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

[iccaros]

I bought a Max 1771 just to test that build, waiting for it to come in, I have lots of 555, from a EE project going back 10 - 15 years.. but wanted to test the different power setups, once I get it up and running I'll give a report

as for fitting in the little box... well that is too be seen, It may go into my Snoopy lunch box I just mounted a 2" 3watt speaker into..

[Scruffie]

I bought a Max 1771 just to test that build, waiting for it to come in, I have lots of 555, from a EE project going back 10 - 15 years.. but wanted to test the different power setups, once I get it up and running I'll give a report

as for fitting in the little box... well that is too be seen, It may go into my Snoopy lunch box I just mounted a 2" 3watt speaker into..

I beleive I sold you that MAX1771  I sent it last... Thursday? Wednesday Maybe? So it should arrive by tommorow i'd have thought.

I'm not actually putting mine in a 1590BB but that PCB should fit one, i've got a sheet metal case i've had lying around that should be just perfect.

Does anyone have a place to get a transformer suitable for this in the U.K. that isn't bluebell audio? They don't take paypal and have no ordering cart which is just a pain for me.

[iccaros]

I beleive I sold you that MAX1771  I sent it last... Thursday? Wednesday Maybe? So it should arrive by tommorow i'd have thought.

Na, customs is stupid in the states, my last package sat in NY for two weeks before being sent out to me.

I had forgotten who I bought that from.... been so long 

I am getting ready in the next week to order two of OTPP5 from http://www.musicalpowersupplies.com/6.html  but that does not help you, I can see what they cost to actually ship if you need one though...

http://uk.rs-online.com/web/p/audio-transformer/2106475/ *not sure if they take pay pal

[Scruffie]

I beleive I sold you that MAX1771  I sent it last... Thursday? Wednesday Maybe? So it should arrive by tommorow i'd have thought.

Na, customs is stupid in the states, my last package sat in NY for two weeks before being sent out to me.

I had forgotten who I bought that from.... been so long 

I am getting ready in the next week to order two of OTPP5 from http://www.musicalpowersupplies.com/6.html  but that does not help you, I can see what they cost to actually ship if you need one though...

http://uk.rs-online.com/web/p/audio-transformer/2106475/ *not sure if they take pay pal

Ahh damn, well hopefully they get to you soon!

Haha, I can't even remember when it was, got the proof of postage knocking about somewhere in the pile though.

Yeah I just checked that link... $14 shipping, kindaaa pricey.

I'll have to register to RS later to see what shipping and pricing options they do, cheers for the link.

[misterg]

Thanks, so did you use the 15K from the transformer you posted? I am in the states, so I could not find it here, but @ 9 pounds that is what $24 plush shipping and the hammond is only $34 here

I used 22K on the 125A & 26.5 k on the RS transformer. (See reply 202  )

The RS transformer was < 1/2 the price of the Hammond 125A here (UK). It's gone up nearly 50% since I bought mine.

Andy

[iccaros]

in the US, musical power supplies has a 22K 5 watt PP made just for the Firefly for $24, he charges strait shipping so I think it was $8 which is what USPS charged me to ship one to my brother.

[iccaros]

new question, what is the rating for the inductor, I have a Radio shack 2 amp and a 1.5 amp from mouser, the 1.5 fit on the PCB layout, the 2A does not..

or do I need to order another one

[jaapie]

I got mine working with the 2A inductor from RS (that was the only one they had in stock), but I had to move the inductor, mosfet/heatsink and 330uf cap because they wouldn't fit the layout.

[iccaros]

so is that a no on the 1.5 amp?

[jaapie]

I've only used the 2A radio shack inductor (nominally 100uH, my meter told me it was around 80uH), so I can't tell you anything about the 1.5A one.  If you've got both I'd try both of them and see which works better.

[iccaros]

I've only used the 2A radio shack inductor (nominally 100uH, my meter told me it was around 80uH), so I can't tell you anything about the 1.5A one.  If you've got both I'd try both of them and see which works better.

Thanks
This is the RS one but red.. not that it matters.. I got it to fit on the board, had Govmnt_Lacky etch me two, did a awesome job.
I will try the 1.5a on bread bard, in case it does a painful death..

[Scruffie]

I've only used the 2A radio shack inductor (nominally 100uH, my meter told me it was around 80uH), so I can't tell you anything about the 1.5A one.  If you've got both I'd try both of them and see which works better.

Thanks
This is the RS one but red.. not that it matters.. I got it to fit on the board, had Govmnt_Lacky etch me two, did a awesome job.
I will try the 1.5a on bread bard, in case it does a painful death..

Well I guess if your power supply you use is less than 1.5A... then it should be fine.

[Govmnt_Lacky]

Silly but important question. 

Can someone provide a manufacturer or a link to the 1K trimmer that is used for Rick's board? I cannot find one that fits the footprint (larger than your standard Bourns 3386-series)

Thanks from noob-ville 

[iccaros]

@Greg, I used a Radio shack one, I had to straiten out the one leg to fit, but it was not so bad that it was in danger. 
http://www.radioshack.com/product/index.jsp?productId=2062300


I am awaiting a transformer that does 22K to finish, so I will let you know any issues. but others that have completed this can weigh in..

[iccaros]

First test of my SuperFly


This is running thought a 70v line transformer (10watt) using the .65watt , 2.5 watt and common tap with 2.5 being center using a 8ohm on the 4ohm tap to give me about 16000 ohm CT.

It fats out, but that may be the transformer, Its only until I receive my transformers. 

Just wondering does this get clean at all? I did use the bias adjust switch mod, but my switch could not take the iron and the 4.7K tap does not work, so I will fix that before I put it in a case.

I want to add a tone control, so That may be on the second build  or a quick mod of this one

Thanks to Govmnt_Lacky, he etched me some boards.. Good work


Test video to review how it sounds and to ask if those tubes are suppose to shine this bright?


Thanks

[iccaros]

Lessons learned building this amp

#1
Always connect the transformer to the right connections, on accident I connected to the 2.5 watt connection on the 20v side not the 70v of my line transformer.. Well let say It lets the smoke out

#2
create sokets for the tubes using this type of 8pin dip --> as the tubes make better connection than with the spring type
I used the spring type for connecting to the board as you can see from a picture earlier in the thread. I would get lots of oscillation until I double socket-ed them, I am sure if you used non sprint types in the beginning you would have the better results..

#3
This amp is louder than you think, I need to do some measurements, but I am sure its close to 1.5 watts, maybe 2...


#4
try different tubes, the 6111 in the power position stays cleaner but the mode for bias control between 820R and  4.7K does not do much
6021 well they add overdrive of their own, and sound good, but so far they really go into oscillation, but that may be the batch I got.
6112 is a good preamp, but gives horrible output in comparison to the others. Its quieter than the 6111, I think that is due to current sourcing..


I believe my IRF740 was damaged when I hooked up the transformer wrong, it was the only time this thing get hot for me.. It smoked a little before I hit the power switch, but it works at 165v 6111 and 170v with the 6021 in the power amp section, but any higher and it starts to tremlo.. so I should replace that and test again.

I get lots of ground noise, buzzing and such, with the 6112, 6111 combo its not bad and is not as noticeable. I know I am getting oscillation but I need to connect the scope, may be after vacation when I box this up.

one for the tube glow..

[frequencycentral]

My tame shred master Rich Russell did me some soundclips: http://dl.dropbox.com/u/967492/Superfly%20Montage.mp3

[jaapie]

Got mine working this morning! I'd finally soldered everything up yesterday, but i was getting some intense, gnarly motorboating and oscillations so i got discouraged and went to bed...turns out i hadn't grounded the OT shield or secondary. I fixed that, shortened and shielded a couple leads, and it works like a charm now! I need to do a few modifications (it's a bit muffled sounding at the moment and the distortion is kind of cruddy-- i think i need to filter out some bass in the beginning) but it sounds pretty great already. I ended up wiring the amp section point to point on terminal strips screwed into a block of wood-- now I've gotta figure out how to fit it into something.

My phone battery is dead now, but I'll try and take a couple pictures a bit later.

[jaapie]

I changed out the coupling caps with the prescribed 0.022s (i had been using 0.047) and it sounds much, much better--the distortion isn't nearly as 'grainy' or muffled. I have a few questions regarding some refinements I'd like to make:

First of all, the most annoying problem has to do with what happens when i roll down my guitar's volume control. When the pot is between about 90% and 30%, a very loud and annoying hum dominates the signal. It isn't present when the guitar volume knob is all the way up, but as soon as i roll it down just a hair (where tend to keep it) the terrible hum joins the party. As I roll the knob down from there, the hum lessens with the signal to a certain point where the hum isn't too bad-- but the guitar is too low to really hear, either.  I don't think it's an issue with the guitar wiring since it doesn't happen with any of my other amps, but it's odd that it only happens when the knob is rolled off slightly. For what it's worth, the 'chassis' is still a block of wood, although the input lead is shielded.

Secondly, the distortion is still kind of harsh sounding-- it sounds to me like a little LP filtering in the preamp might clear it up a little. Any suggestions on where to start trying (small) alterations? I'd prefer to stay away from adding a tone control at this point

Here're a couple of pictures:
http://a7.sphotos.ak.fbcdn.net/hphotos-ak-snc6/254785_10100171549934573_22201673_46643081_2026845_n.jpg
http://a6.sphotos.ak.fbcdn.net/hphotos-ak-ash4/224462_10100171549764913_22201673_46643078_193336_n.jpg

[Perrow]

Here're a couple of pictures:

"The Log"?