Tube Rolling My Nighthawk MK3
I ordered the Nighthawk MK3 a few weeks back and have about 250 hour on it now. I’m not sure if it’s fully broken in, but it should be close and I’ve been anxious to roll a few tubes just to see if it can get any better. I ordered it with a few upgrade tubes; 1950s Brimar 13D9 in row 1, Philips JAN NOS 12AT7WC in row 2 and RCA Clear Top 12AU7 in row 3 and from the get-go it sounded spectacular to my old ears.
I’m not exactly a tube rolling novice as I’ve been rolling preamp tubes in a number of hybrid headphone amps for several years. I have a decent inventory of 12AT7 and 12AU7 and their equivalents and have picked up a few of Dave’s recommendations. Needless to say, I have enough to keep me busy and entertained for the next year or so.
Tube rolling is time consuming – it’s not like you slap in a new pair of tubes, give them a quick listen, then slap in another pair – it just doesn’t work that way, especially if we’re talking NOS tubes which maybe haven’t been lit up for 30-40 or more years. They need some burn-in time for them to settle down and show their real character. I personally like to have 50+ hours on them before I really start to judge how they sound.
Being a long-time retiree, I pretty much listen to and enjoy music all day every day – for me, tube rolling adds just another dimension to that enjoyment and it appeals to some and for others not so much. I know from experience, that quest for the perfect pair of tubes or combinations of pairs can quickly become a deep and dark rabbit hole that is difficult to find your way out of ….. but like they say, it’s the journey.
So, back to reality – at about 150 hours, I rolled in the following: 1950s Mullard 3 hole CV4024 in Row 1, Amperex NOS Red Globe ECC81 in row 2, and Raytheon Black Plate 12AU7s in row 3. After about 50 hours, I can’t honestly say it was better, what I can say is: it was different, a bit smoother and more liquid. I would attribute that to the Raytheons and maybe a bit goes to the Amperex. Out of curiosity, this morning, I reversed Row 1 and Row2 and put the Amperex Red Globes up front with the Mullards in row 2. Maybe Dave could explain it, but that made an immediate and marked change – primarily enhanced detail and separation.
I’m going to live with this for a little while and enjoy it before taking another roll in the Nighthawk.
As the Raven folks have already said; as long as you follow a few basic rules – NO 12AX7s and only 12AU7s in row 3 then the possibilities are endless and quite fun I may add.
Yep, it's not only about the tube pairs you choose - but what position/row you put them into and what other tubes you team that pair up with. This is also about your room, your speakers, your sources and system placement within any environment. We have several RavenHeads with the incredibly 50's era Brimar 6060 Yellow T's which are considered some of - if not THE very best 12AT7 tube on this planet. But they like them better in row 2 that row 1~! So this is a very common thing in the Raven Audio amp and preamp world.
The Brimar Yellow T's (or the Brimar black plate CV4024's, and Mullards etc.) teamed up with German tubes such as the Valvo, Seimens, and Telefunkens are the best matchups that I know if. I personally prefer the angled getter Telefunkens, or the Valvo and Seimens E81CC's with the Brimars because the German tubes are more dry and delineating and just a tad clinical compared to the nice warm, thick, and unusually bold British tube types. My preference is the Brimar black plates over most Mullards - but it depends upon your speakers. And there are some really great Mullards out there believe me. The Three-Hole Mullards are fabulous. I am not a great fan of the copper/charcoal plates but there are other people that LOVE those.
The Amperex on the other hand are kind of in-between the Mullard/Brimar and the German tube types. So if your speakers are really high end and well-designed, you will immediately be able to tell the difference in your system if you use the German/UK tube combo over regular street-level tubes. The difference between great old antique tubes is rather large IMO. With the currently available and manufactured tubes like JJ's, Electro-Harmonix, any Chinese or Russian tubes actually, there is not a single one of those tubes that can touch an authentic German or British tube from the 50's and 60's, OR most USA made tubes like the fabulous RCA, Philips, Raytheon and Sylvania black plates. NONE~!
The closest currently made tubes that can compare to these great antique ones is probably the Gold Lion gold pin B739 (ECC81/12AT7) and B749 (ECC82/12AU7). I DO NOT TRUST ANY CHINESE TUBES IN MY AMPLIFIERS... there, I said it. I don't give a rats ass is they are the bees knees according to anyone else... I will NEVER recommend the use of Chines tubes in a Raven Audio amplifier. It's like putting cheap gas into your fine Italian sportscar! I have just had too many go dead.
The quality control over in China is non-existent to bullsquat. They will never care enough about what is going to be shipped to the USA for me. Not for now anyway. I and many of my customers over the last decade have had literally DOZENS of expensive Chinese tubes either outright fail, blow-up, or test so poorly from the start that I will NEVER trust them. And for the money they charge you can usually get a great pair of wonderful antique NOS or slightly used old USA and European tubes. So why on earth anyone would ever want to buy a Chinese tube and put it into a really high quality American made amplifier is just beyond me. OK, sorry... but I just had to get that out there and off my chest.
The same goes for Chi-fi amplifiers~!!! Why in the heck would ANYONE EVER put a wonderful high quality antique tube into a cheap Chinese POS amplifier?!>?! I see this all the time too. On the tube roller groups I see literally dozens if not hundreds of guys buying these $200 Chinese POS amps off of Amazon or Ebay only to drop a beautiful Mullard or Brimar or RCA tube into it and waste that great old tube. You are never going to make that amp sound great. Even though they go on and on and on about how much better it sounds... yeah, and you don't know what a real amp sounds like... so PLEASE do not waste that great old glass on such crappy electronics. You might as well plug those tubes into a cow paddy or dog pile. Maybe it will make it smell better???
Now, back to the subject.
The 1950's era RCA black plate 12AT7, and 1940's especially, and even the 50's era Philips shiny plate 12AT7's and 12AU7's are all just friggin' wonderful. Raytheon, CBS, Sylvania, as long as they are black plates they are almost always wonderful tubes. I have them here in stock now. Just let me know and I will send you on a trip that you will thank me for, for the rest of your life~! It is important to know which tubes will be best when teamed up in rows 1 and 2 in your Raven Audio amps, so know that I am always available to talk about this.
Dave, I have a pair of GEC A2900s / CV6091s - would you put them in the Mulllard/Brimar class, or more like the Telefunken/Valvo tubes? I haven't tried them yet and not sure what I should pair them with.
The 1950's era "Yellow T" 6060 was Brimar's answer to the famed British GEC A2900. I personally like the Yellow T's but the A2900 is no slouch. These two tubes are the best ever made along with the Telefunken E801CCS rounding out the top three. Since you already have a Raven Audio amplifier it will depend upon your room and speakers which tube you will like better. The A2900 is warm yet lively and offers a highly delineated soundstage with nice tight bass and fabulous upper end extension. The latter is where the Brimar is better in my opinion, but both are so close that it is going to be about your own perceptions and interpretation of how they sound in your system and only you will be able to decide which one you may like better.
Teaming two British tubes together in my opinion is not always the best idea. However as I said previously it will be about how your speakers are able to interpret their character, and of course it will also be about the source and music chosen. If your speakers are a tad towards the sibilant, then these two tube types may indeed be able to work together to tame that problem. But that is the only time I would use British tubes in row 1 and 2 of your Raven Audio Avian Series amp.
If your speakers are highly accurate it is going to be better to use either the GEC A2900's or the Brimar 6060 Yellow T's teamed up with something German like Seimens, Telefunken or Valvo to clean up the soundstage. German tubes are always a little bit more towards the clinical side which makes them the perfect team for the warmer bolder British tubes.
In the same sense, using a pair of USA made Philips shiny black plates, or the rarer 90 degree wing plates with the Brimar or Mullards also works very well, because they too are somewhat clinical in comparison. They are a wonderfully clean and excellent all around world class tube that i would put into the top ten any day. The well-known and loved RCA black plates from the 50's and 60's are more on the warm side, similar to the Mullards and Brimars. So a Philips/RCA team is going to be similar to a Mullard/Valvo team... or a Brimar/Seimens team etc.
One thing for sure is... the GEC A2900's are absolutely among the top ten greatest 12AT7/ECC81 tube type. They may be in the top 5 - but that discussion is going to be more towards the opinion side than actual science. Once you hit the top 10 of any tube type you are in rare air and your speakers and system are going to take over. It's then all about how those "best in the world" tubes react within your system and room. I will say this... I have never had a single person dispute the opinion that the 1950's era Brimar 6060 Yellow T's are the best tube on this planet. Ever. This tube is just so darn good that coming second to it is still going to normally cost you $500 or more. And the Yellow T's are getting as rare as the A2900.
They are all going away and every year the prices will keep going up. Tubes like this are extremely valuable and collectible. Some people collect wine or art for the increasing value - but these types of tubes are going to always be in the same category. They were made over 60 years ago, and they are unduplicated since. What is now worth $500-$600 per pair will be worth a grand in another five years. I've seen it going this way for decades. I am glad I got in early.
And by the way..... if you do not absolutely love those GEC A2900's and want to round out YOUR collection, PLEASE give me the first chance at them. I only have one pair now and would love to own another just for the coolness factor and to round out my collection. You will probably be surprised and extremely happy at what you will be able to end up with - in trade for them~!
Thanks Dave, got it. I have a pair of Valvo 6201 pinched waist that I could pair with them and possibly a pair of the Philips shiny black plates. When I get my hands on a pair of the Yellow Ts, it will be fun to compare them.
As a comparison to your A2900 photos, mine are the military version and marked CV6091 and don't have the GEC stickers on them, but have the GEC markings.
Hi Dave have a question you have your favorite tubes to listen to.At some point are you going to sell tubes on your website that maybe we can buy some of your favorite tubes to listen to with are raven amps thanks chuck.
I remember you well Sir!
You need to go ahead and call or email me direct. What Raven amplifier do you currently own? I remember you had a Nighthawk MK2 once. What speakers? That way I can start to recommend which tubes to try out first. Because of the rarity of the tubes I collect, I ONLY sell to RavenHeads.
Thank Dave I sent a email with the information of my amp and speakers.