Hi Guys
MickM here- as you know I dont think manufacturers should actively participate in these forums as it is too hard to stay unbiased, and I believe the quality of the product should do all the talking from the manufacturers side.
However, the ongoing issue of noise and microphonics needs to be addressed as there seems to be a basic misunderstanding of it.
It's all related to the TOTAL gain of the preamp/power amp system.
All amplifiers, pre or power, have an inherant noise floor that in a compatible system is inaudible.
The Syrah or Chardonnay , with their gain switches set to max are very high gain preamps. Used with a low gain, or low sensitivity power amp the noise floor remains inaudible, but if you connect a high gain power amp, then the gain of the preamp and the gain of the power amp gets multiplied together and the inherant noise floor, which is hum, hiss and microphonics, also becomes amplified and becomes audible.
Bryan W has noted that his Cortese is very quiet without a sign of microphonics- this is simply because the Cortese has lower gain than a Syrah or Chardonnay with gain set to max.
But if you use the gain switches on the Syrah or Chardonnay, it is possible to adjust gain to approx the same level of the Cortese and eliminate noise and microphonics.
Unfortunately there are some power amps around these days which have ridiculous anounts of gain- they are designed to be used direct with a CD player (horrible sound!)and are more correctly called an integrated amp and aren't ideal for use with a preamp with any gain.
However, realizing that it's not a perfect world, I included the gain switches on the Syrah, Chardonnay to counter this.
With the combination of the two gain switches (top and back mounted) it is possible to remove any noise components from your system, and adjust the sonics to suit.
It does require a bit of patience, but it is possible to achieve your own "sweet spot" using the gain controls.
If you tap the side of the Syrah's 6SN7's with gain set to max, you will hear microphonics. Set the gain switches to "low" and a tap will result in no microphonics.
These refinements make the Syrah and the Chardonnay extremely versatile preamps able to drive any power amp, tube or SS.
Please note that the noise issue has nothing to do with impedance- that's more to do with the drive capabilities of the preamp, but all the Supratek pres have low output impedance and can drive anything.
I hope that makes it clearer - now I can disappear back to my work bench!
I have to say that I never thought this thread would last so long- unfortunately I dont have the time to check it often, but I'm alway's available at supra@supratek.biz to help when needed.
Thanks for all your support-I've made some great friends through Supratek and I hope your enjoyment and appreciation of the joy of music has been heightened by the use of my pres. Which is the sole reason for their existence- dont fret too much about hi-fi, just enjoy the music.
Best Regards to all.
MickM
PS
The tube compliment of the Syrah is 5842,6GK5,6N8P(6SN7),6L6GC and 5AR4.
The tube compliment of the Cortese is E180F (in this configuration just about the most linear tube available),E88CC(6922),6N8P(6SN7)6L6GC and 5AR4.
Regulator tubes can be either 6L6GC,5881,EL34 and KT66 on all models.(And the exotic WE350,7027- although too expensive to justify)
You can use any of these in the regulator position as it is self biasing, but not 6550 or KT88.
PPS- my favorite tweak is a new CD,vinyl.
