"Superfly" - submini tube version of Doug H's Firefly

[tranceracer]

The Hammond 125A xformer came in!  Wired it up w/ the center tap to B+ and it works.. awesome BUT the tube glows on pin 1 kind of bright.
The glowing goes down when I have the gain turned all the way up and I'm playing thru it.  When I stop playing the glowing comes back.
Is this normal?



Thanks!
Byron

[frequencycentral]

Check your wiring and tube pinouts. Tubes should glow steadily.

[tranceracer]

Thanks FC!
I couldn't get the tube to glow right w/ the Sub Zero power amp wiring so used Doug Hammond's Fire Fly power amp w/ your Sub Zero preamp section and was able to get relatively loud output w/ normal glowing tubes.  So I have a hybrid of both amp designs using only 6111WA tubes.  It sounds really good w/ and w/out Tube Screamer in front of it!  I'll share the schematic as soon as I'm done doing some tweaks to the circuit.  If anyone is interested, let me know and I can post some sound clips.

Again Thanks FC!

[thomasha]

Hi,

I was looking for some SMPS ideas using the MAX1771 and found this:

http://lucythesoloist.blog33.fc2.com/blog-category-64.html

instead of using a 4.7uF electrolytic capacitor, they use two 2.2uF film capacitors... and it has two output power stages running in SE...

As I'm out of low ESR high voltage electrolytic capacitors, is there a problem using 400V film capacitors instead?

Nick, have you tried using high voltage film capacitors? Are they an improvement over regular electrolytic capacitors?

Thomas

[Magnus]

Hello,
I am working on my Superfly and I have two questions:

1) The tube-pinout is as shown on my grafic right?



2) The voltage - do I have to adjust it with or without tubes installed?


Greetings from Germany
Magnus

[thomasha]

Hi Magnus,

1) Tube pinout is OK

2) With tubes installed, with load the voltage will decrease. The best setting is the lowest noise setting.

How are your submini projetcs?
Cheers,
Thomas

[Magnus]

Hello,
thank you, Thomas 

I have to finish the layout for the submini-jcm, but first I will build the Superfly 


Greetings
Magnus

[Magnus]

Hello,
I have two last questions:

My inductor (Murata) has two different long legs - does it have a polarity? (I don't think so)

Where do I have to measure the voltage at using the trimpot?


Greetings
Magnus

[thomasha]

Hi Magnus,

I don't think the inductor has a polarity, I never considered it in my builds.

The voltage you measure between ground and high voltage, in orange on the layout.
The trimpot works as a feedback resistor reducing the output voltage.

Thomas

[Perrow]

No polarity on the inductor.

And keep your fingers away when measuring the voltage, or whenever your board is powered for that sake. I soldered an extra wire from the high voltage so I could crocodile clip the DMM to it. That way I didn't need to handle the board when powered, plus I got visual confirmation that the voltage went down after powering down and before handling it.

[Magnus]

Thank you, thomasha and Perrow 


Greetings
Magnus

[Peppercorn]

Hi guys.

I've been reading the 1st 5 pages of this thread and have decided I want to make the Superfly. I'm a newbie but have successfully built 5 fx pedals including Bajamans tube distortion pedal before but still have plenty to learn. I am not very good at reading schematics at this stage but, I CAN work it out if I can see the pcb and work backwards. (but there's so much I don't know)

However, I think this is the perfect next project for me

I have a few questions. Is the pcb layout on the 1st few pages the layout I should use or has there been an update I don't know about??
When buying the Nixie power supply kit which one should I buy as there are different kits for different applications. Valve Radio, Valve clocks etc??

As I understand it, the pcb that's shown on Page 2 of this thread shows the power supply on the board right? Then there is discussion about how it shouldn't be on the same board because of noise or hum. What is the thinking on this now?? Should I go ahead as it is on page 2 or ??
I'm sure there will be more questions but just those two for now thanks!

ps I'm a much better muso than I am an electronics builder, repairer, guy thingy

[exabrial]

I'd read the whole thread before you order parts... There's at least three schematics available! It depends on what tubes you can find and what size enclosure you're going to stuff it into. There's a Russian tube version, the original version that uses a handmade SMPS, and a version that uses a MAX chip for a simpler SMPS. I was actually thinking of buying a prebuilt SMT Nixie power tube supply off ebay (Something like this: http://www.ebay.com/itm/171374739771) to simplify the build.

On a side note, thanks to everyone "I'm going down the rabbit hole" - Liam (on building tube stuff).

[Jayallen]

That transformer is single ended. It won't work with the Superfly's self split push/pull arrangement as there is no centre tap. You could modify the output section to work, but best get a Hammond 125a. Just building a Superfly myself today.

How would I go about modifying the output section to make this work with with a single ended transformer? I only have a hammond 1750a. I just wired 1 & 8 together on tube 6111 for now. I got sound but not loud. Thanks.

[Magnus]

Hello,
just two questions about the output-transformer-connection:

Hammond 125A:
Pin 5 to output-jack-ground (is it grounded with the input-jack- and circuit-ground too?)
Pin 2 to output-jack-tip


Greetings
Magnus

[347sixtyseven]

Is there a kind soul out there who could share with me how to tie the gain and tone controls from the Superfly Special schematic into either the above pcb layout or the perf layout?

I have tried working it out for myself but i keep ending up thinking that some of the connections to the tubes differ between the layouts and the schematics. I am not good at circuit design but i follow instructions well

any assistance would be greatly appreciated

Gary

[Scheissami]

Hi, guys, I need some help debugging my build. Spent a lot of time on this thread, read all of the little hints and suggestions but still don't have a working amp. I'm using the PCB layout, with added Tone, Bias, and MV controls.

When I plugged in my power supply (center positive but I wired appropriately) and flipped the power switch, my LED lit up, and I immediately got 12V at the center tap. The tubes' heaters began to glow, and I figured in a couple of seconds I'd see the voltage start to climb. Then, nothing. LED goes off, voltage drops. No smoke, crackles, sizzles, pops.

I went over everything I could think of, including checking the tracing for solder bridges or other shorts in the wiring. I think the tube polarity is correct (gap towards the NE555, right?). The VR was a little bent after getting it to fit, so I replaced that: no change. I also swapped out the BC547 transistor (I had socketed per FC's suggestion) as well as the NE555 without any change. When adding the tonestack, I omitted both R16 and C8. I didn't bridge the gap left by the absence of C8 (reading the updated schematic, none of the remaining connections went to ground), I figured trying that without a filter cap would only potentially fry more components.

What would be the other potential culprit components to check? I've built a few pedals and tube amplifiers so this isn't completely new to me, however problem solving beyond the simple stuff is over my head.

Thanks for any ideas!

https://dl.dropboxusercontent.com/u/23281298/IMG_3827.jpg
https://dl.dropboxusercontent.com/u/23281298/IMG_3830.jpg
https://dl.dropboxusercontent.com/u/23281298/IMG_3828.jpg

(Sorry, I had originally included the pics in my post, but they were massive and I wasn't sure how to resize them in dropbox...)

[jsbull23]

Hey guys. I'm in the process of ordering parts to build the Superfly and I just had a small question: What are those sockets the tubes go into called? The ones normally used for 8-pin ICs.

Thanks in advance!

[amptramp]

This should be the upper limit on pricing:

http://dhost.info/mhdtlab/socket.htm

eBay also lists 8-pin submin sockets.  They are used in the Eico HFT-90 FM tuner and HFT-92 AM/FM tuners to hold the 1M3 tuning eye tube and in a number of European radios for similar tubes.  On rare occasions you may find them in surplus stores.

[frequencycentral]

...or $0.12...

http://www.taydaelectronics.com/8-pin-dip-ic-socket-machine-tooled.html

...or make your own, expensive at $0.39...

http://www.taydaelectronics.com/30-pin-dip-sip-ic-sockets-adaptor-solder-type.html