[RDavidson]

Of course that's only when one remembers to put the amp in the low-power "Standby" mode in between listening sessions. Otherwise during normal "On" operation, whether a source is playing or not, low or high volume, it will have close to the 200W power consumption.

That's just the price of Class A admission, like tube amps, but generally without the maintenance, adjustment or parts replacement.

Steve

The standby switch is on the front of the amp. The main power switch is on the back. As such, the standby switch serves basically as the on/off switch. Unless you're going on vacation, you'd use the standby switch all the time.......unless you're one who prefers to leave their system powered up ALL day and night. I don't see the point in that, because most electronics (except maybe some sensitive digital gear) these days will reach thermal stability in like 30 minutes to an hour max.

[srb]

.......unless you're one who prefers to leave their system powered up ALL day and night. I don't see the point in that, because most electronics (except maybe some sensitive digital gear) these days will reach thermal stability in like 30 minutes to an hour max.

I think 24X7 amplifier power-on is pure silliness and wastefulness.  Pass put in the low-power standby circuit (unlike some amplifier's standby circuits which only serve to keep trigger and remote control circuits active) to provide some output device biasing and keep sound capability at 100% for the purist.

But even if I turn the whole thing on and off with a trigger (like brj), I don't mind operating at 95% sound quality for the 30 minute thermal stabilization period! 

Steve

[RDavidson]

I think 24X7 amplifier power-on is pure silliness and wastefulness.  Pass put in the low-power standby circuit (unlike some amplifier's standby circuits which only serve to keep trigger and remote control circuits active) to provide some output device biasing and keep sound capability at 100% for the purist.

But even if I turn the whole thing on and off with a trigger (like brj), I don't mind operating at 95% sound quality for the 30 minute thermal stabilization period! 

Steve

Couldn't agree with you more.
Off subject, but the only gear I've had trouble with were a couple of DAC's warming up from a complete power down. They needed several hours, maybe even a full day. It had something to do with their clocks or other highly sensitive components needing a lot of time to thermally stabilize (because the parts are so small and barely produced heat). How this affected the sound was that the DACs would have trouble handling jitter (even with just CD quality rips) and I'd get intermittent pops and clicks. It was super distracting. But hey, the more you know.....

[brj]

Just to be clear... the triggers on Pass amps take the amps in and out of standby in an identical fashion to the standby switch on the front of the amp.  The main power switch on the back of the amp has to be flipped to "on" for either the standby switch or the 12V trigger to function.  (The 12V trigger input is a standard +/- pair of speaker binding posts.)

And yes, I also leave my amps in standby until such time as I actually sit down to listen.

[SoundSound]

Thank you very much! 

@I.Greyhound Fan noted: “Having high current and headroom makes a difference.” I understand you are referring to Amplifier headroom here? 

Could you please help me to find what the value of this parameter for XA30.5 is: to use the SPL Calculator “Amplifier headroom” parameter needs to be entered? For example, McIntosh MC452 has headroom of 1.8dB only. 

About current delivery: XA30.5 has Maximum Output Current of 20 Ampere. Is this enough for my Monitor Audio RS6 speakers? 

On heat dissipation. @srb estimated it at 680 BTU/hr. Under this condition BTU Calculator gives an estimate of 20 degrees Celsius.

In my mind, this correlates with what was observed by @RDavidson: “If it raised the ambient room temperature, it didn't do so any more than maybe a 2nd person in the room would (due to body heat). The XA30.5 was never more than warm to the touch, not hot. … The XA30.5 produced negligible heat in comparison.”

Would you recommend using external forced air cooling for XA30.5 (small desk fan, e.g.)?

@brj, could you please explain what device I need to implement your approach of “… I use the 12V trigger inputs on mine, driven from my pre-amp.” My Primare PRE30 has an RCA-type socket providing 5V output for remote link. Yes, it’s a silly one, but this demonstrates you my level of experience… 

P.S. BTU Calculator can be found here:
http://www.calculator.net/btu-calculator.html?roomwidth=1410&roomwidthunit=feet&roomlength=14&roomlengthunit=feet&ceilingheight=10&ceilingheightunit=feet&insulation=normal&temperature=20&temperatureunit=c&calctype=heat&x=30&y=9

[srb]

My Primare PRE30 has an RCA-type socket providing 5V output for remote link.

The 5VDC trigger output on the PRE30 is actually a phone jack that accepts a mini 1/8"/3.5mm phone plug.  The trigger input on the XA30.5 will work over a range of 5VDC - 12VDC.

You can just use a 3.5mm mono phone plug to 3.5mm mono phone plug cable and cut off one end and strip the wires to connect to the XA30.5 trigger binding post connections or attach low-cost spade terminals or banana plugs if you don't want to use bare wire.

Steve

[RDavidson]

Thank you very much! 

@I.Greyhound Fan noted: “Having high current and headroom makes a difference.” I understand you are referring to Amplifier headroom here? 

Could you please help me to find what the value of this parameter for XA30.5 is: to use the SPL Calculator “Amplifier headroom” parameter needs to be entered? For example, McIntosh MC452 has headroom of 1.8dB only. 

About current delivery: XA30.5 has Maximum Output Current of 20 Ampere. Is this enough for my Monitor Audio RS6 speakers? 

On heat dissipation. @srb estimated it at 680 BTU/hr. Under this condition BTU Calculator gives an estimate of 20 degrees Celsius.

In my mind, this correlates with what was observed by @RDavidson: “If it raised the ambient room temperature, it didn't do so any more than maybe a 2nd person in the room would (due to body heat). The XA30.5 was never more than warm to the touch, not hot. … The XA30.5 produced negligible heat in comparison.”

Would you recommend using external forced air cooling for XA30.5 (small desk fan, e.g.)?

@brj, could you please explain what device I need to implement your approach of “… I use the 12V trigger inputs on mine, driven from my pre-amp.” My Primare PRE30 has an RCA-type socket providing 5V output for remote link. Yes, it’s a silly one, but this demonstrates you my level of experience… 

P.S. BTU Calculator can be found here:
http://www.calculator.net/btu-calculator.html?roomwidth=1410&roomwidthunit=feet&roomlength=14&roomlengthunit=feet&ceilingheight=10&ceilingheightunit=feet&insulation=normal&temperature=20&temperatureunit=c&calctype=heat&x=30&y=9

Dude. Trust me. I've owned both. The XA30.5 has far more power than the RS6's could dream of using without reaching ridiculous amounts of distortion (driver breakup). On top of the fact that you have plenty of power and the speakers are easy to drive, you don't have a big room to fill. That's one of the most overlooked factors when analyzing specs : Real world application. You'll never get the XA30.5 to even break a sweat without completely destroying your ears first.

No. It doesn't need forced air cooling. Just don't put it in an enclosed cabinet and it'll be fine. That's what all that casework is for. It's a big heatsink. Go look around on the internet for pics and make note of how often you see someone using a fan with the amp.

You're really overthinking this stuff man. The XA30.5 is pretty much a state of the art amp (even though it isn't the newest), designed by one of the most talented and experienced amp designers in the world. Nelson knows what he is doing and puts a lot of consideration into his work....which is why Pass Labs has such a great track record. It also explains at least part of the reason why customer service is so great. If they only have to repair an amp every blue moon, then it's no big deal to them to bend over backwards to help folks out when needed.

I know it's a big purchase, but calm your mind by reading the reviews. Also understand that if for whatever reason you don't like it, it should be easy to sell. Heck, I've considered buying one again when I've seen them used....which seems to be a rarer and rarer occurrence.

[I.Greyhound Fan]

Thank you very much! 

@I.Greyhound Fan noted: “Having high current and headroom makes a difference.” I understand you are referring to Amplifier headroom here? 

Could you please help me to find what the value of this parameter for XA30.5 is: to use the SPL Calculator “Amplifier headroom” parameter needs to be entered? For example, McIntosh MC452 has headroom of 1.8dB only. 

About current delivery: XA30.5 has Maximum Output Current of 20 Ampere. Is this enough for my Monitor Audio RS6 speakers? 

On heat dissipation. @srb estimated it at 680 BTU/hr. Under this condition BTU Calculator gives an estimate of 20 degrees Celsius.

In my mind, this correlates with what was observed by @RDavidson: “If it raised the ambient room temperature, it didn't do so any more than maybe a 2nd person in the room would (due to body heat). The XA30.5 was never more than warm to the touch, not hot. … The XA30.5 produced negligible heat in comparison.”

Would you recommend using external forced air cooling for XA30.5 (small desk fan, e.g.)?

@brj, could you please explain what device I need to implement your approach of “… I use the 12V trigger inputs on mine, driven from my pre-amp.” My Primare PRE30 has an RCA-type socket providing 5V output for remote link. Yes, it’s a silly one, but this demonstrates you my level of experience… 

P.S. BTU Calculator can be found here:
http://www.calculator.net/btu-calculator.html?roomwidth=1410&roomwidthunit=feet&roomlength=14&roomlengthunit=feet&ceilingheight=10&ceilingheightunit=feet&insulation=normal&temperature=20&temperatureunit=c&calctype=heat&x=30&y=9

First off, don't get too caught up in spec's and numbers.  That Pass amp will have plenty of current and power to play those Monitor Audio speakers with a Sensitivity of 91db plenty loud to ear bleeding levels.  A trait of a good amp is if it can double its power from 8 ohms to 4 ohms which the Pass can do.  20 amps is high current.  My X250 is rated at 20 amps, my Parasound A21 is rated at 60 peak amps but it can't double its power from 8 to 4 ohms like  my Pass and it pales in comparison to the Pass. ( A21- 250wpc at 8 ohms and 400 at 4 ohms, Pass 250wpc at 8 ohms and 500 at 4 ohms.  I can tell you that the Pass plays louder and is much more dynamic than the A21.)

I did some checking and Stereophile did a review of the 30.5 and measured 6dB of headroom before any distortion.  That is plenty for an easy to drive speaker like the RS6's.  They loved the amp.  You will love 30 wpc of Class A power, 60 wpc at 4 ohms and 6db of headroom of distortion free power.

http://www.stereophile.com/solidpoweramps/pass_labs_xa305_power_amplifier/index.html#ysA0xtjkZJ4Rwv1H.97

Get the amp, don't worry about specs, heat and current, be happy and enjoy.

Larry

[guest61169]

...My “cave” is only 14x14x9! Should I be concerned? Mind you, I seldom, if ever listen at concert levels… 

Those are pretty modest requirements and your speakers easy to drive.  Get a used Bryston 2B-LP Pro (newer version with detachable power cord) and enjoy the sound, local service in Peterboro Ontario, low power consumption at idle, great resale value and the remainder of a 20-year warranty all for what will likely be $600-700.    Sometime try to find an alternative to that square room. 

[SoundSound]

Thank you all, as always! 

@srb noted “The trigger input on the XA30.5 will work over a range of 5VDC - 12VDC.” It is very important for me to have practical confirmation on the subject as one of the articles, “Trouble shooting for dummies”, on Pass Labs website suggests “The supplied voltage for the trigger is to be 12 volts direct current.” Thank you @srb! 

@RDavidson: “I know it's a big purchase, but calm your mind by reading the reviews.” 

@I.Greyhound Fan: “You will love 30 wpc of Class A power, 60 wpc at 4 ohms and 6db of headroom of distortion free power… Get the amp, don't worry about specs, heat and current, be happy and enjoy.” 

This is what I have been doing, and all the reviewers just confirmed what you guys have been telling me all the time – it is an exceptional amp! 

The hunt begins! 

Last but not least… What would you consider to be a fair price nowadays for XA30.5 in excellent condition, please? 

P. S. @noway: I have had a chance to audition the Bryston 3B³ stereo amplifier, and, quite frankly, found it to be only a lateral move from my Acurus… 

[I.Greyhound Fan]

I figure about $3000 plus or minus $200 would be a fair price depending upon age and condition.

FYI, this Mark Levinson No 334 amp is a good buy-

https://www.audiogon.com/listings/solid-state-levinson-no-334-125-w-pc-stereo-amplifier-demo-2017-04-25-amplifiers-10507-bedford-hills-ny

http://www.stereophile.com/solidpoweramps/142/index.html#rEYtCMexlwtUGDPf.97

https://www.audioasylum.com/messages/amp/15397/

[srb]

@srb noted “The trigger input on the XA30.5 will work over a range of 5VDC - 12VDC.” It is very important for me to have practical confirmation on the subject as one of the articles, “Trouble shooting for dummies”, on Pass Labs website suggests “The supplied voltage for the trigger is to be 12 volts direct current.” Thank you @srb! 

I did not verify that from my own experience but it was taken from page 6 of the XA30.5 Owner's Manual

"On the rear panel you will also find a pair of 5 way binding posts for external turn-on control.  Applying 5 to 12 volts DC at this connection will override the front panel stand-by switch and turn the amplifier on."

Steve

[RDavidson]

The only thing I'd caution about looking at Mark Levinson is that they seem to burn through power supply capacitors rather quickly....ie less than 10 years of use, and maybe even closer to 5-7 years which is very odd for modern solid state, let alone vintage solid state. I don't know if this applies to certain models or years of production or what, but the same has been said of the baby ML line, Proceed. If you go with ML, be sure to do plenty of reading. In other words, "proceed" with caution.

If you keep an eye out, you can get a very nice XA30.5 for around $2750...give or take maybe $150. That's pretty close to what Mark at Reno HiFi is selling them for too (on the higher side). If you go to Mark, rest assured you will get absolutely first rate customer service and will do what he can to make sure you're happy. He also has a very generous trial period as well as upgrade period (4 months).

[SoundSound]

Thank you all, as always!  

It is very reassuring to know the trigger will definitely work with my PRE30. Thank you @srb!  

@I.Greyhound Fan: Excellent find! S/N 1245 (as far as I can see from the picture) suggests it was manufactured sometime around the year of 2000. A bit dated, shall we say? 

@RDavidson: “… about looking at Mark Levinson is that they seem to burn through power supply capacitors rather quickly....ie less than 10 years of use, and maybe even closer to 5-7 years… ”  

I think I will pass this ML amp.  

I have just checked Reno HiFi, and found they have XA30.5 with the following description:
"Used, Excellent condition, about two years old, one year transferable factory warranty, all factory accessories, new factory double-boxing, Satisfaction Guaranteed. S/N 28934. $3295. " Would you consider this to be a fair price, please? 

Last but not least… What amp stand would you recommend, please? My 17” stand will not be able to hold this little “monster”…  

[RDavidson]

Thank you all, as always!   

It is very reassuring to know the trigger will definitely work with my PRE30. Thank you @srb!   

@I.Greyhound Fan: Excellent find! S/N 1245 (as far as I can see from the picture) suggests it was manufactured sometime around the year of 2000. A bit dated, shall we say? 

@RDavidson: “… about looking at Mark Levinson is that they seem to burn through power supply capacitors rather quickly....ie less than 10 years of use, and maybe even closer to 5-7 years… ”   

I think I will pass this ML amp.   

I have just checked Reno HiFi, and found they have XA30.5 with the following description:
"Used, Excellent condition, about two years old, one year transferable factory warranty, all factory accessories, new factory double-boxing, Satisfaction Guaranteed. S/N 28934. $3295. " Would you consider this to be a fair price, please? 

Last but not least… What amp stand would you recommend, please? My 17” stand will not be able to hold this little “monster”…   

Yes, this is a fair price. Mark may be able to negotiate a little bit with you. Keep in mind his prices are retail. He has overhead etc. to pay for. You'll always get the lowest price on the used market, BUT if paying a little more for customer service and peace of mind are worthwhile to you, then go for it. In the grand scheme, his price is really not that much higher than the used market. When Mark says that an amp is "excellent" it is basically mint. Something I always try and factor into my purchases is my intent : Is it more out of curiosity (try then trade/sell), or is my intent a long-term investment? If the latter, then I don't necessarily hunt for the lowest price. I look for the best, safest, most reliable option that I know I can happily live with. Keep in mind Mark's very generous trial option as well as trade-in option.

[srb]

Last but not least… What amp stand would you recommend, please? My 17” stand will not be able to hold this little “monster”…   

The Sanus EFAB would do the job and is rated for 125 lbs ($80 at Audio Advisor).

For just a little more money, the VTI 404 is better looking, rated for 200 lbs., and comes in a variety of color combinations (black or silver frame, posts and caps and black, cherry or oak color shelf), available at www.standsandmounts.com for $111.

From there you can go nuts with more exotic metals, 2" - 4" hardwood slabs, etc., for ~ $350 and up or you could probably DIY a wood slab (butcher block?) and footers for half of that or less, keeping in mind the footprint of the XA30.5 is 19"W X 19.2" D.

Steve

[RDavidson]

Another nice option is a 3" thick Michigan Maple Block. This is what I use. You can find these on Audiogon now and again. You can order custom sizes too. Put some Herbie's Tenderfeet underneath and you have a very solid and beautiful stand that will last you a lifetime....and then some.

[brj]

Last but not least… What would you consider to be a fair price nowadays for XA30.5 in excellent condition, please? 

A handy reference, though I don't get the sense that it's info is especially complete:

http://kruipen.com/pass-labs-xa-30.5.html

(Note that it's not good about differentiating variations on a product name, such as including a space ala "XA 30.5" vs. "XA30.5", etc., so you might have to try a few variations and mentally merge the results.)

As for an amp stand, you might want to mention the floor surface.  When I had mine on carpet, I was using furniture sliders for a while (frugal-man's approximation of Herbie's giant fat gliders), but moved to the extra-firm version of Herbie's Big Tall Tenderfeet on top of a maple block when I put the amps in the (fully sealed and conditioned) crawl space below my listening room.

[I.Greyhound Fan]

Another amp to consider if you want to buy new is this Vincent Audio

http://www.audioadvisor.com/prodinfo.asp?number=VISP331MK

http://www.tnt-audio.com/ampli/vincent_sp331_e.html

[srb]

Another amp to consider if you want to buy new is this Vincent Audio [SP331MK]

It seems to me that older models used soldered-in tubes, but I see this model has socketed tubes.  (I know they're small signal tubes that likely wouldn't need replacement, but they are tubes and it's certainly possible some could require replacement due to noise or failure).

Ample capacitance (80K uF/channel) and 10W in Class A.  It's not balanced though, is that still a requirement?

Steve