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the Amp [message #30848]

Sat, 05 March 2005 17:54

PakProtector
Messages: 935
Registered: May 2009

Illuminati (2nd Degree)

hey-Hey!!!,
It seems the amp has been settled upon. It will use the guinevere power Iron comfortably.

PP 1624's. this is a glass enveloped version of the 1619. Front end will be a cascode differential amp. One grid grounded so it will SE:PP phase split. One GZ34 rectifier, two 2.5V/2.5A Hammond filament TX's( or perhaps a 5vCT/2.5v-parallel connection with seperate 2.5v windings( PN TBD ). One L-C filter. The 10 Hy/300 mA Hammond is a likely suspect. Perhaps a custom Heyboer... OPTx will be a 10k a-a with g2 taps at 20 and 30%, perhaps 40% as well for future as yet undetermined application/experimentation.

CCS for the cathode of the input stage would be very similar to the Guinevere plate loads. Additional CCS for Ec2 ref would be LND150N3 based and similar construction.
regards,
Douglas

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Re: the Amp [message #30850 is a reply to message #30848]

Sat, 05 March 2005 18:40

Manualblock
Messages: 4973
Registered: May 2009

Illuminati (13th Degree)

Sounds good to me.
Now I just need a little TLC.
On the filament trans I ran one wire from the secondary to each lug on a strip then connected a diode on each lug to the secondary wires. from there I tookthe opposite end of both diodesd and soldered them to one end of a two ohm resistor. I then took the other end of the resistor and soldered it to the pos. end of the first filter cap, with the other end of the filter cap to ground. I also grounded the CT of the RS trans.secondary.
Then I took one end of the second 2 ohm resistor and tied that to the pos end of the second filter cap and ran the neg end of the cap to ground. I then took the tab with the res/cap pos end and ran a wire to pin 4 of the 5687. I then ran a wire from pin 5 to ground. Is this correct?

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Re: the Amp [message #30851 is a reply to message #30850]

Sat, 05 March 2005 18:54

PakProtector
Messages: 935
Registered: May 2009

Illuminati (2nd Degree)

Looks good to me. Apply voltage slowly while observing for any unexpected behaviour. Use a variac so that you can apply just a little at first if you are worried.
regards,
Douglas

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PCB for CCS [message #30852 is a reply to message #30851]

Sat, 05 March 2005 19:50

colinhester
Messages: 1349
Registered: May 2009
Location: NE Arkansas

Illuminati (3rd Degree)

What do you think it cost to etch approx. 20 boards? I'd much rather go etch than perf board again.....Colin

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Re: PCB for CCS [message #30853 is a reply to message #30852]

Sat, 05 March 2005 20:37

PakProtector
Messages: 935
Registered: May 2009

Illuminati (2nd Degree)

I don't know, never done it. Enough practice with perf board and it isn't too hard to stay ignorant about such things...
regards,
Douglas

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Re: the Amp [message #30855 is a reply to message #30848]

Sat, 05 March 2005 23:13

Wayne Parham
Messages: 18792
Registered: January 2001

Illuminati (33rd Degree)

I like this idea. Sounds great!

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Re: PCB for CCS [message #30856 is a reply to message #30852]

Sat, 05 March 2005 23:15

Wayne Parham
Messages: 18792
Registered: January 2001

Illuminati (33rd Degree)

I can get boards etched for us. But we probably better get 100 minimum, and maybe more than that. Anything less than 100 is a waste of money because it will cost almost the same as 10.

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Re: PCB for CCS [message #30857 is a reply to message #30853]

Sun, 06 March 2005 05:46

Manualblock
Messages: 4973
Registered: May 2009

Illuminati (13th Degree)

First let me say I have a buddy who did PCB's himself all the time for little projects and it did not seem too difficult to me. He used to spit them out quite frequently. I am going to try the RS stuff and see what happens. I have the CCS on perfboard but I am curious.

Thanks for reading my wiring post T; It is just the 12v ct heaters that threw me.

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T-220 mounting sockets [message #30859 is a reply to message #30857]

Sun, 06 March 2005 06:16

colinhester
Messages: 1349
Registered: May 2009
Location: NE Arkansas

Illuminati (3rd Degree)

Found T-220 mounting sockets at Digikey. They are around $1.50 per. Any interest? I know they would sure help me out, since I broke a lead screwing around last night....Colin

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