Cornford Hurricane Build: 10lbs of crap in a 5lb Chassis

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dorrisant
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Cornford Hurricane Build: 10lbs of crap in a 5lb Chassis

Post by dorrisant »

Ok, I'm building one of these in a ~13" x 7" chassis. I don't have room for a reverb tube, let alone a tank... What should I be aware of when removing the reverb in this circuit? In particular, what is the principal when just one input is used instead of the two with the mixing resistors? Should the 100k from the effects return be removed entirely? Or reduced to another value? I guess I'm asking how to compensate for a different input impedance for V2A.

I figure that i should drop the 100k to ground at the reverb input tap as well.

For the PT I'm using an AnTek AN-1T300, two 300v windings and two 6.3v windings. I'm using a seasoned OT from a McGowan M335... 6,375k @ 8 ohms. I think it will work... looks factory fresh. It was designed for 35w. It has 4 and 16 ohm taps too.

I was kinda proud of the way I mounted the turret boards. Tilted at that angle i could get 5"+ of board width into about 3 1/2". I know, 10 pounds of $#%+ in a 5 lb sack. Anyway, when it all works out, I posted it here first, :D

I'm thinking about using cathode bypass attenuation... Separate cathode resistors and bypass caps on a 3-way switch for 3 levels. Never tried that but I'm hoping it works like I've heard about.

I love builds like this, it's not for a customer, just me. I don't have to stop and ask too many questions. Anyway... waiting on parts. (I can't believe I ran out of noval sockets)
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martin manning
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Re: Cornford Hurricane Build: 10lbs of crap in a 5lb Chassis

Post by martin manning »

dorrisant wrote:Ok, I'm building one of these in a ~13" x 7" chassis. I don't have room for a reverb tube, let alone a tank... What should I be aware of when removing the reverb in this circuit? In particular, what is the principal when just one input is used instead of the two with the mixing resistors? Should the 100k from the effects return be removed entirely? Or reduced to another value? I guess I'm asking how to compensate for a different input impedance for V2A.
For a single input jack, delete the upper one in the schematic and keep only the 68k connected to the grid of V1A. Connect that remaining 68k to the input jack's tip lug and keep the 1M going to ground where it is.

There are two 100k in series from the effects return, with the V2B grid connected at the junction. Keep both and ground the second one, same as the reverb footswitch does.
dorrisant wrote:I figure that i should drop the 100k to ground at the reverb input tap as well.
No, keep that and you can leave all other parts in that area the same.
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Re: Cornford Hurricane Build: 10lbs of crap in a 5lb Chassis

Post by Leo_Gnardo »

dorrisant wrote:I was kinda proud of the way I mounted the turret boards. Tilted at that angle i could get 5"+ of board width into about 3 1/2". I know, 10 pounds of $#%+ in a 5 lb sack. Anyway, when it all works out, I posted it here first, :D
:D here too, those tilted boards look sporty. Good description, does this build have a name? Consider "Blivet." You gave the definition already. WWII vets would recognize that term in an instant.

What Martin said ^^ and my only change would be, put the input stopper resistor at the tube end of the lead. Carbon comp recommended for stoppers and you can cut the value to 33K or anything close to that.
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dorrisant
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Re: Cornford Hurricane Build: 10lbs of crap in a 5lb Chassis

Post by dorrisant »

Thanks for the replies.

Martin, from what I gather... Coming off V1-1, past the 4n7 coupling cap, I would still keep the 100k to ground just before the volume pot. And I would keep the 100k to ground on the other side of the volume pot too. Correct?

Lou.. I love the name... "Blivet" it is. I even love the images for blivet... I'll have to incorporate that image into the faceplate somehow.

Thanks again guys, you are awesome!
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Re: Cornford Hurricane Build: 10lbs of crap in a 5lb Chassis

Post by Leo_Gnardo »

dorrisant wrote:Lou.. I love the name... "Blivet" it is. I even love the images for blivet... I'll have to incorporate that image into the faceplate somehow.
Well now *I* had to look that up, when did a poiuyt turn into a blivet or verse visa... no, the poiuyt is a poiuyt, everybody knows that, somewhat related to the ambihelical hexnut. Someone "cleaned up" the blivet definition, I always knew it to be "10 pounds of . . . " or something close, 5 pounds in a 2 pound bag. How you're going to fit THAT image on the faceplate? :shock: ;)
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martin manning
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Re: Cornford Hurricane Build: 10lbs of crap in a 5lb Chassis

Post by martin manning »

dorrisant wrote:Coming off V1-1, past the 4n7 coupling cap, I would still keep the 100k to ground just before the volume pot. And I would keep the 100k to ground on the other side of the volume pot too. Correct?
Like so:
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dorrisant
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Re: Cornford Hurricane Build: 10lbs of crap in a 5lb Chassis

Post by dorrisant »

How about a pic of a half-open can of biscuits... You know, when you pull the little tab and the cardboard pops..

Maybe the image below... The one on the left of course! :wink:
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dorrisant
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Re: Cornford Hurricane Build: 10lbs of crap in a 5lb Chassis

Post by dorrisant »

Thanks again Martin! That's what I needed to know.
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Re: Cornford Hurricane Build: 10lbs of crap in a 5lb Chassis

Post by John_P_WI »

Mmmmm biscuits ......
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Re: Cornford Hurricane Build: 10lbs of crap in a 5lb Chassis

Post by JazzGuitarGimp »

Nice job of fitting the boards in - That looks like" thinking outside the box, whilst clearly remaining inside the box"! :-)
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martin manning
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Re: Cornford Hurricane Build: 10lbs of crap in a 5lb Chassis

Post by martin manning »

BTW, you don't need the 1M to ground off of the loop return.
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Re: Cornford Hurricane Build: 10lbs of crap in a 5lb Chassis

Post by Stevem »

I don't smoke , but I would love to drop a hot cig butt on that discussing Butt just to get out of my view!
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Re: Cornford Hurricane Build: 10lbs of crap in a 5lb Chassis

Post by Structo »

That is genius!

How did you mount them at an angle?
Tom

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Re: Cornford Hurricane Build: 10lbs of crap in a 5lb Chassis

Post by Leo_Gnardo »

Stevem wrote:I don't smoke , but I would love to drop a hot cig butt on that discussing Butt just to get out of my view!
Yikes! OW my eyes... Not what I wanted to see over morning coffee. OK it was fun but maybe we'd best get away from "blivet" and concentrate on the angular aspect, lots of power & sporty powerplant. "Mazerati" has already been taken, and "Corniche" a tip of the hat to its design heritage, a respectable drive, but not quite the thing. Howsabout you transform the name of a powerful wedge car with a deliberate misspelling: "Corntach". ;) Also a reference to where it was developed, between a river and a cornfield.
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rp
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Re: Cornford Hurricane Build: 10lbs of crap in a 5lb Chassis

Post by rp »

Boards = brilliant. Looks like some '50s milspec or valve computer miniaturization attempt. TAG employee of the month nomination.

So did you cut the stand-off in half at a bevel, then sandwich the board btwn the two pieces?
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