[vo_obgyn]

I appreciate all of that, but my original question remains: when listening on headphones what is the source of the microphonic vibrations?

Hi Crgreen. My understanding is that the tubes themselves are the source of microphonic vibrations. Maybe some others can chime in?

 

[ABQ2]

This is great info Jason, very nice of you to provide it.

In case you have some kind of influence I'd like to share a need! Now that this market is growing, I really hope headphone amp designers will start to consider that not all their customers use these at a work desk sitting in and office chair. A lot of us have this type of amp installed in their living room and relax on a sofa a few feet away from the equipment. For this type of use, a remote control for volume adjustment is crucial and again a lot of us want a headphone amp that is similar in functions to an stereo integrated, not have to control the volume with the source/DAC.

Thanks a lot and please continue sharing future development, we love it!

I too listen right at the source, not at the computer. I have the Mullards and listen to vinyl with an MC cartridge with the Mac MP100 preamp and the the MHA200. Focal Utopia phones. After paying special attention to phono cable routing and connections I have very black background and fantastic sound. Volume control on the subject amp is a pain but well worth it for the result. I have vinyl from the sixties that sound brand new.

 

[vo_obgyn]

Mullards make the MHA200 a tad more aggressive. Assertive in dynamics

I just received my Mullard CV4024's. Agree with Jason - more aggressive dynamics by a tad. Sounds great though. Jason, or others, what other differences besides dynamics do you hear when you compare the Mullards to the stock JJ tubes?

 

[Yesthereisgasinthecar]

Hi Crgreen. My understanding is that the tubes themselves are the source of microphonic vibrations. Maybe some others can chime in?

Since you invited ; in this scenario, I would lean towards snake oil. At least, you'd need many double blind tests to remove the placebo effect and get a legitimate before and after consensus of sound quality improvement. Given that tube manufacturers and users of tubes, from an OEM standpoint, want to put their products in the best light possible, you would think that they would bring such dampers 'in house' to take advantage of their benefits if they did in fact exist. The fact that they remain aftermarket probably tells us all that we need to know.

 

[Crgreen]

Since you invited ; in this scenario, I would lean towards snake oil. At least, you'd need many double blind tests to remove the placebo effect and get a legitimate before and after consensus of sound quality improvement. Given that tube manufacturers and users of tubes, from an OEM standpoint, want to put their products in the best light possible, you would think that they would bring such dampers 'in house' to take advantage of their benefits if they did in fact exist. The fact that they remain aftermarket probably tells us all that we need to know.

Audio Research do provide dampers, two for each of the smaller tubes, with their products.

I suppose my point was that although tubes are known to be microphonic (something exploited by certain guitarists) my understanding was that the cause of the vibrations is external sound waves, such as from speakers (which won’t play a part in headphone listening) not the tubes themselves. I accept however, that some suggest nearby transformers can generate vibrations picked up by tubes.

 

[qboogie]

Regarding tube ruggedness (aka its ability to resist microphonics and vibrations), one might want to pay attention to whether the tubes are designated military spec (for example vacuum tubes used in aviation or in naval applications). Another sign of ruggedness is the use of triple mica spacers, being more stable than tubes with double mica. One will encounter these terms questing for decent vintage 12AT7 tubes for the MHA200

 

[valphil7780]

I purchased an Alpha-Core Goertz TQ2 cable to connect my BlueSound 2021 with the MHA200. Is it a good choice ? This allows me to connect it balanced from RCA (BlueSound) to double XLR (MHA200)

 

[Newsee]

I purchased an Alpha-Core Goertz TQ2 cable to connect my BlueSound 2021 with the MHA200. Is it a good choice ? This allows me to connect it balanced from RCA (BlueSound) to double XLR (MHA200)

Why would you make it complicated? From RCA go to RCA, from XLR go to XLR.
However, if you have invested already in a silver interconnect cable and you like it, just use it.

The MHA200 is internally single ended, so there must be something inside that transforms the XLR to SE before the amplification. I do not remember if it was particularly discussed here. Usually it is a small transformer. When it is implemented properly it shall not affect the sound too much.

 

[valphil7780]

Why would you make it complicated? From RCA go to RCA, from XLR go to XLR.
However, if you have invested already in a silver interconnect cable and you like it, just use it.

The MHA200 is internally single ended, so there must be something inside that transforms the XLR to SE before the amplification. I do not remember if it was particularly discussed here. Usually it is a small transformer. When it is implemented properly it shall not affect the sound too much.

I therefore committed a stupidity by buying cable ... I thought that it would make it possible to use the balanced inputs of the mha. the bluesound does not have an xlr output

 

[Deleeh]

You can easily use a cable from XLR to Rca - there is nothing wrong with that.
I did this on my Dac as it only has one RCA output and the XLR was free.

What I can't say is whether 4 volts then arrive at the Mcintosh instead of 2 volts.
At best, it is regulated down.

 

[valphil7780]

You can easily use a cable from XLR to Rca - there is nothing wrong with that.
I did this on my Dac as it only has one RCA output and the XLR was free.

What I can't say is whether 4 volts then arrive at the Mcintosh instead of 2 volts.
At best, it is regulated down.

thank you for the information. what equipment do you have to power the mha200?

 

[valphil7780]

thank you for the information. what equipment do you have to power the mha200?

thank you for the information. what equipment do you have to power the mha200?

Otherwise for the cable I had a 2 RCA / 2 RCA AudioQuest Big Sur but I preferred to change to the balanced Goertz

 

[ochre korg]

So now I have replaced the original 12AT7 tubes for Gold Lion Ecc81 tubes, and the first hour playing sounds great, only on the V3 position I notice on the top on the left side the “orange dot” or little light shines weakly, and on the right side no light at all, is this a bad thing? Does it matter? Or is this ok?

 

[Newsee]

So now I have replaced the original 12AT7 tubes for Gold Lion Ecc81 tubes, and the first hour playing sounds great, only on the V3 position I notice on the top on the left side the “orange dot” or little light shines weakly, and on the right side no light at all, is this a bad thing? Does it matter? Or is this ok?

A picture would help to decide what sort of orange dot you have. Red plating was discussed around here:
https://www.head-fi.org/threads/mcintosh-mha200-impressions.957625/post-16719317

Is it similar to the one on the tube on V4 position?

 

[ochre korg]

Hey hey Newsee it’s not red plating, I mean you see near the top of the tube the orange/red dot? It should lighten up when the tubes are on, but on v3 it’s almost unnoticable