Author Topic: "Superfly" - submini tube version of Doug H's Firefly  (Read 335999 times)

Marcos - Munky

Re: "Superfly" - submini tube version of Doug H's Firefly
« Reply #580 on: May 09, 2018, 12:26:20 PM »
Question on that 440r cathode resistor. How important is to use this value? I mean, what's the difference if I use a 390r or 470r instead?

rankot

Re: "Superfly" - submini tube version of Doug H's Firefly
« Reply #581 on: May 09, 2018, 01:42:34 PM »
Perhaps not too important, but you can use two 220R in series. ;)
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Marcos - Munky

Re: "Superfly" - submini tube version of Doug H's Firefly
« Reply #582 on: June 22, 2018, 11:20:53 PM »
Ok, so I'm almost ready to test my Superfly. Just need to solder the pots. I just have two more questions (that may be answered in this topic, but I'm still didn't finished to read all the posts):

1- What's the output power of the Superfly? The version without a tone pot.
2- I'll use the enclosure as the heatsink for the IRF740. Do I need to isolate the IRF metal tab from the enclosure?

bluebunny

Re: "Superfly" - submini tube version of Doug H's Firefly
« Reply #583 on: June 23, 2018, 06:02:49 AM »
1- What's the output power of the Superfly? The version without a tone pot.
2- I'll use the enclosure as the heatsink for the IRF740. Do I need to isolate the IRF metal tab from the enclosure?

I don't recall any power output being mentioned, other than it being "wife-worryingly loud".   :icon_wink:

My datasheet doesn't show how the tab is connected, but it would be easy enough to find out with a DMM.  If it's the source, then I guess it would be fine (the schematic shows it's connected to ground).  I'd be inclined just to insulate the tab regardless.
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Marcos - Munky

Re: "Superfly" - submini tube version of Doug H's Firefly
« Reply #584 on: June 23, 2018, 11:30:01 AM »
The datasheet I used doesn'tshow the tab connection too, I just checked and it's connected to the drain. So, it needs to be insulated. Bad news, since the next store that sells electronic stuff is about 25km away from home, but I should be near the store this week.

As for the power, it's really not mentioned and I didn't found this info on google. I asked because the original Firefly transformer is a 3.5W one (oversized). To keed the size down, I ordered a 1W transformer. Since the max plate dissipation is 1W, the output should be lower than 1W.

xaxxop

Re: "Superfly" - submini tube version of Doug H's Firefly
« Reply #585 on: July 03, 2018, 02:09:20 PM »
Thank you guys! I'm really happy with the sound of this amp!

I made a PDF file with layout, and schematic, the link is:

https://dl.dropboxusercontent.com/u/10420127/Superfly%20Project.pdf

The PCB board is already scaled (that's why it's a pdf file...)

Tomorrow I will make a sound sample, if possible.

Greetings,

Thomas

Thank you guys for sharing all these beautiful mini amps, I would like to have a look at the pdf file but the link is broken, could someone please post it again or send to by pm. I would appreciate it. Thanks 

jma38

Re: "Superfly" - submini tube version of Doug H's Firefly
« Reply #586 on: April 02, 2022, 01:35:12 PM »
I've built the original Superfly, everything looks good and all connections are properly soldered but for some reason when I turn on the power the tubes won't even light up. Has anyone else had this issue?

bluebunny

Re: "Superfly" - submini tube version of Doug H's Firefly
« Reply #587 on: April 02, 2022, 05:50:40 PM »
Are your tubes known to be good?  Do you have 6V across each heater?  (Pins 3-6.)
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jma38

Re: "Superfly" - submini tube version of Doug H's Firefly
« Reply #588 on: April 02, 2022, 07:11:06 PM »
The tubes are good, I even swapped them out for extras I got(just in case) I also used my multimeter to see if the power is actually getting to the amp and nothing.

frequencycentral

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Re: "Superfly" - submini tube version of Doug H's Firefly
« Reply #589 on: April 03, 2022, 04:06:44 AM »
...everything looks good and all connections are properly soldered...

Clearly not!
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bluebunny

Re: "Superfly" - submini tube version of Doug H's Firefly
« Reply #590 on: April 03, 2022, 05:42:55 AM »
You need to trace where your 12V enters your board and find out where it stops.  Can you post photos?  More eyes might help.
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jma38

Re: "Superfly" - submini tube version of Doug H's Firefly
« Reply #591 on: April 03, 2022, 11:37:59 AM »
...everything looks good and all connections are properly soldered...

Clearly not!

True now that you mention it

jma38

Re: "Superfly" - submini tube version of Doug H's Firefly
« Reply #592 on: April 03, 2022, 11:53:36 AM »
You need to trace where your 12V enters your board and find out where it stops.  Can you post photos?  More eyes might help.



Here's a picture of the soldered board. I'm realizing I'm definitely not as adept at soldering as Rick(the soldering on the back of those first Superfly prototypes was downright beautiful).
« Last Edit: April 03, 2022, 11:18:43 PM by jma38 »

frequencycentral

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Re: "Superfly" - submini tube version of Doug H's Firefly
« Reply #593 on: April 03, 2022, 05:30:01 PM »
...everything looks good and all connections are properly soldered...

Clearly not!

True now that you mention it

Sorry if that seemed harsh! I spend a lot of time helping people debug. The absolute worst starting position is "I've done everything right and it doesn't work". First step of debugging is to own not having done everything right. Second step is to find out what dumb thing you did. 😀
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jma38

Re: "Superfly" - submini tube version of Doug H's Firefly
« Reply #594 on: April 03, 2022, 05:37:50 PM »
...everything looks good and all connections are properly soldered...

Clearly not!

True now that you mention it

Sorry if that seemed harsh! I spend a lot of time helping people debug. The absolute worst starting position is "I've done everything right and it doesn't work". First step of debugging is to own not having done everything right. Second step is to find out what dumb thing you did. 😀

Oh no problem, I didn't interpret that as harsh :) and yes it's true, the first step to finding the problem is admitting that something wasn't done properly. I enjoy this DIY stuff so much I'm not even frustrated going in to debugging the board.

jma38

Re: "Superfly" - submini tube version of Doug H's Firefly
« Reply #595 on: April 04, 2022, 03:46:23 PM »
Just to eliminate a possible power supply issue I've ordered a new 12v 500ma power supply. It should be here in about a week.

bluebunny

Re: "Superfly" - submini tube version of Doug H's Firefly
« Reply #596 on: April 04, 2022, 04:42:38 PM »
Have you measured the power supply as requested earlier?
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jma38

Re: "Superfly" - submini tube version of Doug H's Firefly
« Reply #597 on: April 04, 2022, 05:19:44 PM »
Have you measured the power supply as requested earlier?

Yes, my meter was reading absolutely nothing.

antonis

Re: "Superfly" - submini tube version of Doug H's Firefly
« Reply #598 on: April 04, 2022, 05:31:32 PM »
Yes, my meter was reading absolutely nothing.

Your meter might need power supply, also.. :icon_wink:

More seriously, what do you mean with "nothing"..??
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jma38

Re: "Superfly" - submini tube version of Doug H's Firefly
« Reply #599 on: April 04, 2022, 06:06:05 PM »
Yes, my meter was reading absolutely nothing.

Your meter might need power supply, also.. :icon_wink:

More seriously, what do you mean with "nothing"..??
  :icon_lol: It isn't reading a voltage at the power input of the amp. Nowhere on any other part of the circuit either.