Blues Briefcase

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JMPGuitars
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Re: Blues Briefcase

Post by JMPGuitars »

crgfrench wrote:
Wed 07/03/19 9:13 am
Notice below the switch it's clarified, "SHU x 1,000". Like on a tachometer.
lol! I didn't see that, but I still think it's funny that they're all really pepperoncini. ;)
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Re: Blues Briefcase

Post by crgfrench »

Assuming we agree that the Trini Scorpion is 1.5 million SHU rather than 2M (I'm referring to the Butch T version not the Moruga), the approximation formula for conversion would be:

Scoville Heat Units = [-9,579 * Ohms] + 3,000,000.

So with no resistor at all we would max out at 3 million SHU, or pepper spray territory.
No amp could get all the way to pure Capsaicin territory.
And any resistor higher than 313 Ohms is a mere Bell Pepper.
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Re: Blues Briefcase

Post by crgfrench »

JMPGuitars wrote:
Wed 07/03/19 9:30 am
...they're all really pepperoncini.
This would be true if you thought Ohms=SHU.
That's why you need to use my formula to convert them.
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Re: Blues Briefcase

Post by JMPGuitars »

crgfrench wrote:
Wed 07/03/19 10:34 am
JMPGuitars wrote:
Wed 07/03/19 9:30 am
...they're all really pepperoncini.
This would be true if you thought Ohms=SHU.
That's why you need to use my formula to convert them.
Well, I think if Ohms does not equal SHU then we'll need to setup a board of directors to setup a standard equation we all agree on. This is serious stuff!
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Re: Blues Briefcase

Post by crgfrench »

Ah I finally got the Hakko warmed up again and got my fair share of lead/tin poisoning for the day. I was soldering up a new stompbox -- and there was my Blues Briefcase circuitboard, patiently waiting for its V1 plexi bias resistor and bypass cap to be laid down properly instead of standing up all erect and lonely, the way I botched it at first.
Screenshot_20190722-121557_Gallery.jpg
So a little desoldering surgery and resoldering, now it's a proper piggyback in the middle of the board.

And my "Lil' Hare Pi" [it's a bunny] pedal is coming along nicely too.
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Re: Blues Briefcase

Post by crgfrench »

Replaced the 125 Ohm 8 Watt bias resistor with a 150 Ohm 12 Watter.
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Re: Blues Briefcase

Post by JMPGuitars »

crgfrench wrote:
Thu 07/25/19 1:08 am
Replaced the 125 Ohm 8 Watt bias resistor with a 150 Ohm 12 Watter.
Those are good resistors. I have the 20W version on my EL34 36W Superlite TMB.
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Re: Blues Briefcase

Post by crgfrench »

crgfrench wrote:
Wed 07/03/19 7:43 am
There is room for another OT in the briefcase so I'm thinking of adding a Classictone 40-18031 or a Hammond 125ESE like this:
20190703_082112.jpg
...So I'm finally getting back to my briefcase project after it sat on the back burner all summer. I'm just ordering the 125ESE now.
One issue I see with my dual OT concept is: i believe ithe setup in my schematic would result in 2 in-phase signals being combined when the switch is set to the single-ended position. This could be problematic? I'm going to try it anyway unless you guys all think it would blow up my workbench...

EDIT: I meant to say, "I believe it would result in 2 out-of-phase signals going into the same side of the transformer when in SE mode. This could be problematic?"
Last edited by crgfrench on Sun 09/01/19 11:12 am, edited 1 time in total.
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Re: Blues Briefcase

Post by geoff 1965 »

have a look at this schematic,he has the power section switchable between single end and push/pull with the same OT but LTP but you might be able to improvise!
p18sc02.jpg
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Re: Blues Briefcase

Post by crgfrench »

geoff 1965 wrote:
Sun 09/01/19 11:08 am
have a look at this schematic,he has the power section switchable between single end and push/pull with the same OT but LTP but you might be able to improvise!
p18sc02.jpg
Thanks Geoff. The switching on this and on mine is all after the PI so the PI type probably doesn't matter. The ampmaker one is interesting, works by turning off one output tube which would also significantly lower the Wattage. Mine keeps both output tubes running and would keep similar Wattage in double ended or single ended mode.
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Re: Blues Briefcase

Post by crgfrench »

Glacial pace continues, got the 20 gauge wires soldered to the board today, everything but the shielded input lines.
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Re: Blues Briefcase

Post by crgfrench »

Finally decided it's too tight to shoehorn the 5E3+ PCB into this Hammond 1444-10 chassis. Would not have even had room for my second input jack. Now I'm working with my V2 Fullerwell protoboard ...much better fit! Also not sure I need shielded input lines with only a 3" run from the jacks to the sockets, but this cable is fun to work with.
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