aks07
Well-Known Member
- Joined
- Nov 4, 2008
- Messages
- 332
- Points
- 63
Cables;
I would use any reasonably quality shielded cable for all the positions you mention except for ground where I would use solid copper wire of about 22 gauge.
Safety
The schematic as displayed seem to represents the PCB wiring scheme. The 200V AC is post the power transformer.
Delay:
I would much rather has a power on delay for the main HT. Tubes are said to be happiest when the HT is applied after the heaters have been on for about 10 seconds. A tube rectifier has a built in delay feature whereas a solid state rectifier will present the full HT the moment power is applied.
However, if you are determined to add a delay then consider a scheme that normally shunts the output to the ground and opens it with a delay of about 5~10 seconds after power on restoring the out put to the amplifier. And no, shorting the output to ground wont normally damage your line stage. This way you avoid passing your precious audio throu a metallic relay contact.
I have seen this schematic earlier in vt4c forum where Chinese members reversed engineered the original GG design. However, I also have a schematic of the real thing (courtesy GeorgeO) and there are differences. I had built a proto and it cost me nothing as all parts were available, but a reasonable guesstimate will put it at about Rs. 1,000 using ok parts available in India.
The original has separate PSU for the + and HT rails. This clone doesnt have that and that is a big compromise. Do consider incorporating that at a later stage. Ultimately a shunt regulated PSU will improve things considerably. There are several good designs available if you Google.
The GG line stage is an excellent design and you shall not be disappointed. Happy building !
I would use any reasonably quality shielded cable for all the positions you mention except for ground where I would use solid copper wire of about 22 gauge.
Safety
The schematic as displayed seem to represents the PCB wiring scheme. The 200V AC is post the power transformer.
Delay:
I would much rather has a power on delay for the main HT. Tubes are said to be happiest when the HT is applied after the heaters have been on for about 10 seconds. A tube rectifier has a built in delay feature whereas a solid state rectifier will present the full HT the moment power is applied.
However, if you are determined to add a delay then consider a scheme that normally shunts the output to the ground and opens it with a delay of about 5~10 seconds after power on restoring the out put to the amplifier. And no, shorting the output to ground wont normally damage your line stage. This way you avoid passing your precious audio throu a metallic relay contact.
I have seen this schematic earlier in vt4c forum where Chinese members reversed engineered the original GG design. However, I also have a schematic of the real thing (courtesy GeorgeO) and there are differences. I had built a proto and it cost me nothing as all parts were available, but a reasonable guesstimate will put it at about Rs. 1,000 using ok parts available in India.
The original has separate PSU for the + and HT rails. This clone doesnt have that and that is a big compromise. Do consider incorporating that at a later stage. Ultimately a shunt regulated PSU will improve things considerably. There are several good designs available if you Google.
The GG line stage is an excellent design and you shall not be disappointed. Happy building !
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Are you in Bangalore? I would love it if you come over one day and check it out. I would not trust modding my GG (for PSU and output delay) with anybody else except you and George's friend (can't recall his name). 
