Wing
Head-Fier
- Joined
- Jun 22, 2001
- Posts
- 80
- Likes
- 10
Lately for the last 2 months or so, I've pretty much dropped off headwize and headfi. The reason for this is I have been spending time pursuing a profound audio revelation from a simple tweak I made to my MG Head. To put it simply, I have discovered true Single Ended Triode amplification without global negative feedback. All I did was remove the negative feedback by desoldering (and insulating) the green wires leading to the contact on circuit board with the label NF. I had noticed the negative feedback from the supplied circuit diagram in the owners manual and had reasoned that the musical signal which has been phase shifted through a cap and transformer, could not be fed back without somehow damaging the output. Time coherence is all screwed up, resulting in lost details.
The music I hear is now in another dimension altogether. People who have been raving about the MG Head ain't heard nothing yet. Details, imaging, palpability. The music is REAL. In fact, in a head to head comparison with KurtW's Microzotl, all I could do was laugh. Kurt himself admits that the Zotl sounded flat in comparison and the modified MG Head had more texture. This is no fault of the Zotls ZOTL innovation but it's push pull topology. Single ended will kick butt on PP in terms of imaging and detail most, if not all of the time. I have gone through my CD collection and now can't seem to stop listening to music once I start.
There is a advantages and drawbacks to removing NF. ALL is revealed, including the character of the tube used, the quality of the audiophile recordings you spent big bucks on, details in CDs you own you never knew about, as well as, the poorer quality of the $7 transformers in the MG Head. For one, the frequency extremes are rolled off (Kurt brought his really cool hi tech Neutrik audio measurement devices, which measures everyting except the most important measurement, real music). Subjectively, the rolloff does not detract too much from musical enjoyment. The biggest problem would be the noise created by the power transformer inducting some low level hum (not too audible) in the audio OPTs as well as amplifying any kind of ground loops in the power lines, for some reason in the left channel (quite annoying). Fixing the ground loop in the chassis itself helped quite a bit but did not remove the buzz. Gain went up by quite a bit, the low/hi impedance switch now makes a difference with my HD 600, with hi Z sounding louder and better. The stock tube sounds pretty good but is a little overbright and not as refined as the Mullard. It is also quiet, unlike my Sovtek 12ax7LPS which hissed and sounded brittle. Too bad I sold my Telefunken and other NOS or I would roll em again.
I have been researching tube audio esp. SET, hanging out at the Tube DIY forum at Audio Asylum, reading the Morgan Jones book, the Rosenblitz audio myths book and I have a long way to go. What I have heard has finally shown me why those craze SET tube heads are raving about (I guess I'm one now too). My next steps are replace the transformers with power torroids and name brand OPTs (Magnequest, Electra-Print etc). I will keep you guys updated and if I'm satisfied with what I got, show it in the next BA headwize/headfi meeting.
Try it for yourself and listen, especially if you own the HD 580 or 600, a Mullard CV4004 driver tube and an MG Head. You may also see the light and become a true believer. There, I have finally stopped procastinating on my report and said my peace. Let him who have good ears, hear.
PS. Just in case the improvements were hallucinations, I have another MG Head with another Mullard for baseline.
The music I hear is now in another dimension altogether. People who have been raving about the MG Head ain't heard nothing yet. Details, imaging, palpability. The music is REAL. In fact, in a head to head comparison with KurtW's Microzotl, all I could do was laugh. Kurt himself admits that the Zotl sounded flat in comparison and the modified MG Head had more texture. This is no fault of the Zotls ZOTL innovation but it's push pull topology. Single ended will kick butt on PP in terms of imaging and detail most, if not all of the time. I have gone through my CD collection and now can't seem to stop listening to music once I start.
There is a advantages and drawbacks to removing NF. ALL is revealed, including the character of the tube used, the quality of the audiophile recordings you spent big bucks on, details in CDs you own you never knew about, as well as, the poorer quality of the $7 transformers in the MG Head. For one, the frequency extremes are rolled off (Kurt brought his really cool hi tech Neutrik audio measurement devices, which measures everyting except the most important measurement, real music). Subjectively, the rolloff does not detract too much from musical enjoyment. The biggest problem would be the noise created by the power transformer inducting some low level hum (not too audible) in the audio OPTs as well as amplifying any kind of ground loops in the power lines, for some reason in the left channel (quite annoying). Fixing the ground loop in the chassis itself helped quite a bit but did not remove the buzz. Gain went up by quite a bit, the low/hi impedance switch now makes a difference with my HD 600, with hi Z sounding louder and better. The stock tube sounds pretty good but is a little overbright and not as refined as the Mullard. It is also quiet, unlike my Sovtek 12ax7LPS which hissed and sounded brittle. Too bad I sold my Telefunken and other NOS or I would roll em again.
I have been researching tube audio esp. SET, hanging out at the Tube DIY forum at Audio Asylum, reading the Morgan Jones book, the Rosenblitz audio myths book and I have a long way to go. What I have heard has finally shown me why those craze SET tube heads are raving about (I guess I'm one now too). My next steps are replace the transformers with power torroids and name brand OPTs (Magnequest, Electra-Print etc). I will keep you guys updated and if I'm satisfied with what I got, show it in the next BA headwize/headfi meeting.
Try it for yourself and listen, especially if you own the HD 580 or 600, a Mullard CV4004 driver tube and an MG Head. You may also see the light and become a true believer. There, I have finally stopped procastinating on my report and said my peace. Let him who have good ears, hear.
PS. Just in case the improvements were hallucinations, I have another MG Head with another Mullard for baseline.