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Stewart World 2.1 crapping the bed?

#22
Wasnex said:
I have never seen parallel mono on anything but a Crown amp. You choose bridge mono or parallel mono based on the impedance you need to drive.
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My Carver PM1400 (a GREAT amp btw) does parallel mono (also referred to as dual mono), where you plug into channel 2 and the same signal goes to both channels, and the volume of each channel can still be controlled independently with the knobs on the front of the amp. This is the way I've always used it with a 4 ohm Acme B2 on each output channel.
http://carvermanuals.com/manuals/Amplifiers/PM-1400 Owners.pdf
 
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#23
BassmanPaul said:
Hmm. I never thought that I had such a stance. I think that for someone who is aware of the negatives involved in Bridging, and respects them, Bridging is fine. For others not so much. More than a few speaker systems have been damaged due to the power released in Bridge.
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It is one way of teaching.
We've all damaged something in our lives do to not following good procedure.
At least no one gets hurt when an amp dies.
Plus, it might help folks learn. I think that most speaker failures resulted in the poor driver trying to tell the user that it was in trouble (before failure) if they only learned to listen to the warning cries.
 
#25
I would like to learn the anti-bridge rationale. I jumped on this Crown Micro-Tech 600 because it was a cheap way to approach the limits of what my AK cab can do, and I needed more loud than I could get with my 210-watt Peavey power amp. 750 watts/4 ohms in bridge mono sounded perfect.

It certainly hits harder on the low notes. But what am I risking running it bridged, apart from not wanting to short it by plugging/unplugging the cab with the amp switched on?

If this is too much of a thread derail I apologize and won’t be offended if you tell me to go crap in my Easter hat.
 
#26
In bridge you should never use Banana plugs or 1/4" Phone plugs. Both the connections are live with respect to ground and twice that to each other. This is definitely a shock hazard. Only SpeakOns should be used when running this way. When a phone plug is withdrawn there is a momentary short tip to sleeve. This in essence shorts both outputs of the power amp to each other and your amp can fail pretty quickly.

If you do a search on the ramifications of Bridge Mode you should find more information.
 
#27
zombywoof5050 said:
My Carver PM1400 (a GREAT amp btw) does parallel mono (also referred to as dual mono), where you plug into channel 2 and the same signal goes to both channels, and the volume of each channel can still be controlled independently with the knobs on the front of the amp. This is the way I've always used it with a 4 ohm Acme B2 on each output channel.
http://carvermanuals.com/manuals/Amplifiers/PM-1400 Owners.pdf
Click to expand...

Dual mono is not the same thing as parallel mono. In parallel mono both outputs are tied together to drive one load. The Crown amp is specifically spec'ed to do this. I have no idea what would happen if you tried it with your amp, but I don't recommend it.

I see the term parallel mono in the index of your amp's manual. It don't see it anywhere on page 8. Page 8 does describe dual mono operation, but not parallel mono.

I have attached a Crown manual so you may see the difference. See figure 2.1 on page 8.
 

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#28
BassmanPaul said:
In bridge you should never use Banana plugs or 1/4" Phone plugs. Both the connections are live with respect to ground and twice that to each other. This is definitely a shock hazard. Only SpeakOns should be used when running this way. When a phone plug is withdrawn there is a momentary short tip to sleeve. This in essence shorts both outputs of the power amp to each other and your amp can fail pretty quickly.

If you do a search on the ramifications of Bridge Mode you should find more information.
Click to expand...

Thanks! In my initial tests I’ve been using banana on the amp side and 1/4” into the cab’s combo jacks. That’s what I had on hand and I wanted to hear them watts!

I see from your explanation some ways in which that could end badly.

The amp has just the two pairs of binding post outputs. Maybe the safest thing would leaving the amp end of the cable cranked down in the binding posts, and a Speakon on the other end. The speaker cable could live in the case, always attached at the amp end. No shorting risks that way.
 
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#31
Wasnex said:
Dual mono is not the same thing as parallel mono. In parallel mono both outputs are tied together to drive one load. The Crown amp is specifically spec'ed to do this. I have no idea what would happen if you tried it with your amp, but I don't recommend it.

I see the term parallel mono in the index of your amp's manual. It don't see it anywhere on page 8. Page 8 does describe dual mono operation, but not parallel mono.

I have attached a Crown manual so you may see the difference. See figure 2.1 on page 8.
Click to expand...
Thanks for the info.
That entry in the Carver manual is the reason that I thought Parallel Mono was the same as Dual Mono, because they called it Parallel Mono in the index, but then they changed it to Dual mono on the page where it was discussed. Now that you mention it, someone in the past pointed this out to me (that Parallel Mono and Dual Mono are not the same), but I had forgotten about it. So the entry in the index of the Carver manual should be Dual rather than Parallel. Thanks again for the correction.
 
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#32
It's really Crown that is the exception to the rule, in that the output stage is configured in parallel topology while the bridge mode is series topology.
 
#33
zombywoof5050 said:
Thanks for the info.
That entry in the Carver manual is the reason that I thought Parallel Mono was the same as Dual Mono, because they called it Parallel Mono in the index, but then they changed it to Dual mono on the page where it was discussed. Now that you mention it, someone in the past pointed this out to me (that Parallel Mono and Dual Mono are not the same), but I had forgotten about it. So the entry in the index of the Carver manual should be Dual rather than Parallel. Thanks again for the correction.
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No worries. My first power amps were Crowns and I assumed every good professional power amp could be configured in parallel mono mode. Years ago, a friend of mine had purchased a big EAW speaker system. He had good amps but not enough to run at the impedance of the system (oops). So he had to rig up some series cables which greatly reduced power. I suggested configuring his amps in parallel mono to maximize power, but the amps were not Crowns, so obviously it wasn't possible o_O. That's how I learned that Crown is the only company that has this feature ;).
 
#34
zombywoof5050 said:
Thanks for the info.
That entry in the Carver manual is the reason that I thought Parallel Mono was the same as Dual Mono, because they called it Parallel Mono in the index, but then they changed it to Dual mono on the page where it was discussed. Now that you mention it, someone in the past pointed this out to me (that Parallel Mono and Dual Mono are not the same), but I had forgotten about it. So the entry in the index of the Carver manual should be Dual rather than Parallel. Thanks again for the correction.
Click to expand...
Dang, I just noticed in the Carver manual that they do have entries in the index for Dual Mono AND Parallel Mono, and I only saw the entry for Parallel Mono, so I thought they changed it from Parallel to Dual on page 8, but they totally should have just left out the mention of Parallel mono in the index (because it apparently doesn't even exist on this amp). I'm claiming that I was led astray by the error in the manual, yeah that's it.
 
#35
zombywoof5050 said:
Dang, I just noticed in the Carver manual that they do have entries in the index for Dual Mono AND Parallel Mono, and I only saw the entry for Parallel Mono, so I thought they changed it from Parallel to Dual on page 8, but they totally should have just left out the mention of Parallel mono in the index (because it apparently doesn't even exist on this amp). I'm claiming that I was led astray by the error in the manual, yeah that's it.
Click to expand...
It's not that it doesn't exist, but that Crown uses the same terminology for a different topology. Those of us who work regularly with a wide range of equipment are familiar with this.
 
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#36
BassmanPaul said:
In bridge you should never use Banana plugs or 1/4" Phone plugs. Both the connections are live with respect to ground and twice that to each other. This is definitely a shock hazard. Only SpeakOns should be used when running this way. When a phone plug is withdrawn there is a momentary short tip to sleeve. This in essence shorts both outputs of the power amp to each other and your amp can fail pretty quickly.

If you do a search on the ramifications of Bridge Mode you should find more information.
Click to expand...

The Stewart can run in mono, mono bridged, or stereo. Unless I'm mistaken, I'm running it mono but not bridged.
 
#38
1583461178978270303323728395068.jpg
 
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#40
MassacreBass said:
View attachment 3733128
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You have the amp in bridge mode, but the speaker is not properly connected for bridge mode operation.

Per the manual:
Mono / Stereo Switch
This switch is used to configure the amplifier for 2-Channel Stereo mode (factory setting) or to “bridge” the amplifier for Mono (single channel) operation.
​
For bridge mode operation the speaker should be connected to positive terminals of both channels. If you were to connect one speaker to channel 1 and another speaker to channel 2, they would be out of phase with each other.

Per the manual:
Hookup Diagram 6 Bridged Connections
Bridged (Mono) Operation, use only Channel 1 Input. Be sure to set Operation Mode Selector Switch to “Mono” position. Channel 1 Output (+) is Speaker Positive. Channel 2 Output (+) is Speaker Negative.
​
Manual attached for your convenience.

I don't know if operating the amp like this posses a risk, but you are not operating it as it is intended. Perhaps @agedhorse will comment.

IMHO to use the amp as connected put the switch to stereo mode.
 

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