Pure Class A SS vs Tube Amp

jetter1,598 posts02-26-2020 5:41amI've never heard any Pass Labs amps, but would love to try a XA25.

I have yet to find a Pass or pass design amp, I didn't like. All to varying degrees. I haven't heard the latest and greatest, But Nelson Pass has and still is a very big part of "simple is better". His First Watt amps are custom to the T as per application. Very simple, VERY special. You may want to look there. I haven't looked at all the post, just a thought. Very reasonable on pricing and the best support out there, plane and simple.
Decware is another great choice, but a little on the spendy side. I had a pair of their 60s. I just couldn't find "THAT BASS". Not that it wasn't great it was wonderful, it just wasn't "THAT BASS". They also worked very well on old Klipsch Horns, La Scalas, Corner Horns, ect. I'm not a Klipsch guy per say, But some of the coolest looking and really "Sounding" speaker are Horn loaded, super high E.  Super efficient can also equate to a lot of floor noise if your not careful. Extra care on ground loop noise for sure.

First Watt also made a B5 unit for OB application, Active XO, cool little creature. I have one and currently rounding up the goods for a pair of Alfa/Beta dual 15 builds, I'll use planar mids and highs for the center baffle. They are a neet, efficient, DIY speaker. I'm making mine out of 
Stair Flats, 1 inch thick, red oak skins over black oak butcher block. Glued and biscuited joined for 18" width. Harder than the hubs of Hell to cut..
Nelsons designs are made for just that. Wonderful bass response warm mids and NOT earbleading hiper highs. Uses a lot of WIMA caps, close tolerances. GOOD stuff mate. 5-15 watts your in heaven. Now I'm more of a HP guy. VTLs, Class D, Macs, AB stuff, push and the pulla!
Momma Mia. 

Regards

Special thanks to everyone for great contributions and response
@lowtubes 
Thanks for your great detail response 
keep it coming 

Hello Lordrootman, I usually do not write on forums but every once an a while, I’ll post my opinion. I’ve been in this hobby for around 30yrs now and I’ve seen a lot of people recommending all sorts of components. Some I agree and some I highly disagree with. I do understand that we are all in different places with experience in this hobby in addition, system synergy is at play too.  But I cannot recommend enough that you stick with a pure class A solid state amp, even if it is a lower powered amp or a tube design. Do research and find a well regarded design that seems to be liked by many people. Not all pure class A solid state amps are good, so be careful!  Some are ok and others are outstanding. For tube amps, I’m sorta bias, so I’ll let you know that right away. I prefer power tubes like the 300b designs and EL34’s. I like other tubes also like the 45, EL84, 6L6, 211, 845.  I personally have owned and will never purchase again the newer tubes like the  KT88, 6550 and many of the newer power tubes that are being used more frequently by designers today.  For my taste, the 1st batch of power tubes I mentioned gives me musicality along with detail that is just so beautiful to hear. IMO, honestly, I have heard the same magical musicality and detail that I have received from my very expensive 300b mono amps from a well designed Solid State class A amp. So be careful in all the recommendations out there and TAKE YOUR TIME, —-RESEARCH— and get the right amp FOR YOU.  My recommendations of amps will not necessarily work for you but if you still with the base information I’m presenting, you’ll find that these kind of amps produce the best musical experience IMO.  

@lowtubes 
"...and others will lean on the very musical side." 

Exactly.  





...

My Schiit Vidar amp (according to what I read about it) is class A/B and it's supposed to be class A at lower volume levels and switches to AB at higher volume so if most of your listening is at lower volume I don't think you need a class A amp. I'm pretty sure any A/B amp will accomplish the same thing. 

I don’t think it really matters whether the amp is tubed or class A design. What really matters, is that you pick an amp that is designed well and will give you the sound you’re looking for. Some very well made amps will have a clean, detailed sound and other will lean on the very musical side. Ultimately, you would want an amp that matches well with your system and gives a magical, musical experience.  I have 5 amps sitting on my floor at the moment in which I frequently  rotate in an out. I like the sound each one gives and I have a log book I use to keep track of which speakers, speaker cables, power cords sound best on each amp. This consist of, a 50watt class A SS, 100watt EL34 tube amp, 22watt 300b amp, 18watt 300b mono amps and 9watt 300b mono amps.  Each of these amps are very special and give a glorious sound.  Point is, stick with an excellent class A SS or tube design and you’ll be fine.  

Just FYI, all single ended tube amplifiers, large or small, run in pure Class A, and some. When pushed, they will run in Class A2- if the power tube grid becomes positive and draws grid current. Designing a pure Class A tube amplifier is not only possible, but also very cost effective at well under $6K. IMHO. Best wishes, Aric

+1 Reno Hifi

https://www.hifi-advice.com/blog/review/analog-reviews/amplifier-reviews/line-magnetic-part5/
The two chassis LM-845 Premium.
Reasonable price too!

now I need deal or recommended dealer

Based on my experience and a great many others that have been reported here I would **very** highly recommend Reno HiFi.

Good luck.  Regards,
-- Al

Personally, I think adding in-line attenuators to a Pass XA 30.8 would be like adding a big lift kit to a Tesla Model S.

Thanks everyone for great response
I think I’m more towards passlab xa 30.8 now
I think it will work now and future speaker focal Electra upgrade with some suggestions tweaks recommended by @almarg thanks 
now I need deal or recommended dealer lol 

Running a pair of Tannoy’s with the XA25, driven by a LTA microZOTL pre. Fantastic sound. Speakers aren’t nearly as efficient as the Klipsch and I’ve got juice for days.

Preferred the XA25 to the LTA Ultralinear, but just personal preference. Both great amps. Also compared to PrimaLuna, First Watt & more. 

2 low power SS amps I’d like to try are the Valvet E2se and the new Bakoon 13R. I’ve spoken with 2 people that preferred the Valvet in direct head to head over the XA25. See the listing here on agon that has all of the reviews (including w/ focal & magico speakers).

I presume the Bakoon will be quite similar to the XA25 but just speculating.

XA25 and done!

OK just cked the specs on your Prima Luna EVO300, 
has SIX!!!! 12AU7's in pre stage, wow, go with 6 E80CC's, wow, huge mod there, yes dump the EL34's and go with KT150's. 
also get rid of most of stock caps, install all M SGO caps. 
= Class AAA sound. Best out any Jadis intergrated. , or lets say, be a  nice shootout for sure...
later

Lordrootman 2-28-2020
Now I’m thinking about XA 30.8
since eventually I may move to focal Electra 1038 when my 4 months twins grow little bit
I want separates and I really want to keep my Michi P5 Preamp gain is complicated with first Watts J2

The Focal Electra 1038be is of course a very different animal than your Klipsch speakers, and I doubt that an amplifier choice can be found within a given price range that would be optimal for both. And specifically I suspect for a variety of reasons that the XA30.8 would be a much better choice for the Focal speakers than the First Watt models you have been considering.

And in that regard I recall from some years ago that a member who no longer posts here but for whom I have great respect very successfully paired an XA30.5 with a comparable Focal model.

However, as has been said the 26 db gain of the XA30.8 could very well be problematical given the gain of your preamp and the sensitivity of the Klipsch.

So here’s an approach to consider, if you believe that changing to the Focals is a real possibility in the foreseeable future. If you purchase the XA30.8 (or some other amp providing comparable gain or more), and you find that the gain is unacceptably high for use with your preamp and the Klipsch speakers, insert a pair of Rothwell attenuators at the inputs of the amp. They are offered in both balanced and unbalanced form, and with a choice of 10, 15, or 20 db of attenuation.

Some members have reported here that Rothwell attenuators seemed to compromise dynamics in their systems, while others (including me) have used them with no evident side-effects. I suspect that impedance considerations have contributed to at least some of the disparity in those findings. And if so the 50K/100K unbalanced/balanced input impedances of the XA30.8 and the 470 ohm/100 ohm unbalanced/balanced output impedances of the preamp would seem encouraging in that respect. But in any event you would presumably just be using the attenuators temporarily.

Finally, I would recommend against any make of inline attenuator other than the Rothwells, as the others I am familiar with have unreasonably low impedances for most consumer (non-pro) applications.

Good luck. Regards,
-- Al

Wow. Just saw two se’s listed for $5100 and lower. Incredible value. IMO

Very surprised that the fabulous Audio Research Ref 75 or the se version hasn’t come up. They can be had for $6500(se) downwards. A truly great mid power tube amp that’s a classic. Check out the many A+ reviews. 

In that case get an Atma-Sphere MA-3. I love watching tubes glow. It's that primitive human thing.

@moto_man 
pm sent 

I’m all in on tubes but many NOS sold are fakes and to get ones that are not are is both difficult and can cost more than the amp . And do so more than once.

I have the Pass X-25 many times and to my hears it is a bit too warm . Of course it's only my ears .

With Heresy IIIs I tried 2 Aegirs out of curiosity based on the positive reviews, and it was 2 only because #1 was defective (Schiit sent a new one immediately...great service from those people)...I use a Dennis Had Firebottle HO single ended pentode amp driven by a Freya, and comparing the Aegir to that was interesting. Suffice to say although the Aegir possibly performed as designed, when I switched back to the Had amp...well...really the Aegir had no chance, and was sent home (sad...). I’m possibly or absolutely seduced by the tonal purity of the Had amp, or simply used to it...I seem to need it...Tube Mojo Addiction issues maybe, and this removed me from the path of trying the also well regarded Pass XA25 as another self indulgent experiment. Maybe I could borrow one of those...otherwise...meh...

I second the Plinius recommendation for an excellent SS amp that plays in both Class A and AB (switchable).  My SA100 MkIII was fully upgraded by Vince Galbo, with new caps and various other things.  It is a phenomenal sounding warm amp with the convenience of leaving it on all the time and not worrying about it.  I also have a PrimaLuna Premier HP (75 watts) with EL34 tubes.  That is also fantastic and is maybe 20% better with my Focal Utopia III's than the Plinius, which is also great.  With my Joseph Audio Pulsars, I think that the difference is less.  The Plinius is certainly more convenient, since it is on all the time and no worries about forgetting to turn it off, or tubes wearing out over time.  On the other hand, the PrimaLuna makes tubes about as easy as they could be, with auto biasing, and various bells and whistles.  You just have to remember to turn it off at the end of a listening session.  I am going back and forth between the two and which speakers to keep, so I'm in the middle of critically listening.  If you have any questions, PM me.

I’m in the middle of a Classic Class A SS shoutout.  Although my reference is a pair of Coincident 28 watt 845 SET tube amps, the classic SS amps I’m reviewing are really good, outstanding for the cost. In particular, original. Bedini’s (not Mark II or DE) any wattage, Bel 1001’s and a Sodderberg modded Forte 4.  All under $1500.   Last night I had a group of audio buddies over and although they all agree the Coincident amps clearly ruled the roost, the SS Classics performed above their weight.

While you can use the hifi front end for video, it may eat up limited tube life, depending on how much you watch. 

I found it easier (if more expensive) to have two amplification paths - one for audio, all tube, and one for video, solid state. Just switch the speaker leads from one power amp to the other, takes 2 minutes.

Now I’m thinking about XA 30.8
since eventually I may move to focal Electra 1038 when my 4 months twins grow little bit 
I want separates and I really want to keep my Michi P5 Preamp gain is complicated with first Watts J2 
the question is passlab XA 30.8 is better than Parasound A21+ 

Any of the Pass Labs  XA amps would be a great fit for your system. You can get one here and other sites and the resale value is great in case you decide to go tube.  You would be doing yourself and injustice if you don’t try a Pass Labs amp.  

Seems like with gain complications I’m still not going to get great benefits with Michi P5 and passlab first Watts J2 ?

@mozartfan I have an EVO300 integrated, currently with stock tubes. But not for long :-)

Prima Luna are great amps, made by  Spark ,,,I perfer Spark's own line Cayin,,,for a  better price and almost same  design, but i perfer Cayin's design.
which Prima  Luna do you have?

Lordrootman,
Your decision of the Aleph First Watt is a good one. Too bad about no xlr input. I had a Pass Labs Aleph 30 and it had balance inputs and was a very good sounding class A amp.
But I have to say that the tube amps I’ve had since then sound much better at low volumes, which you mentioned is important to you. So I’d look into a tube amp w/ balanced inputs if this is a factor for you.

You might want to check out Aric Audio. Tube products. Preamps with variable gain, maxing out at 20dB. Tube amps, SET and push-pull. I recently purchased his Special pre and am loving it. Has a nice Web site.

I’ve been here.  Look into 2A3 SET amps. They will be excellent and as pure as you’ll ever want. Or Nelson Pass’s First Watt series of amps. All you need is 7 watts and you can still drive yourself out of the room. 

Just keep in mind that a 100db speaker plays 100db volume with 1 single watt of input. With a speaker like that, 90+% of audio preamps and amps provide either more gain than makes sense for the system or more power than you could ever use and probably both.

A preamp that would make sense would provide about 6 db of gain and a tube amp would not need to be more than a few watts for most listening and certainly anything over 10 watts is simply overkill and a waste. You really just need enough headroom to stay within the amps ability to deliver what you need and not push it to where distortion increases. 

Classic triodes and triode wired pentodes would be where I would go. 

Used Krell 400cx. Because you can never have enough power. 

No one has mentioned Primaluna yet. Any reason they wouldn’t be a good fit for the OP?

really enjoying mine at the moment...

SS as i hear the amps, are ~~Dinosaurs~~~ back in the 70's, yeah we loved our Marantz,,,but now with so many stunning tubes amps, its a  easy choice. 
now with your 100db, you could go in any direction, with 805;s, 845's, 812's, etc. . ,  superior match  is a  Single Ended 845/300B combo from Cayin @ $3K.... works as both intergrated and pure amp. 
Thats cayin for ya.

And because Ralph ( @atmasphere ) doesn't want to push his own products, I'll note that if you go with tubes, you should also consider the Atma-Sphere S30.  

Damn, I got in here to opine and saw all the best commenters have already done the service.  You've gotten really good advice... 

I'll just add my voice to the chorus suggesting Nelson Pass' First Watt line if you go SS.  If you do decide to go with Pass or First Watt, I'd encourage you to send them an e-mail with your speaker model (and specs) and ask which amp they'd recommend.  A wonderful company that's always happy to help people enjoy better sounding music (even when it hurts their profits).

Having just recently purchased the Pass xa25 I can attest to the sound.  Tight bass, amazing resolution and clarity.  A 'you are there' quality to the sound.

check out Decware.com - all tube gear, made in IL - excellent amps. I have their entry-level amp paired with a 99db 8" open baffle. Have not heard it with your Klipsch, but the owner, Steve Deckert, can probably help you. He is very open, honest and helpful. I have been dealing with them for 20+ years now. Excellent gear and company.

@almarg 
thanks you’re right I google it and has XLR connection 

@atmasphere 
thanks for great detail response any tube amp recommendation ?

The J2 does in fact provide XLR as well as RCA inputs, according to its manual and the description at the First Watt site.  I'm thinking that you might have been misled by photos at the Reno HiFi site which are shown under links referring to the J2, but which actually depict the F6.

The Pass XA amps other than the XA25 provide balanced as well as unbalanced inputs, but while the XA25 has a gain of 20 db, all of the other XA amps have gains of 26 db, which as has been said is most likely too high.

Good luck.  Regards,
-- Al

@ihcho 
i did little upgrade to it


1. Titanium tweeter diaphragms
2. A-55-G midrange drivers
3. Crites crossovers with new internal wiring
4. Ciare 12" woofers
5. Sealed cabs with PL Premium X3
6. Added front to back bracing (minimal)
7. Swapped the stock metal jumpers with 10 guage Mogami jumpers. This one surprised me.

@charles1dad 
Raven don’t have any affordable tube amp only integrated I really want to go separates thanks I will the rest out 

Thanks for great response I really appreciate everyone inputs
After reading all the comments 
I narrow it down to this amps 
passlab XA25 first Watts j2 and SIT 3
too bad no balance XLR 
any passlab that has same qualities with  XLR output ?

$6K amp for Klipsch KLF-30 may be a bit of over kill.
I've had Klipsh KLF-20 (and KLF-C7, KSP6) for over 20 years. Mine is not modified.
I've tried a few different amps (NAD, Rotel, Nakamichi, Plinius), and AV receivers (Yamaha RXV-3000, retail $2000 and Denon AVR 3803CI, retail $1600) for KLF-20, and to my ears, not much difference. My KLF-20 sounds just good.
However, I've had a few different speakers (Tyler Taylo, Tyler Linbrook, Apogee Diva, Harbeth C7-ES) and they all sound better than KLF-20 on stereo music (especially on classical and jazz). Though for Rock and heavy metal, KLF-20 sounds more live, but I don't listen to them often.
So, I use KLF-20 in my home theater setup with Denon, and other speakers in 2 channel stereo.
My 2 cents.

I have had a pass labs INT30A. with Kllipsch Heresy and Crites Cornscala. .Sound good to me. INT60 even better. . Now have Pass Labs Monoblocks with same speakers   Really nice.Got over tubes a long time ago. Others will differ.