Has anybody built a firefly and some other things.

[bigdaddy]

As I have said before I cannot build anymore. So I just wondering if anybody built a firefly? They sound pretty good on youtube videos.

I was also wondering if anybody in the USA could possibly build one for me if I supply some of the parts as in chassis and whatever I have left over parts wise. Cash or trade for your services.

I have a bunch of stuff I don't need and will never use. I am breaking a lot of the stuff down and selling them on ebay. Right now some guitar pickups and a Celestion blue. I will be selling them pretty cheap because I know how broke everybody is. I have BF champ type chassis and Hammond transformers a lot of stuff has to go. I have a bunch of JD Newell champ head and combo cabs in both white and brown.

If you checkout the buy sell here things will be up there as long as Doug doesn't sell similar. You can look at my ebay stuff at: http://shop.ebay.com/bluesmandot59/m.html?_nkw=&_armrs=1&_from=&_ipg=&_trksid=p4340

I will be putting up a bunch of Hammond transformers on the buy and sell today. And if anybody is seriously interested in building a firefly for me please contact me.....thanks.

[bnwitt]

I have built the firefly.  Check your email BD

[tubesornothing]

Sent ya an email. 

thanks

[Ritchie200]

Hey Bigdaddy, I have built almost two dozen.  The problem is I have no time due to my business, or I would be honored to build something for you.  I noticed TON and bnwitt sent you responses.  If I can help, please give me a shout!

Jim

[bigdaddy]

Bnwitt is going to build one for me. I probably have 99% of the parts already.

I just cannot even do a simple amp like that, it broke my spirit a bit and frustrated the hell out of me. I tried to build stuff but it doesn't work and rather then go through all that I figure let someone else do it and save me from myself. I just don't have the windows to do it anymore.

Nothing better then building an amp, firing it up and sound coming out the way it should.....like magic. The worst is when you build it and you get nothing, then think about all the pain you were in trying to steady yourself to solder knowing you probably made numerous mistakes and poor solder joints. Then you turn it on and either nothing or you fry a PT, yes that's what I did..... .

SO if anybody has a good firefly design lay it on me. I really need something with a "tone stack". So if someone has any schematics of a firefly with a full tone stack that would be great. Every schematic I see has a boost, volume and tone. Just looking for a low wattage amp but with some clean headroom, the biggest issue with these amps seems to be when you turn your guitar volume down the amps still is very distorted. IMO A good amp design has some type of sensitivity to the input signal and will clean up a bit when you lower your guitar. That might be the sticking point in the overall design. It might be worth it to add a longtailed PI and master volume.

[jojokeo]

Will send you an email BD

[bigdaddy]

Thanks Joe and Jim.......

If anybody would like to add anything in terms of a schematic or ideas on how to improve the firefly design or add a longtailed PI and master volume that would be great.

[Fresh_Start]

Tone stacks:
http://amps.zugster.net/articles/tone-stacks#Overview

tubenit's SCH files of tone stacks:
http://www.el34world.com/Forum/index.php?topic=732.0

However, I think you need a different topology alltogether to get the clean headroom and touch sensitivity you're looking for.  Geezer's "Little Wing" with a TMB tone stack, LTPI, and 6BM8 power tubes is only 6 or 7 watts IIRC.  Based on the clips I've heard, that might meet your goals better than the Firefly.  Two totally different beasts though...

HTH

Chip

[bigdaddy]

6 or 7 watts is too much, this thing has to be no more than 2 watts. Believe I tried every tone stack on my many builds and for me the BF Fender is the one I prefer to get my sound.

That's the whole issue, it has to be no more than 2 watts or LESS even.

So how do you build an amp that has some headroom and tone yet is no louder then your TV turned up a bit. When someone says it can't be done, then I know it can and should be done. Like people said we'll never get to the moon, we did. That's what drives the mind into great thoughts, proving people who say it can't be done wrong and doing it.

I appreciate any thoughts but lets keep this in the box a bit and remember that it has to be 2 watts or less NOT 5 watts or more. I have amps that sound great at 5 watts!!!! Even a Blackheart out of the box sounds pretty good. They are all too loud. Even a pretty much stock BF/SF champ amp is way too loud once it's made into a tone machine.

[jojokeo]

BD,
On a small amp of 2 watts having a tone stack is really debateable at that level. When the soundstage is higher/louder it becomes necessary but at that lower level it's more about the tubes, speaker, and guitar's settings for the sound and performance. There's too much loading down of the signal when everything's so small and is why I use only a tone control which can be bypassed. Do you think there's much bass response at 1 or 2 watts - no, there isn't. It would be easy to build in, no problem at all for sure - but worth it? Not in my experiences. You actually want bass at that low level. I think the smaller amps sound really good w/out a stack at all and I tailor the response w/ the use of coupling and bypass caps to sound it's best at all levels (but it's really only one level at that point which is mostly between 5 & 10 for the little guy mostly being set to 9 and forgetting it). With something small and simple, overdoing it w/ unnecessary things is easy to do and can easily be detrimental to the sound and performance. Less is more and in this case it's also practical. Too many controls that don't do much except look cool isn't the way to go.

Maybe you just like the scooped mid sound? Hmmm, you just gave me an idea of producing it w/out any pots and the signal may not suffer very much at all? I may give this a go later and see how it sounds & performs.

[bigdaddy]

Well I have a East Studio 2 watt amp that runs a full longtailed PI and a pair of 12AT7s that has a full tone stack and it is necessary without a doubt.

I have a Killer Ant which I removed the cathode driven preset tonestack and it made the amp sound 100X better with a change to a 12AY7 power tube and a 5751 preamp tube. But it needs a tone stack without a doubt.

I have been playing for 45 years and about 37 years ago started playing in bands and doing gigs. I think I know that I need a tone stack. I have owned many amps and the ones without a tone stack were always the first to go because I could not get my sound. One of the best sounding amps I owned was a brown deluxe, what a sound but it did not have a tones stack and I always struggled with it so it was sold.

Think of a Gibson Goldtop Les Paul with P-90s or even PAFs plugged into the normal channel on a real 1965 BF Super reverb with the voluming on 10, treble on 10, bass on 1-3 with the neck pickup on and that's my sound pretty much. Although a 50 watt Plexi MKII through a 120 watt Marshall cab from that time set pretty much the same way with the mids and bass down and presence down vol 10 treble 10 into the channel with the .0022 coupling cap, I forgot which channel had that was. It's been a long time since I was able to use amps that loud. But that has been my sound for so many years it's something that is not going to change anytime soon.

I NEED A TONE STACK........

[JB]

I've been building low power single ended and push pull amps for a few years now. I've tried a variety of output valves - 12AU7, EL91, 6BM8 etc. In each of these I've tried no tone controls, single tweed type control and full TMB (cathode follower and anode driven). Despite the relatively low volume I find a full tone stack sounds best. low power doesn't have to mean bass light. The bottom end can be a bit unruely and need some control over it.

Each to his own but for me a "standard" pre-amp with all the usual controls coupled to a midget power stage gives me good results.

[jojokeo]

One or two watts doesn't perform or sound the same as those larger amps. There's alot more going on interplaying each other but if you say so. It appears you just don't like bass but lots of highs and mids if those were your settings. I can see that when speakers are pushed but again at 1 or 2 watts this doesn't happen. The tubes I'm talking about are a 6an5, el95/6dl5, 6ar5, and even a cold biased 6aq5. Others are 6ak6 and 6au6s. Once you go up to a fully biased 6aq5, 6v6, or 6bq5 then there's much more power to actually get a speaker cone moving - then stacks become useable and justified, IMHO. These little ones barely vibrate the cone. Just my opinion and experience.

BD - if you want a stack then you would get one if I made you an amp. No problems, I'd actually love to prove myself wrong and change my mind on it. I just haven't wanted to sacrifice any gain or as little as possible using the small stuff when I play with it.

[bigdaddy]

As a rule I always felt bass is best left for the bass player. By not having a lot of bass in your sound it leaves a nice hole for the bass player to fill and makes his playing more transparent, which might be a bad thing if he can't play well. I hate bass players that use the buzzy high end, it cancels out a lot of nice mids and highs coming from other instruments and vocals. But the bass player wants to compete for being heard. So give the bass player his place, the only thing he has to compete with then is the drums.

Believe me I know this stuff from playing and doing live sound with my own systems. It's all about making music and that means leaving a space for everybody in the sound spectrum. Which is what I do by having that sound. It makes the sound of my guitar fill a narrower frequency band as not to interfere with other instruments.

The thing about a Fender tone stack is when the treble and volume is on 10 there is plenty of low end. It's just NOT pushed to the front and allows the mids and highs to breath. By breathing I mean it allows the speakers to reproduce those frequencies without the cancellations a lot of low end will do to guitar speakers. Like an old Jensen for instance, especially the Oxford models which got their name Oxfart for a reason. Add some lows to an Oxford and it does actually get a farty sound.

So my sound was developed at a time when Rock, blues rock and blues were all meeting at a place musically and the Fender amp was pretty much supreme for a guitar player but the Marshall stack was gaining ground.

As for a one or two watt amp, well there are issues in terms of electronics as well as acoustics. No reason a well thought out and designed 1 watt amp cannot have a fully operational tonestack.

[jojokeo]

I like your way to describe the band stuff and makes perfect sense. I'm not trying to argue about bass being used and infact depending on the volume and speaker, there's definately a sweet spot there to be dialed in. Once my gain, vol, and other settings are dialed in, I usually will turn the bass down completely and slowly bring it back up where needed to hit this sweet spot, kind of the same way I tune the strings to pitch.

I have to re-wire an extra 3 resistors and 1 cap and I can create a Fender two knob Bass/Treb stack out of my tone control. It will be used as a Bass control and being variable w/ the Treble & Mids being fixed. It shouldn't take more than 10 or 15 minutes unless the wife interrupts?  

[jojokeo]

I've only played it a few minutes but the results are in and... I will man-up, it is more variable and adjustable still w/ great tone (maybe even better) even for a little guy. I will also say Big D that w/ the bass controlled - it will help you to be able to tone that down which will help you stay quieter in your apartment complex and keep the peace. I also still used the switch to lift the stack and after this comparrison the tone did muddy up more w/out further filtering.
The amp's voice got clearer and more balanced and it still has plenty of gain running only a 12ay7 at the moment. With the bass turned full up it got a little Marshally mid scoop going and I'm only using 10k for the mid resistor.

[bnwitt]

Which amp are you talking about Jojokeo

[jojokeo]

I drew up a simple single ended 9 pin 12a_7 into a small pentode 7 pin tube citing the earlier tubes to interchange a bunch of them with. Reading Bigdaddy's posts a while back I thought it would be fun to mess around with for a change of pace. It's surprising how big sounding and loud they can be for such small wattages. A 3 watt 6ar5 seems almost as loud as a 6v6 or 6bq5. It's got a 3 way switch that controls V1a's bias points for gain levels and freq response and 4/8 ohm taps for various impedances.
There's a few friends that would like something like this so if I can keep it simple and cost effective yet sound good and be versitile then why not? I'm having a blast with it and still learning, today's lesson compliments of BD. I should know better than to think I know already.

[JB]

There you go! Tone stacks and mini amps can work well!  On my SE version I put the stack between the pre-amp and power amp (I know Bigdaddy you've said this doesn't work for you) which allows me some pre-amp distortion and reduces the drive to the output stage to a sensible level.  With scope/sig gen and some tweaking it's now set such that the output stage begins to distort then with increased input (turning up the guitar or the amps volume) the pre-amp starts to bend too.  So I'm getting a blend of both. 

Bigdaddy - I did try a LTPI version of the FireFly and it sounded better - more like a bigger amp's tone/distrotion characteristic.  I don't think I ever optimised the drive though - the LTPI has too much gain and ends up hitting the output too hard if you're not careful.  Think I had a cross line master in there at one point but tweaking of the LTPI itself to lower it's output would be better.  I've moved on to small power pentodes since then instead of the ECC82/12AU7 so don't have it running anymore.

 

[bnwitt]

Well now you've got to show us a gut shot.

[jojokeo]

- my bad. I didn't take any inside of the finished product before I changed from the tone control.  Check out the single bass control wired using my favorite Treb/Bass stack  - floating style. The "stack" can be switch out of circuit and I really like it that way too w/ all the richness. It gets bright w/ the Treb "full up" on certain settings and especially w/ a 6DL5/EL95 tube in it. I may have to add another resistor at the 500p to simulate it being at about "8" but then the tone pot on the guitar helps too. The bass control really changes the flavor in a very cool way at various levels, BD was right on w/ this one. I'd rather have this control than the treb control 'cause I like that up a lot anyway.

[shortfuse]

I wimped out on the Hoffman 50 for the 1st build and found some stuff on the firefly and decided to go with it for a 1st build.  I just got my parts in from Doug for a firefly and here are the schematics i ordered from.  Can you guys tell me if there any glitches to this before I start.  I woundered about a tone stack or at least a single tone knob.  I like the idea of the bypass.

[jojokeo]

>Can you guys tell me if there any glitches to this before I start.

I don't think so but didn't build it exactly like it is in the schematic. I found it a little noisy w/ the high gain therefore I raised the heaters which helps.

>I woundered about a tone stack or at least a single tone knob.  I like the idea of the bypass.

Didn't make one and may not really need one IMHO. The guitar's tone controls will work okay and since it's meant to be overdriven and cranked - and how I run mine most of the time, it's a moot point. You might like to atleast have a bypass option for the most gain you can get to take full advantage of what this thing does and you can get musical feedback at modest levels.

[jojokeo]

Little Giant update with bypass-able Bass/Treble stack. Runs very well with a 12au7 upto a 12bz7 and uses 6aq5/6ar5/6dl5 for output tubes.