My Grounded Grid Preamp Project

jjaudio

Ground Grid Preamp DIY Kit

OVERVIEW
Grounded Grid tube preamplifier DIY module, simply called as CG preamp, circuit designed by famous tube amp designer: Bruce Rozenblit from Transcendent Sound. Bruce has profound power in design tube amplifier, and good at creating special and unique sound effect. His design is received good comments from US media.

Grounded Grid preamp will not make any artifacts to the sound, and play 100% originally and naturally

For many years, Grounded Grid tube preamp has been tested and verified by many worldwide DIYers. This DIY kit adopts the same amplifying stage which is invented by Bruce Rozenblit. The simplicity of this circuit enables the beauty of circuit symmetricity, and also simplify its power supply circuitry. This kit can be supplied only by using one main transformer (toroid main power transformer T30)

The high voltage supply for the tube preamp is come from the secondary coil (200VAC) of T30. This kit corporates with the RC filter to reduce undesired power supply ripple.

The static current consumption of GG tube preamp (2 channels) consumes approximately 8mA, taking the power consumption of ZENER rectifier part into account, the total current consumption is just about 13mA. The power supply of the filament is come from the secondary coil (12.6VAC ) of T30, with the low voltage dropout of the LT1085CT and relative large surface area of the heat sink, the temperature of the heat sink almost remain the same and it is very stable.

The signal grounding of this small signal preamp is very crital to the overall perfomance, better signal grounding can reduce the noise distortion or addition to the original weak audio signal. In practical experience, either using the method suggested by Bruce Rozenblit: The bypassing the GND of RCA input with a 10ohm (0.5W) or the GND of filtering capacitor via copper strip to the metal chasis, it can greatly reduce the surrounding noise interference. There is no much different of the two methods.

A GND hole for copper strip is designed for this purpose. Just using a copper strip to connect this hole to metal chasis, good shielding and low noise will be resulted.

ben62670

Very nice ad. How much are you selling them for.

ben62670

http://www.analogmetric.com/store/index.php
You should really post shipping prices on your website. Pitching sales like this is really frowned apon.
Thanks for the eye candy
Ben

fredv

Dear Fellow Polkies,

This is Bruce Rozenbilt of Transcendant Sound's design. Ben, take a look at this schematic and the one in Audio Reality, then you know what I am talking about. Webmaster, please remove this post, and it possible, remove this member from this community. The only purpose of the first post is to spam us with a stolen design, not some one that we need here!!!!

Edit: for those are interested buying the ground grid, buy from Bruce!!!!

ben62670

You see his sight it is all stolen designs.

fredv

Hey, I have a genuine factory built GG from Bruce and a scratch build of my own. I know this design pretty well :-) These are one of those pirate kits sold from the far east where Bruce simply doesn't have the big $$$$$ to go after on the legal ground, sigh.

fredv

Lasareath wrote: »

Fred,

while you are at this page: http://www.transcendentsound.com/preampkit.htm

the "preamp kit" link on the left does not work.

Las

Hee hee, I suppose Bruce isn't too savvy in web page He should use frame instead of multiple look alike html pages. There is a typo that has an extra space (%20) in the url.

zingo

He even calls it the same name as the one he is stealing the design of! What a thief and get this joker out of here.

ben62670

I reported this thread. I guess ~J~ won't listen to me:(

zingo

Lasareath wrote: »

Is he cheaper?

Of course, or else China wouldn't be in business!

zingo

The real Grounded Grid preamp kit sells for $499. (Which is a steal if you ask me)

The Chinese version sells for $343.

jjaudio

Sorry..not Chinese version. It is Hong Kong version! Excellent components used.
WIMA, Nichicon cap, dale resistors.

I bought for $158.0 only one month ago from the following link:

http://www.analogmetric.com/store/goods.php?id=393

engtaz

AnalogMetric Complete Kit ref Grounded Grid Tube Preamp (Basic version) (2 channels)
Subtotal $158.04
$32.00 Air Parcel Need about 5-10 business days $1 insurance
191.04 total

other shipping is:
$43.00 EMS Need about 3-5 business days, Insurance is optional
$20.00 Surface Parcel Need about 30-45 business days No support insurance

FYI

engtaz