Mating power cords with APL 3910

I am using both the Ps audio uo high current version and the hydra2 in my system. I am running the power amplifier (ML331) through the Hydra2 and the cd-player-preamp ML 39 through the UO. Accoring to my experiences, the UO is shifting upward the soundprint of the system. The combination Ps audio Lab cable (original) and the UO proved to be the right combination to return to a more equally balanced soundprint ( or how I was accustomed to).

First, to answer Sean's question about wiring and voltage drop in the Hydras. The Hydra 8's outlets are all wired individually and run from each outlet to the internal chassis that has the Copper buss system and FeSi 1002 compounds within, so with the 8, the point is moot.

The Hydra models 4 and 6 duplex outlets are connected consecutively with 2" silver/rhodium plated buss straps--as pictured on our web-site. The measured Voltage drop across a 2" 9 gauge silver plated buss strap is so small that it is irrelevant to operation and could not possibly create a voltage sag that would harm or otherwise alter the performance of electronics that are connected. There will always be a common point at which current converges no matter the wiring or buss arrangement, so pointing to this as evidence of inexpensive construction quality is far off the mark. Running wiring from the individual outlets in the 4 and 6 would actually be *less expensive* than designing and manufacturing the silver/rhodium buss straps. Caelin made that design choice to improve the units performance, not to cheapen manufacturing. We did have measurements posted in our technology section that show the outlet-outlet isolation in the 8 but Caelin wanted to update that and re-post with more complete test results. Caelin will be re-posting a recently completed set of measurements representing the circuit isolation of all the Hydras. In the mean-time, the fluke 43 power analysis results can be seen via our SoundStage Hydra 8 review-link:http://www.soundstage.com/revequip/shunyata_hydra_8.htm

To answer the other questions regarding Hydras, the most relevant difference between the units performance in Audio/studio applications is not the number of filter elements used, necessarily, but the difference in the units buss architecture. The Model 8 uses all copper wiring and a massive (7lbs) Copper buss, milled from solid ingots of CDA 101 copper. It also has the patented compounds surrounding the buss structure. The Hydras 6 and 4 are more minimalist in design (purposefully) and use the more direct-connection-silver buss (minimal contact impedance, minimalist AC path) construction. These differences mean that the Hydra 8 will have a more robust tonal presentation, it will sound more rich, full-bodied, but slightly slower(subjectively speaking) than the more immediate, forward presentation of the 6 and 4 models. The Hydra 2 splits the difference tonally because it has no buss and only has the 9 gauge copper wiring running from IEC to outlet. The Hydra 8 is definitely our reference, and that is the product I generally recommend when working with studios, but the smaller units might actually be preferred in predominantly tube or all analog systems--it depends on one's preference. Sony Music New York preferred the models 6 and 4 because to they seemed more "Transparent" with mastering equipment, while other studios such as Astoria and Rick Rubin preferred the 8 and the 2's because they had more weight and richness...

When working with 2-3 dedicated lines, it is best to try model 2's for amps on separate lines whenever possible, and then choose the Hydra to evaluate that best suits the number of components that make up the rest of the system. If cost is no object, then an 8 is our reference, but the 4 and 6 might be worth trying if you only have 2-3 other components.

I hope this helps answer some of your questions.

Regards,

Grant

Samuel aka Grant: Thanks for taking the time to respond and provide more info. I was beginning to wonder if this was going to be like the last thread where i asked questions of a manufacturer and they never responded. They did respond to others within that thread both before and after those questions / comments, but they somehow seemed to overlook what i threw their way. Wonder how that happened ??? : )

As to my previous comments, i based them on the info and pictures available on your website. As such, you might want to update your website and check the wording used. While you state that the Hydra 8 is parallel wired rather than daisy-chained, where would the use of copper buss bars come into play then? The info on your website makes a big deal of how heavy the buss bars are that are used in the Hydra 8 and even shows them, but doesn't actually show the internal construction of the unit. As such, one is lead to believe that these units are all based on the same basic design / operating parameters with the only variables being the amount of outlets available. Evidently, such is not the case. This is confusing to say the least.

"The measured Voltage drop across a 2" 9 gauge silver plated buss strap is so small that it is irrelevant to operation and could not possibly create a voltage sag that would harm or otherwise alter the performance of electronics that are connected. There will always be a common point at which current converges no matter the wiring or buss arrangement"

I never said that voltage sag would result because the Hydra's used buss bars. What i did say is that there was more potential for sag or "modulation of the voltage" for the outlets later in the line because of this type of lay-out / wiring scheme.

If a device is plugged into the first outlet that pulls gobs of current on a dynamic basis, all of the outlets wired behind that first outlet will demonstrate at least a small amount of ripple. There is the potential for greater sag as the current draw increases. That's because the current will go where it is being drawn first and then whatever is left will "meander" downstream accordingly. If there is enough pull "upstream" at the first outlet, there's not as much current left to wander "downstream" to the other outlets. That lack of current is what causes voltage sag.

If you had multiple rivers ( individual outlets ) with their own feedpoints ( parallel branch wiring ) to the ocean ( wall outlet ), the potential for any starvation downstream is reduced. That is, so long as the ocean ( wall outlet and power cord ) could provide enough flow. That's because each parallel branch doesn't see what the other branches ( outlets ) are pulling whereas with the daisy chain arrangement, one river ( outlet ) feeds into the next in a series arrangement. If the first river ( outlet ) restricts the flow, all of the other rivers ( outlets ) feel the consequences.

Based on the info that you provided in this thread, this type of situation could only apply to the units that are wired in "daisy chain" fashion i.e. the 4's & 6's. As mentioned elsewhere in this post, the use of buss bars within the 8's still leaves me a bit confused though.

As to the link that you provided ( THANK YOU for making it simple for all of us to follow along ), i never, not once said that the Hydra's couldn't provide noise reduction. Anyone that has ever experimented with parallel noise suppression circuity would know better than to make such a claim. What i did question was the amount of isolaton as referenced over a specified bandwidth that the Hydra's provided from outlet to outlet. The test results that you linked to here didn't cover anything like that.

For sake of reference, my main concern is what happens when a component plugged into the Hydra generates AC noise / interference / RFI and tries to pump that back into the AC system??? Not only would such a test tell us how well each component is isolated from the other within the confines of the Hydra itself, it would also tell us the level of noise suppression that the unit is capable of providing for the incoming AC too. I hope that i'm clear enough in my explanation as to the type of info that i'm looking for.

Thanks again for the timely response and looking forward to any further info you would like to provide. Sean
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Puremusic- a cost effective way to isolate your 3910 is the ISO-21 from ESP. For "value-per-dollar" power cords check out the Supra LoRad.

I agree with Sean, that there doesn't appear to be much in the way of outlet to outlet or AC line isolation on the Hydras.

A former Hydra user with a full digital system recently upgraded to the new Audience AdaptResponse power conditioner which has 12 full isolated outlets, and says it's a hugh improvement.

Ajahu, Thanks for your input on the UO and your suggested correction for its tipped frequency spectrum.

Kana813, Thank you for your two suggestions. I'll check them out.
John