Octal driver idea

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Octal driver idea

Postby TerrySmith » Mon Nov 08, 2010 5:41 pm

Here's a point-to-point all octal driver idea for the ST-70. Since the Ike circuit worked well in my MK-3's I thought I would try it in the '70 I just got.

I fabbed a panel from front panel express to replace the board and should have it in a couple weeks. It will use a 6SL7 - 6SN7 x2 combo. This panel could also work with the Blackburn circuit, but would be all 6SN7's

Also I made a cover for the DIY-70 board, the PCB will be spaced underneath with just the sockets sticking out. Resistors will be mounted on top and capacitors on bottom. The picture shows 6GU7 for PI tubes because that's what i'm using. This cover is mainly a safety thing!

Anyone can feel free to copy and modify if you like!

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Postby Geek » Mon Nov 08, 2010 6:03 pm

Point-to-point panels are fun!

I use them as "test beds" before making PCB's for the ST-70

Cheers!
-= Gregg =-
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Postby mesherm » Fri Nov 12, 2010 2:53 pm

Keep in mind that 7L7 and 7F7 can be used also. Just have to use Locktal sockets. I find it cheaper to get them NOS than their 6*N7 octal brothers although more people are wising up now. ;)
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Postby TerrySmith » Fri Nov 12, 2010 11:14 pm

Locktals sounds like a great idea! Plus the 7F7 and 7N7 have a mirror-image pinout.
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Postby burnedfingers » Sun Nov 21, 2010 5:45 am

Quote:
It will use a 6SL7 - 6SN7 x2 combo.

I'm still waiting to see your schematic for the 6SL7-6SN7 combo ;) ;)
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Postby TerrySmith » Sun Nov 21, 2010 10:34 am

No problem on a schematic, the driver board portion is here on pg 17, everything between the input jack and C3 & C4:
http://www.diytube.com/ike/IKEREVB.pdf Power supply resistors are yet TBD, but in place of the 6.8k and 22k I'll start out with 3.3k and 120k like in a stock Eico HF89.

Got my plates in from FPE, they are really nice! Here's a couple of pics of the trial fit.



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