Very hard to say (IMHO and a little experience) which tubes in a particular design will 'make a difference' in sound. Possibly the manufacturer can comment? or others owning the same brand/component? IIUC these are pretty new in the line but earlier designs may be similar enough. I'd stick with the stock tubes for quite a while (6 months or more) so you can get a good feel for what it sounds like in your system/room. Read up on things in the meantime ... Do one set of tubes at a time ... let them and your ears settle in for another period of time, maybe swap back to get impressions of what changed ... can be a lifelong experience which isn't painful at all. My limited experience: McIntosh C220 sounded too 'soft' (altho amazing, organic, etc.). One set of tubes in that preamp are mostly 'buffers' (it's a hybrid) but did affect the sound. I got some used old measured good Telefunken ribbed plates, then new Gold Lions. The GLs stayed in there, seemed to me to 'clean things up' a little, improved resolution and musicality (or something). I put some $50 silver fuses in there too, the 'mains' fuse made a difference, the other internal ones ... no change that I could tell (and the clamp things are SUPER tight so I just left them in there, didn't want to damage the circuit board!). Present 300B amps: Changed 300Bs (got some >$300/pair 'Princess' ones) ... no difference in sound that I could tell! but the glowing open mesh plates look much sexier (originals have solid plates, can't see much glow). Changed driver tube to NOS Siemens, this tightened things up considerably (higher res, better overall). "I doubt that the 40 WPC Evo is going to satisfy with your speakers and your room and will probably sound worse with the 4-ohm tap (look for slightly exaggerated midrange)." Errrr, unless he has direct experience with your amp and speakers, I'd read this with a grain of salt, sorry.
@Lebowski definitely swap the taps to 4 Ohm. And the reason I had asked if you were running through a power conditioner was that my PL sounded wimpy and brittle when I ran it through my Niagra power conditioner. It came right back to life when I plugged it straight into the wall, which is how it's run now. Don't know how you're set up.
I guess I'm lucky because I've not had a tube amp or preamp that hums. That would really bother me. Hum/his through the speakers is a sign my power tubes are aging and ready for replacement. Looking at the graph of the speaker impedance, the speaker is requesting twice as much power to reproduce 35hz - 400hz than it is to reproduce the treble range. It wouldn't surprise me if it sounds "sharp" using 8 ohm taps when it might be running out of gas trying to deliver that much power to the low frequencies. The transformer can be thought of as a transmission that has multiple gear ratios. Flipping to the 4 ohm taps should change the gear ratio the tubes see as they try to drive the speakers making it easier to deliver more bass, depending on the output impedance of the amp. The trade off can be less dynamics however with a bonus of lower distortion. Another way around all that though could be an amp with more power.
Yes, I'm going to give it a try. Might not be until tomorrow evening (going to see Steely Dan tonight!) I'm not running it through a power conditioner, it's straight into the wall. The only thing I have in the way of a power conditioner is an Emotiva CMX-6, which isn't really a conditioner I guess. (my current amp and every other component is plugged into this)
Various tube set ups can better match the amp to his speakers and his musical preferences. I have owned both PL and LM amps and they are both nice amps, either should serve your needs nicely. The differences in sound between them will be more due to the tubes that you run, than any other factor. The Adaptive Autobias is a really nice factor and does make things easier, regardless if you are a long time tube amp owner or a tube newbie. Understand that the CM's use KT-120 power tubes and produce 100-Watts of power, as compared to the 40-Watts that the PL will produce. Very nice remote. Most tube amp remotes only control the analog volume pot, while some made add a mute function. I used KT77's in my Line Magnetic 211iA, and I think they are nicer overall sounding than modern production EL34's, which I have not particular fondness for. Class A/B amps are usually designed around operating in the ultralinear mode. While I prefer the triode for Jazz, Vocals and Instrumentals, I think that having the triode mode option is best served with more powerful amps and tends not to sound as effectively nice with lower power amps. Lower power amps tend to loose definition when run in the triode mode, which is why many don't offer triode mode as an option. I run my Rogue M-150 KT88 monoblocks in triode mode all the time, which provides 75-Watts of power, as opposed to the 150-Watts that the ultralinear mode provides. See below... The warmness is going to come (at a low cost), with the small signal tubes. Don't look toward the output power tubes to provide warmth. The Cronus should not hum, be it from mechanical hum from the transformers or hum that you hear through your speakers. With any tube amp, you may experience a tiny bit of hum, but should be only audible when you put your ear up close to the speaker. I think that KT77's sound nicer than modern EL34's do and have better bass. I don't think that modern production EL34's have any sort of midrange magic that you hear everyone talking about. I do think that you notice the midrange more, mostly due to a lack of bass, not because they have more or better midrange. Rogue's owner, Mark O'Brien, once commented that the KT88's have about the same midrange as EL34's do but with far better bass. I had a PL Prologue Five and I ran it with modern stock KT88's and was very pleased with its sound. And, I ran it through the vintage Altec Lansing A7 horn speakers, which are highly sensitive and are very revealing. I was very pleased with the sound of the PL Prologue Five and only retired it because I bought some other tube amps and ended up running the Five with the Zu Omen Definitions (MK I). For my tastes, as far as modern tubes go, I prefer the KT88's as power tubes. Bigger, fuller sound than the EL34's, about the same midrange, maybe better and definitely better and more solid bass. Keep in mind, as Synthfreek commented, it all comes down to the tubes that pair best with you speakers, which in the same power range, may matter more than which individual amp you are using. Some speakers, like Harbeth's may like and require more power and sound better with a tube that is both more linear and has more of a top end like a KT-120. But, do keep in mind, that when rolling KT-120's into a 40-Watt amp, you are still going to end up with a 40-Watt amp. They are not going to give you the additional power and sound signature that KT-120's will in a Cronus Magnum. My Altec's don't need the additional power that the KT-120's provided in my Cronus Magnum (version I). I think the KT88's with the Altec's provide a more natural relaxed tube sound than do the KT-120's. If I was listening primarily to big orchestral music, that has a wide range frequency range and demands a big fuller sound, then I would use KT-120's. But, as this is not my musical preferences, I prefer the KT88's overall. Your better bet for that magic midrange is to go with NOS power tubes. Fortunately, you can still buy nice NOS RFT EL34's from sellers on eBay from Germany. They will run around $400 for a quad, or less. These RFT EL34's do have that magical midrange that vintage EL34's power tubes are known for. I run these tubes in a Audio Note Kit L4 power amplifier and the amp, with these power tubes sounds close to the two single ended class "A" tube amplifiers I have owned. Not only is the midrange lush with vocals, which I consider of the utmost importance. but the bass is uncanningly strong, more like a KT88 than a modern EL34. I would make sure that the EVO-100 first of all, has the power you need to properly drive your speakers within your audio environment. If so, fine, but it you are lacking in power, then you will never be able to achieve the desired volume or desired dynamics, no matter what tubes you go with.
I agree with this correction, that the warmth comes from the small signal tubes, but whre I say the larger power tubes help is that with, IMO, more extension both top and bottom it gives you more to warm up with the gain tubes. The added bass from a larger tube like a KT-120 certainly adds to the overall effect vs an EL-34. Insofar as the power tubes are boosting what the small signal tubes feed them, the larger tubes putting out more power and more bottom end depth are going to grab that Mullard or Brimar warmth and deliver more of it. That's what I was getting at. If you keep the stock gain tubes, and just add larger power tubes, totally agree that you've added no warmth to your system.
i put that link so u could see what the tube cage looked like. i would recommend to buy new, trade something in, etc if possible. except for a nos tube made in the 50s i have had only one tube that needed to be replaced in almost 3 years of use.
@SandAndGlass, you are correct with your comments on modern EL34 and KT88 differences. It didn't occur to me that the EL34's leaner bass would make the midrange sound more pronounced. I agree that KT88 does have the same 'magic midrange' but perhaps not as pronounced due to the fuller bass/sound. I believe there's a consensus that most of those who commented on this topic prefer modern KT88 to EL34 tubes. If the sound is on the brittle side then it would be wise to look at warmer sounding small signal tubes.
Wasn't going to participate because I'm currently out of the country in my other home and havn't listened for several months.I have the PrimaLuna Prologue Premium Integrated and before that the rouge sphinx v2,and for me it was a very good move,I run the GL-KT77 power tubes and Brimer cv4003 in the front 2 middle spots and I love the sound I have now, i usually let it warm up for at least 1 hour using a CD before critical listening to vinyl as it smooths out to my ears...The Classic is the entry level as was when I bought mine I chose this one because I don't want to spend for so many tubes to tube roll and had the bigger transformer than the classic.And like you is my first Tube amp, never listened to any others so nothing to compare it to before purchase as where I live is to far to go,Its my end game system now which is listed in my profile.Hope you find what you want, and enjoy the music.
If the EVO 100 is comparable to your current amp, I would not make a lateral move just for the sake of having tubes. Integrated amps take a huge step up around the $4.5-5k price point. Better to wait and save up until you afford the top of the line Primaluna or maybe a Line Magnetic 805. At that point you would be set for life.
I don’t. I’m perfectly happy with El34 tubes, and I totally prefer them to KT88’s or KT120’s, at least in my Dialogue Premium Integrated. I didn’t make it clear before because I thought it wasn’t relevant in this topic until now. Anyway it’s just my opinion.
Mine has straight 12AU7's across the front ,and my 2 middle ones are the preamp tubes...They have changed it to have AU and AX front row not sure why..
They've changed their stock tube configuration a few times in the past from what I can see. I believe you can substitute 12AU7s for 12AX7s and vice versa (and 2ATs too) in all their models, but it's worth a call to Upscale Audio to confirm. Like that article says, the front two are your gain stage and have the most influence on sound. Switching to the Brimars for me was an immediate impact, and I love the sound so much that I haven't rolled anything else into those positions. I'm just about done breaking in the Tung-Sol 12AU7s in the driver stage. At first they were way too relaxed and the bass was mushy, but they settled in within the first dozen hours or so. The bass has tightened up nearly to where it was with the stock drivers, and the top end has gained definition. Overall everything is very relaxed now, even at top volume. I also find myself listening in Triode more than I was. Although I'm not sold on the effect on the overall soundstage. I will give them some more time, and then perhaps try Gold Lions.
You can't substitute any tube from the 12a*7 family with a different one, they all have very different gain, it could be dangerous and it won't sound well anyway. Regarding the Evo 100, I'm not familiar with the model, but the ones in the center, either 12AU7's or 12AX7's should be the imput tubes. Anyway, even if those 2 are the ones that have the most impact in sound change, in my amp that has 6 12AU7's, they all affect the sound when replacing, and even exchanging them has an impact in sound.
I've had a Prima Luna Dialogue 2, for about 6 years and love it. I've only replaced power tubes once in that time period. As a guitar player with several vintage tube amps, I have a closet full of NOS tubes (starting hoarding them years ago). I ended up with Mullard Cv4003 and Telefunken 12ax7 in the preamp section. Played around with some different EL34s, SED 6550Cs, but ended up with KT88s for power tubes. Plus I'm not going use NOS EL37s or 6L6s for this application. Definitely easy to swap out and try different stuff.
I stand corrected and PL confirms. Their service guy says no to substitution among the 12A*7 family as it would add distortion. Thanks for correcting that. Looks like purely 12AU7s for me.
I am suggesting, that if the OP does want more warmth, regardless of the output tubes, as you suggest, Mullard small signal tubes will provide more overall warmth either way. I did also comment, as to my system, that I prefer a nicer, more tube like sound of the KT88's to the more linear KT-120's that I have in the Cronus Magnum. My first modern venture into tubes was the purchase of a used pair of Rogue M-120, KT88 based monoblocks. As these had been in use for some years, I decided to use Rogue's upgrade program to bring it up to one of their new currently available power amps. They make a KT-120, higher powered version, the M-180 monoblocks, but I purposely elected to go with the KT88 based M-150 monoblocks, because I prefer the sound signature of the KT88 power tubes. Although the bass on the M-150's is tighter than the bass on the older M-120's that I had, I think I prefer the sound of the older M-120's than the newer and more linear M-150's. As I have not used the KT-120's in the Prologue Five, I reserve comment on them in the PrimaLuna. I do find that the KT-120's in the Cronus Magnum sound a lot like the KT88's in the M-150, when the M-150 is driven in the ultralinear mode. I do primarily operate the M-150's in the triode mode. Either way, Mullards as the small signal tubes are likely to help alleviate the any brittleness that the stock tubes may have. I think that ultimately, a choice of KT88's or KT-120's would depend more on the OP's selections of music and which might be a better match with the speakers he is using. With modern tubes, I would also strongly consider KT77's. Overall, I would recommend the NOS RFT EL34's, as they do provide a more magic midrange (as specially on vocals) than any of the other options and provide more of a true tube experience that more linear tubes like the KT-120's. My findings were that the NOS RFT's provide bass that is more like a modern KT88, than I have previously experienced with any EL34 power tube.
This is correct! I am not familiar with your amps and suggest that you do confirm this with Upscale Audio. The gain tubes (preamp tubes) are going to have the greatest audible effect on the overall tone, while the driver tubes will, to a lesser effect. Yes, while both tube types are pin compatible, the have different gain characteristics which are matched to the particular stage that they are driving. NEVER, substitute either of these tube in ANY amp!
Thank you for clearing this up. I've mistakenly made a sweeping statement, may I ask if you've compared both KT88 and EL34 in your Dialogue Premium? What about the EL34 did you prefer? I only ask as my experience with comparing both were quite different. In my Cayin integrated I tried rolling Genalex Gold Lion KT77 (EL34 substitute) vs the stock KT88 (Cayin branded) and the stock KT88's won hands down in my opinion that I ended up selling the Gold Lions.
@Lebowski My thoughts, as unpopular as they may be. Tubes are all fine and good but it's all about how the circuitry is implemented. Some tube amps will sound like solid-state while others will sound mushy and everywhere in between. There are different types of tube amps ; push/pull and SET. SET, one can argue, is the purest form of this and will likely yield the tube magic you're expecting out of tube amps. Personally, for the same price, I'd pull the trigger a 2nd time on my current gray market Line Magnetic 508IA. Sure, it's been replaced by the far more expensive 805IA but there are only a couple of differences which may or may not be of prime importance to you. I believe the 508IA to be in a superior bracket and considering its North-American price being about 2K more during its tenure, personally, I think it's a better buy. For that price, a true SET 300B-based tube amp which will, IMHO, inevitably perform terrifically. Great quality transformers are bulky heavy things and are greatly responsible for the sound you'll hear as well. For SETs, weight is at least an indicator of some sort as to the quality of those parts. While the PL weighs shy of 40 pounds, the 508IA weighs just under 89 pounds. As someone who's replaced a couple of output transformers from guitar amps, I can vouch for their heft and quality having the utmost impact on the sound. Not something sexy to spend money on but the end result spoke for itself. As for tubes, you could spend yourself into oblivion with NOS tubes that'll cost an arm and a leg but in the end, if the amp left you indifferent straight out of the box, again purely my opinion, it isn't quite likely to completely blow your mind with a tube change. Again, some will likely dispute that and state their amp sounded like a garbage fire prior to a miraculous tube change but even though I agree tubes make an enormous difference, in the end, the amp is what it is and there's a limit as to what tubes can do. For this reason, I'd suggest going for an amp you find a pleasure to listen to straight out of the box after which you can tweak via tube rolling and enjoy the big positive pushes toward nirvana. If this amp weren't tube-based, it would've been returned to the dealer pronto. From your posts, I gather you find it OK but nothing groundbreaking or even interesting when compared to your current amp. IMHO, the new amp should be able to dethrone your current one while using its stock tube configuration. I'd therefore suggest bringing your amp to a dealer or two and comparing it to tube amps in the price bracket you're willing to spend. Maybe you'll need to spend more to find something that'll sound fantastic. Maybe it's a question of synergy. Maybe you plain don't enjoy the PL sound. Who knows? Bottom line is I don't believe the solution is spending more to try to make an amp that's disappointed out of the box into something it likely won't ever be and instead would urge you to perform some comparisons if only to know generally the direction you should take to get something you'll enjoy.
My only experience is of hybrid tube amps from Pathos. I tried the Pathos Logos II, which is tube pre-amp and class A/B power I loved the way that made the music sound; really nice midrange and treble and you could just turn it up, definitely warmer than SS and the kind of character I was looking for. I was lucky enough to get a really amazing deal on a second hand Inpol 2, which again is tube pre-amp, but this time class A solid state power. Only 45watts, whereas the Logos II was 100w, but the Inpol 2 was just way more powerful. It had a bit more of a SS state sound than the Pathos II, but you can still hear the tubes. I was happy getting a second hand Pathos, and it's been fantastic. I might feel less confident if there were tubes on the power side. I imagine pre-amp tubes will last a lot longer than the power amp ones. Anyway, @Lebowski you must love the sound to begin with. Otherwise it could be an expensive mistake. I want to try some Mullards at some point, but I love the Pathos the way it is, so make sure you love whatever amp you get from the off.
Sure, the first 6 months I did a lot of tube rolling, I placed a few orders, and I also exchanged tubes with a friend with a similar amp. I didn´t know much about tubes, so I started a thread here so I could get some advices, some of the people that helped me, and gave great advices to this tube newbie are posting here as well. So, besides the stock chinese EL34´s, I´ve tried Tung Sol´s KT120, GL KT88´s and JJ KT88´s, from the KT88´s family, and these tubes from the EL34 family: GL KT77, 6CA7 EH, Tung Sol EL34b, and just plain EL34´s: Winged C, JJ, Mullards. Keep in mind I´m talking in all cases about reissues, only NOS tubes here are Winged C. I´ve settled down with Winged C´s for most of the time. I´m just talking about my system, and in my home, but I find EL34´s sound more natural, and more suitable for long sessions. From time to time, I put a quad of any of the bigger tubes, I like them at first cause it´s like having a different amp, and doesn´t sound bad at all, but after a few days I always come back to my Winged C´s EL34. Sometimes with the KT´s tubes I need to roll some small signal tubes to make sound more rounded, but small signal tubes is another story.
I have to agree with @Strat-Mangler about waiting to roll tubes until you are sure the piece is something you are happy with and plan to live with for a long time. Tube rolling is for fine tuning.
