[JMT]

I performed the mod on my MG Head a couple of days ago. First, I agree with everyone here. What an improvement with my HD600s. I just got some AKG 501s and I am anxious to try them with the modded Head.

I am not getting any buzzing sound, however I have always had a very quiet "hum" out of both channels. The mod doesn't make it any better or worse, and it is hardly noticeable when there is music playing.

For what it's worth: Sylvania Gold Brand 5751, NOS Ei (Yugo) EL484 tubes

Thanks Wing for sharing this simple, yet effective mod.

 

[darkclouds]

I've also performed the mod and believe that it's a definite improvement.

I do however have a problem with my left channel (unrelated to the mod). Every-so-often, I get static in the left channel and it would cut out. But if I turn the power switch off and back on quickly, this would fix the problem... temporarily. Any idea of what's the problem is would be appreciated.

Thanks

 

[joelongwood]

Sorry darkclouds, I can't help you on that one., but I've still got that damned BZZZZZZ. We need a resident electronics expert around here.

I'm hoping they'll read our posts and miraculously solve our problems.
OK...after further research into the buzzing matter, I think I've discovered something, but I have no idea what it means. With the amp upside down and the bottom plate removed, and my CD3000s plugged in, the hum is present UNTIL I put my fingers near the two red wires leading from the front switch. As I approach the wires (very carefully I might add), the buzz lessens and then disappears entirely when I touch the wires (either one or both, it doesn't seem to matter.) As soon as I let go and pull away, the buzz reappears. Also, if I pull the rectangular switch housing out of the front of the chassis, the buzz gets much louder. The buzz at times is centered in my head, at other times it's only in the left channel. I'm assuming that my body is acting as a ground somehow and that is what is reducing the buzz. Touching the wires leads to total silence. I removed the ground from the rear and scraped some more paint off the chassis to make sure there was a good connection. No improvement. If anyone has any ideas how to permanently remove this buzz it would be greatly appreciated. I really don't want to have to stand there with my fingers on the wires while I'm listening to music...........but if I have to......

Any help is appreciated. I'm going to post this in the DIY section as well......I think the electronics guys are in there.

 

[Wing]

I think your on to something joe. It does seem that it might be possible to somehow reduce the buzz with some grounding/shielding scheme. The low hum that JMT noticed will always be there because the power transformer is inducting it onto the output side if the output transformer. How do I know this? I hear it with all the tubes out of the sockets. Looking at the schematics at this arrangement makes that the most likely conclusion. I have to work late nowadays but if I get some free time this weekend, I will replace the transformers and report the results.

I've also noticed that dimmer circuits causes noise in the MG Head. Maybe it's our neighbours that are causing the MG Head to buzz :>. Like I said, the modified MG Head is a good way to test your power conditioning solutions. Does anybody have a balanced power or an AC regenerator setup that they can share their results with? I know for a fact that the Monster Power HTS2000 doesn't do squat for this problem.

 

[Wing]

darkclouds, try the usual clean the tube socket, wiggle the tubes, swap output tubes. It sounds like you may have a dry solder joint that shows up when the circuit is hot. One of my coupling caps (the PPFMX? MultiCap) had a bad joint that I had to resolder. You might have a similar problem. If all else fails, you can always send it back for waranty repair/replacement.

So JMT, how does the modded MG Head compare to those transistor opamp based amps? (Hehe!) I know the MG Head loses out on the bandwidth due to the OPT limitations and in noise performance (both which can be fixed). What about the music? Which do you enjoy more? Which is more palpable and real? Tell us the truth :>.

 

[chych]

You know whats funny? My MG Head does not hum and it is in a dimmer controlled lighting area, which is on the same circuit. The outlet also says it has some line fault according to my surge protector... And when I plug it to an outlet that supposedly is fine, the MG Head buzzes...

 

[neilb]

Hi all. I also did the mod and really enjoy the improvement. I'm getting no buzz but after a while I did experience some static type noise. I had some other el84s in one of my guitar amps and swapped them into the Head and the static went away and the unit is still very low noise. I think this modification is wonderful but believe it reveals any and every possible imperfection that may occur in your system.

 

[JMT]

Funny thing, last night I began listening to my new MG Head with my 600s and that hum did turn into a buzz. It isn't affected by the volume pot, but it is definitely there. When I plugged in my new AKG 501s the buzz became less apparent, but there nonetheless.

 

[darkclouds]

I was looing into getting a complete set of NOS and the Monster
HTS2000.
Wing, would the Monster HTS2000 be a complete waste of money then?

Thanks

 

[fredpb]

Before anyone spends big bucks on AC line conditioners or monster "Monster" products.... Check out:

Brickwall brand filters/surpressors website

The website will speak for itself. I am very happy with my unit.
NO clicks, pops, buzzes, etc, come through that filter.

 

[JMT]

Quote:

Originally posted by Wing So JMT, how does the modded MG Head compare to those transistor opamp based amps? (Hehe!) I know the MG Head loses out on the bandwidth due to the OPT limitations and in noise performance (both which can be fixed). What about the music? Which do you enjoy more? Which is more palpable and real? Tell us the truth :>.

For me, it really depends on what TYPE of music, and what headphones I am going to use. The MG Head simply sounds "richer" to me than the Creek or my Cmoys. The sound has much more "body" to it. With classical music and soundtracks the HD600s and the Head are just beautiful. I just aquired a pair of 501s from joelongwood, and have not had an opportunity to do any critical listening with the Head and them. I still like the Creek and my Cmoys/CHA 47s with the Grados and the Etys for jazz and the light rock that I listen to. Like joelongwood, I do not care at all for the Grado/MG Head combo.

But to answer your questions about palpability and reality......it depends.

 

[Wing]

darkclouds, I can't tell you if the Monster HTS 2000 is a waste of your money but I can help "save" some if you were going to buy one anyway, by selling mine to you for half what it would cost you new. Howzabout it?

Thanks for your comments JMT.

Well people, this is a good time to put those power conditioning solutions to the MG Head test. Personally, I would prefer to tinker with the MG Head so that it is more immune to line noise but that's probably not everyones cup of tea.

 

[Nick Dangerous]

I agree with the following equation:

Grado + MG Head = Blech

This was my least liked combination at the Dallas Head-fi gathering. Ewwwww.

(HD580's with it, though, were just as wonderful as the Melos SHA-1... thanks to General Telefunken and Lieutenant Amperex)

 

[Videoshielded]

I didn't have much of a buzzing problem with the stock MG Head (one I resoldered the tube sockets, that is).

However, as I upgraded the unit with modifications, and the noise floor dropped, the left-channel buzz some of you refer to became apparent.

The feeds to the power switch, which carry household AC current in an unshielded package, are the culprit. I posted the fix in the DIY forum in joe's thread. It's not a tough job. Shielding them does the trick. I don't call myself "Videoshielded" for nothing!

 

[chych]

Well there is ASL QA for you... My leads to the switch already happen to be a twisted pair, guess I got lucky or something.