All this talk about Doug Hammond's firefly has got me interested in starting an amp project. However, I'm stuck between the firefly and AX84's P1. I already have the tubes (spares) to build the P1. But, I'm interseted in the volume level issue. I currently play through a 1st generation Crate vintage club 50 (I know there's some Crate-Haters out there, but it's decent). I believe it's rated at 40W, uses 4 12AX7's in the pre and 4 EL84's in the power and a 3-10" combo set up. I'd like to get about a 1/3 maybe a 1/4 of the volume of this amp for practice purposes. I guess that I'm a little worried about versitality and loudness. Does the firefly just stay cranked, or can it do clean well? I'm looking to get the volume up enough to feel good vibrations--just before the room starts to vibrate. It's hard sometimes judging soley on soundclips. I would like to hear what you'all have to say about this.
Hey, I've built both, so I'll try to tell you what I can. The P1 (standard, not hi-octane) can do very chimey clean and good "on the edge" breakup, and when it's driven hard there's a lot of power tube distortion, which is great for classic rock stuff (ACDC, Aerosmith, etc). Through a single 12 inch speaker it's very loud, requiring shouting to be heard over it. It's a huge 5-7 watts. After awhile, though, I find myself craving some more preamp distortion, which perhaps could be obtained with the Hi-Octane version of this amp (although boosting it with the clean boost on my Sparkle Drive sounds pretty darn good).
The Firefly breaks up soon with my 2 12ax7s in the preamp. It can't get all that loud on the non-boost setting without breaking up, although the breakup is very smooth and desirable. Rolling back the guitar volume helps with this. But the distortion is definitely the highlight of the Firefly, as is does it extremely well. I am having some problems with squealing on the boost channel (not because of the circuit- completely my sloppiness in the layout), so I can only vouch for the non-boost setting. It sounds amazing! Thick, warm, rich, tight, smooth, focused, SWEET. And based on the sound clips on Doug's page, the boost setting is incredible! Listen to those clips and be amazed! The volume on the non-boost is very adequate for jamming my pants off at home, it's loud enough that I can sing (screech?) without others hearing me over the wailing, which is good for them. :) I can't say how loud the boost section would be, although the squealing on mine is ear-piercing :) .
In conclusion, these are both great amps and very fun builds. If you're looking to be able to do clean stuff, I'd go with the P1, and I'd recommend trying the hi-octane version, which adds another preamp stage for higher gain, and I've heard great things about it. This way you'd get good distortion sounds and still be able to get clean sounds at decent volumes.
I hope my analysis is correct, it's based on the (questionable) assumption that my stuff is built correctly. I hope I covered enough to help you out.
Alex
heh, i should have a look at the firefly.
my current main amp is a P1 power section with an EF86 preamp, out of the vox AC15. sounds like a zillion dollars to me. i want to get a better OT tho.
funny, this forum has been crossing over into talking about amps a fair bit!
I think a lot of people have been surprised by how much popularity the FireFly has attained around here, but you can be assured it isn't without really good reason. :D Plus, just install a direct out jack and a dummy load and the FireFly becomes a tube distortion device. ;)
I have a self-split 12AU7 amp with a slightly different preamp and it sounds fantastic to me. The overdrive of the 12AU7 sounds surprisingly "large". I've also done parallel triode 12AU7 and 12AT amps that are much like a Fender up to the third stage connected to the reverb send point. With a 4th stage for a serious overdrive I've been able to hit a whole bunch of absolutely agazing tones using a variety of coupling caps and absolutely nail the Jefferson Starship "Ride the Tiger" lead tone. 8)
If you want more power it's a simple matter of using a direct out and plugging that into a tube buffered phase inverter + EL84 or EL34 or 6L6 power stage. You'll get all the volume you want that way.
The ultimate effect for me is tube overdrive and these little tubes can do it quite well in the right context.
Build a FireFly today! :D
Take care,
-Peter
I was actually thinking of doing both a firefly and a High Octane. But then I come to my next problem: how do I drive my reverb tank with tubes? I have a reverb tank here, might as well use it. Any suggestions?
You could mod the Firefly to use an EL84 and it would be a lot louder. My slightly modified (but more-or-less stock) Firefly (Rev. 3) gets pretty loud for 1.5 watts, but it's not loud enough to have to shout over. But it would be great for studio work in an isolation room with a good mic, nice distortion at low volume levels.
I would also say it's a "Must Build".
This is good stuff. I guess there is the P2 version that has two channels that can switch between the P1 and the High Octane. I can do crystal clean at low volume on my current amp. My cost projections see the P1 and Firefly running about the same. My speaker choices would either be Jensen reissiue-type 10" with the alnico magnet or two 8" ceramic magnet speakers. Maybe, the Firefly would be a good platform for future mods that would lend it to increased versatility. Living in a duplex has made this "downsizing" a must. I have been practicing through my PodXT with earphones and I'm noticing that my hearing is being damaged through this and other ways. That's why I need some volume, but not too much. My ears have become a little foggy, so I appreciate moderately loud volume. However, I realize that too much volume at close proximity is leading me to early hearing loss. Being deaf and thirty isn't cool if I can help it.
Quote from: idlefaction
my current main amp is a P1 power section with an EF86 preamp, out of the vox AC15. sounds like a zillion dollars to me.
That sounds really nice. One of my future plans it build a mini-voxalike with a 6au6 input stage. The amp I'm getting started on right now uses a 6sj7 metal pentode input stg. I'm really curious to hear how these pentode preamps sound, I've heard so many good reports.
Quote from: idlefaction
funny, this forum has been crossing over into talking about amps a fair bit!
Yes, and for Aron's sake I'm a little uncomfortable about it, since this is his stompbox forum. I kind of wish we could move these discussions over to the ax84 forum. They discuss a lot of the exact same things, and there are more knowledgable people over there to answer questions.
Doug
Quote from: gorohonThis is good stuff. I guess there is the P2 version that has two channels that can switch between the P1 and the High Octane. I can do crystal clean at low volume on my current amp. My cost projections see the P1 and Firefly running about the same. My speaker choices would either be Jensen reissiue-type 10" with the alcino magnet or two 8" ceramic magnet speakers. Maybe, the Firefly would be a good platform for future mods that would lend it to increased versitility. Living in a duplex has made this "downsizing" a must. I have been practicing through my PodXT with earphones and I'm noticing that my hearing is being damaged through this and other ways. That's why I need some volume, but not too much. My ears have become a little foggy, so I
appreciate moderately loud volume. However, I realize that too much volume at close proximity is leading me to early hearing loss. Being deaf and thirty isn't cool if I can help it.
I can tell you right now that a Firefly through a 1x12 or even 2x8 will be *way* too loud for a duplex. You should think about using an attenuator or building a direct setup like Peter suggested. For that matter, the P1 and it's variants will be even louder. These amps push the power tubes hard to get their distortion sounds. So you have to turn them up for that tone. They are not master-volume preamps. Part of the reason they sound so "big" for their size is that they are pounding the signal all the way to and through the output stage.
Please be careful with the headphones. They can really sneak up on you and cause problems. I quit using them years ago because I noticed a very faint ring in my ears when everything was quiet. It was like, "Okay, that's enough for me..."
Doug
Quote from: Doug HYes, and for Aron's sake I'm a little uncomfortable about it, since this is his stompbox forum. I kind of wish we could move these discussions over to the ax84 forum. They discuss a lot of the exact same things, and there are more knowledgable people over there to answer questions.
Why not ask Aron or Peter to make a seperate forum for amp questions? I do notice more and more people asking for amp help, so why not? :?
Quote from: smoguzbenjaminQuote from: Doug HYes, and for Aron's sake I'm a little uncomfortable about it, since this is his stompbox forum. I kind of wish we could move these discussions over to the ax84 forum. They discuss a lot of the exact same things, and there are more knowledgable people over there to answer questions.
Why not ask Aron or Peter to make a seperate forum for amp questions? I do notice more and more people asking for amp help, so why not? :?
Because:
1. For the purely selfish reason that I'm one of the very few "amp guys" answering questions. I don't feel qualified to answer everything about amps and don't have time to field a lot of questions anyway. There is a much broader base of support over at ax84. If I don't feel like answering one day, someone else will (and vice-versa), and chances are it will be a more intelligent answer anyway.
2. Why duplicate something we already have? Lots of firefly/P1 builders over at ax84 already. The P1 came from ax84 and Chris mentioned he would like to add the firefly as an "official" project. It makes more sense to me to just move the discussion over there. You all are more than welcome. It is a *very* friendly group, one of the best forums of this type on the internet. It's a great place for beginner amp builders too, much better than Ampage, IMO.
Doug
True ;)
The next thing I would like to add to my Firefly is a line-out jack for going straight to a board. I think you could also use a cabinet simulator with it, too. Something like a Bulldog, maybe? What do you do for a dummy load? Is it just an 8 ohm/5 watt resistor connected across the speaker jack?
I've put up one post so far at the AX84 forum. I'm just sharing some of my tweaks with the guys here since this is where I first heard about this amp. 8)
BTW, that 124 ohm resistor on the B+ supply drops the voltage by 3 volts. A 470 ohm drops it by 6 volts. So, I was thinking that maybe a 1K-2K resistor might be good. I currently have a 470 ohm installed. It seems to add a slight amount of compression. Maybe I'll have my wife listen to it tonight and see if she can hear any difference.
All the replies have been fantastic. I have recently explored AX84 and will use that more. But, since the Firefly has been mentioned in this forum so much, I thought it would be a good place to get input on it.
Referring to volume, I guess how well the speakers deliver or, for a lack of a better word, throw the sound makes a big difference in perceived loudness, wouldn't you'all agree?
Doug, where would you put a carbon comp resistor(s) in your V.3 Firefly?
I have no idea what Aron thinks about this and it is his forum, but personally I have no trouble with a little crossover just to spark interest in a fairly different end of electronics. Once that spark is lit (at least for tube folks), http://www.ax84.com is a much better place for the reasons Doug has mentioned.
The people who get excited about little solid state amps (Gem, Ruby, etc.) don't seem to have as much of a good option out there. Hopefully somebody can suggest a good spot, but in the looking I've done it seems like there's an instant jump from guitar amps into audiophile/audiophool territory.
On dummy loads, sure you can just use a resistor like an 8 ohm watt, but watch out for the heat of any dummy load resistor. In Ham radio, dummy loads are very often in cans of oil to deal with heat dissipation. You can use a Switchcraft 12A switching jack to select either the dummy load or the real speaker just by plugging in. If the plates don't see the impedance of the speaker, bad things will happen. Using the switching jack doubles as a safety mechanism. For a better dummy load, check out http://www.aikenamps.com/spkrload.html at http://www.aikenamps.com/ for more information.
Finally on hearing..... For a number of years I worked in nightclubs and for a big concert promoter. I was often in locations in the house where the sound was *much* louder than it was on the floor. In my younger days I was also a fan of the punk rock scene in San Francisco and that crowd tends to like volume. As a result I have tinitus and trust me.... you don't want it. It's a real bummer to be hiking 20 miles from the nearest road when you stop to enjoy the silence and realize that you will never hear real silence again. I constantly hear what sounds like a 17-20KHz ringing in my ears. When I was really young I couldn't even venture near the TV section of the local department store because the 15.75KHz sound from that department was actually painful. Now I can't hear that sound at all.
Hearing Education and Awareness for Rockers
http://www.hearnet.com
You can always swap gear, but your ears are for life.
take care,
-Peter
"In my younger days I was also a fan of the punk rock scene in San Francisco "
Peter, did you ever get a chance to see the Dead Kennedys with Jello fronting the band? I was in high school 78-82 and I lived for the LA scene. Went to school with and am still close with members of Adolescents, Social Distortion, Agent Orange, etc. Fun and exciting time in music, I wouldn't change a single thing given the chance.
Take care, Jered
Hi Jared,
Unfortunately I never saw DK. :( They were on their last legs just as I was discovering that universe, but they will always be one of my most favorite bands. I'm always listening to them and somehow I just never get tired of them. I haven't even listened to anything post-Jello after following the behind-the-scenes garbage with the breakup.
I saw Social Distortion at least once I believe (some of that time is a bit blurry). I remember seeing Circle Jerks, MDC, The Mr. T Experience, Bad Brains, RKL (rich kids on LSD), Verbal Abuse, GBH, Attitude Adjustment, and a whole bunch of nameless locals. What a fun time :D. For me it was an escape from alcoholic parents and the music was just so honest and alive. I know what you mean. :D
When evolution is outlawed, only outlaws will evolve. ;)
Take care,
-Peter
Hi Peter, aaahhh...the Bad Brains, I can't recall a band that is so tight, that rocks as hard as the Bad Brains, and the amount of pot these guys would smoke was unfxxxing believable! But they are devout Rastafarians and have thier ways and beliefs.
I was lucky enough to spend a day with them in Vanqouver Canada when I was doing the guit tech for Cadillac Tramps and they played a show together.
A few months back a friends band was opening for DK at the Key Club in Hollywood so I went and DK was pretty unimpressive. Original bass and guit player but very lifeless set filled with mistakes. To be honest...it was awful.
I heard Jello has a radio show in the bay area? Is it a music show? Political? He's a pretty bright guy, great lyrics.
Jered
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Quote from: Paul MarossyThe next thing I would like to add to my Firefly is a line-out jack for going straight to a board. I think you could also use a cabinet simulator with it, too. Something like a Bulldog, maybe? What do you do for a dummy load? Is it just an 8 ohm/5 watt resistor connected across the speaker jack?
Adam Alpern has a nice writeup on attenuators:
http://amps.zugster.net/articles/attenuation/index.html
He mentions that simple resistive L-pads work fine for low-power amps.
You are correct in that you will want some kind of EQ too. I think the many "speaker simulator" eq's are good candidates.
Quote from: Paul Marossy
BTW, that 124 ohm resistor on the B+ supply drops the voltage by 3 volts. A 470 ohm drops it by 6 volts. So, I was thinking that maybe a 1K-2K resistor might be good. I currently have a 470 ohm installed. It seems to add a slight amount of compression. Maybe I'll have my wife listen to it tonight and see if she can hear any difference.
I don't think 3 volts is going to make an appreciable difference. But even if it is psycho-acoustics who cares? As long as you like the sound, that's what matters.
Doug
Hey, csj,
I think you nailed my jones. I've been salivating over the 18w site. My Crate is awful hard to move around, so I thought to my self, do a small amp then do an 18w or a November. I like to play clean as well, overdriven, and some higher gain. I have a problem in that my own music is less gain dependent, but for fun I like to burn. I started playing guitar after seeing my first concert--Gun's`n'Roses opening for Iron Maiden. I didn't get into the "hair" scene though. I got into punk retroactivley because of Gun's, which then turned me on to Mudhoney and Soundgarden. My own style came by way of discovering Big Star and Badfinger. My favorite guitarist of all time is Mick Ronson R.I.P. So, why the long story? I've been trying to figure out how to satisfy my complex tone jones, and the amp building is becoming my mainman. I like building pedals and coming up with new sounds, but I prefer letting my amp do the talking. I like big and small sounding amps. I would love to have a Supro or a Champ. If I had the money to burn, my main amp would be a Matchless Cheiftan. My Crate would be better if it wasn't all pcb--it doesn't lend itself to much experimentation. Man, I take up alot of space on these things.
I changed that resistor to a 1K last night. It drops the voltage by about 12 volts now. A more noticeable difference, subtle as it is. I wonder, what effect it would have if you put a capacitor in parallel with it?
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Thanks again, Clay. I'm going to check out Westlabs and see what it's all about.
Quote from: Peter SnowbergPlus, just install a direct out jack and a dummy load and the FireFly becomes a tube distortion device. ;)
Voila! No more OT problem!
Thanks all, for a nice discussion.
Ben