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DIY Stompboxes => Building your own stompbox => Topic started by: mremic01 on February 16, 2012, 04:13:29 PM

Title: Connecting multiple Rubies to a single cab
Post by: mremic01 on February 16, 2012, 04:13:29 PM
I'd like to build 2 or 3 Rubies into one enclosure and have them all connected to a single speaker to use as a practice amp that a whole band could plug into. Is this possible, or will it cause some sort of impedance issues having the outputs more than one Ruby all going into one speaker?
Title: Re: Connecting multiple Rubies to a single cab
Post by: iccaros on February 16, 2012, 05:26:59 PM
It would be better to use a mixer on the front end then to try and mix to the speaker.
Then you would have one ruby with multiple inputs.
As the ruby amp was not designed for this, you will have issues on quality of sound.
Title: Re: Connecting multiple Rubies to a single cab
Post by: gregwbush on February 17, 2012, 08:29:34 AM
Yeah but each instrument having it's own ruby would result in a more dynamic sound wouldn't it??

Say, have 3 ruby's, THEN mix 'em together into another power amp connected to speaker

i dunno...
Title: Re: Connecting multiple Rubies to a single cab
Post by: R.G. on February 17, 2012, 10:11:10 AM
Quote from: mremic01 on February 16, 2012, 04:13:29 PM
I'd like to build 2 or 3 Rubies into one enclosure and have them all connected to a single speaker to use as a practice amp that a whole band could plug into. Is this possible, or will it cause some sort of impedance issues having the outputs more than one Ruby all going into one speaker?
Iccaros is correct. It is possible, but will give problems unless you isolate the outputs some way, like perhaps with series resistors for each output. This prevents the individual outputs from fighting each other for different instantaneous voltages, but also lowers the output. Any kind of power output tends to not play well with another power output trying to control the same thing.

QuoteYeah but each instrument having it's own ruby would result in a more dynamic sound wouldn't it??
It depends on what you mean when you say "dynamic sound". It'll be different. But you'll get better results by having only one power amp driving the speaker whichever way you do it.

QuoteSay, have 3 ruby's, THEN mix 'em together into another power amp connected to speaker
This is by far a better idea than trying to gang the outputs. Whether it's better than mixing before one Ruby depends on other issue, like instantaneous output levels.
Title: Re: Connecting multiple Rubies to a single cab
Post by: DavenPaget on February 18, 2012, 03:29:35 AM
It can also be a rather better idea to send 3 rubies , mix 'em into a TDA2030 amp instead of a speaker
Title: Re: Connecting multiple Rubies to a single cab
Post by: pinkjimiphoton on February 18, 2012, 06:32:20 PM
whoever drives the ruby hardest will win...and fry the others. NEVER connect two amps to one speaker...recipe for disaster.

one of my good friends bought a beautiful accoustic 360 bass amp off another friend...and decided to a/b that and a 1200 watt walter wood bass amp into the same box.

he forgot to dis-connect the accoustic. the big amp won.

fried the accoustic all the way up to the input stages. he sold the husk on ebay after several failed attempts at re-populating the board.

you'll get more control with a simple mixer going to one amp to one speaker.
Title: Re: Connecting multiple Rubies to a single cab
Post by: mremic01 on February 22, 2012, 02:41:03 PM
Thanks guys. This sounds like it will be a lot harder than it's worth. I think I'll just build 3 Rubies into one box with three inputs and three outputs and just use separate cabs. Now I just need to scavenge some old speakers from Goodwill or the Salvation Army.
Title: Re: Connecting multiple Rubies to a single cab
Post by: iccaros on February 23, 2012, 07:07:59 AM
Depending on how much volume you need, you may really want to test those speakers. Non insterment speakers are very inefficent, and could make that  .5watt amp sound like a .0005 watt amp. speaker efficiency is more import than wattage in some cases.