Balanced power amplifier

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RDavidson

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Re: Balanced power amplifier
« Reply #100 on: 25 May 2017, 10:36 pm »
I'll weigh in on the trigger topic.  While RDavidson gives good advice about amplifier power sequencing, it also depends on the equipment.  Some components have built in muting delay and they also differ in turn-on and turn-off transients and power supply charging and discharge.

While it's possible that some scenarios could damage a driver, I probably would personally give the trigger a try.  If turn-on and turn-off noises are subtle, I would use the trigger.  If they are not subtle, then I would revert to manual power sequencing and ditch the trigger.

It obviously works in many scenarios or Nelson Pass wouldn't have provided the trigger connection.

Steve

Understood regarding on/off sequence. But if you go by my very simple method it is essentially fail safe. Like you said, not all gear has a muting relay and that's where the danger can be. So if you just make a habit of amp on last and off first, then there's much less to worry about. :D Yeah....not sure how that'd work with a trigger relay. Just have to be sure you understand how your equipment works to ensure no mishaps. Another option is a surge protector with programmable relays....in which case the amp on/off sequence still applies.

SoundSound

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Re: Balanced power amplifier
« Reply #101 on: 26 May 2017, 10:44 pm »
Thank you very much, dear friends! :)

For now I will just "manually" follow what was kindly suggested by @RDavidson: "ALWAYS turn your amp ON last, and ALWAYS turn it OFF first." :)

The beast has arrived, and now am waiting for a good neighbour of mine, a strong young gentleman, to come back home from his business trip and help me to unpack and set it up into my rack. :)

Any final suggestions, please? :scratch:

Would you consider Pass Labs XP-10 to be the best solid state fully balanced preamp (operates in pure Class A!) under 3K used to work in tandem with XA30.5, please? :scratch:


I.Greyhound Fan

Re: Balanced power amplifier
« Reply #102 on: 27 May 2017, 03:47 am »
Thank you very much, dear friends! :)

For now I will just "manually" follow what was kindly suggested by @RDavidson: "ALWAYS turn your amp ON last, and ALWAYS turn it OFF first." :)

The beast has arrived, and now am waiting for a good neighbour of mine, a strong young gentleman, to come back home from his business trip and help me to unpack and set it up into my rack. :)

Any final suggestions, please? :scratch:

Would you consider Pass Labs XP-10 to be the best solid state fully balanced preamp (operates in pure Class A!) under 3K used to work in tandem with XA30.5, please? :scratch:


I can't say that the XP-10 is the best SS preamp but it is a Pass preamp and you have a Pass amp.  There will be synergy and it is a safe choice.  Certainly other preamps can sound better but it is trial and error.  But other factors come into play such as your speakers and music source such as you DAC,  CDP or TT.  I prefer a tube preamp and SS amp but you never know how different manufactures will sound together.  The Pass XP-10 is an excellent preamp and well regarded.  I have a friend that uses one and he loves it.  It sounds best with XLR as did my Pass X-1 preamp.  You can't go wrong with it.  Another good SS preamp is a Parasound JC2. 

Here is a review of the XP-10

http://www.dagogo.com/pass-labs-xp-10-preamplifier-review

http://hometheaterhifi.com/reviews/amplifier/preamplifier/pass-labs-xp-10-stereo-preamplifier/

RDavidson

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Re: Balanced power amplifier
« Reply #103 on: 27 May 2017, 03:49 am »
The XA30.5 has very high input sensitivity, so you really shouldn't need a preamp with a lot of voltage gain. In fact, you might not want any gain.

The Pass XP10 is a very nice preamp. Really hard to go wrong with an all Pass setup.

I've owned a few really good preamps, including a rare Bent Audio AVC, but I suggest looking at the Wyred 4 Sound STP-SE. EXTREMELY good preamp at a reasonable price. It is a passive preamp with a buffered output. It only applies gain if you crank the volume WAY up. I owned one for several years. These rarely show up used. Go to 6 Moons and read the review for the original unit. There's also a newish review for the fully upgraded unit. The original, "basic" unit is excellent as-is. You may only feel the need to upgrade it if the bug bites. But it would probably make more sense to upgrade other things before upgrading it. Your system would need to be REALLY well sorted first. Go read about it. I'm sure others will chime in.

I.Greyhound Fan

Re: Balanced power amplifier
« Reply #104 on: 30 May 2017, 09:11 pm »
So how do you like the Pass amp?

ricardoosusa

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Re: Balanced power amplifier
« Reply #105 on: 31 May 2017, 01:08 am »
Audio gd Master 3. I've had mine for almost 3 happy years no problem. Also it's around $1500.                                 
     http://audio-gd.com/Master/Master-32015/Master-32015EN.htm.

SoundSound

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Re: Balanced power amplifier
« Reply #106 on: 4 Jun 2017, 05:10 pm »
Dear audiophiles, my dear friends!  :D

Thank you, thank you very much for all your most appreciated help!  :)

First and foremost, my sincere apologies for not getting back to you with the words of gratitude for all your time and efforts educating yours truly in the field of High-End Sound. Please believe me, an unthankful pig I am not: my “motor” was giving me grief lately and I have just come back home on Friday…  :oops:

What can I say: everything you told me, everything I read about this truly amazing amplifier is true. I keep listening to my favorite compositions (vocal, organ, piano, orchestral, chamber, symphonic, jazz, pop, rock…) discovering nuances I have never heard before, and, mind you, many of those compositions I know by heart... Something really wonderful has happened to my speakers: it’s like instead of my entry level Hi-Fi Monitor Audio RS6 I am enjoying High-End Wilson Audio Sasha. The images became even more holographic with clearly defined instruments positioning, and all of this is built upon the foundation of rich, velvet, excellently articulated BASS…  :D

As usual, a couple of silly questions from yours truly…  :oops:

What is the purpose of Pass Labs XA30.5 meter, please? During my listening sessions the needle is always around 12 o’clock… What does this mean?  :scratch:

For quite some time I have not had a chance to look at the back of my components, and have just “discovered” there are a few unused XLR and RCA inputs on my Primare PRE30 preamplifier. Would you recommend me to employ Cardas Protective Caps (please se at http://www.cardas.com/protective_caps.php - in my understanding, effectively shorting out the inputs), plugs from Neutrik (please see at http://www.neutrik.com/en/accessories/sealing-accessories/ndf - effectively providing just protection from dust) or do nothing in this regard?  :scratch:

srb

Re: Balanced power amplifier
« Reply #107 on: 4 Jun 2017, 05:54 pm »
What is the purpose of Pass Labs XA30.5 meter, please? During my listening sessions the needle is always around 12 o’clock… What does this mean?  :scratch:

The meter is indicating bias current to the output devices, and because it is a Class A amplifier that will be a constant most of the time.  If you listen at loud volumes with bass content you may see the meter move a bit as you momentarily drive it beyond Class A into Class AB.

Steve

SoundSound

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Re: Balanced power amplifier
« Reply #108 on: 6 Jun 2017, 02:13 pm »
Thank you very kindly Steve!  :D

The needle hardly moves at all: it is glued at about 5 to twelve o'clock position.

mav52

Re: Balanced power amplifier
« Reply #109 on: 6 Jun 2017, 02:27 pm »
I'm not saying that's excessive standby power consumption necessarily, but if it is 15W standby, it is poor product copy in that by no one's definition is 15W a "few" watts and Pass should just publish the numerical spec.

Steve

I own the xa30.5. I used to run a Pass XP-10 and I tried a few tube pres, but now I use a W4S STP-SE and it is sounds pretty darn good.

PS:  and per Kent English at Pass support regarding standby

Stand=by is less than 0.5W.   Approx 2000hr for 1 kW/hr draw

SoundSound

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Re: Balanced power amplifier
« Reply #110 on: 7 Jun 2017, 12:22 am »
Thank you very kindly @mav52! :)

Could you please help me to understand the differences between the "stock", Stage 1 Upgrade, and Stage 2 Upgrade? :scratch: Which variant do you prefer? :scratch:

Would you recommend using a table fan (e.g. something like http://www.matthewsfanco.com/index.php?page=cinni) to cool XA30.5 down? Not sure if this even necessary... :scratch:

JackD

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Re: Balanced power amplifier
« Reply #111 on: 7 Jun 2017, 12:48 am »
SoundSound

When the STP-SE was introduced nine years ago it was done to a "price point" with parts available at that time.  The two upgrade stages give you the option to move up in internal parts to far more expensive variants if you desire.  I have owned the stock unit for going on four years and it is an "award winning" preamp as is.  You can always upgrade it at a later date if you wish.  You might want to consider a used unit to see if it's to your liking and then if you feel the need send it in for the upgrade.  Just my opinion.

RDavidson

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Re: Balanced power amplifier
« Reply #112 on: 7 Jun 2017, 01:13 am »
Thank you very kindly @mav52! :)

Could you please help me to understand the differences between the "stock", Stage 1 Upgrade, and Stage 2 Upgrade? :scratch: Which variant do you prefer? :scratch:

Would you recommend using a table fan (e.g. something like http://www.matthewsfanco.com/index.php?page=cinni) to cool XA30.5 down? Not sure if this even necessary... :scratch:

No. A fan isn't necessary if you don't put the amp in an enclosed cabinet. The entire case of the amp is essentially a big heatsink. That's part of the reason the amp is so large. If Pass felt the amp needed a fan, they would've built one into the unit.

Start with a basic STP-SE. It is really really good. Even the basic unit uses excellent parts. That's why the upgrades are so expensive. To better the parts that are in the basic unit, they had to go way up ladder to get an appreciable improvement that was worth the time and labor effort to install them. Go read about it and come back with questions after you've done your research. If you want to start a preamp thread, do so. This thread is titled Balanced Power Amplifier. :scratch:

And if you start a new thread PLEASE just start a single one, instead of starting two and asking almost all the same questions in each (some questions multiple times). I think you already asked about the need for a fan or another form of external cooling. Several here already answered that.

For the love of AudioCircle, please stop the craziness. As you can tell, we don't mind helping, but you're walking a thin line between needing help and needing your hand held. Please do your research versus relying on us to build your system for you. This is your journey to experience, not ours.

mav52

Re: Balanced power amplifier
« Reply #113 on: 7 Jun 2017, 02:24 am »
Agree with RD, do not put the Pass in a closed cabinet.  If you have no choice I say modify the cabinet and put some major vents in the cabinet and even some quite cabinet fans at the rear to draw the heat out and up.   But I never had an issue with the xa30 except when it's 90 outside and the dew point is at 78 and humidity is around 80 then is a little uncomfortable but that's what the AC is for. 


I always wanted to try the stage 2 upgrade for the W4S STP-SE but the cost threw me Off.  Maybe one day if my unit ever gives me trouble but right now it's very neutral and soild.

SoundSound

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Re: Balanced power amplifier
« Reply #114 on: 9 Jun 2017, 10:26 pm »
Thank you very much for all your most appreciated help! :)