OTL Asylum

OTL, Output Transformerless Amplifier User Group.

Return to OTL Asylum

Message Sort: Post Order or Asylum Reverse Threaded

2 amps - 1 pair of speakers

96.42.65.70
Posted on May 28, 2012 at 08:16:24
Unistar


 
When I have "background" music playing for hours, I often disconnect my m60s, and switch in my w4s sit-500 integrated. However, since my Benchmark Dac1 has balanced and single ended output, I have thought about connecting the dac to the sti-500 by the single ended connections and the m60 to the dac using the balanced connections.I would the connect the sti to the speakers using lugs, and the m60s to the same speakers using bananas with different cables. My m60s use Speltz autoformers.

Question: is there a risk of damage to either amp in doing this. I do not intend to e ver run them at them same time.

 

Hide full thread outline!
    ...
RE: 2 amps - 1 pair of speakers, posted on May 28, 2012 at 18:47:54
Lew
Audiophile

Posts: 5285
Location: Bethesda, Maryland
Joined: December 11, 2000
 One amp will "see" the output impedance of the other amp in parallel with the speaker impedance. Granted that you say one amp will always be "off" while the other is "on", I guess the output impedance of an M60 when it is powered down would be infinite, and therefore it would be OK vis the other amplifier. But do check whether there is a finite R across the outputs of the other amp when IT is powered down, before you go ahead with this, and DO check to make sure I am not wrong about the M60. (Just put your ohmmeter across its outputs when there is no AC applied.) And DO install some safety mechanism, so you won't forget not to power up both amps at the same time. At the other end, check also what's going on.

 

RE: 2 amps - 1 pair of speakers, posted on May 29, 2012 at 09:57:22
baileyler
Audiophile

Posts: 217
Location: Chadds Ford, PA
Joined: January 17, 2007
 You might have an issue with your DAC output when both balanced and unbalanced are hooked up. I have an Electrocompaniet ECD-1, and one of the outputs goes very soft (low volume) when I have both hooked up (probably something about current flowing to the lowest impendence point).

 

Yes,..., posted on May 29, 2012 at 11:06:36
Lew
Audiophile

Posts: 5285
Location: Bethesda, Maryland
Joined: December 11, 2000
 the inputs have to be completely isolated from one another, balanced or not balanced. It sounded like he has switchable inputs. I mentioned that as an afterthought, but it's major.

 

RE: 2 amps - 1 pair of speakers, posted on May 29, 2012 at 11:48:48
Unistar


 
Thank you for your responses. The complexity and risk was not worth the time savings.

I moved things around and now can easily plug the speaker cables into either the M60s or the Sti integrated. I will see if I can leave the DAC (a Benchmark DAC1) connected to both units. If not, I can now also reach it easily and rotate between the connectors.

I do not want to risk inadvertently turning on both sets of amps at the same time.

 

Page processed in 0.014 seconds.

[ Top Top of Page ] [ Contact Us ] [ Support/Wish List ] [ Copyright © 2013, Audio Asylum, all rights reserved ] [ Take5 ]
[ General ] [ Speakers ] [ Tubes ] [ Vinyl ] [ Digital ] [ Hi-Rez ] [ Video Asylum ] [ Cables ] [ Tweaks/DIY ] [ Music ] [ Films ]