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

[Perrow]

Inspired by another thread I've collected some of the information in this thread on my wiki page about the Superfly (feel free to add to the information there).

I'll post the lists I made of pre and power tubes here as I believe it to be useful (at least as reference for those browsing ebay and other sites).

Pre-amp tubes
In order of preference
6112 (gain about 70)
6021 (gain about 35)
6111 (gain about 20)

Power-amp tubes
In order of preference
7327 (unknown gain)
6021WA (gain about 35)
6021 (gain about 35)
6111 (gain about 20)

Hope this helps someone.

[MetalUpYerEye]

Hey guys, i'm getting my stuff together for this build... Having trouble finding a 7327 in the US... Was wondering if I could do two 6112's instead of a 6112 preamp and 6111w power amp... Whats a good place to get the output xfmr? A google search didn't turn up much in the way of Hammond 125a...  I'm going to add a three band EQ to it, based on the P1 at ax84.com... Should make it a bit quieter but... If I use a 6112 (gain of 70) vs. a 6111 (gain of 20) in the power section, shouldn't it be louder?

[Taylor]

6111 can be found on ebay.

trafos here should be good:

http://www.tubesandmore.com/scripts/foxweb.dll/catalog@d:/dfs/elevclients/cemirror/ELEVATOR.FXP

[frequencycentral]

7327 are indeed hard to find, but it's not the end of the world. I've had a standard 6111 (ie not the W or WA derivative) running in a Superfly for about a year now, although the data sheet specifies a 150v maximum it's coping with 185v just fine. It is socketted (using SIL strip) just in case.

6112's spec makes it not really suitable for the self spilt output stage. Just as the Firefly uses a high mu 12AX7 for the preamp and a low mu 12AU7 for the output stage, so the Superfly does the same. But you could try it with a 6112 (socket it maybe), I haven't myself, it might work/sound fine for all I know.

Hammond 125A should be really easy to source in the US. I'm in the UK and always use Bluebell

[MetalUpYerEye]

Any chance I could get one of you guys to try a 6112 in the power section before I buy tubes... ?

[craigmillard]

hey rick,

Great work on the superfly:) love the look of your amps!

Im based in the UK and was wondering exactly what you use for the nixie supply.

I want to get 310v to power a preamp pedal and was wondering exactly what parts from where you used to get the 310v?

cheers
c

[frequencycentral]

Any chance I could get one of you guys to try a 6112 in the power section before I buy tubes... ?

As I'm not recommending it I'm not trying it. 

hey rick,

Great work on the superfly:) love the look of your amps!

Im based in the UK and was wondering exactly what you use for the nixie supply.

I want to get 310v to power a preamp pedal and was wondering exactly what parts from where you used to get the 310v?

cheers
c

The SMPS I use is in the first post. The critical parts would appear to be:

• the inductor, Rapid part # 88 1630 MIN RADIAL INDUCTOR 100UH RC, but I'm sure others will work.
• the ultrafast diode UF4004, just don't even bother trying non ultrafast type diodes
• MOSFET - I've used both IRF740 and IRF840.
• The voltage rating of C4 in the SPMS schematic 350v or 500v or whatever. It's value is less important, the higher the better really. Now I'm using 4.7uF / 350v, It's a trade-off between spec and physical size.

You can also screw around with the ratios of R4 and R5, which dictate at what voltage the BC547 switches off the NE555. That's your govnor right there and really dictates the maximum voltage. Just be careful - it's possible to put out enough voltage to melt/combust the MOSFET and reservoir cap!

[craigmillard]

thanks rick that is a great help!!

Im about to put a big order in at farnell and dont want to have to pay the extra at rapid just to ship some inductors, do you think these will work?

They look similar spec to the ones you use?
I take it in an inductor we are looking for low dc resistance and high current, what about the Resonant Frequency?

http://uk.farnell.com/panasonic/elc10d101e/choke-100uh-0-110ohm-1-7a/dp/1308459
http://uk.farnell.com/panasonic/elc16b101l/choke-100uh-2-6a-0r072/dp/1749179


Cheers
C

[Perrow]

I've been sourcing parts for this and dreaming about building it, while doing so I reworked the PCB to my own style It's Ricks layout but with two jumpers removed (and Q2 flipped to do so). It's also one row and one column smaller

Refer to Ricks layout for connections and mods.

N.B: As of this writing this is unverified.

[Perrow]

So I'm stocking up parts to build me one of these and as I'm on a tight budget I'm hoping to use (for a start at least) this salvaged output transformer. The problem is that I'm not really sure what I've got, so please help me, can this be used? I know there's ideally impedance matching to be considered, but at least the secondary side should be safe considering it's attached to the speaker 

I know there should be three wires going from the output tube to the transformer and that there are four here, I just don't know enough about this subject to know if it's at all possible to use this or if I'll have to fork out for a 125A.



More images here

Grateful for any light you can shed on this.

[Johan]

So I'm stocking up parts to build me one of these and as I'm on a tight budget I'm hoping to use (for a start at least) this salvaged output transformer. The problem is that I'm not really sure what I've got, so please help me, can this be used? I know there's ideally impedance matching to be considered, but at least the secondary side should be safe considering it's attached to the speaker 

I know there should be three wires going from the output tube to the transformer and that there are four here, I just don't know enough about this subject to know if it's at all possible to use this or if I'll have to fork out for a 125A.



More images here

Grateful for any light you can shed on this.

that could be one of those ancient speakers that used the filtering choke from the powersupply as an electromagnet in the speaker, instead of alnico or cheramic...I say could be, since I dont know. .it might not be an output transformer, so dont just assume it to be...I guess someone like PRR would know thou..

[danielzink]

Inductor question:

They were cheap - so if one is wrong - I'm not out much.....

I got these two inductors:



One is labeled as a 100uH RF Inductor the other as an RF Choke Power inductor.

Are they functionally the same re: this circuit ?

Thanks !

Dan

[Hides-His-Eyes]

Did anyone ever make this in eagle? I've got this penned for a summer project, I liked the look of the vox lil' night train but this is just amazing!

If not, I might eagle it myself sometime. It's an extremely elegant design, what are people's solutions to the standoffs?

[frequencycentral]

@ Dan: Well they look right physically, but the ones I use are labelled '104'. I think inductor labelling is the same as cap labelling, so (to me at least, I'm happy to be corrected), the '101' markings don't look right.

@ Hides: I'm using 15mm nylon standoffs from Banzai.

[frequencycentral]

[Perrow]

Nice as allways.

I'd love to see a component side shot of your board.

Is there anything like to large for the high voltage electrolytes? I found two 400V 22uF while looking at the switching PS in an "old" network switch recently, that aren't that big so they might actually fit (a bit high maybe, but that's all). I think you said earlier that "the bigger the better" and I know that that's mostly the case when it comes to electrolytes.

Still hoping someone would have an educated guess about the OT I posted above.

[Dr.maligno]

hi all, this is my last submini amp version.

here is the BumbleBee:

-One triode preamp
-cathode follower
-complete tone stack
-One triode in class A mode

and sound amazing, and more powerfull than the jj´s submini, that is based in.










thanks rick for inspire all to do little thinks

[Poste]

Could someone please point me in the right direction regarding the transformer.

Which one of these is the correct one to use.
http://www.x-on.com.au/results-deep-new.asp?sq=125A+transformer&tp=

And where is the cheapest source for this.

Is there a cheaper option?

Thanks in advance.

[misterg]

Which one of these is the correct one to use.
http://www.x-on.com.au/results-deep-new.asp?sq=125A+transformer&tp=

None of the above.

You're looking for a Hammond 125A (not anything else, even 125ASE) - e.g.

http://gb.mouser.com/ProductDetail/Hammond-Manufacturing/125A/?qs=sGAEpiMZZMv0IfuNuy2LUXxqWx0SplZ5kwH0lm%252bN3RM%3d

if you're in the UK:

Bluebell Audio or Das Musikding  - if you can cope with a physically larger transformer, this one is better (IMHO) and cheaper.

If you're in the US, I'll leave someone else to advise you. (But I've heard they grow on trees there )

Andy

[Poste]

I would like to hook this up to a cab with a switch to choose between a tiny giant and the superfly, can I run 15V through this circuit instead of 12V.

And is the tone stack a good feature to include?

Thanks in advance