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Old 27th May 2007, 09:12 AM   #11
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Default and another one

Heres another. The phono section is to the top. the fist uppermost socket is the 6sl7 with the lower of the 2 the 6sn7
Further below that is the 6sn7 in srpp topology.
This is my second amp ever, so please excuse any mortal sins i may have committed The power supply is a variation on the following.. I supply a link so as not to infringe copywrite issues. With all credit to the original authors for the work.
http://eshop.diyclub.biz/article_info.php?articles_id=3
Thanks
Nick
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Old 27th May 2007, 11:16 AM   #12
SY is offline SY  United States
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Top view?

IIRC, this is the schematic:

http://www.hagtech.com/images/cornet2schem.gif

Is that correct?

And the red and white wires that are bundled together, are those power distribution? Where are the input signal leads for the phono?
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Old 27th May 2007, 02:29 PM   #13
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Default Wires

Hi
Yes the schematic is the one you have listed.
The red and white wires are input signals. the selector switch is inbetween the middle valves.
Power distribution is either side.. in the larger picture you will see red and grey wires coming form the back panel.
I have given you a top shot
Thanks for your help
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Old 27th May 2007, 02:30 PM   #14
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Default And the PSU

heres the psu
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Old 27th May 2007, 02:31 PM   #15
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Default I could have cleaned the dust off them

They were clean 2 days ago!!
Heres both together
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Old 27th May 2007, 02:34 PM   #16
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Default input into phono

You can see a short white wire near the 47k resistor on the right side of the close up photo --- to the left of the bundle of red/grey wires in top right corner of photo
Thanks
Nick
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Old 27th May 2007, 05:36 PM   #17
dvisves is offline dvisves  United States
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Hai duderduderini

With such a lot of wiring it is really impossible to control feedback and hum.You are much better getting a pc board made.I can help if you send me the schematic and design a simple pc board
DeeVee
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Old 28th May 2007, 04:23 AM   #18
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Default Thanks

Hi.
I really appreciate that very kind offer. I would consider it but that would be contingent to Jim (the owner of the circuit being cool with it).
I am thinking maybee i can reduce it by trying a few things and failing that maybee some form of noise cancelling circuit, the likes of which i have seen on tubecad.com.
So I will take a raincheck on your very generous offer but if i cant reduce the hum and more importantly Jim Hagermann says its ok then I will contact you
Thanks
Nick
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Old 28th May 2007, 04:39 AM   #19
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Default To Sy its the comet or cornet OCTAL not the image you posted

HI
I just realised its not the schematic you posted.. its the OCTAL version
Nick
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Old 28th May 2007, 03:26 PM   #20
SY is offline SY  United States
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If you can find a link to the octal version, post the link here. In any case, I'd look at the order of the grounds. From your photo, it appears that you have a star ground in the middle of the row of input jacks, with the phono grounds separated from the star point and a few other grounds tacked in between. The grounds from the phono input and the first stage grounds (i.e., the cathode and grid leak resistors) should return directly to the star point without any other grounds in that path. Return any other grounds to that point using separate wires.
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