OT - FireFly Done

[Paul Marossy]

I'm all done wiring it and getting the details worked out. Tonight I will go through and double check all of my wiring against the schematic to make sure everything is correct. Then I will do the smoke test...  

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[mattv]

Wow! Looks great!

[MarkB]

Nice work, Paul!!!
can't wait to hear how it SOUNDS!
"-)

[RDV]

You've been doing something besides changing diapers!!

Looks Pro

RDV

[Mike Burgundy]

Great work, nice cab. Now for a matching speakercab
(I'm working on a Marshall-style slanted 4x3" cab for mine )

[Doug H]

Wow, beautiful work Paul!!

Probably too late to mention this quick tip, but what I usually do is smoke-test the power supply before I connect it up to the amp circuit. Not absolutely crucial, but I find it helps my confidence to verify it a piece at a time.

Good luck on starting it up and let us know how it sounds!

Doug

[Doug H]

Great work, nice cab. Now for a matching speakercab
(I'm working on a Marshall-style slanted 4x3" cab for mine )

That's a very cool idea.  I've collected a couple 8" speakers over time and have considered building a 2x8.

Doug

[Paul Marossy]

Thanks guys.  

I'm looking forward to hearing it myself! I'm excited to hear it, but I'm going to double-double check everything before I flip the power switch.

[Peter Snowberg]

That looks great Paul!

Take care,
-Peter

[Prive]

IT LOOKS REALLY PRO''''

COOL!!!!!!

Saludos, Marcelo.

[smoguzbenjamin]

Excellent work, Paul! Hope I can make mine look just as good :lol:

[Arno van der Heijden]

Wow.... Amazing!!! Your stuff always looks so good, it's not fair  :wink:

And I wish I was as quick a builder as you are Paul....

[javacody]

Awesome. I want to make one so bad, but I must admit, I'm a little frightened of the high voltages.  Are those three gray caps the ones you have to discharge before working on it? How do you safely discharge caps?

[Paul Marossy]

Thanks guys. Not bad for a first time build, huh? It helps that I had a cheap Crate bass amp to steal a chassis and an enclosure from and cut down. Making an enclosure is pretty easy, but making a chassis isn't...

I stayed up way too late every night this week building this thing. I've been only getting only about 5 hours a night. Once I start building something, I kind of obsess on it until I get it done.  :oops:
I've always been that way.

I'm glad that I double checked my wiring! On the turret board layout that someone sent me, there is a wiring error, which I reproduced.  :cry:
Fortunately, it wasn't too hard to fix. If anyone has this Rev 2/3 turret board layout showing the added resonance control, beware. On the 12AU7, pins 3 & 8 are shown connected together, but it should be pins 3 & 6. And, the .0022uF/1KV cap shown connecting pins 1 & 6 together should be between pins 1 & 8. Other than that, it checks out OK.

Well, I will check things one more time and then do my smoke test. Keeping my fingers crossed....  

Yes, those gray caps are the filter caps. Here is a description on how to discharge them: http://www1.korksoft.com/~schem/mods/capdischarge.htm

I like the 2x8 speaker cab idea. I bet that would sound a little better than a single 12 would. I would probably build a closed back cabinet. Any opinions on open-back vs. closed with this liitle amp?

[aron]

It looks great!

Good Luck!

[bobbletrox]

Looks fantastic!

[Paul Marossy]

OK, I have one last question for Doug:

The input jack... what would happen if I don't use the grounded input input jack. Will it squeal? I didn't have one of those jacks in my possession, so I used a std. 1/4" jack.

Also, (I guess that's two questions) what affect does it have to use a 100K pot instead of the 250K pot? Will that lower the gain? I didn't have a 250K pot, either, so I wired it with a 100K temporarily, I think...

I'm going to test it tonight. I couldn't last night as our 7 week old baby is sick and tested positive for RSV. We had to wait up late last night for medical equipment to be delivered to our house, so I didn't get around to it.

[Doug H]

I like the 2x8 speaker cab idea. I bet that would sound a little better than a single 12 would. I would probably build a closed back cabinet. Any opinions on open-back vs. closed with this liitle amp?

I would suggest going closed back for better bass response.

Doug

[javacody]

I've been thinking about building a mini tweed cab with 4 8" speakers. I think it would look and sound awesome.

[Doug H]

OK, I have one last question for Doug:

The input jack... what would happen if I don't use the grounded input input jack. Will it squeal? I didn't have one of those jacks in my possession, so I used a std. 1/4" jack.

Also, (I guess that's two questions) what affect does it have to use a 100K pot instead of the 250K pot? Will that lower the gain? I didn't have a 250K pot, either, so I wired it with a 100K temporarily, I think...

I'm going to test it tonight. I couldn't last night as our 7 week old baby is sick and tested positive for RSV. We had to wait up late last night for medical equipment to be delivered to our house, so I didn't get around to it.

2 things about the input jack:

1) It usually has it's gnd insulated from the chassis to reduce noise,

2) It has a switch that grounds the input when the cord is removed.

Will it work without this? Yes. You may get more noise if you don't insulate the gnd from the chassis. This is part of the idea of star-grounding (see R.G.'s excellent article for more info). The switch just keeps things quiet when you unplug your cord, not necessary, but a nice professional touch. You can start out without it and replace the jack later when you get the parts. I like the Cliff jacks that Antique Electronics sells.

Using a 100k will give you less gain out of the cascode and less low-end response. By all means, give it a try, don't let it stop you from trying it out. Get the 250k later and sub it then.

Good luck with your baby!

Doug