Blues Briefcase

18watt-specific Tech Talk - Building, Fixing, Parts, Mods...

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zuceno
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Re: Blues Briefcase

Postby zuceno » Fri 06/14/19 4:10 pm

crgfrench wrote:
Thu 06/13/19 1:59 pm
By the way, did y'all know about that time Keith electrocuted himself in 1965 playing "The Last Time" in California -- brushed his guitar strings against an ungrounded mic stand, blew him backstage in a flaming blue electric arc, ended the whole show. Almost killed the poor bloke!
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Re: Blues Briefcase

Postby crgfrench » Fri 06/14/19 8:43 pm

JMPGuitars wrote:
Fri 06/07/19 5:00 pm
I don't recommend having less than 3/8" for a speaker baffle, and even that is on the thin side. Are you mounting the speaker on the same side as the circuit and transformers?
The good news is, with the tweed and the fur it is 3/8". I'm certain this red crushed velvet fur is growing to contribute meaningfully to a creamy blues tone.
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Re: Blues Briefcase

Postby JMPGuitars » Sat 06/15/19 7:26 am

crgfrench wrote:
Fri 06/14/19 8:43 pm
I'm certain this red crushed velvet fur is growing to contribute meaningfully to a creamy blues tone.
LMAO I agree! Check out this amp mod video I did in 2011: https://youtu.be/_pM1KmdKPHE
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Re: Blues Briefcase

Postby crgfrench » Sat 06/15/19 7:57 am

JMPGuitars wrote:
Sat 06/15/19 7:26 am
crgfrench wrote:
Fri 06/14/19 8:43 pm
I'm certain this red crushed velvet fur is growing to contribute meaningfully to a creamy blues tone.
LMAO I agree! Check out this amp mod video I did in 2011: https://youtu.be/_pM1KmdKPHE
OMG That grill cloth! Love it -- nice video Josh, thanks for sharing.
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Re: Blues Briefcase

Postby crgfrench » Tue 07/02/19 12:58 pm

I finally installed the sockets onto the chassis,; I only had 4 of this shielded kind and one went missing so I had to order a replacement. So now 2 fully shielded CV4004s and 2 base-shielded EL844s.

Next steps are to wire the board and reinstall it into the chassis, wire the transformers and rectifier diodes.
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Re: Blues Briefcase

Postby crgfrench » 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
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Re: Blues Briefcase

Postby crgfrench » Wed 07/03/19 8:49 am

Class AB usually runs cooler than Class A so to complement the single-ended / double-ended switch I might add 2 more brown devils connected via this switch
https://tubedepot.com/products/three-po ... ary-switch
Like this:
20190703_093915.jpg
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Re: Blues Briefcase

Postby crgfrench » Wed 07/03/19 8:53 am

I know, I know, this is so wrong. But I had to translate bias into something normal musicians understand, like Scoville Heat Units.
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Re: Blues Briefcase

Postby JMPGuitars » Wed 07/03/19 9:05 am

Those numbers are way off. SHU: Ghost is 1M, Scorpion is 2M, and the Reaper is 2.2M. If you wanted to go directly from SHU to Ohms, then they'd all be Pepperoncini. :lol:
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Re: Blues Briefcase

Postby crgfrench » Wed 07/03/19 9:13 am

JMPGuitars wrote:
Wed 07/03/19 9:05 am
Those numbers are way off. SHU: Ghost is 1M, Scorpion is 2M, and the Reaper is 2.2M. If you wanted to go directly from SHU to Ohms, then they'd all be Pepperoncini. :lol:
Notice below the switch it's clarified, "SHU x 1,000". Like on a tachometer.
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Re: Blues Briefcase

Postby JMPGuitars » Wed 07/03/19 9:30 am

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

Postby crgfrench » Wed 07/03/19 10:17 am

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

Postby crgfrench » 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.
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Re: Blues Briefcase

Postby JMPGuitars » Wed 07/03/19 12:18 pm

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

Postby crgfrench » Mon 07/22/19 11:39 am

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.
Screenshot_20190722-121941_Gallery.jpg
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