The Mullard has been sitting in the Head for almost a year and a half now. It's been removed few times for rolling and such so who knows. In any case, it's good that I have a spare and that I plan to rebuild the Head with another even cheaper and good sounding tube set ( 6N1P, SV83 ) so these...

My expensive Mullard CV4004 (driver tube) just developed a crack and bit the dust today. Pulling out "Getting the most out of vacuum tubes" by Robert Tomer, I found out that the most probable cause for the crack are the tight tube sockets. The contacts on the tube pins are supposed to float...

Hello all, I've been away for quite some time but I had to come back to report something quite nice. The stock Valve Art (?) EL84s were OK but I felt it had had a touch of cold brightness/brittleness. Doing a little research I found a modern, inexpensive tube that is almost an equivalent to...

2 channel - The transformer was reoriented in the only way possible, by rotating it 180 degrees so that the output wire bundle is further away from the OPT. Any other kind of rotation will not allow it to be remounted on the original holes in the chassis. Sorry no pics. Like I mentioned in my...

I moved the power switch to the rear and that fixed the left channel buzz. The low level 60hz hum was fixed with power transformer reorientation. Harsh and grainy sound is probably the 12ax7. I fixed mine with the delicious Mullard CV4004. Haven't tried the better 5751s although I didn't like a...

I use the RadioShack digital cable and DH Labs BL1. One tweak you might want to try is to swap the output opamps with some nice Burr Brown OPA 2134 or 2604. You can hear a difference. The stock ones seems a little "brassy" to me.

Maybe this article and many others by the same author has some answers :> http://www.meta-gizmo.com/intro/ECSTACYBOOK.html

I just heated up the bad lead on the cap, pulled that side up and soldered it to the lead of the resistor it's supposed to be connected to. Sort of a point to point wiring. Worked for me. No board removal. The trick is to figure out which lead. Prodding and jumpering helps.

Snipping two wires inside the MG Head. Hehehe!

Kelly, You want some negative comments about the ZOTL? Here it it: My no NFB MG Head images better and has more details than the ZOTL. Thats just the way it is single ended vs push pull (generally speaking, for now). Yes, the MG Head is midrangey but what an amazing midrange. The ZOTL may...

Nick, you really should check out the Mullard CV4004 with transformer output. I tried the Some premium grade JAN 5751 from upscale and they seemed to roll of the upper midrange too much with OPTs.

I believe JMT also posted his impressions CMOY vs MG Head on the same MG Head tweak thread. I haven't heard the CMOY but I have compared the MG Head to the Corda, the Headroom Cosmic(?), and owned a TA. I'm not listening to opamp based headphone amplifiers anymore and I'm building more tube amps...

I've been gathering parts for my own SET amp and I was wondering if there was something in your calculations that precludes the use of a single 6h30 to drive the whole thing. The 6h30 seems like a pretty robust tube with high current capabilities and low plate impedance. I'm going to build mine...

This hum you are talking about is not the left channel buzz right? That's caused by the power lead to the on/off switch. The general low level hum on my MG Head seems to have gone away when I remounted the power transformer 180 degrees around so that the output wires were furthest away from the...

You guy don't hear how tranformer coupled with no NFB sounds more palpable, real and image better than in OTL mode? Try the Mullard CV4004 for something smooth and detailed.

I don't really know about the 8370 but I own the 8550 which seems to be quite similar. Although the HK is good value for money, the audio output is less than optimal. Use it as a transport with a decent DAC if you will. I use it with a tweaked XDAC and the difference is real. Ironically the...

Check out the Sound of Electronics and other articles at http://www.aloha-audio.com/library/index.html

I think Eric Barbour explains it well. http://www.spectrum.ieee.org/select/0898/tube.htm dustychalk - Life changing experience, uh, I can relate to that :>.

I would disagree with the statement that SS is more accurate, has more details or more bass. Thats some sweeping generalization. It really depends on how the circuit is implemented. I would almost say the opposite is true if I could. I prefer the modded MG Head over all the other SS amps I've...

I have confirmed Videoshielded's diagnosis of the MG Head left channel buzzing problem. The cultprits are indeed the leads to the power switch. The switch itself, I believe, is too close to pins of the left channel output tube (VB2). I don't know if using shielding cables will completely solve...

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...

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...

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...

Crossfeed? We don't need no stinkin crossfeed. All you need is a good SET amp. Hi Kurt :>. It seems some people find crossfeed beneficial. I, for one, don't seem to be affected by the lack of crossfeed. I own the TA and have used the Corda HA1. Must be an individuals psychoacoustic thing.

I would like to clarify that I did not discover the mod independently. Joseph Lau I believe had posted an article on how to mod the MG Head to OTL. Part of that mod was to remove the NFB. Nobody, as far as I know, nobody had posted anything on the boards regarding the results of trying out the...