karma said:really nice work chris 😉
Thanks,
and I must thank BrianGT again..
Cheers
Chris
chris ma said:GC #2 is almost there.
Very nice work Chris 🙂
Where did you get the heatsinks ? I have seen Conrad's in another post but I just don't feel like paying that much money for heatsinks at this time. Your's look like something I'd be willing to live with 😉 if the price is right.
Fireman,
Those heatsink I bought from local chinese store on Queen St E. next to Active Surplus a couple years back for my very first diy project the JLH 1996. Because I made a mess of that one I disassembled it and never thought to use them again until the GC comes along. I paid around $10cdn each it measured 8" X 4.5" and not sure about the depth of the fins. There are rows and rows of TO-3 holes pre-drilled in the middle. If I see them again I'll pick up a few for you. How many do you need?
Back to the topic of the thread...
First time power up of GC#2 tonight, no hum, DC offset at binding post -109 and -98 mV not as good as GC#1 weighted in at -68 and -34 mV.
I am now looking forward to mmum buy/make a circle jig..I hate partsexpress...😡
Regards,
Chris
Those heatsink I bought from local chinese store on Queen St E. next to Active Surplus a couple years back for my very first diy project the JLH 1996. Because I made a mess of that one I disassembled it and never thought to use them again until the GC comes along. I paid around $10cdn each it measured 8" X 4.5" and not sure about the depth of the fins. There are rows and rows of TO-3 holes pre-drilled in the middle. If I see them again I'll pick up a few for you. How many do you need?
Back to the topic of the thread...
First time power up of GC#2 tonight, no hum, DC offset at binding post -109 and -98 mV not as good as GC#1 weighted in at -68 and -34 mV.
I am now looking forward to mmum buy/make a circle jig..I hate partsexpress...😡
Regards,
Chris
chris ma said:Fireman,
If I see them again I'll pick up a few for you. How many do you need?
That'd be so nice of you. I'd need two for now as I am awaiting my first GC kit.
chris ma said:
I am now looking forward to mmum buy/make a circle jig..I hate partsexpress...😡
I bought mine from Lee Valley. They actually sell the Model 400 Jasper Jig which will cut circles from 1" to 7-1/2" in diameter in /16 inch increments. They also sell a universal circle jig that is capable of cutting circles from 6" to 40". I have bought the first one six months ago and have since made 8 pairs of speaker enclosures with it. I absolutely love it.
I've been a client of Lee Valley for a number of years and have no complaints whatsoever about that store. The service is top notch and the products always of the highest quality.
If you need to cut larger holes but are afraid the universal jig might not work, Jasper sells quite a few jig models that might fit the bill for you.
HELP!!!
OK I wired up my power supply tonight. I turned on the power and everything seemed ok, no smoke, sparks or noise. So I decided to check the output per Brian's instruction V+ & PG+, PG-,& VG-. As soon as I touched the DMM probe to the PG + there was a small spark & the fuse blew. Could this mean I have my + &- switched? Or perhaps I'm not measuring properly. Unfortunately (or maybe fortunately) I can't find my spare fuses so I'll have to try again tomorrow. Any advice for this newbie would be welcome.
OK I wired up my power supply tonight. I turned on the power and everything seemed ok, no smoke, sparks or noise. So I decided to check the output per Brian's instruction V+ & PG+, PG-,& VG-. As soon as I touched the DMM probe to the PG + there was a small spark & the fuse blew. Could this mean I have my + &- switched? Or perhaps I'm not measuring properly. Unfortunately (or maybe fortunately) I can't find my spare fuses so I'll have to try again tomorrow. Any advice for this newbie would be welcome.
Re: HELP!!!
Are you sure you were measuring voltage, and not current or resistance?
kestrel200 said:As soon as I touched the DMM probe to the PG + there was a small spark & the fuse blew.
Are you sure you were measuring voltage, and not current or resistance?

DC offset
Does anybody worry about the 1452mV DC offset at speaker output when power off GCs?
Regards,
Chris
Does anybody worry about the 1452mV DC offset at speaker output when power off GCs?
Regards,
Chris
Don't you hear hum from your speakers? I got 30-40mV off set on one channel, and around 20-30mV on the other. I still hear hum even I am sitting 2 ft away.😕
GC hum at idle
The only connections made to the GC when the DC measurements taken were the power cords.
When connected to the system with input and output. I could only hear a very faint hiss with my ears three inches from the ribbon driver when the CD tray is open. And that hiss reduced much much further once the DVD players' laser pickup engaged like when the CD info is displayed and waiting for instruction. My listening position is around 12 to 15 feet away. My speakers are 10 feet apart. To me that's no hum to worry about.
Regards,
Chris
The only connections made to the GC when the DC measurements taken were the power cords.
When connected to the system with input and output. I could only hear a very faint hiss with my ears three inches from the ribbon driver when the CD tray is open. And that hiss reduced much much further once the DVD players' laser pickup engaged like when the CD info is displayed and waiting for instruction. My listening position is around 12 to 15 feet away. My speakers are 10 feet apart. To me that's no hum to worry about.
Regards,
Chris
For me, I think low DC offset will be better to your speakers. And I never see some skillly constructed GC got DC offset over 100mV. Maybe it is the way I test the output dc offset different from yours. I connect my laptop/MD/CD player straight to the input, and measure the binding post DC offset while it is connecting to the speakers. It is two bookshief speakers which sitting on the desk while I am doing homework. So I am really close to it. If the hum is not a problem, then it is fine. (I think)
Hi,
Both were set at 2000mV the next one(lowest) on the dials are 200mV. Sorry about the low resolution picture.
Regards,
Chris
Both were set at 2000mV the next one(lowest) on the dials are 200mV. Sorry about the low resolution picture.
Regards,
Chris
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