Big Bottle clean amp ~30-40 watts

[llama]

Hi all,
I've been asked about building a bigger amp with plenty of headroom for pedal board use.  Not sure If I'm ready to take on  a bigger amp, but...

here is the question from the player: "I am looking for a 1 channel head 30+ watts that has tremendous tone and head room... straight clean is fine as I have tweaked my pedal board for this style amp.... I have a Rivera Jake Studio Combo now, 35 and 55 watts (switchable). I love the el 84s but I have read that the EL 34s allow for more headroom... Let me know your thoughts.."

Not having the experience hearing a lot of different amps, what existing amps types might work for him.  I suppose, I should find out more about his effects and where he places thin in his chain with respect to the amp. (effects loop or input).

I'm concerned about the juxtaposition of his quest for "tremendous tone" and the use of a pedal board...

any thoughts?

[Willabe]

Any of the BF Fender PP amps with a pair of 6L6"s/5881's take pedals really well.

He mentioned EL34's and you could build an AB763 with EL34's for the output. You should also built where it could use either 6L6 or EL34.

I bet there's schemos already here in the schematic library for it.

Dougs got the iron set for it too.


             Brad      

[Ed_Chambley]

I agree with the AB763 circuit.  It is not a difficult build until you add Reverb and Tremolo.  Then it is just more parts.  It is really not harder to build, just more to do.  The only problem with building for 6:L6 and EL34 is the output transformer.  While EL34 will run with an OT around 5k, they prefer 3.4k.  I have 5 different versions of this circuit in amps.  Four are built like super reverbs.  One is a BlackFace Deluxe.  One I built in a head and I experiment a lot with it.  It is built with the tubes up and the reverb pan is mounted to the top of the head.  It has a PPIMV Master volume and 2 effects loops.  When I installed EL34's in it, I did not like it very well as the amp is mid scoped by nature and EL34's shine best in mids and upper mids.

The best one of all is a 73 Super Reverb which I converted to a AB763.  No master volume or effects loop.  It is a 4, 10 and has Weber Alnicos on top and Weber ceramic on bottom.  It has a few tweaks to cap values, but not much.  It has a switchable Negative Feedback.  I get far more complements on this amp than any others I have.  One other thing is it has bias vary tremolo instead of the roach and has no effects loop.  The only drawback to no loop is delay.  Delay sounds better to me if not running into the front input.  The delay is fine unless you are using reverb at the same time.  Everything else is great.  The cool thing about the AB763 is it takes on a different character with guitar changes and no guitar sounds muddy, humbuckers or single coil.

If all your client is needing is a clean amp you can just build a lite version and not incorporate verb and tremolo.  I have tried the circuit with many different tubes and to me 6L6's just sound better and have more flexibility.

[smackoj]

llama; I can see the reason for your apprehension. I think the "player" may have a confused idea about what he is trying to find? IMO There is no quest for "tremendous tone" when you are looking for a vehicle to strap your pedal board to. Whatever tone the amp has would be covered by pedal-itis. What he may want for tone is a good 2x12 or 4x? speaker cabinet. That's where "tremendous" tone happens. Then, he needs a straight forward and solid power amp to lite the speakers up. I would personally steer clear of EL34s for this duty because they color the sound more towards Plexi Heaven and, as stated before, they won't match up with the OT well on an American tube design i.e. the BF/SF AB763. Stiick with the 6L6/5881 designs.

I know there is a lot of good info with schemes and layouts of AB763 "Lite" types already on this forum. Here is a link to one of Sluckey's well designed amps called a Deluxe Lite because it uses the 6V6 power tubes....maybe he can steer you towards one that uses bigger output tubes?

http://home.comcast.net/~seluckey/amps/misc/AB763_Deluxe_Lite.pdf

 

[SILVERGUN]

I'm with these guys....
The best part about Sluckey's is he did all of the work for you  

When I think clean headroom, I think 6L6 (and yes, they will be a huge improvement over EL84)

It really doesn't get any simpler than his Lite design  

[llama]

Thanks guys.   This is the first time someone's asked me to build something that I haven't tried yet.  

I suppose the next step is to build a BOM and get prices to figure out my cost.

What kind of rate should i charge for my time?  I tend to go too cheap, because I'm still learning, but, then again papa needs new strings...

Thanks again!!

[SILVERGUN]

You're gonna spend more time in this process than you could possibly charge this guy if you were trying to calculate hourly...

An amp builders time is worth what the end result justifies....If you change your last name to Dumble it'll be about $1500/hour 

Total up the actual parts, add $100 to cover misc. items: wire, solder, hair that you will lose, etc., etc.
Then just put a number on it that makes you happy.......if you were a master builder, this amp should take you a day to assemble @ $80/hour
8 hours X $80 = $640

Add that to the parts total, and you're gonna be around $1100 minimum 

The customer would love to pay about $400 total, so there's gonna be a little difference in your numbers 

 

[tubeswell]

EL34s don't have as much headroom as 6L6s (all other things being equal) due to the lower bias voltage of EL34s. If you want max headroom, build him a BF style amp.

[eleventeen]

30 years ago I built essentially a single channel Super Reverb in a SF Princeton Reverb. This involved replacing the power and output trannies, changing to 6L6, little beefier power supply parts and reworked bias circuit. I used the power and output trannies from a Dyna mono 35 amp, so those are probably a smidge better quality than Fender trannies would be...in terms of bass response (which I like bec I am more a jazz player) Not very hard, really. I only wish I had bot ten of those things because as many PRs as you wanted for $$75-$125, I could have found them. Nobody wanted 6V6 power back then. I used the princeton choke which technically is undersize, I suppose.

The amp turned out spectacular; I ripped out the tremolo and threw in another gain stage. At first it was right on the edge of out-of-control. My Gawd, that was a loud little SOB. I vowed to try to reduce the gain of the thrown-in stage but I could not get it right....I had little access to a bench where I could tweak values, and frankly did not know how to chop the gain.

20 years later, I completely forgot what I had done as far as mods, so I ripped out all the mods and turned it back into very much a single channel straight ahead Super Reverb. (still no tremolo) No extra gain stage.  I'm very happy with the amp. IMO, if you want clean or part clean or mostly clean and the 35 watt range, you go with 6L6s and that's an easy decision.

Fender now makes (or recently made) an amp along these lines, the so-called "VM" (Vintage Modified) series. They have a princeton sized one with 2 6L6 and a 12", pretty much the same as my little booger.

[smackoj]

that is a very cool story 11teen....I'd like to see a picture if you would share one?

thanks     

[eleventeen]

It'll take me a bit to get pix...it's in No CA and I am in LA, but am planning on returning up there.

But there isn't a heck of a lot to see. It looks exactly like a SF PR....bigger power trans in the same place as the old one, and, stand-up output tranny moved to the far end of the chassis. Little hairy splicing the OT leads, because they have to travel over the top surface of the chassis to be fed down thru the grommeted hole the old ones' leads go thru. But I used Hi-grade/hi-voltage rating wire and loads of plastic tubing around the spliced leads. It's been fine for 30 years, so there you go.

The (much bigger, replacement) output tranny had to be moved because it interfered with the spider of the (now) 12" speaker. I did similar to a Deluxe Reverb and had to rotate the speaker just a skosh so that the (centrally-mounted) output tranny would actually poke slightly into the space between spokes on the speaker! That was tight. I also have an Altec 417-C speaker in there; those have sort of deep spiders. JBL D-120's are much shallower speaker in terms of how much space the spider takes up. But those were the speakers I had...and still do. Nowadayws I NEVER hear anyone speak about Altecs or JBLs....those were the shizzle back when I was more active playing.

 

[HotBluePlates]

here is the question from the player: "I am looking for a 1 channel head 30+ watts that has tremendous tone and head room... straight clean is fine as I have tweaked my pedal board for this style amp.... I have a Rivera Jake Studio Combo now, 35 and 55 watts (switchable). I love the el 84s but I have read that the EL 34s allow for more headroom... Let me know your thoughts.."

...

I'm concerned about the juxtaposition of his quest for "tremendous tone" and the use of a pedal board...

You are right to be worried.

No one can crawl inside the guy's head and figure out what "tremendous tone" and "headroom" mean, or why he wants 30w+, but already has an amp that does that.

I would suggest that most guitarists wouldn't equate "perfectly clean" or "mondo headroom" with "tremendous tone" because what makes the amp sound tubey to them is subtle or non-subtle distortion.

I suppose the next step is to build a BOM and get prices to figure out my cost.

Seriously, no this should not be your next step. Maybe I'm nervous or cynical, but I think your next step should be to get the guy to rigidly define what he wants, and how it needs to be different from what he already has.

30w+ and headroom? How bout a 100w Twin Reverb? That was a gigging staple for decades for folks that needed clean no matter what and got distortion/effects from their pedals. Or what about a solid-state power amp with a tube preamp? Or an all solid-state amp is the sounds are coming from the pedals and clean is what's needed. People have done that, too.

What does he need this amp to do that his present amp doesn't do? Clean louder or quieter than the amp he has now? Other features/controls needed? Speakers in the amp? Which ones (cause the amp will sound different, maybe radically, with different speakers)?

You might need to go with the guy to a music store as he auditions every amp in there, whether he thinks it will do the job for him or not, to hear for yourself what the guy wants/doesn't want.

I'm worried for you because players tend to get a fantasy in their head of what an amp will sound like, and use vague terms to describe what they want. Then they get upset if you do your best to make an expensive handmade amp, and it doesn't match the fantasy they had and didn't adequately communicate to you.

[SILVERGUN]

I don't know who this HBP guy is, BUT when he speaks,,I listen....

If your customer is a friend who you can be 100% honest with, I would just print that out and let him read it !

-Did your amp turn out exactly like you thought it would? 

I suppose the next step is to build a BOM and get prices to figure out my cost.

Seriously, no this should not be your next step. Maybe I'm nervous or cynical, but I think your next step should be to get the guy to rigidly define what he wants, and how it needs to be different from what he already has.

You asked a good question and you got a great answer..........priceless

He's got me re-thinking my own expectations

[llama]

I contacted the player and told him that I would like to work with him, but want to find out more, and discover what he really wants.

Thanks for your words of wisdom HBP!

I get the 6L6 tube idea for clean headroom.  Do the 6V6's have good headroom as well for their output, Are they 30watts for 2 in P-P?

Eleventeen,  I have a similar amp in my "shop".  It used to be a mid sixties Princeton Reverb, but now has monster trannies, 6L6's and an extra gain stage in the recto socket location (SS recto now).  The owner calls is a MesaBoogie, as that is what Randall Smith used to do with them.  The pics is below, I wonder Who JG is (logo) .

Thanks again guys!  All great info!!!

[SILVERGUN]

I get the 6L6 tube idea for clean headroom.  Do the 6V6's have good headroom as well for their output, Are they 30watts for 2 in P-P?

HBP will be back I'm sure......
But in the meantime,,,,,we need to adjust your definition of headroom  (in simple terms, cause I'm a simple person)

Picture headroom as being the maximum volume you can achieve before the signal distorts at the output tubes.
This is why HBP recommended a 100 watt Twin Reverb----you'll never want to crank it up loud enough to create distortion
That's where your headroom will be ---you'll have 100 watts available, but you'll never use it, and therefore the amp won't easily distort

The 6V6s will be the exact opposite....If you use 2- 6V6 as your output stage your limiting your max. output to ~20-25 watts,,,and then if you do want to get 20 watts (lets say),,,you'll have to turn the Master vol. on the amp up, which will push the tube towards distortion (break up)

Consider headroom the opposite of break-up,,,,if that helps 

[SILVERGUN]

Just for the record....
If I was trying to do max. clean headroon, for as loud as I would ever need it to be,,,I'd try to create a D'ble Steel String Singer Type (4x6L6) 100watt'ish
I'm sure it's been done,,,,, and if you really want to build something special, it's worth a Google...
Without all the bells and whistles, it's still a fairly simple design....
Someday..........

Here'as a quote from Stevie:
Right now, I use a Howard Dumble 150-watt. He calls it the Steel String Singer; I call it the King Tone Consoul [laughs]--that's s-o-u-l. It's like an overgrown Fender tube amp. Some Dumbles, like the Overdrive Special, you got to know what you're doing with them, because they'll get away from you and take you with 'em.

If that sparks your interest,,,check with Tubenit,,,,I think it may have sparked his at one time