Banjo pickers and low cost 5F1

I'm not sure if we can tweak one of these little amps to suit the need of a friend and local musician who seems to think this little head unit I just finished if it can be tweaked to give him the clean tones hes after will have his sore back thanking him....Is this possible..I would be proud to see some of the locals enjoying the tones of this little 5F1 champ but many of them are acoustic players....can we dial these amps in to suit their ears..

I asked one of the local legends if he would test drive the 5E3 I built to give his opinion this past long weekend Country/bluegrass music festival we attended...got up on stage plugged straight into it with his tele, and because we didsn't have enough time to mess with it as the crowd waited, he said not enuff headroom and out came the deluxe reverb to do his set... Sheesh humbling...

I met a local up and coming phenom over the weekend who has a "partial" 5E3 circuit with a SS recitifer and after confirming with his amp tech he got back to me saying that the majority of the headroom he's getting from the amp is because of the solid state recitfier....

Although I love the tone from both these amps I'd love to have a few of them being used by some of my friends around here that are out playing all the time...what can I do to get these "cleanly" dialed in..

PS, The Champ I built in a head version and have a closed back 12" Blackheart cab...Thank you

I had a similar request last year and I can tell you what I did.
Increase the cathode resistor from 470 1W to 470 10W.
Switch the OT to a Classictone 40-18031
Switch 6V6 for 6L6 or KT-66
If you want to use an EL-34 then tie pins 1-8 together.
What you will end up with is a huge increase in headroom, more than a single coil could overdrive unless you dimed everything and really hit the strings hard.
The friend I did this for is a steel pedal player and he loves it, but it wasn't for my rock and roll ears. If I don't have some output tubes barking at me I'm lost.
There ma be easier ways to achieve what you want, but I know this works.

"Not Enough Clean Headroom" for a Bluegrass festival? I can see that. Don't be humbled. Those who do not know the beast, fear the beast. LOL.

Way I figure it AA764 (BF Champ) is a clean -ish amp that can be tweaked to play uber clean.

BF is clean enough to make a decent jazz amp.


5F1 is a dirt box so I tweak it to play uber dirty.

A tweaked tweed can be so nasty you'll crave tuned down guitars and Cookie Monster vocals. :lol:

...[QUOTE=boredguy6060;4184664]I had a similar request last year and I can tell you what I did.
Increase the cathode resistor from 470 1W to 470 10W.
Switch the OT to a Classictone 40-18031
Switch 6V6 for 6L6 or KT-66
If you want to use an EL-34 then tie pins 1-8 together.
What you will end up with is a huge increase in headroom, more than a single coil could overdrive unless you dimed everything and really hit the strings hard.


I not sure I understand how the wattge rating can effect tone as I thought it might be the resistance (470ohm) that would alter..But who am i to question....when i built the 5F1 I installed a 5 watt thinking thats what went in them but I see ceriatone schematic is 1Watt....so increasing the wattage will help increase headroom ??

I looked at the classictone 15 watt OT....do I not require changing up the 5Watt PT also if it's only producing 5W ?

good un Much...I guess the primary reason I went after the 5F1 was because of its compact size over anything else figuring once it was running I could tweak it to suit, and the the hunch back players I seem to jam with appear to be standing straighter due to it's small frame

http://i271.photobucket.com/albums/jj134/livtohunt60/editedcokecan.jpg

I had a similar request last year and I can tell you what I did.
Increase the cathode resistor from 470 1W to 470 10W.
Switch the OT to a Classictone 40-18031
Switch 6V6 for 6L6 or KT-66
If you want to use an EL-34 then tie pins 1-8 together.
What you will end up with is a huge increase in headroom, more than a single coil could overdrive unless you dimed everything and really hit the strings hard.


I not sure I understand how the wattage rating can effect tone as I thought it might be the resistance (470ohm) that would alter..But who am i to question....when i built the 5F1 I installed a 5 watt thinking thats what went in them but I see ceriatone schematic is 1Watt....so increasing the wattage will help increase headroom ??

I use 5 watt cathode resistors in my Champs which is way overkill. 5 watt is plenty for a 6L6 or an EL34. The stock cathode resistor is 2w carbon comp.

Carbon comps don't like heat.

The theory is to raise the power output of the amp so you get the same volume without having to drive the amp as hard. All else being equal (it isn't.) you gain 3db headroom by increasing your pwoer from 5 watts to 10 watts.

A 5F1 preamp is a dirty little monster. There's quite a bit of gain on tap there. Gain is volume until a tube stage saturates and clips. Then gain becomes distortion.

I looked at the classictone 15 watt OT....do I not require changing up the 5Watt PT also if it's only producing 5W ?

Remember I said, "All else being equal (it isn't.)"? One of these days I should run frequency sweeps comparing a stock Champ OT with premium iron. Be interesting to see how much the stocker rolls off the bottom end.

They call transformers "iron" because that's waht the core is made of. More iron = more bass.

good un Much...I guess the primary reason I went after the 5F1 was because of its compact size over anything else figuring once it was running I could tweak it to suit, and the the hunch back players I seem to jam with appear to be standing straighter due to it's small frame

Maybe there's something wrong with me but I never get tired of building 5F1s. Just when I think I've wrung every last drop outta that design I find another tone I didn't know was in there.

...[QUOTE=boredguy6060;4184664]I had a similar request last year and I can tell you what I did.
Increase the cathode resistor from 470 1W to 470 10W.
Switch the OT to a Classictone 40-18031
Switch 6V6 for 6L6 or KT-66
If you want to use an EL-34 then tie pins 1-8 together.
What you will end up with is a huge increase in headroom, more than a single coil could overdrive unless you dimed everything and really hit the strings hard.


I not sure I understand how the wattge rating can effect tone as I thought it might be the resistance (470ohm) that would alter..But who am i to question....when i built the 5F1 I installed a 5 watt thinking thats what went in them but I see ceriatone schematic is 1Watt....so increasing the wattage will help increase headroom ??

I looked at the classictone 15 watt OT....do I not require changing up the 5Watt PT also if it's only producing 5W ?

good un Much...I guess the primary reason I went after the 5F1 was because of its compact size over anything else figuring once it was running I could tweak it to suit, and the the hunch back players I seem to jam with appear to be standing straighter due to it's small frame

http://i271.photobucket.com/albums/jj134/livtohunt60/resizedandcropped.jpg

I hope you signed a deal with Coke before you posted those pic's...Trademark rights and all that.

Would Love to Hear it through my old 15" Electro Voice.

I'm a recovering banjo player. Wouldn't it be better to come up with a device that makes the banjo HARDER to hear?

MuchXS Quote..........

I use 5 watt cathode resistors in my Champs which is way overkill. 5 watt is plenty for a 6L6 or an EL34. The stock cathode resistor is 2w carbon comp.

Carbon comps don't like heat.

BUT HOW DOES INCREASE THE WATTAGE EFFECT TONE?? (SORRY ABOUT THE CAPS BUT I WANTED IT TO STAND OUT)

The theory is to raise the power output of the amp so you get the same volume without having to drive the amp as hard. All else being equal (it isn't.) you gain 3db headroom by increasing your pwoer from 5 watts to 10 watts.

A 5F1 preamp is a dirty little monster. There's quite a bit of gain on tap there. Gain is volume until a tube stage saturates and clips. Then gain becomes distortion. quote

SOUNDS LIKE YOU'VE PAID YOUR DUES WITH THESE LITTLE AMPS MUCH,,WHAT IS YOU TAKE ON ME GAINING AMPLE HEADROOM TO SUIT MY BUDDIES NEEDS WITH HIS ACOUSTIC ??

ALSO, if I need to order up a classictone 15watt OT, I'll likely order 2 of them buuuut, will or do I need to get a bigger Ironed PT as well...no sense doing half a job..thank you

Wileyone..whos advertising...where did you get that photo of that name brand beverage?? I too would like to hear a 15" and this little champ..it sounds great through that cheaper EH 12" that Ralph gave me thorugh that closed back blackheart cab....good looking tele in your avatar...nice colour! :lol:

New SteveH...lol..too funny...we're doing all we can to keep him doing chops thorughout the songs....drives me beyond crazy when someone with either a harmonica fiddle or banjo seem to think that playing melody throughout the entire song at normal volume is acceptable because it sounds good, because it simply Does Not...hang back, tone it down and come on in and let er rip for a "lead only"...it's taken time and patience but our banjo player is thankfully getting the hang of it..

MuchXS Quote..........

I use 5 watt cathode resistors in my Champs which is way overkill. 5 watt is plenty for a 6L6 or an EL34. The stock cathode resistor is 2w carbon comp.

Carbon comps don't like heat.

BUT HOW DOES INCREASE THE WATTAGE EFFECT TONE?? (SORRY ABOUT THE CAPS BUT I WANTED IT TO STAND OUT)

The theory is to raise the power output of the amp so you get the same volume without having to drive the amp as hard. All else being equal (it isn't.) you gain 3db headroom by increasing your pwoer from 5 watts to 10 watts.

A 5F1 preamp is a dirty little monster. There's quite a bit of gain on tap there. Gain is volume until a tube stage saturates and clips. Then gain becomes distortion. quote

SOUNDS LIKE YOU'VE PAID YOUR DUES WITH THESE LITTLE AMPS MUCH,,WHAT IS YOU TAKE ON ME GAINING AMPLE HEADROOM TO SUIT MY BUDDIES NEEDS WITH HIS ACOUSTIC ??

ALSO, if I need to order up a classictone 15watt OT, I'll likely order 2 of them buuuut, will or do I need to get a bigger Ironed PT as well...no sense doing half a job..thank you

The wattage should not do anything to the tone (I am guessing tone means distortion) to any great extent unless you get to the point where you are heating up the resistor to the point where you are changing its resistance. At that point I doubt it will live to a ripe old age.

With any dynamic range, 5 watts is not going to give you much clean output no matter what you do. Basically get the most efficient speaker you can. A better solution is to go P-P. The power transformer is already putting out a fair amount of current to run a Class A amp, not a heck of a lot more weight going to two output tubes. You can get another 5dB by adding another lb or two to an amp's weight.

Going to a larger output tube is an option but you do need the appropriate OT and PT to give the tube something to work with.

The wattage should not do anything to the tone (I am guessing tone means distortion) to any great extent unless you get to the point where you are heating up the resistor to the point where you are changing its resistance. At that point I doubt it will live to a ripe old age.

With any dynamic range, 5 watts is not going to give you much clean output no matter what you do. Basically get the most efficient speaker you can. A better solution is to go P-P. The power transformer is already putting out a fair amount of current to run a Class A amp, not a heck of a lot more weight going to two output tubes. You can get another 5dB by adding another lb or two to an amp's weight.

Going to a larger output tube is an option but you do need the appropriate OT and PT to give the tube something to work with.

Thanks Printer, but I went P-P and the amp still has too much gain to suit any acoustic players ears.. I'm driving a closebacked Blackheart cab with a 12" 75W 8ohm Electro Harmonics EHVR8 with no advertised sensitivity rating, but I mean it's sound ok as the price was right as a friend gave me 2 of them like brand new...

Thanks for also helping to clarify that the wattage of those cathode resistors shouldn't have any effect on tonal qualities...Adding another power tube would require a whole different board..Right?? cause i was thinking if I went to a beefier 15watt OT would I not have to up the output of the PT also....so therefor going to a 15 watt PT??

Adding another 1lb of weight will gain 5db,,,,different trannys would account for some of that and would beer cans without the tabs pulled help??

Thanks Printer, but I went P-P and the amp still has too much gain to suit any acoustic players ears.. I'm driving a closebacked Blackheart cab with a 12" 75W 8ohm Electro Harmonics EHVR8 with no advertised sensitivity rating, but I mean it's sound ok as the price was right as a friend gave me 2 of them like brand new...

Thanks for also helping to clarify that the wattage of those cathode resistors shouldn't have any effect on tonal qualities...Adding another power tube would require a whole different board..Right?? cause i was thinking if I went to a beefier 15watt OT would I not have to up the output of the PT also....so therefor going to a 15 watt PT??

Adding another 1lb of weight will gain 5db,,,,different trannys would account for some of that and would beer cans without the tabs pulled help??

I might not have read things properly but I thought the whole problem was the acoustic player had a problem with not enough clean output. Either a bigger SE amp or a P-P with more watts will go a ways to solve that. Thought one option was the 5E3 one (with a few modifications to go cleaner) or going to a 6L6 or the like and beefed up transformers, yes you need upgraded power and output.

While the 5E3 does have some clean output I would add some NFB to clean things up a bit. You can also use lower gain tubes in the preamp Getting rid of the bypass capacitors on the second stage and introduce NFB at that point will do wonders to clean up the amp. Also I would swap the input and output to the volume pots to the arrangement of latter Fenders. See the Harvard for both.

http://www.prowessamplifiers.com/schematics/fender/harvard_5f10_schem.pdf

Whether 15 watts will do it depends on the player and how loud the band is.

With any dynamic range, 5 watts is not going to give you much clean output no matter what you do. Basically get the most efficient speaker you can. A better solution is to go P-P. The power transformer is already putting out a fair amount of current to run a Class A amp, not a heck of a lot more weight going to two output tubes. You can get another 5dB by adding another lb or two to an amp's weight.

I've got my AA764 builds to play clean. Stock tube lineup, virtually the stock circuit.

I didn't think it could be done, either.

I'd really like to achieve sastisfactory headroom in this small package if possible simply for the weight reduction and low cost or production....

is adding a NFB to the circuit a big deal and where would you guys start with resistance...it goes V2 pin7 ??
would replacing the tube or having a switchable SS rec make any difference or worth the trouble...I suppose if it was you guys might have already mentioned it though huh..

I'd really like to achieve sastisfactory headroom in this small package if possible simply for the weight reduction and low cost or production....

is adding a NFB to the circuit a big deal and where would you guys start with resistance...it goes V2 pin7 ??
would replacing the tube or having a switchable SS rec make any difference or worth the trouble...I suppose if it was you guys might have already mentioned it though huh..


Take a look at AA764, the BF Champ schematic. The underlying circuit is essentially 5F1 with tone controls added.

The feedback loop is a little different. It's got a 2.7k instead of the 5F1's 22k but it's connected on the other end of the V1b cathode resistor. There's effectively around 3k in the NFB loop.


All the SS recto does is raise the plate voltage. Class A is "on" all the time so sag doesn't come into play the way it does in a Class AB1 amp.

Champs will play clean with 320v on the 6V6 plates. Raising the plate voltage makes sense if you're swapping to a tube that's designed for higher plate voltage such as a 5881 or an EL34.


You could always shoehorn an AA764 board into your homebrew. You get tone controls and lots more headroom.

I'd really like to achieve sastisfactory headroom in this small package if possible simply for the weight reduction and low cost or production....

is adding a NFB to the circuit a big deal and where would you guys start with resistance...it goes V2 pin7 ??
would replacing the tube or having a switchable SS rec make any difference or worth the trouble...I suppose if it was you guys might have already mentioned it though huh..

Just to be on the same page, we are talking on your current 5E3, right?

http://ampwares.com/schematics/deluxe_5e3.pdf

To add NFB as done with the Harvard, you remove the capacitor from across the 1500 ohm resistor attached the feedback resistor to pin 3 on V2. I would start with 56k, the value of resistance in the Harvard (I am guessing they used the same output transformer and speaker impedance) and adjust up or down to taste, easiest to put it inline with a switch and switch it in and out to see how much effect it gives. If you find you get feedback when you turn the amp up, the resistor is going to the wrong side of the output winding and you will have to reverse the leads (if you decide to try it).

Going to SS rectifier is not a bad idea, it will give you some extra voltage on the output and the preamp tubes giving them some extra headroom. I doubt you would have to rebias the tubes but it would be good to make sure to check them for red plating.

One other thing you could do is put 220k resistors inline with the output of the volume pots. This will cut a bit of signal and make the volume controls less interactive. Basically as the Brown Face Deluxe without the second tone control if you swap the input and output leads to the volume controls.

You can follow the progression Fender did with these amps to make them more clean. Starting from the 5E3 (not to say they did it in this order) you see with the Harvard, the volume control wiring change and going to fixed bias (which I would not bother with). Then you have the mixing resistors of the Brown Deluxe and the Long Tailed Pair phase inverter. Next is the Black Face (AA764, as suggested by muchxs, not a bad one at that) amps with the gain sucking tone stack that reduces how much dirt you can dial up. Along the way Fender kept increasing the voltage to get more headroom.

So with the least amount of effort you could do the following, feedback resistor, the diodes, change the volume pot hookup and add the mixing resistors.

It would be fun to put a Hahvard inside a 5F1 chassis.

5F1 Printer....

I'm still studying here Much

5F1 Printer....

I'm still studying here Much

Well then... ...Much?

It would be fun to put a Hahvard inside a 5F1 chassis.

Don't see why not. My table top amp is basically a Harvard, 6AQ5 rather than 6V6 and cathode bias mind you.

http://i406.photobucket.com/albums/pp142/printer2_photo/guitar%20amp/TabletopBackinside.jpg

If I can squeeze it and the treble and bass option in it, why not?

cool looking build Printer.. Well last night we finally got the new build sounding more like I needed it to Again with the help of you guys and also Crusinhome (not that he knows much, but I'm grateful he doesn't keep his opinions to himself :) )

Playing the tele/5F1 in it's stock form made everything super muddy with no definition of notes while the amp was dimed running it through a 12" EH 8ohm....because I couldn't find any specs on the speaker and didn't know what the rating was, I made a wire up to run my Eminence Cannabis Rex which is in my 5E3 combo, which did sound better but still really muddy..

we ended up changing the R13 22K resistor to a 10K which Really cleaned it up allowing more NFB....then wanted to try even less resistance and only could get a 4750ohm and again so much cleaner still so i left that alone....then changed the first stage cap from .022 to .01K and I can't get over how much cleaner and clearer the amp is...so I'll wait and let the guys test drive it now and see what they think..

I really want to order up a pair of 15watt Classictone transformers and try and set of 6L6's in there just to hear the difference....then if I can move this one build a AA764....

Well then... ...Much?

What was the question?

You are good at leading others in the finer points of the 5F1 (among other things), just throwing the ball to you. Just an oddball shot at humor implying P-P is not on the table. OK, it was a wee bit humorous to me, but then again almost anything I say amuses me.