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GROUNDED GRID #1

This is the project of a lifetime. I promised looooong time ago to build this amplifier for a guy here in Sweden, but I have so far just come half-way and I am "sort of stuck there", even though the rest to be done is made in a "pig's blink of the eye".

My most sincere excuses to A, who ordered the amp for not having gotten the amp, nor me together to finish it up. This IS a spectacular project and I'd be most happy myself that I cannot get 'my ass out of the cart' or the 'thumb out of my ass' (local Swedish expressions).

A, who wanted me to build this thing had some requirements that at first seemd difficult to fulfil, but there were some ready-made modules to include in the design:

Amplifier based on Bruce Rozenblit's GroundedGrid-amp.
Remote control of valume (and source)
Compact design
Certain nice cosmetic features like thicker frontplate, visable tubes and illuminated by a spooky blue light and the same spooky blue ight to indicate used input.<7P>

The main problem was the remote control, but I found a module at DIYclub.biz in HK. This kind of module can be found almost anywhere. It contains a motorized potentiometer and six relays to control the inputs. All microprocessorized.

The chassis was another history. A such a small design may cause serious problems. Heat is one factor to take in consideration and keeping live wires apart from smallsignal wires another.
After checking some of my own smaller chassis I finally went for a smallish thing from Italian company HiFi2000. It's one of the Slimline cases. Really well worth the low price. A made a thicker (10mm) front plate and rounded the knob intented for the chassis.

I ordered a special transformer, but when I was almost through wiring the stuff up I change my plans and got me a smaller, toroid, tranny. Both came from Frag Jan Zuerst.

So what's left to do ... well, almost everything. I made a new subchassis for the tubes that also will hold the potentiometer That is a small work. I am not very happy with how the PSU is mounted, so I will make a new alu subchassis for the amp, the motorpotentiometer and the PSU. Hopefull this work will start within days.

SCHEMATICS

This is the basic principle of this amplifier..

 

PHOTOS

 

LINKS

DIYclub.biz

HiFi2000

Frag Jan Zuerst

Audio Reality on Amazon

Audio Reality from Transcendent Audio