Preamp Deal of the Century

The anode of the first 6SN7 triode stage is connected to the grid of the second stage in the Chenin. The output wires in the stock version are connected to anode II and cathode II.

I did not change any operating voltages in my Chenin. The only thing I did was move the two output wires from II to I, and plug in the adapter with the 7193s. From what you say, maybe varying the voltage might produce even better results, but my aim was to keep the Chenin as close to stock as possible, yet still able to run 7193 tubes.

Sorry, but I hesitate to pull the Chenin out of my system, open it up and take internal pictures at this point, since the only internal change is moving the two wires.

Okay thanks! So it means that the triode in the 6SN7's are Directly coupled and both seems to be voltage gain stages.

No, I was not asking for changing the OP of the Chenin. Apologies if somewhat my statement sounded like that. All I am saying is, the preamp now run the 7193's using the Chenins 6SN7 designed PSU. So, it is possible that the change in sound is from variation of the operating voltages typical for a 7193 like changing its PD (Power Dissipation) due to different bias levels from that optimized or selected by Mick for the 6SN7.

Apologies again, I am not asking for a pics of the internals, just the outer layout. I just want to see what tubes were use in your Chenin since as far as I know, there are three versions (not sure but two I am pretty sure) of the preamps phono section and can be distinguish by what tubes being use in conjunction with the 6922's.

Thanks!

regards,

Abe

Thanks Ait.

Yes, our Chenin are different from each other then. Mine uses 6C4's.

Great project you have there! That's a nice Tuner!

I do not use my Chenin anymore. In fact it is on the sideline now. Maybe when the mood is right, then I will have the urged to listen to it again. Yes, I like the Chenin but like you put it, my Chenin is "so last week" also. Just kidding, I love the preamp and I am very happy that I invested my money on it.

On my system page is the preamp I recently built. This is what I use nowadays. You can also see it on this link http://img177.imageshack.us/img177/1681/img4095gy6.jpgor http://members.myactv.net/~je2a3/friends.htm my system is at the very bottom of the page.

Have fun tweaking then!

regards,

Abe

National Union vs RCA vs Ken-Rad 7193 tubes.

Since I have converted my Chenin to 7193s, I have been evaluating the different brands of 7193s available (in addition to enjoying the great sound!). Let me say that they are all excellent tubes, but there are some subtle differences between them, both in sound and in construction. All have black, relatively flat plates, with small boxes in the center.

National Union: The NUs have the smallest bottle of the three 7193s, and the getter is not visible from the exterior of the tubes. They have a round top and bottom mica. These were the first 7193s I ever heard, and they sound very good indeed. These are silky smooth, with a rich midrange. They are a little rolled off on the extremes compared to the other two tubes, but it is a not a huge difference.

RCA: The RCAs have a larger bottle than the NUs, with a bottom getter and round top and bottom mica. They have more extended highs and lows than the NUs, with fuller bass and a little more detail on top. Not quite as smooth as the NUs, and not quite as warm in the midrange.

Ken-Rad: The biggest bottle of the three, slightly larger than the RCA, with bottom getter and non-round top and bottom mica (looks like a round mica with a section cut out in each quadrant). The best bass of the three - the impact of kick drums is sensational, and bass lines can be felt and heard in great detail. The highs are nice and airy, with very good detail, and the midrange is very sweet as well.

So overall, in my opinion, I would rank the 7193s as follows:

Ken-Rad: best overall - it has everything

National Union: smoothest and warmest sounding, but a little less top and bottom than the others

RCA: Similar to the Ken-Rad, but not quite as smooth in the highs.