Solid State vs. Tube power amps: PASS Labs XA30.5 vs. ...

SoundSound · « **Reply #60 on:** 28 May 2017, 01:36 am »

I am so very happy I found AudioCircle community: what a nice bunch of guys you are!

I will use my UPS as a surge suppressor for some additional protection. Thank you very kindly, @RDavidson!

I am not sure if my Primary PRE30 preamp could be considered to be on par with XA30.5...

I notice some of you have XA30.5, and would very much like to learn what preamps you consider to be the best to pair it with. Some great recommendations I received: Pass Labs XP-10, Parasound JC2, W4S STP-SE, to name a few solid state ones. What is especially attractive about XP-10 is that it works in pure class A, and can be found for less than 3K used (also an important factor for me)!

FullRangeMan · « **Reply #61 on:** 28 May 2017, 11:47 am »

Quote from: SoundSound on 27 May 2017, 04:03 pm

Can I employ the CP1500PFCLCD (please see at https://www.cyberpowersystems.com/product/ups/cp1500pfclcd/) as a surge suppressor, please?

Do you need a surge protector if you will running the system under rain or heavy wheater.
Flash lightning with clear wheater is rare but exist, mainly in soils w/much iron.

msommers · « **Reply #62 on:** 3 Jun 2017, 04:22 pm »

Any follow up impressions of the amp? I'm looking at this one too to pair up with my Totem Arros.

SoundSound · « **Reply #63 on:** 4 Jun 2017, 05:12 pm »

Dear audiophiles, my dear friends!

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…

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…

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

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?

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?

kingdeezie · « **Reply #64 on:** 4 Jun 2017, 06:02 pm »

The meter reads "bias" from what I understand. Being at 12 o'clock for the XA series is absolutely normal.

If the needle begins to bounce past 12 o'clock, to the right, it means you are exceeding Class A output. For the XA series, that likely means you are running out of juice.

RDavidson · « **Reply #65 on:** 4 Jun 2017, 06:07 pm »

Quote from: kingdeezie on 4 Jun 2017, 06:02 pm

The meter reads "bias" from what I understand. Being at 12 o'clock for the XA series is absolutely normal.

If the needle begins to bounce past 12 o'clock, to the right, it means you are exceeding Class A output. For the XA series, that likely means you are running out of juice.

Yup. Left of 12 o'clock you're in class A. Right of 12 o'clock you're in class A/B. With your speakers and size of your room you may never see the needle move hardly at all...which is a good thing. Glad you're happy with it. I knew you'd be blown away.

I.Greyhound Fan · « **Reply #66 on:** 4 Jun 2017, 06:08 pm »

Don't waste your money on the end caps. Save your money for another day or a better preamp.

JakeJ · « **Reply #67 on:** 4 Jun 2017, 08:43 pm »

^100% agree.

SoundSound · « **Reply #68 on:** 6 Jun 2017, 02:09 pm »

Thank you guys!

No protective caps than.

Yes, better preamp, but which one? That is the question! What do you think of solid state BAT, please?

As @RDavidson succinctly put it, "I knew you'd be blown away.

" Absolutely correct! I am!

And yes, I never see the needle move hardly at all, it is glued at about 5 to twelve o'clock position.

I.Greyhound Fan · « **Reply #69 on:** 6 Jun 2017, 04:03 pm »

BAT gear is awesome, I own a VK-51se and pair it with my X250 amp. I haven't heard their SS preamps but they are supposed to be very good. Do you prefer a warmer or more neutral sound?

I would try and stick with a Pass Pre like an XP10. Others to consider are a Conrad Johnson ET-3se, Parasound JC2, ARC LS27, BAT VK-32se, 52se and 42se (this one is a SS).

brj · « **Reply #70 on:** 6 Jun 2017, 05:42 pm »

Protective caps (i.e. non-shorting) may reduce oxidation of the connectors, but will typically do little else.

You may want to consider shorting caps on the unused RCA analog inputs of the pre-amp if you get "pops" as you click past them when switching inputs, or if you hear any cross-talk on those open inputs from the active input. (Either dead-short or resistor versions are likely fine, but versions with an internal 470 Ohm resistor are often specifically recommended for phono inputs - a 100x factor relative to the typical 47,000 Ohm impedance of a MM phono input.) If you're not getting pops or hearing cross-talk, I wouldn't worry about it. Shorting XLR inputs is also not usually needed. Asking the manufacturer is always recommended.

Do NOT put shorting plugs on analog outputs or digital connections or you risk damage! Also, do not short the RCA inputs of the Pass amp, as they are paralleled with the XLR inputs, so you would thus block the input signal.

And yes, the meters on XA30.5 won't move off of the 12 o'clock position unless the power draw exceeds the roughly 30W of class A operation. That said, the XA30.5 has lots of headroom above that as it moves into class B operation. Stereophile calculated the upper limit to be 153W into 8 Ohms.

As others have said, little will protect against a direct lightning strike unless your house was designed for it from the start. That said, I prefer whole-house surge protection over point-of-use options. The cost can be similar, and you protect everything in your house. Yes, the common ones typically have sacrificial MOVs which can be somewhat electrically "noisy", but the wiring length from the mains panel to the amp alone is likely long enough to filter that limited bit of noise out by itself. The common ones (Eaton, etc.) can typically be found at your local hardware stores in the $50-150 price range, so even when you add in the cost of an electrician to install it, you're still in a similar cost ball-park as your decent point-of-use protectors. If you want to step up from there, look at the Environmental Potentials EP-2050. Typically $700 plus install. (If you're going to go that far, you may want to look at the EP-2750 ground filter as well.)

rollo · « **Reply #71 on:** 6 Jun 2017, 05:49 pm »

Response Audio IMO makes some of the finest tubed preamps available. Not a dealer. Contact Bill Baker. Many different price levels available. If you lived in NY I would invite you over to listen to tubes/SS gear, etc to learn the differences had.

charles

kingdeezie · « **Reply #72 on:** 6 Jun 2017, 07:32 pm »

If you want to try a solid state preamplifier from the Pass stable, I would email/call Reno Hifi, and see if they can send you out a HPA-1 for demo.

I have a headphone/nearfield set up, so I use the HPA-1 to serve two masters. Considering its relatively low asking price, it is a pretty awesome solid state preamp mated with my 30.8. I was actually pretty surprised how good it sounded.

Other than being a headphone amplifier and a preamp, it has zero features. No remote, no balance control, only two inputs, one output, and single ended only. It surely is feature limited, but I think it would give an XP-10 a run for its preamp sound money at a lower entry fee.

I do dream of an XP-30 though.

SoundSound · « **Reply #73 on:** 7 Jun 2017, 12:03 am »

Thank you very kindly guys!

I have reviewed the specs for the preamps suggested, and, quite frankly, cannot make up my mind as to which way to go about preamp for my Pass Labs XA30.5: tube or solid state…

What I noticed, SS usually have better specs vs. tubed designs. I certainly understand the specs do not tell the whole story, but still, can we not submit “the good specs are the precursor for the good sound”?

There MUST be differences in presentation between SS and tubes! But what are those differences?!

Charles, could you please briefly describe what differences in sound you notice when switching between SS and tubed preamps? Ideally, in a system with a class A power amp…

I am truly sorry to bug you guys with all these silly questions, but in my neck of the woods I simply have no opportunities to go and learn the differences between SS and tubes for myself…

@brj, I was switching between the inputs (XLR, RCA, open, connected to the sources, active and inactive) of my preamp: heard no sound of any kind coming from the speakers. Is this the experiment you suggested me to conduct? If it is, how can we interpret the results obtained, please?

In my understanding, based on sacrificial MOVs surge protection is “current-limiting” and may negatively impact the sound. I wonder if EP-2050 and EP-2750 are free from such “trait”?

RDavidson · « **Reply #74 on:** 7 Jun 2017, 01:23 am »

Not true. You do have opportunities to try things. The proof is that you just bought a Pass amp and you have the internet.

I lived nearly in the middle of nowhere in South Dakota for 4 years. During that time I bought, sold, and traded more gear than I care to divulge. I've been in this hobby for 20+ years. Those 4 years were the most informative in this hobby that I've had since I started out.

The point is that if you are willing to try things and learn things on your own, you will develop an understanding of what you like and what you don't. It's your system. You have to live with it...and hopefully enjoy it.

Also, please start a (singular) preamp thread, if you want to get into a preamp discussion.

I.Greyhound Fan · « **Reply #75 on:** 7 Jun 2017, 02:43 am »

You are just going to have to read the reviews on Preamps and bite the bullet and buy one that has attributes in sound that you may like. If you don't like it, flip it and sell it. Going the used route is a better way to do that. All the preamps that I listed are great sounding and one is not necessarily better than the other. It comes down to personal preference. Tubes can be a hassle sometimes and are another thing to go bad, but they can make a difference. Not all tube preamps have a tube sound.

A better preamp should give you more transparency, wider sound stage, more detail, better bass and be more musical. Some will have some warm bloom and others will be more neutral. Other people will say a preamp should get out of the way and not influence the sound. I never understood that because every piece of gear imparts a sound.

For warmer or a slightly darker sound, BAT is a good choice. Pass can be slightly warmer to neutral. ARC is neutral for the most part as is the Parasound JC2. The ARC LS27 has a very transparent sound with a very wide sound stage. BAT has a fuller and thicker midrange with a little more depth and very powerful bass and dynamics. These are generalizations from my experience with various preamps.

Don't worry with MOV surge suppressors. I have not noticed any fall off in sound. If you don't want MOV, get a Brick Wall, Zerosurge or Surgex. They do not use MOV's but they do use the same technology which I believe Brick Wall used first but I could be wrong. I have a friend that uses a Brick Wall and it does not degrade the sound. I am going to buy one if that helps.

Don't sweat the small stuff, you are trying to analyze everything to death. Just enjoy the music, because it is all good. There are no bad choices.

brj · « **Reply #76 on:** 7 Jun 2017, 04:01 am »

Again, note that I was referencing a whole-house surge protector installed at the mains panel, not a point-of-use surge strip into which your audio gear is directly plugged. A MOV installed at the mains panel won't matter, and those units are designed to handle the entire electrical load of your house, so it won't be current limiting either. (Also, in the EP units, the MOV is not the primary means of protection anyway - it is secondary to the main non-sacrificial surge protection circuit and intended as a last line of defense. They have 5 year warranties, if that helps put things in perspective. I don't know about the more common units like Eaton, etc.... I'll leave that to you to look up if you're interested.)

If you heard no popping from the speakers as you switched your preamp across unused single ended (RCA) analog inputs, then I wouldn't worry about shorting them.

mav52 · « **Reply #77 on:** 7 Jun 2017, 12:13 pm »

On the meter, yes I own this very amp. this write up in Stereophile 2009 nails it and its the way mine operates. ""According to Nelson Pass
that the front-panel meter, which indicates the amount of current being drawn from the wall, “should
sit somewhere in the middle” and “won’t move if you’re running in class-A.” During most of my listening sessions, the
meter would bounce between the middle and, say, the three-quarters point of its range.""

I live in the Lightning capt of the US and a surge protector will not save you from mother nature if she hits. A whole house or any fancy $$$ protection you buy, its will fry like fresh cooked hush puppies if you are hit. . I get into the habit if I leave home and a storm in projected for my area, I unplug my gear as its better to be safe than cry latter.

Pre-amps used, Quicksliver , ARLS27, Pass XP-10, W4S STP-SE. The W4S is currently in my system It really seems to mate well with the PASS for overall dynamics a tight lower end which allowed the xa30 to do its stuff. To me out of the pre's I tried, the W4S was the most natural of the bunch which is what I want a pre-amp to do and compared nicely to the more expensive xp-10. If money was no object the xp-10 after its broken in is one heck of a pre-amp but it comes at a cost. Cables used, Acoustic Zen, Kimber, BlueJean, DH Labs, RCA and XLR. By all means XLR it just sounded better to me. ps speakers used Kef 201/2, GE Triton 2+, Vapor Breeze. Room size from a small 10x12x12 office to a 25x18x12 family room. The bigger room I got to try the Pass INt-60 wow but $$$

SoundSound · « **Reply #78 on:** 9 Jun 2017, 10:27 pm »

Thank you very much for all your most appreciated help!

rbwalt · « **Reply #79 on:** 19 Jul 2017, 02:45 pm »

what is the impedance of the the speakers? if they dip below 6 ohms then stay with solid state. Tubes are best for speakers in the 6- 8 ohm range. for solid state i would look at Belles and even Rega. Both will be in the 3k range and will sound very nice.