Phaez gives away EL84 design

[tedmich]

Phaez amps guy Randy Fay (ontariomaximus on youtube) has kindly made his EL84PP design available over at AX84. Its quite simple and has a wonderful tone.

clips
YouTube - Phaez Daisycutter 14 watt with EL84's
discussion
AX84.com - The Cooperative Tube Guitar Amp Project
schematic
http://tubeampmods.com/18w_daisycutter_april_2010.jpg

[Bruce / Mission Amps]

Sounds like a moderate dose of reverb and digital delay mixed in there too.
Ho hum... just what we need, another wanky, over driven El84 amp... but I guess that's what the AX84 site is all about anyhow, so... have fun children.

[Gaz]

Bruce burn. Ouch.

[tedmich]

Sounds like a moderate dose of reverb and digital delay mixed in there too.
Ho hum... just what we need, another wanky, over driven El84 amp... but I guess that's what the AX84 site is all about anyhow, so... have fun children.

its two amps with a delay to the second one I believe, as Randy states he likes that sound and dislikes FX loops.

AX84 is about collaboration and community and many very smart people enjoy it, hardly children.

It may not be what YOU need Bruce, but that's been open to much conjecture over the years, usually involving something with a relatively high velocity

[Hardtailed]

So basically, he wanted to add a tone stack to the Tiny Terror, so he switched to a (pardon me here but I don't know the exact name for that one-triode PI) and used the extra triode to drive the tone stack.

I'm not sure why he's driving it with the anode though, I'm guessing max gain was the point here.

A high-gain 2XEL84 is actually something that a lot of rock guitarists are asking for at the moment. Even Marshall came out with the Haze15 (6V6 actually) which is... really not that good, but it shows what people are asking for.

It's true though that in practice, especially with a band, high-gain does not always go so well with low-power.

[d95err]

I think the use of a concertina directly after the tonestack is rather clever. The concertina has a gain of (slightly below) 1, so whatever signal level comes out of the tonestack is what has to drive the power tubes. It works with EL84s, but probably not with bigger tubes.

[Albert Kreuzer]

It works with EL84s, but probably not with bigger tubes.

Many old EL34 amps use a cathodyne/concertina PI. The Dynacord Eminent EMT comes to mind.
Beam power tubes like 6L6 need more voltage swing, so an LTP would be a better solution.

Cheers,
Albert

[d95err]

Many old EL34 amps use a cathodyne/concertina PI. The Dynacord Eminent EMT comes to mind.
Beam power tubes like 6L6 need more voltage swing, so an LTP would be a better solution.

Cheers,
Albert

The concertina is typically preceded by a gain ("driver") stage to get maximum output through the PI. The clever part of this design is skipping the driver stage, despite the tone stack dropping the signal level significantly.

It works here because EL84s don't require very high signal levels to drive, and because it's a high-gain design that doesn't need to smash the output stage with insane signal levels to get distortion.

[tedmich]

someone at ax84 postulated the varied bias points on the pre gain stages creates "harmonic complexity"

I don't know, but it breathes beautifully IMO

[Hardtailed]

someone at ax84 postulated the varied bias points on the pre gain stages creates "harmonic complexity"

I don't know, but it breathes beautifully IMO

Most high-gainers (if not all) have varied bias points.

[J M Fahey]

Thanks for posting.
Probably not a ground breaking design, but has the interesting trick of having the Master volume *just* before a gain-of-one PI, which turns it into the functional equivalent of a PPI Master Volume.
I think it's a little overpowered for a bedroom-warrior musician, the classic 5 watts typical of AX84 being better suited to the task, and it definitely is underpowered for stage use.
Yea, I know that driving 4 x 103dB/W Fanes in an old Hiwatt cabinet or 2 15" JBLs in a Dual Showman cabinet it will be deafening, but the real world commercial speaker within its builder's budget will not be that loud.
As a side note, I like different AX84 versions very much.

[Bruce / Mission Amps]

its two amps with a delay to the second one I believe, as Randy states he likes that sound and dislikes FX loops.

AX84 is about collaboration and community and many very smart people enjoy it, hardly children.

It may not be what YOU need Bruce, but that's been open to much conjecture over the years, usually involving something with a relatively high velocity

That was tongue in cheek but...
Right, not only do I not need them, I hate the juvenile sounds of massive preamp overdrive and thin over driven EL84s... Bumble bees in a paper bag... wanker stuff.
To be honest, I guess a guy should give the end user what ever they think they want, it's their money.... but I don't know anyone who actually plays out, (even once in blue moon, semi-professionally), that uses those kind of amps.
I do know know lots of kids and youngsters who try to use them and I hear them furiously wanking away like mad every time I stop by the local Guitar Center to visit some friends, then I run to the restroom and vomit.... with the other adults.
And by the way, it's just a hobby but I've known and supported Chris at AX84 for many years... so I am quite aware of what turns the crank and squirts the grease there.

At least the Ark Amps are cool looking!

[Chuck H]

Hey... Wait a moment. I gathered the toungue in cheek, but I didn't think you really had such disdain for the late model run of OD EL84 amps on the scene. I'm thinking about the Tiny Terror, the Badger, the Dr. Z offerings, The Vox reissues and of course the Trainwreck Liverpool clones. The Marshall "18 Watt" thing is a crossover distortion, over done buzzy mess, but there are some viable options using this power tube. My 2009 NAMM show offering for Dean Markley was in this genre and I think it's a really good amp.

The OD EL84 thing is really "last week" in the amp biz though. My design was actually shelved in favor of a 6L6 Chinese labor MV model cheapo...

With the economy in the tank the market has become very specific. Bad scene for some of us. (I don't have to tell you)

Still. don't lump us all in together with the "18 Watt" clones. Some of us designing with EL84"s ARE trying to make good amps.

Chuck

[J M Fahey]

6L6 Chinese labor MV model cheapo...

With the economy in the tank the market has become very specific. Bad scene for some of us. (I don't have to tell you)

Well, you don't have to tell me, neither.
Only thing that saves me, in Argentina, is that our drummers play LOUD, and 18 watters just don't cut it, so kids (95% market share) do consider getting a local made 50 or 100 watter instead of a "famous label" Tiny Terror, Night Train, Haze, or whatever, and those who don't, get swamped by a much louder friend at the next session. God bless loud drummers.
As a side note, I also get to sell a lot of 2x12" SS100W powered guitar boxes, to boost those who bought an underpowered tube amp.

[Merlinb]

That was tongue in cheek but...
Right, not only do I not need them, I hate the juvenile sounds of massive preamp overdrive and thin over driven EL84s... Bumble bees in a paper bag... wanker stuff.

At the risk of you giving EL84s a bad name, they don't have to sound any thinner than EL34s. Both have extremely similar grid current characteristics. The 'traditional' thinness is mainly due to OT choice; EL34s typically use lower primary impedance.