xlr8or Posted February 10 Posted February 10 1 hour ago, MichaelHiFi said: Got my rectifier tube today. As I'm plugging in the tube the plastic (phenolic?) base broke. I'm going to bed. Sorry to hear this. Are you able to share a photo?
MichaelHiFi Posted February 10 Posted February 10 I've probably inserted 1000 tubes in my lifetime. Never a failure until the last 2. Is this what getting older looks like? It's a bad look. Going back and critically looking at what I had done, it looks like the key was not lined up properly. And after a nights sleep, I think that the vacuum was not broken and the tube may still survive. I'll give it a try shortly, after all, what could possibly go wrong, go worng, go wrnog, go
MichaelHiFi Posted February 10 Posted February 10 (edited) I just realized that not having the notch for placement of the tube, I don't have the orientation. I have numbers on the tube base, but not on the socket. I don't think guessing would be a good idea either, but if I were to guess, the notch is at position 1. Edited February 10 by MichaelHiFi
Niekos Posted February 10 Posted February 10 It seems the socket is fine? Maybe this helps: https://www.thetubestore.com/guide-key-fix be careful, easy to make mistakes! 2
MichaelHiFi Posted February 10 Posted February 10 Thanks Niekos. I did enough searches that I felt confident enough to try. And now, music is playing. The tube lives on. B-Tribe 'Hablando' sounded well sorted. I'm also feeling break-in is needed for the 4 tubes. Feels like all the upgrades need to get to know one another. The amount of clarity achieved is solid state like. Vocals are lovely. Depth is peaking in. Of course this is only 15 minutes of music flowing through those tubes. 2
xlr8or Posted February 10 Posted February 10 (edited) It's easy to break the guide key on octal tubes. The best way to remove octal tubes is to wiggle them forwards and backwards only relative to the tube's guide key position in a repetitive motion. If you can't see the guide key position when the tube is inserted, which is often the case, go by the 2 screws holding the tube socket in place. If these screws are concealed wiggle the tube north and south relative to the tube's socket orientation. The guide key will snap off if the tube is rotated in a circular motion trying to remove it from its socket. Also, moving the tube left and right may also cause the guide key to snap off. The tube is fine to use if the guide key snaps off as the micanol base sits adhered to the outside of the tube's glass envelope. You can either mark the position of the guide key notch on the tube's base with a permanent marker to align it each time you reinsert it or you can purchase small thin guide key discs to fit over the pins. The issue with the latter solution is that the tube's height increases out of the tube socket for the given pin depth making the contact area smaller on insertion of the pins. https://www.ebay.com/itm/235758018624 Edited February 10 by xlr8or 2
MrBurns84 Posted February 11 Posted February 11 9 hours ago, xlr8or said: It's easy to break the guide key on octal tubes. The best way to remove octal tubes is to wiggle them forwards and backwards only relative to the tube's guide key position in a repetitive motion. If you can't see the guide key position when the tube is inserted, which is often the case, go by the 2 screws holding the tube socket in place. If these screws are concealed wiggle the tube north and south relative to the tube's socket orientation. The guide key will snap off if the tube is rotated in a circular motion trying to remove it from its socket. Also, moving the tube left and right may also cause the guide key to snap off. The tube is fine to use if the guide key snaps off as the micanol base sits adhered to the outside of the tube's glass envelope. You can either mark the position of the guide key notch on the tube's base with a permanent marker to align it each time you reinsert it or you can purchase small thin guide key discs to fit over the pins. The issue with the latter solution is that the tube's height increases out of the tube socket for the given pin depth making the contact area smaller on insertion of the pins. https://www.ebay.com/itm/235758018624 didnt realise they did a guide key for octals...thanks Kirk @xlr8or 1
MichaelHiFi Posted February 11 Posted February 11 17 hours ago, xlr8or said: It's easy to break the guide key on octal tubes. The best way to remove octal tubes is to wiggle them forwards and backwards only relative to the tube's guide key position in a repetitive vertical motion. If you can't see the guide key position when the tube is inserted, which is often the case, go by the 2 screws holding the tube socket in place. If these screws are concealed wiggle the tube north and south relative to the tube socket orientation. The guide key will snap off if the tube is rotated in a circular motion trying to remove it from its socket. Also, moving the tube left and right may also cause the guide key to snap off. The tube is fine to use if the guide key snaps off as the micanol base sits adhered to the outside of the tube's glass envelope. You can either mark the position of the guide key notch on the tube's base with a permanent marker to align it each time you reinsert it or you can purchase small thin guide key discs to fit over the pins. The issue with the latter solution is that the tube's height increases out of the tube socket for the given pin depth making the contact area smaller on insertion of the pins. https://www.ebay.com/itm/235758018624 Thanks for the tips. The tube is back in action. Aside from the numbers and notch on the tube socket, I also noted the plates and getter are aligned squarely to the chassis, so I might add the chassis cover which will block sight to the base. Don't know how that will work out. The top plate isn't necessary of course, but I would like to see if the Nordost Q-point has any affect on the MP701. After around 10 hours I pulled the 6922's and returned the stock tubes. The LinLai rectifier is a warm sounding tube in my system. Surprisingly, the LessLoss power cord also added a smoother, softer presentation, not entirely to my liking. I replaced that with a Hi-Diamond power cord which seemed more suited to where I wanted to go. I need to revisit the dip switches and their functionality. Yes they add or takeaway gain but it's not source dependent as far as I can tell. I needed gain for my phonostage, a MoFi Master running in current mode. The MP701 changed the character of the Aphelion 2 cartridge as well. I'm not getting the details that the Acoustic Invader brought to the table but what I am getting is warmth, liquidly smooth, that was so engrossing, that playing a track from the new David Gilmour Album 'Luck and Strange' the song 'Between Two Points' which features David's daughter Romany, I spun 3 times in succession. This song glues itself to your mind. I think I'll order the Tungram Haltron e80CC tubes today. Should I get a trio of them? 1
xlr8or Posted February 11 Posted February 11 If the default tube type supplied with the preamp is the 6N1P, which may in fact be the tube type that the circuit has been designed for, may I suggest you try to source the Melz factory version of this tube? It appears the 6N1P was made in at least 5 different factories in Russia. Melz production followed by Novosibirsk production are the best. Vokshod production are only good for the EV version of this tube. You may have heard the Melz factory is most famous for the metal base 6N8S and 6N9S octal tubes. Reference photo attached. 3
MichaelHiFi Posted February 11 Posted February 11 1 hour ago, xlr8or said: If the default tube type supplied with the preamp is the 6N1P, which may in fact be the tube type that the circuit has been designed for, may I suggest you try to source the Melz factory version of this tube? It appears the 6N1P was made in at least 5 different factories in Russia. Melz production followed by Novosibirsk production are the best. Vokshod production are only good for the EV version of this tube. You may have heard the Melz factory is most famous for the metal base 6N8S and 6N9S octal tubes. Reference photo attached. Along the same path, there are the Cryotone 6N1P tubes. I believe at least one forum member are using the Cryotones to great affect. Heard nothing but praise for these tubes. They are expensive however but so are many well regarded preamp tubes.
xlr8or Posted February 11 Posted February 11 3 hours ago, MichaelHiFi said: Along the same path, there are the Cryotone 6N1P tubes. I believe at least one forum member are using the Cryotones to great affect. Heard nothing but praise for these tubes. They are expensive however but so are many well regarded preamp tubes. Yes, agreed, preamp tubes have become very expensive. I've been collecting tubes for 20 years now. Some of my early acquisitions are now worth 100 times what I paid for them back in the early 00's. There are some hidden gems though that can still be found at good prices. Tubes that are yet to be fully utilised as suitable substitutes for the common types. Regarding cryogenic treatment of tubes this article is a very interesting read. I've played around with nitrogen freezing myself and found that the brittleness of the metal alloys amongst other materials used to build the internal structure of the tube increases significantly. Not good at all when heating up the preamp tube to 150-200°C and a large degree of thermal expansion is required. The shock action of freezing introduces distortion and crystal lattice defects restricting some mobility of the atomic structure within these metal alloys. https://www.effectrode.com/knowledge-base/cryogenic-treatment-of-tubes-an-engineers-perspective/ 2 1
Niekos Posted February 11 Posted February 11 47 minutes ago, xlr8or said: There are some hidden gems though that can still be found at good prices. Tubes that are yet to be fully utilised as suitable substitutes for the common types. Interesting! Care to share some of these gems?
Niekos Posted February 11 Posted February 11 On 09/02/2025 at 10:07 PM, Niekos said: Things on my list: Tubes 2x Linlai e-6sn7 (waiting for delivery); still not sure about buffer tube: does it matter? I ordered only two matched tubes, not the buffer. Does the third buffer matter for the sound?
MrBurns84 Posted February 11 Posted February 11 1 hour ago, Niekos said: I ordered only two matched tubes, not the buffer. Does the third buffer matter for the sound? Not so much for sound but needs a tube with balanced sections. its the one in that position that usually goes bad, and you'll be pulling hairs out if one of the triodes start getting microphonic, as its an intermittent problem and can effect 1 channel more than the other...at least in my experience. 1
Niekos Posted February 12 Posted February 12 Ok, good to know! I will use one of the tubes I already have
Klipscher Posted February 12 Posted February 12 On 9/2/2025 at 5:43 PM, MichaelHiFi said: Swiss digital fuse box. https://verafiaudiollc.com/products/swiss-digital-fuse-box I use the Swiss digital fuse box's and been super happy with them. I have one running the wells dragon tube amp. The other one is connected to the MP 701 and the Ares ii dac. They sound much better than the purple fuse they replaced.
MichaelHiFi Posted February 12 Posted February 12 20 hours ago, Niekos said: I ordered only two matched tubes, not the buffer. Does the third buffer matter for the sound? So many tubes, so little money. Now I'm on to those LinLai 6sN7's. Plan was to get the Linlai E274 rectifier sometime after taxes Thanks for the tip Niekos. 1
MichaelHiFi Posted February 12 Posted February 12 1 hour ago, Klipscher said: I use the Swiss digital fuse box's and been super happy with them. I have one running the wells dragon tube amp. The other one is connected to the MP 701 and the Ares ii dac. They sound much better than the purple fuse they replaced. The MP701 MK 3 has 2 fuse locations. How does that work with the Swiss digital fuse box?
Niekos Posted February 12 Posted February 12 If I understand the working of this device correctly it is used only for the first fuse, before power section with the transformer. They use a metal rod (copper, brass, etc) instead of the fuse and put the device in the powercord like a chain. These is a video explaining the installation when you follow the link. Probably a better explanation than mine
Niekos Posted February 12 Posted February 12 (edited) 13 hours ago, MichaelHiFi said: So many tubes, so little money. Now I'm on to those LinLai 6sN7's. Plan was to get the Linlai E274 rectifier sometime after taxes Thanks for the tip Niekos. you’re welcome mine have arrived in my country, very curious what these will bring. Next I will order the bypass caps I think. Improving it step by step, while enjoying the music. Great device! Edited February 13 by Niekos Typo
Niekos Posted February 13 Posted February 13 Yes!!! They arrived And now it is time to enjoy the noble life Also replaced the bennic capacitor with OHVL 8,2 uF. First impression (fresh out of the box): smooth, nicely layered sound, holographic, not a lot of top end? Clear upgrade already! And I think they look very cool as well 2
Niekos Posted February 13 Posted February 13 These are really fresh tubes! Or at least matching was done only 6 days ago. Amazing!
MichaelHiFi Posted February 16 Posted February 16 (edited) I don't know what I'm more excited about. The tubes or the picture you took of the tubes. Outstanding. Glorious. I have to know their break-in journey. You must be living a "noble life" Thanks for sharing and congratulations. Edited February 16 by MichaelHiFi nobile life 1
Yoram Diamand Posted February 19 Posted February 19 (edited) Hi, I bought the 20H choke to upgrade the MP701 mk 2. Even though I think I found the right Audio Note CHOKE-180, 20H 50mA on the net but it being 80 euro all in, I’ll wait. In a silly mood I ordered a WBA class A Blazebird tube preamp to compare my 2 ‘budget’ tube preamps. When I decide to keep the MP 701, I thought to buy the Audio Note choke and the Shuguang WE274B PLUS and 3 Shuguang WE6SN7 PLUS tubes to compare with the Linlai Elite. Since I have understood some prefer them to the Linlai Elite. I’d like to hear. Kind regards Yoram Edited February 19 by Yoram Diamand
Yoram Diamand Posted February 19 Posted February 19 Today, I exchanged the Chinese chokes. The 20H sounds good, perhaps better too. Maybe a bit autosuggestion. I do have a tip in case you update yours: The screws drop down, so you should prevent that. With some tape or something alike. I had to buy a magneto to fish for the screws. IMG 4630 are the 2 dropped screws. IMG 4634 is my magneto 3
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