[meomap]

I’m not 100% sure but try Basil Audio

Tx.

 

[MRHiFiReviews]

@MRphotography What tubes are you rolling with this beauty? I can't imagine you're sticking with the stock tubes

I never stick with stock tubes!!! I always listen first, formulate impressions with the stock tubes, however like any good cook, I make the recipe a little different from the original to make the final dish my own flavor. Waiting on some amprex tubes now. If they give me what I am looking for, then I will roll the output tubes as well.

 

[qboogie]

I did a lot more tube research and have some new tubes coming in:

NOS Sylvania JHS-5751 (aka Military spec rebranded Gold brand) black plate, triple mica, square getter. Manufacture date 8/1957. Tube enthusiasts really seem to love this tube for its forward mids, clarity, and 3-dimensionality. Regarded as one of the holy grail 12AX7 tubes.

Sylvania Gold Brand 5751 gray plate, triple mica - these were manufactured later, are very similar to the black plate type variant but differ by having more lush, bloomy, but lifelike characteristics.

I really love sylvania gold brand because they seem to have pretty reliable construction and sound mid-forward which I like.
The triple mica configuration of the tubes seems to reduce microphonics and noise, compared to more common 2 mica tubed. This might have caused more noise to be picked up in both the stock tubes and the other pair of sylvania GB-6201 tubes I rolled and posted about earlier.

Also one of the my Sylvania GB-6201 tubes died after just 5 hrs of use. I will be selling the other tube if anyone is interested in buying. It is compatible with the 12AX7/12AT7/12AU7/5751 tube family. PM if interested

 

[NoTimeFor]

Just got Susvara. I think they work fine with the amp. I don't listen loud but with my set up I can go lot louder. The amp volume is at 1:10 o'clock with 100 ohm load. I started listening to these using the stock 4 pin XLR cable. My initial impression was it sounded little bright and bass was lacking. After 2 hours of listening, I changed the cable to stock 1/4 inch cable. BAM!! No longer brightness and bass became punch and deeper. Overall tone is just what I am looking for. I am not sure if the cables have different voicing or the MHA200 sounds different between 1/4 inch verse XLR tab.... Wow these cans are amazing. I feel like my head is out of the headphones and music is coming to my head from all different directions.

 

[JDragon]

Ether 2's impedance is 24, and Ether C Flow is approx 19. Both values are lower than the impedance ranges on the MHA200. You're saying they still sound great? That is reassuring.

I have DCA stealth (impedance is 23 ohms) coming in and am hoping this pairing is heaven and brings something that the TT2/M-scaler or Formula S/Powerman can't provide.

I have a Stealth/MHA200 combo that sounds fantastic. I don't hear any of the lack of slam/dynamics that others have complained about, which I'll chalk up to trying to power the Stealth with anemic amps. The Stealth sounds just as vibrant as my Utopia.

A bonus feature of the Stealth being so hard to power is that it feels like the MHA200's volume knob has a lot more usable area.

 

[makan]

In case anyone is looking for one, regretfully, I am selling mine.

 

[qboogie]

I'm getting a lot of RFI from my modem. I tried putting the tube cage back on, and loosely wrapping the tubes in aluminum foil. Neither method worked. I had to turn off my wifi router and put my phone on airplane mode, and that eliminated the noise.

How many hours are recommended for burn-in for both the MHA and NOS tubes in general to achieve more mature sound?

 

[TSAVJason]

I'm getting a lot of RFI from my modem. I tried putting the tube cage back on, and loosely wrapping the tubes in aluminum foil. Neither method worked. I had to turn off my wifi router and put my phone on airplane mode, and that eliminated the noise.

How many hours are recommended for burn-in for both the MHA and NOS tubes in general to achieve more mature sound?

The MHA200 requires no burn in but the NOS will probably require 100 or so hours

 

[Adamtl]

I'm getting a lot of RFI from my modem. I tried putting the tube cage back on, and loosely wrapping the tubes in aluminum foil. Neither method worked. I had to turn off my wifi router and put my phone on airplane mode, and that eliminated the noise.

How many hours are recommended for burn-in for both the MHA and NOS tubes in general to achieve more mature sound?

Mine was close to my modem and streamer and dac with no rfi issues whatsoever, I would suspect based on that, that you have a defective unit. Exchange it

Ps. If you use crappy rca’s it could maybe be the cause, try balanced or better rca’s before exchanging

 

[TSAVJason]

Mine was close to my modem and streamer and dac with no rfi issues whatsoever, I would suspect based on that, that you have a defective unit. Exchange it

I’d like to understand your “defective” conclusion. Please explain at your leisure

 

[Adamtl]

Mine was close to my modem and streamer and dac with no rfi issues whatsoever, I would suspect based on that, that you have a defective unit. Exchange it

I’d like to understand your “defective” conclusion. Please explain at your leisure

I’m not a tech but if he’s getting major rfi audible interference from a device that I can use beside my modem and other gear and cell phone without any then to me his unit is defective. I couldn’t really say specifically in what way but the mcintosh tech who opens it up will find out. I had a wa33 that was like that but they all were so it was no surprise and obviously not a defect. This is the only report of rfi noise so the likelihood is that his unit is defective

 

[qboogie]

I am using vintage tubes and microphonics may be an issue that the stock tubes don't have. I may try also cleaning the pins on these tubes.

I'll try the stock tubes tonight and see if I can troubleshoot a bit more. Turning off the wifi is easy enough though inconvenient

 

[Adamtl]

Oh ok, never tried nos tubes in this amp. I find new gold lions a perfect replacement for the stock tubes in all my mcintosh gear, makes everything sound so much better.

 

[rreynolds]

I am using vintage tubes and microphonics may be an issue that the stock tubes don't have. I may try also cleaning the pins on these tubes.

I'll try the stock tubes tonight and see if I can troubleshoot a bit more. Turning off the wifi is easy enough though inconvenient

Recently installed some NOS RCA tubes on my unit and haven't experienced any sort of noise. I do have all my equipment in a separate room from everything else, did have a friend who experienced RFI from a modem/router, but only when it was extremely close to the amplifier. How far away is your setup from other frequency emitting devices?

 

[qboogie]

About 6 feet.