September 2019, 02:05 AM   #4
indianajo is offline indianajo  United States
diyAudio Member
 
indianajo's Avatar
 
Join Date: Jan 2010
Location: Jeffersonville, Indiana USA
If you're hitting pawn shops & ebay, look at the Allen & Heath mixers. I think they have real differential drive outputs. These are usually on TRS sockets, ie 1/4" stereo phone plugs with the main drive on the tip, invert channel on the ring and the shield on the shaft.

Then some new power supply capacitors, some new pots in the high use areas, you might have something you can use to drive 100' twisted pair.

The differential drive concept goes back to Bell telephone; was used in Hammond organ "tone cabinets" of the late 40's & 50's to have amplification up to 100' away from the organ console without hum.

I'm trying to reuse a PV8 mixer to insert a mike into an Allen organ amp, but the ****ed thing is surface mount parts. I found the bad solder joint but don't know how to correct it. 80's & early 90's mixers have DIP IC's you can actually work on with a $60 soldering iron.
__________________
Dynakit ST70, ST120, PAS2,Hammond H182(2 ea),H112,A100,10-82TC,Peavey CS800S,1.3K, SP2-XT's, T-300 HF Proj's, Steinway console, Herald RA88a mixer, Wurlitzer 4500, 4300

Last edited by indianajo; 18th September 2019 at 02:10 AM.
  Reply With Quote
Old 19th September 2019, 12:03 AM   #5
HavanaWoody is offline HavanaWoody  United States
Stiguini Slayer
diyAudio Member
 
HavanaWoody's Avatar
 
Join Date: Sep 2019
Location: North East Florida
What are ways I can distribute signal to multiple amps over 50 feet
I have re-seated surface mount chips with a $20 soldering iron, It took some bizarre faces and a strained sphincter but I was successful at getting the Sony GPS dongle to work again. While I was winging it When I watch Louis Rossmann he does more or less the same thing with better tools and a microscope, YouTube I think a harbor freight plastic welder could work like the hot air gun he uses.

If you can listen to Dave at EEVblog that long he has a tutorial on surface mount. the whole series is worth watching. YouTube

just practice on something throw away its not that hard just intimidating, most components can take a lot more short time heat than we image (700f for 20 seconds). I used a silver bearing flux for lower heat but eventually it overheated and de soldered again.

Thanks again for the suggestions its been a while since I was a professional in electronic repair (Curtis Mathis Magnavox warrenty) I have to re-educate myself often.
  Reply With Quote
Old 19th September 2019, 12:47 AM   #6
wg_ski is offline wg_ski  United States
diyAudio Member
 
Join Date: Oct 2007
You can run unbalanced signal (even over twisted pair or just speaker wire) hundreds of feet without hum pickup if the impedance is low. By low I mean in the 50 to 100 ohm range. Just hang a 47 to 100 ohm resistor at the receiving end. A small “chip amp” like an LM1875 can drive multiple parallel runs, until the total load hits about 4 ohms.

If you want better fidelity and noise immunity, use double terminated 75 ohm coax. Terminate the load in 75 ohms, use 75 ohms in series at the driver amplifier output. You can hang as many of those 150 ohm loads off the driver chip as it will handle. They make op amps specifically for this (ie. AD815), but a gainclone chip works just fine. An E-bay kit and a wall wart is as good as anything if you don’t want to design it. An LM386, although tempting, isn’t quite up to the task unless it’s just voice where you don’t even care about quality. An LM380 would be ok, but one of the usual gainclone chips is better and can drive heavier loads without distorting.
  Reply With Quote
Old 19th September 2019, 09:42 AM   #7
indianajo is offline indianajo  United States
diyAudio Member
 
indianajo's Avatar
 
Join Date: Jan 2010
Location: Jeffersonville, Indiana USA
Quote:
Originally Posted by HavanaWoody View Post
I have re-seated surface mount chips with a $20 soldering iron, It took some bizarre faces and a strained sphincter but I was successful at getting the Sony GPS dongle to work again. While I was winging it When I watch Louis Rossmann he does more or less the same thing with better tools and a microscope, YouTube I think a harbor freight plastic welder could work like the hot air gun he uses.

If you can listen to Dave at EEVblog that long he has a tutorial on surface mount. the whole series is worth watching. YouTube
j.
Thanks I watched the video. Apparently surface mount boards have a chemical coating that prevents solder from bridging pins. News to me! I have had a huge problem with solder bridging pins even on 0.1" spaced dip packages TO-18 TO-92 & even TO-220 on paper boards & G14 FRP. Have to go in & scrape out in between with a pick, which could overheat the die obviously.

If you're an experienced diy, you can take your analog signal, run it through one op amp, then out to dozens of op amps each driving it's own twisted pair. Just keep the runs short on the main "mixer" op amp, and keep it inside a metal housing with RF barriers at all entry points. Use inverting for main wire and non-inverting for pair wire for best hum rejection. This differential signal requires power amps with 3 pin input jacks and op amp common mode rejection feature. You can use the 1 wire for the signal (op amp output) and the twisted pair for analog ground out and in in the cheap line driver setup used by cheap mixers like my Peavery PV8 and Unity 12.

WG SKI's 50 ohm & 75 ohm scheme with chip amp driver and load resistor at the amp end works, but you have to keep the signal down below 2 vac to avoid overwhelming your amps out in the field. LM3886 and other chip amps are capable of 20 VAC signals if the power supply is high enough.
__________________
Dynakit ST70, ST120, PAS2,Hammond H182(2 ea),H112,A100,10-82TC,Peavey CS800S,1.3K, SP2-XT's, T-300 HF Proj's, Steinway console, Herald RA88a mixer, Wurlitzer 4500, 4300

Last edited by indianajo; 19th September 2019 at 09:53 AM.
  Reply With Quote
Old 19th September 2019, 10:31 AM   #8
wg_ski is offline wg_ski  United States
diyAudio Member
 
Join Date: Oct 2007
A 50 ohm system will work as well (or better) than 75, but the cable is going to be more expensive than video cable. With eiither system you get a natural 6dB attenuation from double terminating (it is a voltage divider), so less likely to overdrive consumer levels equipment inputs. If you’re still concerned, use a pi attenuator (closed loop gain minus 6 dB) on the receiver. In any case, no need to run the power supply up over 18 or 24 volts, and a single supply application circuit can be used.
  Reply With Quote
Old 19th September 2019, 02:47 PM   #9
HavanaWoody is offline HavanaWoody  United States
Stiguini Slayer
diyAudio Member
 
HavanaWoody's Avatar
 
Join Date: Sep 2019
Location: North East Florida
What are ways I can distribute signal to multiple amps over 50 feet
Default Ah so that's were the majic is.

Quote:
Originally Posted by indianajo View Post
surface mount boards have a chemical coating that prevents solder from bridging pins..
I didn't realize that was why either. I know it can bridge when you use too much solder and are sloppy, but I didn't know the surface tension of the solder wasn't the reason the balls coalesce. I just knew if you fiddle with it everything goes were it is supposed to like magic. .

I'm glad my listening to Louis rant about macs and life has been able to help. I really have great respect for Dave and have learned a lot from him, but I wish I could filter that squeak from his voice as it grates on me badly.
Quote:
Originally Posted by wg_ski View Post
A 50 ohm system will work as well (or better) than 75, but the cable is going to be more expensive than video cable.
I already have cable buried, I think it is network cable, it does have 4 shielded conductors but I have not been able to find any specs like the impedance or capacitance. I had an Idea that it would work but was not sure of voltage levels or many of the caveats that you have made me aware of. this should be pretty fun. I'll be experimenting with the cheap Class D amps before I connect to any of my good stuff, I already learned my lesson with the tanberg TR-2055 that lost a channel and needs to go on the bench when I get schematics.

Do have you got any suggestions for terminal strips. I will have a total of at least 64 conductors meeting and I was going to put them in a box on the wall outside my man cave perch. Would a Telephone exchange type work or should I look for some other type ? I'm thinking that new scope needs to be for my Birthday , I don't wanna wait till Christmas.

After going a few years without a decent system hooked up,(self flagellation for doing dumb stuff that broke things) I find that having quality music makes me happier and more productive all day.
  Reply With Quote
Old 19th September 2019, 03:15 PM   #10
indianajo is offline indianajo  United States
diyAudio Member
 
indianajo's Avatar
 
Join Date: Jan 2010
Location: Jeffersonville, Indiana USA
These closed style "euro" barrier strips have screws to hold the wires down and their own insulation. https://www.newark.com/wieland-elect...ion/dp/01M9997 The ones that don't go up to 12 ga like this one are easier to get 26 ga etc under the screws without the wire slipping out. This one goes to 16 ga. There were cheaper ones under mcmelectronics.com but newark closed that warehouse and I can't find them today, although everything moved to n.carolina.

Telephone type punchdown blocks oxidize and block signals on low energy type circuits like line level, 2 vac 0.1 ma. We banned them for our factory data hookups, whereas the screw terminals with crimp on terminals maintained connectivity over a decade. The blocks requiring crimp terminals on the wires are obsolete now IMHO now that closed entry terminal strips are available. Telephone signals were 48 v which is not a "dry circuit", so the punchdown blocks were not a problem on telephones.

I was paying $1.50 for a 12 entry euro terminal block. Make sure it has screwholes for mounting between wire terminals. The ones I bought require 1" long 4-40 screws or 3 mm x 25 mm. Use elastic stop nuts so they don't come unmounted. I get this hardware from mcmaster.com, in packs of 50 or 100. Get the passthrough drill for the mount screws on the same $8 freight, unless you have a #1-60 drill set already.

Scopes are limited to 80 v signals, or cost $600 up. I make do without one. I have a Simpson 266xlpm meter which goes down to 2.5 vac. I can see 50 mv on it. It has no electrolytic caps in it to expire and works still after 33 years. Of course dvm are handier for dc since the polarity doesnt matter, but they miss short pulses like loose solder connection pops and produce random numbers on music signals. The fluke RMS DVmeter stops at 7000 hz so ultrasonic oscillation is invisible. Caught some in an op amp circuit with the Simpson 266. Use a .047 uf capacitor (400 v) series negative probe to block DC from showing up on AC scale. If a signal exists, you can't hear it, and it still passes through a 390 pf blocking capacitor, it is an ultrasonic.

I've quit working since 2008, when I had only a FM radio with a 2" speaker working. I now have stereo 70w/ch in my music room with 2000 LP's and SP2-XT speakers, stereo 125 w/ch with the HDTV with 6" coaxial speakers in newark boxes, and mono 30 w/ch with 2 way 15"+horn wedge monitor in my summer trailer. All amps repaired/improved by me from the glory days of US production. Plus 2 hammond H100 organs working and 2 working pianos.
__________________
Dynakit ST70, ST120, PAS2,Hammond H182(2 ea),H112,A100,10-82TC,Peavey CS800S,1.3K, SP2-XT's, T-300 HF Proj's, Steinway console, Herald RA88a mixer, Wurlitzer 4500, 4300

Last edited by indianajo; 19th September 2019 at 03:27 PM.
  Reply With Quote

Reply


What are ways I can distribute signal to multiple amps over 50 feetHide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Safe way to distribute power to multiple supplies NealJ Power Supplies 13 21st December 2018 07:40 PM
how to split the audio signal to multiple chip amps? wrybread Analog Line Level 7 5th April 2018 12:06 AM
Switching an I2S signal to multiple audio out mendelsd Parts 0 29th August 2011 03:53 PM
How to distribute one audio Signal. moenviconer Everything Else 1 27th July 2008 09:22 PM
Creating a differential signal from a single-ended signal for bridged amps Peter Daniel Chip Amps 45 8th November 2004 12:47 PM


New To Site? Need Help?

All times are GMT. The time now is 08:33 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©1999-2019 diyAudio
Wiki