New (old and busted) bass bins

AngrySailor said:
Didn’t think it would be “good”... but rules were made to be broken. Sort of like putting hockey rink bass bins in your living room!
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The dual 500 run about 122volts per rail. The combined rail is 244 witch is close to the max rating of the mj21195/96. I have yet to torch a mj21195/96 pair in the 500’s. Mj15024/25 melt all time in this configuration
 
laatsch55 said:
Yeah, got some insane output power readings, over 500 watts...but didnt live to long.

The 240 was a dual primary model that was headed to Aussie land.
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I haven’t put a meter on my house circuit yet, I’m running two outlets, one from each hot leg but with Tim and the big carver the kitchen lights dim when shizz gets serious... the shop system with the two MX3000’s could blow two 20a breakers and would drag the line voltage down from mid ~126v to near 110v... slippery slope as rail voltage drops eh...
 
AngrySailor said:
I haven’t put a meter on my house circuit yet, I’m running two outlets, one from each hot leg but with Tim and the big carver the kitchen lights dim when shizz gets serious... the shop system with the two MX3000’s could blow two 20a breakers and would drag the line voltage down from mid ~126v to near 110v... slippery slope as rail voltage drops eh...
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That is what got me thinking to try 240 volt everything is less stressed down stream from the amp and the transformer is quite capable of 240v
 
grapplesaw said:
That is what got me thinking to try 240 volt everything is less stressed down stream from the amp and the transformer is quite capable of 240v
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Now mind that I DID break my house with the power on tap... had a length of copper water pipe unsupported for maybe 6’ and it cracked the day after I put the system in... been fine for 20 years so... it fractured and started dripping, seen the wet spot in my ceiling and caught it before it let completely loose. Checked after I fixed the leak by cranking the tunes up and it was vibrating. Put a few extra hangers in...
 
Our buddy Dan D’Augigistino suggests his new mega amps be run on 220 for optimal performance.

But what about using two transformers and two complete supply filter arrays (without de-rating them)? True dual-mono but besides that it should help with power reserve and recovery. Maybe go with higher amperage torroidals instead of the bricks too…

Where’s Gepetto?
 
And perhaps remote mount the transformers and capacitors. Super WOPL. A big pancake fan could be mounted to the old transformer opening. Pressurize the cabinet, exhaust holes strategically drilled through the rear of the chassis and heatsinks. Bias transistor temperature would be a factor to consider.
So many things to imagine, so little time.
 
Toroids have their own challenges. In rush current , a large magnetic field, and yes you want the power supply close. Joe told us why a couple days ago in another thread. The further you go the more the high frequencies suffer..
 
My Dynaco stereo 400 has a "mystery" connector on the back that I think this plugs into...

Anyone confirm that?
 
I don't think I'd bother reconing. Those woofs don't look like Altecs or JBLs to me. Me thinks some cast basket Eminences would look good in there. Maybe top it out with a pair of Altec 807/511s.......
 
With two phases feeding two sets of windings, is there any fear of issues with each being on opposed phase of the A/C?
 
I had actually considered this approach myself- the four-box monoblocks.

I think physical implementation is critical for it to work well, and not end up a problem. Bottom box (with transformer(s)) top, and top box (everything else) bottom, should be steel, and thick enough for the expected emissions to be squelched, or, why bother? Counterpoint felt that copper plated steel was the hot ticket. The air gap between them is good as EMF is diminished very rapidly with distance, so that takes care of itself.

Female sockets on the top of the bottom, and bottom of the top, exist, and are in alignment such that distance for DC to travel is reduced as short as possible, and massive interconnection reduces loss. Copper "jumper rods" interconnect the chassis to one another. Perhaps integrate these into the feet, so they are "invisible" from the front.

Additional interconnection is necessary to avoid some Darwin award nominee sticking their snot-moistened finger into one of the DC sockets of the bottom cabinet and enjoying the light show of their ignited hair immediately prior to death...
 
The Powerful Difference said:
There's a relatively simple fix for this concern. First, you would remove the whole AC/DC shebang (transformer/full-wave-bridge/large DC coke-can storage caps) out into the separate chassis. (NOTE: This also gives you room to also implement as much or as little 'RFI cleansing circuitry' as you deem necessary.)



****

Maybe the above is only a quarter-baked idea...but I am guilty of thinking down this path every time I look at that dual-primary transformer.

Q: Is this a sickness or what?
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I see you are fitting well with our somewhat crazy ideas here. Although these changes not necessarythree the concept is something a few of us have beeen throwing around. Lee, Perry and myself (Glen) have some toroidal transformers. They are illisr in the dual 500 thread. I plan on using three of them. They are 83 -0- 83 volt 600va primary output. I have been waiting on this project for a variety of reason. But one obstacle is now solved. I get a nice box pan brake so I can form some custom chassis.

so this will be a one off amp. Three toroidal’s running through bridge rectifiers into a common capacitor bank. Magnetic field may be able to be shielded or a separate power supply will have to be created. The toriod’s will have soft start for power on. I also considered a true dual mono with one toroidal per channel into dedicated storage caps. The third would remain off until output current was sufficient to trigger it to power and stay on Or just have a time delay when powering on. the third toroidal would run through two bridge rectifiers to feed extra juice to which every channel needed it If I setup a dual mono power supply. the combined output would be 1800va with 118 volt rails. I think this setup will supply more current under load than the dual500 which has 120 volt rails But as with all the phase linear this voltage drops of under exreme loads. We will see.

I may start this project in the new year. Then again it may never come to life as so many things get in the way.
 
Amen Davis, we've been headed that way a long time. Having an engineer of Joe's caliber hangin and rattling with us is a definate plus...he derinately keeps us on the fruitful line.
 
Maybe go all-in and rectify the 220 A/C to D/C and start there….

(5- box 220 volt monoblocks perhaps???)
 
It's not like you are trying to balance the load in a 100 floor skyscraper!! To get 240 out of the house just as Davis described, alternate 120 breakers..
To get 240 out of those dual primary toroids it's a series connection, so a phase problem really isn't going to manifest itself on the DC side..

Now......if you are not using the 3rd grounding lug, as in some of our old gear, then that could be a concern..
 
I have a plan to pull a 20-amp breaker off the top of the box (first leg this side of the main) and run that with an isolated ground for stereo feeding.

Maybe I should plan on two…. Is 2400 watts enough for a pair of class-A amps running 100 watts output (into 8 ohms)?
 
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