Muzishare X7: Testing and Objective Review
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- เผยแพร่เมื่อ 12 ก.ย. 2024
- This video covers objective testing of the Muzishare X7 on both an analog scope and using the audio analyzer suite. The final video will be a subjective review comparing this KT88 push pull amp to the very similar Wilsenton R8.
Here is a link to the resistors I used: mou.sr/3MJDtVL
Here we go with another popular made in China KT88 Push Pull Vacuum Tube Amplifier. This one was sent in for repairs of the biasing/meter circuit and a full review + mods just like we did on the Wilsenton R8. So far I'm impressed with the quality of the build and we will do sound and measurement tests in future videos.
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You're the best Stephe! This was a great teaching video! You show how it all comes together. Nice work! 👍
Fantastic amp test video- I wish they were all this thorough. Great job!
I have no use for it, but I really want one of these tube amplifiers. They just look so amazing!
Great video. This amp looks good so far. I'm interested in what you think of the sound and the comparison.
Very well done review. Thanks. Looking very much forward to the comparison with the R8. Cheer. 👍
Great video, and such a detailed explanation! Hope to hear more on this X7 in terms of actual listening reviews and tube rolling recommendations. Tq!
Stay tuned!!
Good video. That's a nice amp, both measurements and design. It's a shame the VU meters are not calibrated to both UL and Triode mode, but I guess a little mod can fix that. Did you try to measure the output impedance? I think it would be interesting to see how well it deal with variations in speaker impedance in both UL and Triode mode.
I haven't tried that function yet and also need to play with the phono stage measuring stuff.
To get a better looking square wave on the scope at low frequencies set the scope to DC. On my Tektronix 2445A it makes a noticeable difference.
Your the best.
After living with mine for a year, I've begun trying some tube rolling. I put in a nos ge 12AX7 and a pair of matched rca 12AU7 in the preamp stage. I prefer them over the stock Muzishare tubes. I ordered a matched quad of Chinese Linlai K88-D tubes to see how they compare to the Muzishare ones which I presume are just rebranded Shuguangs. I've heard some good things about Linlai. Supposedly much as PSvane was started by former Shuguang engineers, Linlai is a spinoff from PSvane. Wish real Gold Lions weren't unobtainium.
I rolled in a EH 7025 in place of the 12AX7 and like it. Those RCA 12AU7 tubes do sound good too.
@@SkunkieDesignsElectronics I read your opinion on that 7025 tube and am going to try one of those out.
I love how this amp sounds driving my vintage Khorns.
Great video thank you! Try the JJ'S E83CC for the 12AX7, it's the best new production tube I've found for the X7 up to now, probably on the same lines as your EH I'd imagine 😊
I'll give one a try!
@@SkunkieDesignsElectronics I bought the 7025-EH you recommended and I am quite happy with it. My first tube roll. Was hard to pull out the 12ax7 tube out of the socket without damaging anything. It was really firm in the socket. So I sprayed deox spray on the pins of the 7025-EH to reduce friction before pushing it into the socket. I hope that is ok. To be honest it was difficult to compare in sound because I didnt listen to the 12ax7 before replacing it by the 7025-EH. I didn't want the amp to get hot before tube rolling. But my impression is that especially UL mode is sounding "cleaner" and more accurate now. Before I changed I never really listended to UL because Triode basically pleases me more. Greetings from Germany!
Great review 😀 that i can compare with my amp. My KT88 PP measured exactly the same as this one. What do you do recommend the volume level? I marked down the volume before clipping and keep the knob at that level. while using laptop to control the volume. Do you have any advice because at that volume level, the bias could run up/down on some of the recording songs from 0.05 to 0.10 from the setting. Do you recommend to switch between Ultra/Trio while the amp is On?
I don't see any issues switching from TR to UL with the amp on.
Love the video series, based on the x7 designs which tubes being changed out will impact the sound the more? 12ax7, 12au7 or kt88?
Honestly they all have an impact, I would say the KT88 have the least impact.
Stephe - what was the voltage rating for the unit you worked on? 110, 115, 120V? Or was it the 110/220V dual-voltage version? Any pros to having the regular one-voltage version versus the dual-voltage version? Thanks!
I believe it was a 120V. The dual voltage one will have extra wiring inside you don't need.
@@SkunkieDesignsElectronicsThank you so much!
Hi, thanks for another nice video on the X7, I now have the 10 ohm resistors to install as a precaution against tube volcanoes! You cemented that the VU meters are basically eye candy, so when I go to check the bias, would you rely on the meters to give an accurate reading or do you think it’s best to use an external meter or a DMM 🤔 any comments greatly appreciated and many thanks for all your interesting content.
They seem accurate for setting the bias, especially after installing the precision 10 ohm resistors.
@@SkunkieDesignsElectronics Thanks for replying to my question, the reason I asked is when I checked the bias, I used an external dual meter tester and set the bias to 40 ma, but then when using the built in meters they were reading only about 35ma! Anyway i carried out the resistor mod today and the readings were still at 40ma with the external meter! I will check what the internal meters show next time I use the amp! Many thanks, Alex.
KR Audio KT88s