I’m thinking about giving a full tube setup a go and Primaluna in particular.  Looking to hear people’s experiences with Primaluna in general. My main draw to them outside of tubes is there auto bias and protective features.  Wondering if people generally replace a single bad tube or if people are replacing all tubes of that type when there’s a failure.  Also would be interested if there were any other companies with at least a similar protective feature. The auto bias sounds great but the protective features are a bigger deal to me.  


Prima Luna is good stuff and priced well. Auto bias is nice but biasing tubes is not that hard. On the question of tube life, except for infant death, if you have some hours on your power tubes and one fails it's probably better to replace the whole set. I've never had an issue that required the protective tube system to activate. I have blown tubes on other amps but I have not needed anything other than a new tube.

PL is a good starting point.

Like tires on a car one is bad I replace them all.


My first edition, entry-level Prologue One integrated essentially put me out of the need/want-a-better-amp game. In the ten (fifteen? who knows?) years I've had it, I've probably gone through a good dozen tubes, but by and large the device has been the most reliable piece of amplification I've owned. When a tube fails or you just want to refresh the bunch, you call up Upscale Audio and let them guide you in the selection for the replacement(s). Think of them as wine stewards at a fine restaurant. I'm not a guy who changes speakers on a whim, and I'm pretty sure I went directly from Celestion SL600s to my current NOLA Boxers, and the sound is balanced, mellifluous and ballsy enough to keep me from dreaming of Krells. (I'm just a classical kind of guy even if I do listen (and once played) my share of hard-hitting rock. The amp is three-dimensional as hell. Every once in a blue moon I remove the bottom of the device and lubricate the volume and selector knobs (they'll eventually get noisy), Other parts have failed over the centuries, too, but bottom line, I'm happy as a clam with my PrimaLuna. It's enabled me to put my music-oriented money elsewhere, e.g., a brace of violins. True, I don't think I've ever played my stereo above 85 or so dB, but all in all I can heartily recommend the brand.

I’ve always wondered if continues auto biasing limits headroom?  I had a primaluna HP with KT-150’s and felt after a couple of years music was not that dynamic or engaging.  Probably my room, music preference and hearing.  

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I loved my PLII, bought used.  First time with tubes  and it hooked me.  After a few years  i upgraded to a 4 watt Decware Mini Torii.  Primaluna is a great place to start and end and Kevin Deal was very helpful even though i bought used.

I as well had a PL bought used, had issues with it like noisy vol pot and tubes that went bad quickly. Sold it and went with an Atmasphere S30 that sonically was in another world. 

I’ve had a PL Prologue Classic integrated since 2019 and am thrilled with it! It has been my only tube amp and, like many others, I’m hooked now. I’ve sorta wished I’d have held out for one of the higher models that feature the bad tube indicators adjacent to individual tubes but it’s probably unneeded in the grand scheme of things — I’m learning, somewhat late I confess, that when one power tube goes bad it’s pretty much standard procedure to replace the whole set of four. I’ve had three quads of power tubes in my PL since purchasing it - the original PL supplied EL34s.  Sounded very good…in fact was what got me hooked on tubes. I replaced that quad, still working fine, with Gold Lion KT77s which did provide an extra measure of sound quality to my ears but one of them failed in less than a year (mixed reviews on reliability of those particular tubes) and the Prologue Classic handled it in stride. Just a muffled ‘bump’ noise and the single light on the faceplate lit up red and the amp appeared to be in protection mode. I put the original, PL EL34s back in and played it for awhile before replacing them with reissue Mullard EL34s which I’ve been enjoying for over a year now. Still very much a newbie to tube amps but that’s been my experience with PrimaLuna.

I have been a devotee of tube amplification for many decades. I have owned the prima Luna Dialogue Integrated for three years and it is the easiest to use and nicest sounding to my ears. I highly recommend this brand. You can spend a lot more money for probably not a big sonic improvement.

VAC has autobias, the IQ system, in their newer models and protective warning leds. If the led turns green that tube is getting weak, if it turns red, the tube is drawing excessive current and the IQ system shuts down the main power supply in a fraction of a second (from the manual) so that you can replace the bad tube before it does any damage.

I don’t know which autobiasing and tube protection system works better, nor do I know which brand sounds better.

I bought a Primaluna integrated ten or more years ago for my office system. I have been very happy with it. Detailed and pretty natural sounding (I never bothered fiddling with tube upgrades, I am sure this could make it substantially better). I lent it to a friend of mine who is just starting out and it has allowed his system to get to a level where he could start hearing it’s potential.


Always replace matched pairs or quads or whatever the tube config is. Typically big power tubes last less long than small tubes… so it is ok to just replace those if one develops a funny noise or fails. For my main system I keep around a backup set of tubes, but I listen for three hours a day. For my other systems I don’t. I’s only a couple days or a week to get replacements.

Thumbs up for PrimaLuna.

Auto-bias and protective features are mostly there for marketing. More and more people are coming around to the superiority of tubes. But tubes carry the stigma of unreliability, even though as you can see from the comments here they can be just as reliable as anything else.

To put the protective circuit thing in perspective, tubes have been used for more than a hundred years. They may be new to new customers, but believe me they are not new to tube amp designers. They have like a hundred years experience designing amps to survive blown tubes. Protective circuitry in other words does not have to be anything added. It is just plain good design. Which is why I say for them to draw attention to this is pure marketing.

Auto-bias, same thing. I’ve had amps that had this and amps that didn’t. The amps that had manual bias I have stayed on top of- except for when I didn’t. Times I wanted things to sound really good spend extra time getting bias absolutely perfect. Cannot honestly say I ever heard any difference due to bias, not even the one time I found it had drifted way off. More marketing.

Tubes on the other hand, yes there are differences and yes they wear out and yes it is best to replace the full set. Although again, not that I have noticed any problems. From the beginning when a set was replaced I would keep the old ones around as spares. You definitely want to do this. So when a tube goes bad oh well pop in a spare.

Tubes can go bad in anywhere from an hour to a decade. There are basically two ways they go, the supernova and the slow fade. The supernova is really cool if you see it, blue light storm in a bottle, red hot melting, makes you understand why tube sockets are ceramic. The slow fade they get softer and mellower very very slow and so gradual so it can be hard even to notice. Until you pop in a fresh set and, wow!

Haven’t heard PL, but I do a ton of research before deciding and my short list is Decware, Raven, Audio Hungary, and PL, in pretty much that order. Although honestly you cannot go wrong with any of these. Someone mentioned the Kevin Deal breakdown video. I say breakdown because the man is clearly having one. Courtesy, Raven Audio. Sad. So sad. But he did get one thing right, they all sound good. It is kind of like turntables. Another one where it is almost impossible to go wrong. I’m real happy with my Blackhawk, and have my name on the list for a Decware ZMA. But I’m sure you’ll be fine with PL.

Just go Rogue and you will realize the promise of true high end sound value from a US company. No BS. Or go straight for Audio Research if budget allows. VAC is also cream of the crop it seems but won’t come cheap. Oh and do not forget good old Atmasphere. Or Conrad Johnson.  The video did  increase my appreciation for Prima Luna  

The thing I see that does in most tube amps regardless of build quality with users is mismatching with other gear especially between amp and speakers and amp and preamp. If you get either matching wrong your results will be limited. Run the other way whenever someone tells you otherwise.

Otherwise I pretty much view tube amps like flavors of ice cream . The sound can come in all flavors and for a range of cost. Personal preferences will decide who likes what .

Reliability and customer support always matter as well and probably are more important things to consider than which specific “good sound” to choose. I agree it’s hard to find a bad sounding tube amp after all. Cheap or poorly made….for sure. Plenty of those. Cost alone is not the determining factor of course.

But if you want true good sound, performance comes first. Lots of details that go into that. When in doubt, stick with the well known products and vendors that have a long and wide reputation, not just a particular cult following on the internet.


If only Uncle Kevin would take the back off a Tekton.

Now that would be a video I’d watch.

PL is very nice. Good build quality, I've been in the innards doing my own mods to bring older model up to newest specs. Point to point wiring (exception of auto bias board), nice lay out, nice solder work, nice parts quality, really don't know how much more you can ask for. Add good service from Upscale techs, good sound quality, what's not to like.


The concurrent thread comparing Raven to PL, Raven not in same league, really need to compare to much higher quality competition. I didn't feel deprived when listening to my Dialogue Four (with my upgrades) vs. three of my SET amps in $6-13K price range.

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Also the Aric Audio Transcend Push-Pull amplifier is a wonderful amp.  You can swap tubes from EL34’s on up to KT150’s. Triode / ultra linear switching on the fly and variable feedback (from off to full) gives you several amps in one.  top grade transformers make it way heavier than you think it should be. and the sound is to die for.

It does depend on what you are looking for. Good solid performance for the money (PL great), or state of the art… ARC, VAC, CJ, or there are mid tier solutions.

Auto bias is a nice feature but adds another thing into the design.  Biasing is usually as simple as turning a knob and centering the needle in the middle of the meter.

I had a Primaluna Dialogue Premium Integrated for a number of years. Really satisfying in late night listening but as some mentioned it did have limitations on headroom. 

also I had a number of problems with Upscale Audio tubes. I got bad input tubes at least three times and they refused to do anything about it and just said our testing is sufficient. So not a great experience on customer service for tubes. 

I eventually auditioned an LTA integrated and was blown away at the comparison between the two in terms of how much of a veil came off the music with the LTA that the Primaluna had. Maybe the auto bias, maybe the design, maybe the tubes, who knows but it was undeniably better with the LTA. 

I have an Evo400i, I immediately replaced the stock tubes with NOS Philips EL34. I got a matched set of 2x4 for around $1200. After a few weeks one tube blew. I got worried so I took the bottom of the amp off and measured the voltages for each tube, all good. I also admired the wiring. I got another NOS EL34, replaced only the bad one, works amazingly. Then another tube blew, so I got again only one replacement. The good thing with auto bias is that you can do this plug and play, and it works perfectly. Imagine replacing a whole set of 8xNOS tubes every time on blows. These tubes have been manufactured in the 70’s, it’s quite usual to have some blow. And while waiting for the replacement NOS I plugged back the original PL tube, worked perfectly…

It’s been running on average 4 hours/day since almost 1 year, I can highly recommend it. Sound quality is awesome, but it depends a lot on your sources, speakers materials and cables. 
I’m looking to get a Decware at some point, and I think PL will have a very good resale value in case the Zen sounds indeed better:)

I was introduced to PL last year when a buddy brought over a Dialogue One for me to listen to. He runs the top of the line VAC pre/power amps but started with the Dialogue One. He has >500k into his primary system. He listened to my system and didn't think I was getting the most out of my Magico A3s. Magico Speakers have a reputation of not being the easiest speakers to drive. He was correct! The Dialogue One sounded AMAZING with the A3s but didn't have quite enough power. My wife came up to the listening room and said "How can you go back to the Yamaha after hearing the PL?" She's not into the stereo that much so for her to initiate the decision to upgrade amps was a great and welcoming sign. 

I went with the EVO400 power amp after auditioning ARC, Ayon and Dynaco amps. The EVO400 drives the A3s incredibly well! Amazing body, sound stage and overall sonics. My buddy came over after I got the PL and said he was impressed with how well the EVO400 drove the A3's as well with the overall sonics. His speakers are Magico S7s. 

You get great bones and choices with PL. Ultra Linear or Triode modes, Auto Bias, etc. Being able to run any power tubes in the amp gives you tremendous choices to tailor the sonics to your liking. 

This year I'm planning on adding the EVO400 preamp with a separate phono preamp, The Herron VTSP-3A is the front runner on my short list.

Keep in mind that there is so much that goes into having good sonics. I've heard people say that the room accounts for 50%. Prima Luna is a good bet to be highly satisfied with your amplifier choice considering all of the factors that go into generating awesome sonics.


The one thing that makes tubes fail, aside from vibration, is high plate voltage, ( id not know if this is how it translates to English) 

I have a PL 300i and my partner has 2x 400 in mono. I really like them but they are very dependent on the speaker efficiency. 

With the 300 I have Tannoy Kensington and both of them are really good. I auditioned the Tannoy and Focal Sopra 2 at Upscale. When I was there my favorite music, Spanish Flamenco and guitar, sounded magical on the Tannoy and the 300, no need of sub where the Focal needed subs. But at my home in the US, definitely needed the subs, but they still probably being broken in.

At the courtesy of a peer that is using my home since December the speakers  will have a few more hundred hours of playing and open up as the ones in Upscale. 

With the 400s I tested a few speakers I own just to see how good the 400 are. The speakers were  Tannoy Canterbury (auditioned in my house for 3 months) , Wilson Audio Sashaand my 3 favorite Avantgrade Duo Primo XD, Zignali Client 3.18 EVO and Sonus Faber Aida.

The 400s are very good, however when you put great speakers behind them you start to see some not as good elements on them. I do not have a $10-15K tube amp to compare it yet, a Pathos Heritage is coming, but when I compare them to the Gryphon Diablo 300 (a $13K SS amp) there is no comparison on how they sound.

In the same db range, the Diablo sounds bigger and relaxed much more dynamic and refined and these qualities are consistent across a wider db range but the Diablo is a solid state and powerful so it is not all that fair. The Diablo surpasses the 400s the ability to make the Zignali Client 3.18, Sonus Faber Aida and Avantgrade Duo Primo XD sound as close as they can.

The caveat here is that I usually listen at low-mid volume (4-12, 12 being with the dial at the top middle in the PLs) which it is in my experience that PLs need a little more to get going lets say 10-1 or 2. 

For the $, the PLs sound incredible specially the 300i and the 300s which I made the mistake not to get with a good pre, if I were to give my partner her PLs again I would have given her the 300s.

Would I buy  them again, yep specially for a smaller room and be careful with what speakers you hang from them.  

When I compared to what I internally saw to others, including the Raven in Kevin's video, the PLs are build with care and detail; the others at this price range looked like amps my son was building at 12. Some of them even dangerous given the voltages we are talking on a tube amp.

I am getting delivered a smaller set of Avantgrade for the 300 lets see how they sound.


PL makes great quality good sounding amps.  I owned one.  



--Superb customer service

--Excellent build quality (almost in the top tier)

--Easy to operate, great features, and reliability 

--Some of the best remote controls in the business!

--Can run a variety of different tubes, making it versatile.



--Weight.  But weight means quality, right? 

--Looks.  My subjective view.  I was never jazzed about their vanilla looks. 

--Not the last word (subjectively) in emotion. 

--Lots of competition


There's not doubt in my mind that the products are built like tanks and to last nearly a lifetime.  There maybe a mojo factor missing to the sound and sonic picture (again, my own silly subjective view that you should take with a 1/2 grain of salt). 


Others are spot on when they say this is a great place to start. 

I have an EVO 400. During a very hot summer with the air conditioning broken, I turned off the amp then turned off the rest of the components.

By mistake, I thought that I had forgotten to turn off the amp and I turned it back on again. Instead of reheating the tubes, the amp went immediately into protective mode...with all red warning lights on all tubes lit up. 

I immediately turned the amp off and waited 10 minutes for everything to cool down...the amp was ready to go. No issues.

So far haven't blown a tube in the 2 full years I've owned it.



Also, I have the Primaluna power amp. I didn't get the integrated amp because I wanted a stepped volume pot...something a bit better than the Alps unit the that comes with the Primaluna integrated. The Alps pot is a good enough unit but I just wanted a bit more.

I use a Don Sachs preamp which has a very nice stepped's a very good match with the Evo 400 power amp.

I did compare the Don Sachs Kootenay against the Evo 400 and it held its own. They sound different. The Kootenay is a little drier, cleaner...almost SS like...while the Primaluna is warmer, with more body and tube-like.

Excuse me, but you did not have the Kootenay amp for any amount of time long enough for the caps to run in.  So you never knew what it sounded like.  Sorry, but comparisons with your PL amp are invalid.


Look, I don't really care what amps people like or buy.  I do care when people say things that are not based in fact though.   I have no comment on the PL amp because I have not heard one.  I can however, look at the photos of the inside and see what sort of power supply is uses, see that caps it uses, see the tube compliment, and tell quite a bit about the topology of the circuit.   I am sure it sounds nice.  It does not sound at all like the Kootenay amp though, and I can tell that from photos, and quite frankly, experience rebuilding close to 1000 pieces of vintage tube equipment so that I know what lots of tubes, circuits, and power supply designs sound like.   Enjoy your Prima Luna gear and I am sure it is good value.  But it will sound different than the Kootenay.  I am not saying which is better, but I would be surprised if one didn't have considerably more micro detail than the other.

Hi Don,

The reason I didn’t listen to the Kootenay very long is because it died on me after a one week. Remember? It also arrived a bit damaged. It arrived with a nick on the chrome transformer covers too. Since it still had the blue protective film on the transformer covers, I let that one go.

The amp rattled a bit when I unboxed it. When I opened it up, all the capacitors had broken through their zip-ties. I had to retie the caps and that’s when I noticed all the mismatched screws and the weird angles they were screwed into the chassis. It looked like you were in a hurry.

Every screw on the top of the deck was loose as well. That’s when I noticed you were using shallow countersunk screws on holes what weren’t dressed (countersunk) for them. Half the screws on the rear panel were loose too.

The amp was blowing fuses. That’s when I returned it. It was not a good ownership experience to say the least. I can go on and on about the carelessness of your build quality on this amp. I took many pictures...let me know if you want to revisit this.

Still, you ran this amp for 20 hours before shipment, I put another 30 hours on it. It did start to sound a bit better. But I wasn’t expecting a miracle. Also, the first moment I listened to the Primaluna, I knew I was probably going to keep it. It was close enough to the Kootenay with 50 hours on it, that I wagered it would keep me happy.

Also I was running the Primaluna via my Don Sachs Preamp. Which has been very reliable and sounds amazing. Good job on that!

BTW, I didn’t say the Primaluna sounded better either. I simply stated that it didn’t give much away to the Kootenay. It was only slightly less detailed but just as holographic and more warm. It was more ballsy in the bass. And, the build quality was spectacular. Most of all, it worked...and is still working.

Don, if you’re going to make something....make it great. The little things count. Like using the right fasteners in the right place. If you’re gonna talk the’re gonna need to walk the walk.

Also, when you make a mistake, admit it...don’t blame UPS for your poor boxing. I waited so long for that amp. I paid you good money. The UPS box wasn’t is bad condition at all...just 2 holes where the speaker terminals had punched through. The speaker terminal were bent badly. That’s your fault. You needed to own that and you refused to admit any fault. That’s when I soured on you. I need to believe in the people I buy stuff from. And your behavior led me to not want to own your amp.

BTW, did you notice the way I packed the amp on it’s return to you? I did that to show you how an amp should be packed. I packed it with the utmost care cost be damned. And I paid for shipping. You’re welcome.

I paid the shipping, box was thrown around by shipper who seriously damaged it.  I brought amp back here at my expense and repaired all damage.  Then you didn't want it back so I completely refunded all of your money.  Amp has been out in the world ever since with no problems.   My point was you never heard the amp and were offering opinions that were not based on an amplifier that was undamaged and completely run in for 200+ hours.

You’re gonna need to do better than that Don. Speaker terminals sticking out of the box means all the popcorn shifted to one side and the only thing protecting them were 2 pieces of cardboard.

My point is that to hear an amp, it needs to actually turn on.

It did have a very silent noise floor when it didn’t turn on...I’ll give you that.


Did you realize you can purchase a tried and true 60  Watt tube amp actually built in America 

VTA ST-120 WIRED and TESTED amp with a complete tube set with Sovtek 6550 output tubes > $1780 + shipping

Tubes for HIFI ST-120 assembled 

Kits are even cheaper

I have a PL EVO400 amp.  Best amp I’ve heard, and I’ve owned a lot.  True balanced, single ended, auto bias, 4, 8, 16 ohm taps.  Can be used as a stereo or mono amp. Uses any tube you put into it. El34, kt88, kt120, kt150, etc.  Incredibly great sound, non existent noise floor, triode, ultra linear.    Sounds like silk.   What’s no to like, come on man!

I have two friends that own Fisher 500c receivers. They have auto bias, so no, that's nothing new, but that's not a bad thing. Both units are still working flawlessly and sound pretty good with Klipsch speakers.

Primaluna has 'adaptive autobias'. So not at all the same thing. So many people here like to say autobias has been around forever. But it's not the same animal.

Try putting a kt150 next to an el34 and every other kind of tube in between. Can't do that with other designs. Look at the autobias boards in a Primaluna...not the same animal.


Every design is a compromise...Primaluna gets you close enough to the best but makes concessions to reliability. It's one of the reasons I went with this brand. After a bad experience with a Don Sachs Kootenay, I decided that I didn't need the drama. The Kootenay sounded a little better when it worked. 





In my room I've only had BAT but wonder about how it'd compare to PL, ARC, and especially Rogue.  Yes replace all the tubes at the same time, else your mind will devour itself when you start hearing things that don't quite sound right.  Best feature not explicitly mentioned above is 3 sets of taps to match diff't speaker impedances.  

When I decided I wanted to get my feet wet with a tube integrated I was looking for the best bang for my buck. I went with a Jolida Fusion 6802 on close out from Walter. I like it a lot but that’s coming from a guy that had only had receivers in the past running a pair of Canton Karat 930 bookshelf speakers from ‘93.
Without question tubes are for me. Within the 2 years I’ve had the Jolida, I’ve gotten a hold of a set of PSB Imagine T speakers(not the best but better than the Cantons), MHDT Orchid DAC (For CD Transport) and still waiting for my Decware phono stage. After I receive the Phono Stage, a much better pair of speakers will be next. I then will evaluate where I go with the amp.

I guess what I’m saying is it’s been a learning experience and may be one for you. So don’t hesitate to buy a Prima Luna and enjoy the journey.







+1 for Primaluna.

I started with a used Prologue One and later upgraded to a new Prologue Premium. I have been very pleased with my Primaluna amps. In addition to driving my Harbeths, they also handle my hard to drive Maggie 1.7i’s without breaking a sweat. I also have a Hegel Rost integrated, which I greatly enjoy, but I I keep coming back to the Primaluna as my preference. You won’t go wrong with a Primaluna, and you’ll certainly thank yourself for stepping into the magical sound of tube amplification. (I always buy a new quad of tubes when it’s time to replace.)

+1 for Primaluna.

I started with a used Prologue One and later upgraded to a Prologue Premium. I have been very pleased with my Primaluna amps. In addition to driving my Harbeths, they also handle my hard to drive Maggie 1.7i’s without breaking a sweat. I also have a Hegel Rost integrated, which I greatly enjoy, but I keep coming back to the Primaluna. You won’t go wrong with a Primaluna, and you’ll certainly thank yourself for stepping into the magical world and sound of tube amplification. (I always buy a new quad of tubes when it’s time to replace.)