Preamp Deal of the Century

John-
The imaging issues you are experiencing have not been a problem in my room. I have also not spent any serious effort tube rolling, save for the swapping of the 6SN7s for a pair of RCA grey glass VT231s which I really liked. Like you, I have been interested in doing something about the stock 5AR4 rectifier by going with a GZ34 - but not for that kind of money. I figure Mick knows what he is doing when he ships the tubes it comes with, so I have just been enjoying it.

Re: the imaging: have you experimented with speaker toe in/out since putting the Supratek in your rig? At 9.5 ft apart and 10 feet away, you may have some wiggle room there to account for the overall presentation of the soundstage as reproduced by the Supratek.

Hi, Slipknot1. Thanks much for your insights!

My speaker placement has been stable throughout all of my equipment upgrades to this point, not by neglect or stubbornness, but because there hasn't been any need to change. Leads me to think that the decreased imaging/focus has something to do with the Chenin with its stock tubes.

I will probably give a try to adjusting speaker placement if no other logical options present themselves, but from my previous experience with the sonic effects of changing tubes, it just seemed to me that tubes might be the starting point.

Make no mistake...I am totally thrilled with the dramatic improvement in sonic performance of the Supratek Chenin! Like most, I'm just hoping to 'get it all.'

Hoping for others with helpful experience to chime in!

Two other questions ('cause I'm not an electrical engineer):

1. I know the 6922 is part of the phono stage. Is that just the only one pair? Put another way, which are in the line stage?

2. Just what does the rectifier tube do to the rest of the system sonically??

Best regards, John

Hi John,

Check your manual! It outlines the tube for the phono section. My Chenin have the 6922 and 6C4 tubes for the phono.

The linestage tubes are the 6SN7's (or liestage output tubes). The 5881/6L6 are the regulators. The 5AR4 is the rectifier.

The way I understand it, what the 5AR4 does is to convert the AC voltage (from the wall) to DC voltage to provide the rail voltages needed (B+, B-) by the preamp base on the design criterion. The regulators as the name implies regulates the voltage level so that any sag of the rectified voltage will not produce a ripple on the DC voltage affecting the performance (bias etc. ) of the tubes.

regards

Ikkyu, See my post dated 31-May-06 & Amadarae post dtd. 14-May-06. For very little money you can have a significant improvement with the Sovetek KT66 tubes. These are the same tubes Mike sent as stock for the Six Moons review.

Thanks Amandarae and Dilly. I will look into the Sovtek KT66. At under $50 bucks there's not much risk.

Best, John