Newf Posted November 21, 2024 Posted November 21, 2024 Hi all, I have an MP-701 Mark III on the way. I ordered it with stock tubes and caps with the intention to eventually upgrade them. Reading through the owners thread I did get a lot of ideas but I thought it might be easier for myself and others if there was a dedicated thread listing upgrades, and also maybe the reason why you chose them, to consult in the future. Thanks for any responses! Newf
Alfazeta Posted December 8, 2024 Posted December 8, 2024 I am thinking of trying the new Jupiter Bumblebee caps in this unit. Thomas and Stereo added it to his tube amp and he says it brought richness to the midrange and brings the singer forward with immersive soundstage. He however cautions it slows the presentation and bass woon’t be as clear.
Newf Posted December 12, 2024 Author Posted December 12, 2024 On 08/12/2024 at 5:10 PM, Alfazeta said: I am thinking of trying the new Jupiter Bumblebee caps in this unit. Thomas and Stereo added it to his tube amp and he says it brought richness to the midrange and brings the singer forward with immersive soundstage. He however cautions it slows the presentation and bass woon’t be as clear. I I haven't investigated cap upgrades yet. Post your thoughts if you get them. I now have 2 Electro-Harmonix 12AU7s installed along with a NOS RCA black plate in the buffer position. The sound is more refined with better mids and bass as vs stock. I just ordered 3 matched Psvane 6SN7-SE Tennis Ball Vacuum Tubes, 3 6SN7 to 12au7 adapters and a Psvane 5U4G rectifier to try out too.
landrew Posted December 14, 2024 Posted December 14, 2024 Hello, Am running: Two Linn Majik 4100 amps 7K5 Impedance Linn Akurate 212 4-way, Aktiv (hence two amps) CAPS: (2) VCAP 4.7UF caps (1) Duelund Capacitor 0.47uF 630Vdc CAST-PIO-Cu Pure Copper Foil Series TUBES: (3) Electro-Harmonix 6H30Pi (1) GZ34 5AR4 Siemens Rectifier Tube
Newf Posted January 19 Author Posted January 19 (edited) So here's what I have in place now... Caps 2 Mundorf Supreme silver gold oil 3.9 uF 1200 VDC Stock Bennic power filtering bypass Tubes Match trio Psvane 6SN7-SE Tennis Ball Psvane 5U4G rectifier The preamp is currently going into a set of Fosi V3 monoblocks which are powering Magnepan LRS+. Very happy with the sound now. The Fosi amps are surprising excellent sounding. I found they were missing something in the lower midrange/upper bass region but the mods listed above has solved those issues and also refined the sound while keeping detailed sparkling highs. Edit: In an earlier post I said that I ordered 6SN7 to 12au7 adapters, these are incorrect, 6SN7 to 6922 are needed. Edited January 19 by Newf
Rafael0510 Posted February 4 Posted February 4 Hi there, Why no one talk about 6SN7 rolling over MP-701 MK2-3? Thats is not a good ideia?
Newf Posted February 5 Author Posted February 5 Not sure why there isn't much talk about them in the other thread. There are quite a few manufactures of tube preamps that use 6SN7 tubes, from budget brands like Schitt (Freya) to higher end stuff like Cary (SLP 98), Modwright (LS-100), Atma-Sphere (MP-3), etc. This is my first time trying them and I'm impressed, I may look into getting some NOS versions later to roll in. 1
xlr8or Posted February 5 Posted February 5 (edited) The 6SN7 tube is a far more linear tube in its operating range when compared to other tube types such as the 12AU7/AT7/AX7, 6922, 6N1P, etc. The challenge is finding out what the preamp circuit has been designed and optimised for in terms of its plate voltage, plate current and grid voltage to ascertain which tube type should be used with it. Is Garry able to confirm this information? Rolling different tube types causes the operating points to change and shift resulting in different sound signatures. However, in most cases the tube type will not be working at its desired operating values. For example, for the circuit's given B+, the plate voltage may be fine but the plate current is half what it is meant to be. It's important to follow tube datasheets for proper and optimal operating conditions and use the curves in the datasheets to determine if plate current and grid voltage are set within the correct range for the given plate voltage coming from the tube. Edited February 5 by xlr8or 3
Alfazeta Posted February 5 Posted February 5 The same considerations would apply to 12SN7 tubes as well. 1
Rafael0510 Posted February 5 Posted February 5 3 minutes ago, xlr8or said: The 6SN7 tube is a far more linear tube in its operating range when compared to other tube types Regarding the MP-701 MK 3, what exactly does this mean? In your opinion, would it be a good option to use 6SN7's tubes in this type of circuit? I asked this question on a YT channel and someone vaguely replied that the sound would be "so bright"... I found it strange, with Lilai's I have difficulty controlling the bass in some songs
xlr8or Posted February 5 Posted February 5 1 hour ago, Rafael0510 said: Regarding the MP-701 MK 3, what exactly does this mean? In your opinion, would it be a good option to use 6SN7's tubes in this type of circuit? I asked this question on a YT channel and someone vaguely replied that the sound would be "so bright"... I found it strange, with Lilai's I have difficulty controlling the bass in some songs It would be best to check with Garry which single tube type the circuit has been optimally designed for. Do not mention any tube type in your comms. 3
Newf Posted February 5 Author Posted February 5 It will be interesting to see what he has to say. It ships with Russian 6H1N (6N1P) but lists all the following as alternatives... 6.3V signal tubes: 6N11, 6N1P, E88CC, E188CC, CCA, 6922, 6H23, 6H6, 6H30, 6CG7, (6SN7 with 6SN7 to 6922 adapter). 12.6V signal tubes: 12AU7, 12BH7, E80CC, (12SN7 with 6SN7 to 6922 adapter).
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