Member's recommendations for tube amplification


Your thoughts on options to consider:

- I'd prefer SET (open to DHT but not a requirement).

- I'm not looking for overtly warm, romantic or lush options.

- Minimum power in the teens to twenties, 10W being the floor.

- Open to higher power push-pull amps, but let's limit ceiling to around 60W.

- Single ended is fine though having XLR inputs would be nice (doesn't have to be true balanced)

- I'm cool with single chassis or monos.

- I have preferences for tube types, but leaving it open ended to get broad recommendations.

- I'm currently running an all solid state system, though have had tube based systems built around ARC, BAT, Ayon, Melody, Pathos, etc.

- Preamp will be a Pass XP-20 or the Metrum Adagio DAC direct to the amp.

- I'd like to stay around 3K used but can push the budget to 6K new/used.

- Speaker sensitivity is 94dB and higher.

THANKS!
david_ten
Time has flown. Over three months have passed since Charles' post.

Updates:

- The Tekton Design Special Edition Double Impacts (SEs) went in system on December 1st.
- I chose the Denafrips Terminator DAC over the Metrum Adagio.
- I recently ordered the Lyric Audio Ti 140 Mk 2 Push-Pull Integrated amp.

Particulars:

- The SEs are a 4Ohm design, with a listed sensitivity of 99dB 2.83V @1M 
- My room size is 19 ft wide (front wall) by 26 ft long by 9 ft high; with a partial divide at the midpoint, at 13 ft.
- Speakers are >4 ft from the front wall to the speaker back and ~5 feet to each side wall from the closest speaker side. Equilateral triangle with approx. 8ft sides, center to center to center.
- Most of my listening sessions are not loud. I average 60 to 70dB with max peaks in the high 80s; as measured at my listening position (via an app, A weighted); I often listen in the high 50s out of respect for family, when they are close by; the room, with nominal/regular background noise, runs in the low to mid 40s.
- Current pre and amp are the Pass XP-20 and XA-30.8

The Lyric Ti 140 Mk2 will come equipped with a KT150 quad (70W). Other power tube options are EL34/KT88/KT120;  12AX7 for Input stage; 12AU7 for Phase reversal; and 6SN7s as the power tube driver. Negative feedback is variable/adjustable. Here is the link to Lyric should you want more info: http://www.lyric-audio.de/ti140e.html

My rationale for choosing a Push-Pull Integrated is primarily Educational, to help determine direction and a final tube amp pairing with the SEs. It isn't / wasn't a choice to replace my Pass separates. My system as is, especially after the Sonore Signature Rendu SE and Denafrips DAC additions and with the SEs as the new speakers, is performing fabulously.

I just re-read this thread and it continues to be very informative for me  A number of your amp recommendations are still on my list. Thank you for all of your contributions.

If you have a reaction to the choice of the Lyric amp (positive or negative) please let me know why / your thoughts. If you have advice on how to proceed and evaluate direction with the Lyric as a component, please share. Thank You!!!
Post removed 
Hi Mountainsong, 
The Italians make some really fine 845 SET amplifiers 
Mastersound 
Audio Frontiers 
Viva , which I'm most familiar with and they sound superb. 
Well implemented 845 SETs are beautiful sounding for sure. It's good to see you soon thoroughly happy. 
Charles 
I Bought a compact 845 demo. The sound was so huge, natural and free of color that I went all the way up and I purchased the Monos with the Spettro pre-amp.
After all this years in this hobby I am wondering how matersound is not better known in the audio communities?
I found owners overseas in Madrid and Turkey. They consider the PF100 one of the pinnacle in tube amp design with power to drive anything. The had owned really ultra hi end gear and preferred MS over everything at the end. 
First amps that made my KEF Ref 3 sound musical.
Honestly this gear is at a complete different level.
I am using tonight the compact 845 with Diapason adamantes 25th. Very little to be desire. Music fill my room with natural vocals like a live performance. First time i got the piano right in my space.
Just go and listen to a demo if you can before purchasing anything.
Kind regards and best of luck.

Thanks for the responses to my question about the VAC Phi 200.

@mountainsong  Did you order the Pf100 or the Compact 845 integrated?  The PF is waaaay outside of the realm of possibility. 

Please share your findings and impressions of your Mastersound gear.
David, I can't shed any additional light on your question beyond what Charles and Kenny have said.  Best of luck as you proceed.

Best regards,
-- Al
 
I recently purchased my first SET. Mastersound compact 845. I had owned many desirable pieces in the past 10 years. But guys nothing at this level.
I wish I had discovered them a while back.
I ordered the Pf100 probably one of the best regardless price.
Best of luck.
David,

I would agree with Charles,
Vac made and sold quite a lot of the Phi-200 amps,probably was their best seller and I do believe several folks have upgraded or would like to.

I only have experience with the much older 30/30 and it was a very good amplifier that I wish I would have kept at the time.I had Maggie's at that time and needed more Pwr.


Kenny.
David,
That would be my guess and the fact this was a pretty popular VAC amplifier so there are more of them available. 
Charles 
@almarg  and @swampwalker   since you recommended VAC,

and others who may know:

What are the reasons for the number of VAC Phi-200 listings?

Is it purely due to the replacement Signature 200iQ?
I've been reflecting about the integrated amplifier option for 24 plus hours now and I think it's best for me to stay focused on a pure amplifier at this time.

I'm saying this fully realizing that something like the Octave or Line Magnetic or other higher performing tube integrated amp could and would work beautifully.

Thanks to all of you for reaching out with those options.  
David,

I have heard all of the LM Intergrated amps with the exception of the 508 but if I get the chance to borrow one that is local to me you can beat I will.

The 508 will most definitely accept preamp input and I do believe that the 508 has a pretty good preamp section as is vs other brands of tubed Intergrated amps that I have owned or heard.

Kenny.
Waltersalas,
I’ve expressed on many occasions my unabashed joy with the Coincident Frankenstein. I truly suspect that I’d be just as thrilled with the Line Magnetic 508ia. It is reputed to have high quality output transformers and power supply. 805 tube driven by the 300b? Sounds like a formula for superb sound quality if implemented correctly. My gut feeling is that this is a very top tier amplifier. I will say that the Frankenstein is one of the very best sounding Amplifiers I’ve ever heard. I don’t see how someone could possibly go wrong with either excellent choice.
Charles
"...I just think invariably you may think about upgrading some part of your system again."

Jond has just described the audiophile condition in a nutshell, regardless of what kind of amp you use. :)
@david_ten I would suggest going the straight amp route rather than getting an integrated. No slight to Line Magnetic or any other integrateds mentioned, I just think invariably you may think about upgrading some part of your system again. When you do having a separate amp and preamp gives you more options, also I am guessing you may find yourself wanting a tubed preamp at some point.

Thanks for the shout out, Charles. Yes, I think the Line Magnetic 508ia is an incredible amplifier, so much so that it forced me to reconsider my previous bias (no pun intended) for separates. I do indeed believe that the pre section is pretty great, though I may at some point do some experimentation with a good preamp to see if further improvements can be had by adding a quality pre in the chain. That has always been my experience in the past, but as I said, the LM 508 has resulted in a paradigm shift of what an integrated can do.

I do think it is necessary to upgrade the stock tubes to get the absolute most out of the 508, especially the 300B and 6SN7 tubes, though it also sounds good with the stock tubes. Adding some EML 300Bs and a nice pair of Sylvanias or the 6SN7 tube of your choice will yield very noticeable improvements.

To my ears, it is a stunning partner for the Double Impacts. I've had systems that were more than twice, even three times, as expensive, but I have never had better sound than I have now.
David I'd judge the choices based purely on sound quality.  The Line Magnetic 508ia for example is an integrated amplifier that by all accounts outperforms many stand alone power amplifiers.  Also I believe that the preamp section can be bypassed if so desired. It seems the 508ia has a good pre section that responds to tube upgrading.  Waltersalas can certainly address this aspect. 

A high quality integrated can be built with better parts and transformers than some power amplifiers,  it all depends. 
Charles 
@jmac7  Thanks for bringing up the Line Magnetic integrated. I'm familiar with it. It was a wonderful pairing for my demos of the Devore O/96s.

@charles1dad   Charles, how could I forget, with all the early discussion in the DI thread around it. LM508ia must feel quite neglected now that the thread has moved on to those other two amps!  : ) 

Let me ask again, is it 'better' for me to pursue an amplifier separate for my application or should I also add tube integrateds to the mix. I don't have space issues or other factors that would necessitate a single box and I do have a preamp (which, however, could be used in a secondary system if I did go with an integrated).

Will it make a difference - how so? Are the differences not significant enough to be a factor? Thanks.
hddg, 
I viewed your system page and you have a very nice one,  it must sound fantastic.  I noticed that you have the Gryphon Mephisto amplifier.  Do you alternate between this and the SET Frankenstein MK II?  If so what a "very" stark contrast they must provide given their vastly different power and topologies.  I find this very interesting. 
Charles 
Hi hddg, 
I've the same amplifier as you and have enjoyed it immensely the past 8 years. I've had zero issues or difficulty dealing with the company owner, he's consistently been supportive and responsive during those 8 years. 

No doubt that anyone  is perfect or always pleases everyone. Sorry to hear you had some problems with him. By the way I also have their Statement Line Stage and it is indeed superb. 
Charles 
Coincident Frankenstein MkII - very good sound in all parameters. The manufacturer is not the best to deal with, but sound quality here I must say is of the highest note. You can still improve by asking for caps upgrade before ordering. It drives 89dB speakers to quite nice levels, but I wouldn't use them with large drivers, 10inch max. With bigger ones, it lacks attack and dynamics. Depending on your speaker character, you can play with 300B tubes, the WE300B replica from Psvane is marvelous, and gives incredible details and mids. The Takatsuki TA300B is slightly more balanced (again, will depend on speaker and/or your taste) and gives better bass. The Psvane black bottle does very well too. A good preamp will obviously improve these SET quite dramatically. Although I usually prefer to pair transistor/tube preamp/amps, I have experienced that they match perfectly with their cousin, the Coincident Statement Line. 
Audiogon member Waltersalas uses the Line Magnetic 508ia with his Double Impacts and says the results are stunning.  No shortage of exceptional amplifier options for this speaker. 
Charles 
You might look at the Line Magnetic 508IA, SET, Pure Class A, 48 watts per channel. Here is a link to a site that says a little about it. 
http://widescreenaudio.be/product/line-magnetic-lm-216ia-3-2-2-3/
There is a dealer called GoldPrint Audio that you can contact if you wish. I think that they still sell them.
@rmasoni Rick, interestingly I clicked on one of the Agon ads...for the Voxativ Zeth speaker and one of the ’blurbs’ from a show mention the 6B4G driving these speakers.

@rspyder Ray, I came close to buying an Octave integrated amplifier a number of years ago...ended up going with an Ayon. Another German player, Lyric is newer to the U.S. Any thoughts?

I’ve been focused on an amp and did not specify an integrated as an option in my opening post. I already have nearly 40 recommendations!

Do you and others feel / believe I should be open to a tube integrated amplifier?

Pros/ Cons? Thanks.
David,  glad that was helpful.  This is the same amp Berning uses (in the 6B4G configuration) in this personal system . . . and he is driving 87db speakers. The reason these are "affordable" is because he builds them in his own shop, cosmetics be damned (although there is relatively inexpensive solution to the cosmetics)!!   I have had for years the flagship integrated of Pathos Acoustics - the Inpol2, which is a hybrid design with tube input and MOSFET outputs, fully balanced, 45W Class A.  A new one will cost you $13k. I've got mine listed for $4K.  Its a wonderful amp, but the Berning is significantly better.

Best of luck in your search!

Rick
If you are willing to consider an integrated at the high end of your budget you defintiely should consider an Octave.  A few are finally showing up on this and other audio reseller sites.  You can always add the Black Box or Super Black Box later.

Ray
@rmasoni   Thanks for the heads-up on the 300B or 6B4G specific David Berning amps.

His products are way beyond my reach, but the amp you are using and it's cost are in the doable realm. I wouldn't have considered Berning's amps due to the cost, so your pointing this one out is super helpful.
Call David Berning directly and ask him to tell you about his 300B or 6B4G push-pull amp that he builds on request.  It is spectacular. His ZOTL circuitry, fully balanced, Class A.  He included 47 step Goldpoint attenuator when he built mine - so it can be used as an "integrated", albeit with a single input (either RCA or XLR). Will cost you around $7K, but there is nothing like it - check out Harley's double down on the Flagship 211/845. You get the same sound in a smaller package.
@sbayne @seikosha @mac48025 and @kdude66  Thanks for your recommendations from another thread. 
@jond   thanks for bringing Deja Vu Audio to my attention. 

@djfst  @willgolf and @cougarbradley Thanks for your tips on Viva, Raven and K&K.

@jb505  Another vote for Quicksilver! Thanks.

Appreciate the recommendations. The list is getting quite robust. I'll add these to the Sheet matrix. 
You should audition conrad-johnson tube amps.  I've used various models for 30 years and all were excellent.  Enjoy the quest and the music.
I have seen your post on the TeKton DIfforum... last Sunday the Atlanta Audio Club had a pair of Tekton DI's  for the club members to see and here .  They were driven by an all K and K Audio  electronics.  Line stage, phone stage and pair of monoblocts. (KT 120's) .  The combination was praised over and over again by appprox 35 members. The monoblocks are  very affordable also.  Check out K & K Audio or better yet give Kevin Carter there a call.  ( No I do not work there or have any thing to gain. 
I don't mean to muddy the waters with yet another recommendation. However I will. I run an Audio Note system and I'm very happy with them, but if I had to do it over again and go a different make I would go with Quicksilver. Hand built, excellent quality, great value and holds its value. 
Good luck.
Let me give a recommendation for Raven Audio Tube Amps.  Dave Thomson is the owner and live in Texas.  He is also a Legacy dealer.  He has a pair of DI's that he hooked up to his amps.  I have the Raven Audio Reflection MK2 Integrated amp at 58wpc.  Not only is it beautiful but the sound that comes out of it is mesmerizing.  They are powering my Sonus Faber Homage Amati Traditions.  He has many different tube amps that would meet your needs.  You should give him a call.  Look up his website.   American Made!
The Viva Audio amps fit your criteria almost exactly.  Not warm - very lively and dynamic.  They are Single Ended Triode in the upper teens and lower 20 watt range, but can easily drive most speakers.  
I was picking up my new speakers at Deja Vu Audio the other day and saw a pair of pushpull 6L6 monoblocks that might just fit the bill for you. It was their own build and they build fantastic amps over there. No idea the price but worth checking into plus they give fantastic advice. They also carry two other brands @larryi mentioned Audio Note and Synthesis. Lots of good discussion here,  now everyone take a deep breath and crank some tunes!
Jack Elliano developed a technique to reduce distortion he called 'Class A3' (as opposed to class A or class A2). As a result, his SET amps were the exception to the 20-25% rule to which most SETs adhere. Jack had a patent filed on the concept.

Regarding discourse on the threads, I find for the most part that the best approach is to not take things personally regardless of the conversation. I see it as not really being my problem when someone makes personal attacks. Occasionally I'll get trolled; however the site is moderated, but in order to invoke the moderation you have to report the offending post. I find that its really important to not respond to a post that offends you. Occasionally the thread gets taken over by trolls and at that point I stop posting on such a thread- there is no further point.

These tactics work pretty well regardless of what site I post. There is one site, hydrogenaud.io, that is very much all about objective measurement and also has an unusually high troll content; on that site you have to have a pretty thick skin. But the same ideas apply even there.

When you take all the weirdness and such that are part of the internet forum experience personally, that's when it stops being fun. And the fact of the matter is that there isn't a good reason to take anything said here personally! 
David,
You’re in a good situation, speakers that have made you happy and a top notch Pass Labs XA 30.8 as  your amplifier reference point. Your approach is very rational, taking time to learn more about the "many" fine choices available to you. I believe that your quest will end very successfully. Your thread has generated informative commentary and perspective.
Charles
Perfect. Thanks @clio09

Funny thing is I am feeling the same as you regarding these Agon threads and sense hibernation is right around the corner for me. Things have changed over the years, discourse is rough and angry often times, and I have grown weary.  I am sure my fuse is short and sensitive for this reason. I have a few posts left in me and then will most likely hibernate.  I stay pretty fit and do not have the fat cover I should for this season of change😁   I remember our shared experience with passives, TRL, and general audio years ago.

Enjoy life, loved ones, and your passions!
I'm back for a moment as Ralph contacted me about the thread.

For Bill, first of all I was not upset with your comments. I think Charles summed it up nicely. I left here a while ago because of the misinformation I kept seeing over and over again and how audiophiles were being influenced by it. Again, I come back every once in while because of something interesting I see. Your mentioning the Music Reference RM-10 was just that, as you rarely see that amp mentioned at all, let alone a discussion like this. A true injustice to the amp in my opinion and I owned one long before I started working with Roger Modjeski, the amps designer.

As I read over my last post it dawned on me that I could add a bit more to it to make it clearer. Again, Ralph's comment on SET power is not being disputed. It's true and something I have seen occur on test equipment in Jack Elliano's (Electra-Print) shop. It's not easy to get around the cold hard facts of how SET amps typically behave. Quite frankly some people like the distortion, it gives them the warm and fuzzies, and that's great. Until you know what to listen for, and when those nasty harmonics start to rear their ugly heads, as they will eventually as the power rises, then you should not find things so pleasant.

Jack Elliano developed a set of output transformers that allows two series triodes (in this case an EL-45) to provide about 12 watts of power. He also designed a summing loop that tapered off the rise in the distortion (IMD), which in no NFB SET amps happens pretty quickly after the first watt or two (when power to handle peaks in music is generally needed). So for this circuit IMD is less than 1.5% up to 3 watts (25% of full power). It will rise to 10% at about 7 watts (still extremely clean at greater than 50% of full power). The distortion finally causes the amp to clip at 12 watts (full power). That's why such a design (which we used in 45 and 300B designs as well) can push a 6 ohm speaker like Fritz's Carbon 7's to bliss, or as Charles noted those 4 ohm Hornings.

In a typical circuit without such a summing loop IMD distortion will rise to nearly 30% at 7 watts, and at this level you anyone should be able hear it (although the rise up to that point could be challenging). The first few watts will be fine for the most part (the 20 - 25% of full power Ralph alludes to), but the amp will turn out the nasties quickly after that. However, that's not to say such an amp can't be enjoyable in a given room with a given set of speakers at low listening levels, as I've heard it happen. On the other hand in the A/B testing of these two circuits I could hear the distortion as we cranked it up past 80 dB (on 94 dB 8 ohm speakers). You learn where your limits are pretty quickly.

There are a lot of nice folks here still, but I really would be doing myself a disservice if I hang around. That could change but for now life beckons and I'm knee deep enjoying life in my new surroundings in the Bay Area while still fiddling around with my system when time permits. I hope I answered your question Bill, take care everyone.

And here I thought I was asking a simple question. : )

 @grannyring  @clio09  @charles1dad  @larryi  @atmasphere 

Thanks to all for the vigorous discussion. It has been immensely helpful. It's good to be back in school. 

I've followed convention and general norms on the issue of how much power is "right" by speaker sensitivity, etc.

Terry's findings with the LTA MZ2S with the Double Impact were difficult to accept when he first posted them. It's obvious it worked for him, his music choices, listening levels, his room, etc. though he did augment with slightly more power, though much lower than those 'norms' would dictate. Others followed and tested the same with replicated results, but also acknowledged that a few more watts of power was advisable.

It appears that there are clearly exceptions to the 'rule' and perhaps more than we would think or have tried. @clio09 's example being one that really stands out. Finale another. LTA/Triode one more, etc. etc. based on very specific speaker pairings from yours and others' posts in this thread.

In my case, your posts and the back and forth have made me much more comfortable taking a "risk" with a lower powered SET amp. That's good news, I think,...though it does widen the choices to consider. 

I'm looking forward to @teajay reporting on the Double Impact SEs ... his take will likely help and direct a possible choice. 

No decisions as of yet. I've had to start a Google Sheet to keep track of all the amp choices and who made the recommendations so I can reach out more specifically when I get closer to doing so.

Having the Pass XA-30.8 makes the wait very easy.

-------------------------------------------------------------------------------

If there are other recommendations out there, please post!!!
Note that generally hibernation starts much later in the year as winter approaches, allowing for the appropriate amount of body fat storage. 
I am sort of in agreement with clio09 about the possibility that someone may be satisfied with the result; it all depends on the specifics, such as how easy a load the speaker is, type of music, how loud one listens, how large is the room, and most importantly, what compromises one is willing to make.
Just to be clear I do like to play things louder and always have. I used to play bass in several orchestras and orchestras play loud a lot. If I put on Wagner's Das Riengold (Solti Decca LP) I want the event to come off as if its happening. Its not just head banging (although I do that too).

@grannyring I'll contact clio09 and let him know you meant no harm.
It was well explained and that is clear. Just not sure why he made the hybernation comment and got upset. Are folks even reading, really reading posts here anymore? 
Hi Larryi,
As usual good and well written perspective.  I honestly believe that clio09 did very effectively point out the potential variables and compromise inherently present in these situations.  He clearly recognizes and described his positive experiences with lower power SET without extrapolating to make this a given outcome for everyone else. 

Maybe it's just me but I thought his reply to Bill was very well explained. 
Charles 

While I have, in this thread, cautioned against using the really low-powered triodes in single-ended topology, I am sort of in agreement with clio09 about the possibility that someone may be satisfied with the result; it all depends on the specifics, such as how easy a load the speaker is, type of music, how loud one listens, how large is the room, and most importantly, what compromises one is willing to make.  There is always compromises involved, no matter the budget or any other consideration.  If one does not highly prize extremely deep and tight bass, or if one listens mostly at modest volume levels, a SET amp might work even with speakers not designed to work well with this type of amplification.  Unless one listens to head-banging music most of the time, the average listening level will be such that one would be using less than a watt with even inefficient speakers.  So, the question is: how important to you is it that the sound system performs well for the comparatively shorter time it is asked to deliver higher volume?

When I listen to large choral works with my 6.5 watt parallel 2a3 SET (Audio Note Kageki) driving 99 db/w 8 ohm speakers, I can tell that on peaks, the sound is becoming a little bit muddled and is sounding compressed (not really getting much louder even though it should be).  But, for almost all other types of music, the amps deliver all the power I need, and given my priorities (I demand good dynamics and a full and lively sound at LOWER volume levels), the compromise is worthwhile.  The same holds with my other low-powered tube amps.

Agreed Charles. I do think my comment has some truth. It is for you to decide if there is a modicum of truth. We all have certain biases and bents. Goodness I have my quirks. Just good to see them sometimes. 
Bill,
I believe that I'm as opened minded as you or anyone else.  At the end of the day we all have our unique listening preferences and know what we like.  I have in fact encouraged others on this forum to seriously consider the Lyngdorf 2170 for their audio systems.  

Why would I suggest a product that I have not personally heard? I did it strictly out of respect for your high opinion of it based on your happy ownership and nothing more. Having an open mind means that I can appreciate the positive experiences of other audiogon members and make others aware of them.

Yes I am very fond of lower power SET amplifiers for meeting "my" musical needs.  I have also stated clearly on numerous occasions that these types of amplifiers won't satisfy every listener.  Numerous times I've written this acknowledgement. 

Having an open mind doesn't necessitate having to always agree and have the same outcomes. 
Charles