Tweed 5F4 Super - Tone for Days - No clean?

[beckspeed]

I recently bought someone else's project, a Tweed 5f4 super amp chassis on ebay because he already did most of the work and I got it for less than I could buy the loose parts. Built a head cab for it and hooked it up to my standard 2x12 cab I use for most stuff. IT SOUNDS GLORIOUS! It's got that dirty ZZ top, Keith Richards, vintage rock tone. My question is: Even with single coils, I don't get it to clean up too much (amp volume above 2.5). I roll off the volume on the guitar, and by the time it's "clean" it's at a whisper. Thoughts?

Here is his description:
"Your looking at a 90's fender super amp gutted and converted to hand wired 5f4 Tweed super amp only the two inputs are wired and the first vol bass treble and mids control this is a 35w Tweed circuit

full size pots
Weber power tranny
Classic tone multi tap output tranny 2/4/8 ohm
Currently wired to 2 ohm
Fender replacement choke
(2) 6l6 power tubes
(3) 12ax7 preamp tubes
(1) g 34th rectifier tubeallory 150 series tone caps
F and T Germany filter caps


Any ideas? Thanks!

[SILVERGUN]

You could...
- Replace the first preamp tube with a 12AY7 (less front end gain- as 5F4 was intended)
- Try increasing NFB (put a 56K resistor in parallel with the existing 56K or use a pot and dial to taste)
The builder says "currently wired to 2 ohm" .... there is a chance that the NFB ratio is incorrect because most "builders" don't take this into account when they use a different secondary impedance than what was originally designed
- Most involved - try a different tone stack, since you have all of those empty control locations, you could implement a switchable tonestack network. The Tweed tonestack is mid-heavy and not as lossy as the mid scooped Blackface tonestack. That alone will give you the feel of having a completely different amp at the flick of a switch and should clean it up a bit.
 
I would start by trying to confirm that the amp you are looking at does actually match the schematic for the 5F4 Super...an accurate schematic will help guys help you get it right
 
http://el34world.com/charts/Schematics/files/fender/Fender_SUPER_5F4.pdf

[Tony Bones]

Here is his description:
"Your looking at a 90's fender super amp gutted and converted to hand wired 5f4 Tweed super amp only the two inputs are wired and the first vol bass treble and mids control this is a 35w Tweed circuit

I don't recall any tweed circuits with 12 knobs. I'm thinking it's not an exact copy of the 5f4.  Maybe tracing out a schematic would bring enlightenment.

[beckspeed]

Yeah sorry I changed the output to match my cab at 4 ohm - pretty easy with that OT. He also modified the tone stack to have a Mid control instead of presence. The first 4 controls are hooked up, the other 8 are just dummy knobs.

Would love to dial in dirty. I built an Ampmaker SE-5a and I love the controls. Preamp gain, bass, mid, treble and Master vol. I can blend a hundred different varieties of clean and dirt. I think it's a modified Champ circuit. Thanks!

[SILVERGUN]

Would have to see an accurate schematic to continue...........

[beckspeed]

ok  - I emailed the guy to see if he could enlighten me. if he doesn't respond I'll trace the circuit and compare to the stock 5f4. Thanks!

[Willabe]

Shot in the dark, see if the volume pot is Log or Linear.

Needs to be Log or the volume will jump up way to fast as you turn that pot.
 

[Ed_Chambley]

5F4 should be clean, the cleanest of the tweeds.  The choke position on the 5f4 includes filtration of the plates along with the screens.  First thing to check.  If it is not filtering the plates, it is not a 5F4.  Screen and Plates should be the same voltage.


If the tone stack has been modified and V1 as Silvergun said does not have a 12aY7 it will have some more dirt, but still not much.  What you are describing sounds more like a Pro, but could be anything really.


I still have one of these and even with humbuckers I do not get a tone like the Reverend Gibbons.  The Super 5F4 is a great amp IMO, but not generally associated with the tweed overdriven sound, even though it will do it, you gotta hit it hard.


You can get a schematic, but I really would not trust who built this.  If you want a 5F4, just make it so.

[beckspeed]

Yeah it was a Gamble - for $300 I'm not mad at all. He sold as "parts not working" for a reason - even though it worked fine(ish). I'm honestly in love with the tone, I'm a Marshall fan at heart - I was just hoping to modulate it a little more than I am. I have too many amps at the moment and they're all too big (other than my 5w SE5a) - so I'm on the search to find something in the 20-40W range that I can dial in both my clean and dirty tones. I dont mind kicking in the TS808 if i need to either.

This "5F4" is SO close.

[beckspeed]

Willabe -I'll check for Log or linear - thanks! also here's the preamp tube layout - all 12ax7 (and seller's questionable sheet metal work)

[edthill]

I recently went through a similar problem with an 18watt/5E3 hybrid build. I had a hell of a time getting her to clean up. I think the feedback circuit isn't a bad place to start.
Good luck.

[Tony Bones]

It would be really hard for me to resist the temptation to just rip up everything and start over from scratch.

[edthill]

It would be really hard for me to resist the temptation to just rip up everything and start over from scratch.

I'd definitely clean up the leads and the caps on the pots that aren't insulated, as well as the grounding.

[beckspeed]

Thanks edthill - I'll take a look

Tony Bones agreed! I got it all settled into a new head and I'm trying to resist pulling it back out and overhauling. I'm a metal fabricator so the sheet metal is killing me!

[beckspeed]

Update: Seller isn't saying anything more than it's a stock 5F4 circuit with a Mid control.

I took some time to turn some knobs and play a little more last night and it seems the "dirt" might be connected to the mid control. I rolled off 90% of the mid and about 90% of the bass and it cleaned way up.

I would blame the 2x12 cab / celestions, but I know they're plenty clean when connected to my Silverface twin.

[SILVERGUN]

5F4 should be clean, the cleanest of the tweeds.  The choke position on the 5f4 includes filtration of the plates along with the screens.  First thing to check.  If it is not filtering the plates, it is not a 5F4.  Screen and Plates should be the same voltage.

Thanks for mentioning that Ed...very easy to blow past that on the schematic.
 
beckspeed, can you give us the specs off of the label on that choke?
Just want to make sure that it's got an acceptable mA rating for the application... could be a potential failure if not correctly sized

[sluckey]

"Your looking at a 90's fender super amp gutted and converted to hand wired 5f4 Tweed super amp

I looked at all the 90s Fender super schematics I could find. The choke in all those amps would probably be under-rated for the 5F4 circuit. The easy fix would be to move the OT center tap to the first B+ node like the later supers. The accurate fix would be to replace the choke with a proper one. Probably no sonic difference between either fix.

[Ed_Chambley]

Attached is the 5F4 schematic.  Would you mind marking where a mid control has been placed.  Also, if there is a master volume, how is if implemented.


Modding this circuit is not very common and I have spent a lot of time with them.  I found if you change anything in this circuit, the change is significant and re-voices the amp.


I do not think ripping it apart is a bad idea necessarily, but I think what you are hearing is not a Super 5f4.  As a matter of fact, I am sure it is not.  It is common to replace a 6.8K resistor from lug 3 of the Bass pot to ground with a mid control.  But this is on a Blackface and some Brownface amps.


A 5F4 has 2, 1meg Volume Audio pots, one bright and a 1 meg linear on treble and the same on bass.  The reason I am even mentioning this is I think you dig the tone you have and I do not think it is a 5F4.


Are all the pots 1 meg?  Take a close look at this schematic and consider what would happen if you lifted the ground on the bass pot and added a mid.  Also, what is you mid pot value.  It is possible what is being called a mid pot is actually a raw control.


Maybe HBP will see this.  He knows this circuit very well and may have heard of someone adding a mid as I know he really prefers amps with mid controls.


The Super intentionally was mid scooped.  An easy way to get more clean volume is to remove mids.  This same idea proceeded further when higher power speakers became available.  The Super shared the same Output Transformer as the Pro and Bandmaster and would saturate fairly easily.  This was intentional and the Pro and Bandmaster passed a lot more mids than the Super, so the Super was much cleaner in comparison.


When someone mentions having that Tweed overdriven tone, normally that is a combination of Tubes, OT Saturation, Speaker breakup and a thinner baffle connected top and bottom only.  Both the Pro and Bandmaster were built this way.  The Super is different.  The Baffle was thicker and had 2, 10 inch speakers more rigid so the cabinet contributed less to the loose and wild sound of the Pro or Bandmaster.


This made the amp a lot cleaner.  So much so that is someone is wanting a Tweed tone, I would not recommend the 5F4.  Guess what my favorite Tweed amp is?  I like clean.


As Sluckey mentioned, moving the choke may not make any sonic differences, but there is a reason a larger one was used and we know if cost more to manufacture so someone thought it was worth the additional costs to filter the plates.  So the proper fix would be to get the correct one.


You might want to see if you can find a real 5f4 to play simply to make sure you like it before building one.  There are a lot os samples on youtube as well.  Here is one:


https://www.youtube.com/watch?v=hqtL41DPXnA

[Ed_Chambley]

Forgot to mention, the 5F4 Output transformer is 6.4K originally and changed to 6K in 1957 reflected and the one you have is 4K which is common to Super Reverbs and Bassmans.  The correct one from classic tone is part number 40-18088.  This has a multitap for the 3 speaker Bandmaster.


So it is 6K/2.67, 4 and 8 ohm.

[beckspeed]

I gotta check a bunch of those specs - the OT from Classic tone is #40-18105

the choke is TR-CK-01:
"Suitable Replacement Filter Choke For Fender® Brand 6L6 Amplifiers
TR-CK-01
 Tr ck 01 2
Suitable Replacement Filter Choke for Fender® Brand 6L6 amps. Proudly made in the USA.

This choke is similar to the Fender® Brand 125C1A & 022699 chokes used on Fender® Brand amps such as: Bassman®, Bandmaster, Bandmaster Reverb, Showman, Dual Showman®, Dual Showman Reverb®, Pro Reverb®, Twin, Twin Reverb®, Super Reverb®, Concert, Vibrosonic Reverb, Quadraverb, and some others."

[tubenit]

Maybe HBP will see this.  He knows this circuit very well

HBP and I jammed together quite a few years ago and I had a chance to hear his Tweed Super in person.  I knew very little about amps at the time.  (HBP was my amp building mentor & he is a better guitarist then I am also)

I remember that it had a beautiful clean with remarkable headroom.  And I remember that it had this really lush 3-D sound to it.  I asked him if it had reverb in it.  Obviously, it didn't.  However, I couldn't figure out why it had this remarkable 3-D sound to it?

with respect, Tubenit 

[Ed_Chambley]

I gotta check a bunch of those specs - the OT from Classic tone is #40-18105

the choke is TR-CK-01:
"Suitable Replacement Filter Choke For Fender® Brand 6L6 Amplifiers
TR-CK-01
 Tr ck 01 2
Suitable Replacement Filter Choke for Fender® Brand 6L6 amps. Proudly made in the USA.

This choke is similar to the Fender® Brand 125C1A & 022699 chokes used on Fender® Brand amps such as: Bassman®, Bandmaster, Bandmaster Reverb, Showman, Dual Showman®, Dual Showman Reverb®, Pro Reverb®, Twin, Twin Reverb®, Super Reverb®, Concert, Vibrosonic Reverb, Quadraverb, and some others."

I am not really telling you what you should do, just sharing what I know about the Tweed Super.  For some reason I have always loved Super amps and every time I get rid of one I get 2.


On the Schematic it has the Transformer and Choke numbers.  In the photo the mid pot has 100k written on it which makes me think it is a raw.  You got a good deal in parts, but the parts do not align with a 5F4.  With that Chassis you could build the Bassmam/Marshall crossover.  This is where the left channel is a Marshall 2204 and the center is a Fender Bassman.  I believe you Iron is more suited to a more modern 6L6GC output stage.


Member P2Pamps builds this type of amp and it is really a killer setup.  Here he is and he is a fine fellow.  He is showing the amp in the video.  More on his youtube if interested.


! No longer available

[HotBluePlates]

I recently bought someone else's project, a Tweed 5f4 super amp ... IT SOUNDS GLORIOUS! It's got that dirty ZZ top, Keith Richards, vintage rock tone. My question is: Even with single coils, I don't get it to clean up too much (amp volume above 2.5). ...

Here is his description:
"... 5f4 Tweed super amp ... vol bass treble and mids control ...

...  I found if you change anything in this circuit, the change is significant and re-voices the amp.

... I think what you are hearing is not a Super 5f4.  As a matter of fact, I am sure it is not. ...

... Maybe HBP will see this.  He knows this circuit very well and may have heard of someone adding a mid as I know he really prefers amps with mid controls.

The Super intentionally was mid scooped.  ...

Beckspeed:  You seem to like the amp as-is, so try this... Turn the "Mid" control to zero, and see if your headroom comes back.

Ed has called it right:  The pot in the "Mid" position doesn't do anything to midrange of the audio at all.  Instead it is wired between the grounds for the Treble & Bass circuits and actual chassis ground, as a means to defeat the tone circuit for more gain.  So "Mid" control at zero will return proper grounding to the Treble & Bass pots.  You'll probably find them a lot more effective.

I don't know any good way to add a Mid control to the Super's tone circuit.  Instead, you control Mids indirectly by adjusting Treble & Bass (but the position of each of those controls alters how the other control responds).  The Treble control sits inside a feedback loop, which alone will make it seem to perform in a strange way.

I didn't find the Presence control too useful in my personal 5F4 copy, so I put a switch to defeat the tonestack in its place.  Simple, 2 bits of wire and a SPST switch.

For reference, I was able to play mostly-clean through my 5F4 with the volume up around half, and sound louder than a 50w buzzbomb on a 4x12 (my amp was stock at the time).  Much of that was probably due to the buzzbomb being massively over-compressed with all the preamp distortion, as well as poor choice of tone control settings.  I added a little bit of overdrive to that with a Full-Drive 2 in the Comp Cut mode (less compressed, but also less distortion).  But that should let you know that there is quite a bit clean-ish volume on tap from a properly-functioning Super...

HBP and I jammed together quite a few years ago and I had a chance to hear his Tweed Super in person. ...

I remember that it had a beautiful clean with remarkable headroom.  And I remember that it had this really lush 3-D sound to it.  I asked him if it had reverb in it.  Obviously, it didn't.  However, I couldn't figure out why it had this remarkable 3-D sound to it? ...

Tubenit gives me too much credit & downplays his own amp & guitar skills!

I still think maybe you were hearing poor muting on my part (I often let strings ring when I'm playing, unless they're very-wrong notes)...

[SILVERGUN]

I gotta check a bunch of those specs - the OT from Classic tone is #40-18105

the choke is TR-CK-01:
"Suitable Replacement Filter Choke For Fender® Brand 6L6 Amplifiers
TR-CK-01
 Tr ck 01 2
Suitable Replacement Filter Choke for Fender® Brand 6L6 amps. Proudly made in the USA.

This choke is similar to the Fender® Brand 125C1A & 022699 chokes used on Fender® Brand amps such as: Bassman®, Bandmaster, Bandmaster Reverb, Showman, Dual Showman®, Dual Showman Reverb®, Pro Reverb®, Twin, Twin Reverb®, Super Reverb®, Concert, Vibrosonic Reverb, Quadraverb, and some others."

Ok, as we suspected, that is the wrong choke for the specific application in a 5F4 super.
The reason is because it has the current of the entire amp passing thru it, which includes the plate supply. (the plate supply is the heaviest current load in the amp, by far)
Those other amps that are listed use the choke between the plate supply and the rest of the amp so it doesn't have to pass the heavy plate supply current.
So, if you were to run the amp full out you would be exceeding the current capacity of that choke and it will eventually fail.

As the guys suggested, you can move it to between the plate and screen supply and save it's life.

[sluckey]

I gotta check a bunch of those specs - the OT from Classic tone is #40-18105

the choke is TR-CK-01:
"Suitable Replacement Filter Choke For Fender® Brand 6L6 Amplifiers
TR-CK-01
 Tr ck 01 2
Suitable Replacement Filter Choke for Fender® Brand 6L6 amps. Proudly made in the USA.

This choke is similar to the Fender® Brand 125C1A & 022699 chokes used on Fender® Brand amps such as: Bassman®, Bandmaster, Bandmaster Reverb, Showman, Dual Showman®, Dual Showman Reverb®, Pro Reverb®, Twin, Twin Reverb®, Super Reverb®, Concert, Vibrosonic Reverb, Quadraverb, and some others."

Ok, as we suspected, that is the wrong choke for the specific application in a 5F4 super.
The reason is because it has the current of the entire amp passing thru it, which includes the plate supply. (the plate supply is the heaviest current load in the amp, by far)
Those other amps that are listed use the choke between the plate supply and the rest of the amp so it doesn't have to pass the heavy plate supply current.
So, if you were to run the amp full out you would be exceeding the current capacity of that choke and it will eventually fail.

As the guys suggested, you can move it to between the plate and screen supply and save it's life.

Totally agree with SILVERGUN.

[Willabe]

I took some time to turn some knobs and play a little more last night and it seems the "dirt" might be connected to the mid control. I rolled off 90% of the mid and about 90% of the bass and it cleaned way up.

I would blame the 2x12 cab / celestions, but I know they're plenty clean when connected to my Silverface twin.

Ed has called it right:  The pot in the "Mid" position doesn't do anything to midrange of the audio at all.  Instead it is wired between the grounds for the Treble & Bass circuits and actual chassis ground, as a means to defeat the tone circuit for more gain.  So "Mid" control at zero will return proper grounding to the Treble & Bass pots.  You'll probably find them a lot more effective.

It's not the speakers, as the guy's are telling you, it's that 'mid' control that's not really a 'mid' control.

Like HBP and ? (I can't find the other members post, sorry) said, set that mid to 0 and see if that get's it.

[sluckey]

Guys, take a look at the 5F4 schematic. Where would you even try to put a MID control in this unusual tone stack? I think whoever tried did not know what they were doing.

[HotBluePlates]

Guys, take a look at the 5F4 schematic. Where would you even try to put a MID control in this unusual tone stack? ...

You wouldn't.  Because you can't.  Because that's not how the tone circuit is configured.

I spent a good 15 minutes squinting at the tone circuit and trying to convince myself there was some aspect about it that looked like a Bridged-T filter (in which you can add a Mid control), but it's just not there.

Regardless of how the seller couched it, I think the change is akin to a "Raw" control, but in the old Mid pot position.

... that is the wrong choke for the specific application in a 5F4 super. ...

Totally agree with SILVERGUN.

+2.

As Sluckey said before, move the position of the choke or get the correct, bigger part.

[beckspeed]

Haha you guys are the best!

The guy I bought from said he built and sold 50 hand wired amps last year - this was his personal one, and had some monor issues so was selling as-is. Like I said I'm 100% fine with all of that. It was pretty cheap. (and  like I said before - turning MID to zero cleaned it WAY up)

my questions:
How do I relocate the choke?
It it really going to kill the amp if I don't?
What will do to the tone?

Thanks again

[SILVERGUN]

How do I relocate the choke?

See the attatched pic I snipped from your initial post...wait for someone else to confirm

It it really going to kill the amp if I don't?

It will kill the choke....over-current is not a favorable condition in any circuit

What will do to the tone?

Probably nothing

[sluckey]

Leave the choke alone. It's fine. Just move the OT primary CT as shown in this pic. That's all.

You're not gonna kill the amp if you don't do this. But the choke may fail prematurely.

Your tone will sound SUPER.  All the later Super models (even the 6G4) have the OT CT connected as I'm suggesting.
 

[SILVERGUN]

I had to fix my snip pic.
Sluckey beat me to it.
His is prettier. 

[Ed_Chambley]

Check the fuse in it if you have not.  Make sure it is not tin foil wrapped.  Put in a 2 amp regular fuse if you have one.  Do chokes always fail open?

[SILVERGUN]

...  Do chokes always fail open?

Always, no.
Any time you have wire turns around a core they can also fail by a turn to turn short or a short to the core

[beckspeed]

Awesome guys thank you!

I pulled it apart and I'm creeping through every connection - I noticed only one of the caps on the volume is connected? the other is dangling?




more detail pics - i think they're getting shrunk though.





Thanks!

[beckspeed]

Well sluckey and Silvergun, you guys are freakin' Jedi masters! I moved the OT primary as you showed me and it cleaned the tone WAY up. Not so much that I lose anything, but it gets dirty at 6.5 with single coils instead of 2.5. Also the Mid is working more like a mid control now too? So what exactly did I just do?


Thanks Willabe, HotBlueplates and Ed-chambley for the assist. I also cleaned up the shitty sheet metal work and attached all the grounds with 8-32 threaded into the chassis, (plus a nut on the back side) they're snug now!

 


Thanks again!!

[shooter]

So what exactly did I just do?

Here's what I think you just did;

this takes all the big current to the tubes prior to the choke instead of after, letting the choke live a long and lazy life

[sluckey]

So what exactly did I just do?

You moved it up to the brown face era. 

[Ed_Chambley]

So what exactly did I just do?

You moved it up to the brown face era. 

Need  LTPI and a 350k trebel. Sounds Super.


Hey glad you liked the change. If you really want to know what you did google inductor input tube amp and read, then google cap input tube amp. That is unless you were just saying that.


Basically this is what you did. You really need to check your voltages now as they should have risen a good bit and you may need to cool the tubes a little. Not sure, but your volts surely should have risen.

[beckspeed]

Thanks Ed - While I understand the basic current flow in an amp and I get what all of the parts do (more or less) I'm still trying to learn how you can move one wire, and it changes the sound which also extends the life of components. That's a little of the "magic" of tube amp design that'm trying to better understand.

thanks

[beckspeed]

Ok so after a little reading, input configuration makes more sense was the amp previously wired incorrectly or was the builder being "creative" (or both) ?

"There are two common power supply configurations: capacitor input and choke input. The capacitor input filter doesn't necessarily have to have a choke, but it may have one for additional filtering. The choke input supply by definition must have a choke. Capacitor input filters are by far the most commonly used configuration in guitar amplifiers (in fact, I can't think of a production guitar amp that used a choke input filter).
The capacitor input supply will have a filter capacitor immediately following the rectifier. It may or may not then have a second filter composed of a series resistor or choke followed by another capacitor. The "cap, inductor, cap" network is commonly called a "Pi filter" network. The advantage of the capacitor input filter is higher output voltage, but it has poorer voltage regulation than the choke input filter. The output voltage approaches sqrt(2)*Vrms of the AC voltage."

[shooter]

You moved it up to the brown face era.

From tweed?     trying to "understand" some of the nuance.

thx

[sluckey]

You moved it up to the brown face era.

From tweed?     trying to "understand" some of the nuance.

Your post in reply #36 was exactly what he did. My brown face comment was aimed directly at the choke, not the entire amp.

The replacement Fender choke he used in this amp was designed to carry the current of the screens and little tubes only. It was not designed to carry the current for the plates. But he had it wired to carry the current for the entire amp! The choke was most likely operating saturated and that probably contributed to the lack of headroom. Moving the OT CT upstream of the choke allowed the choke to operate as it was designed without being saturated.

The more appropriate fix would have been to replace that little choke with a choke designed for the high current capacity of the 5F4 circuit. Results would probably have been comparable to the simple mod he made to the circuit.

Big filter caps were  relatively expensive during the Tweed era and big chokes were more affordable. But that flip-flopped in the '60s. That's probably the main reason Fender abandoned the big choke for the entire amp idea. Take a look at the Tweed and Brown circuits side by side. Notice how much the cap values have increased?

[Tony Bones]

They also added 470k screen resistors! Holy cow! (I know, it must be a typo, not to mention off topic. I always notice the stupid stuff.)

[shooter]

Take a look at the Tweed and Brown circuits side by side.

thanks Steve, the model#'s help, names just mess me up

[HotBluePlates]

Ok so after a little reading, input configuration makes more sense was the amp previously wired incorrectly or was the builder being "creative" (or both) ?

"There are two common power supply configurations: capacitor input and choke input. ...

Your amp was very likely cap-input the whole time.  That is, there was almost certainly a cap-to-ground right after the rectifier output.

The too-small (current-rating) choke used was probably saturating early when it was passing all of the amp's current.  Now it's not as it's only passing screen & preamp current.  And the amp is running like it should.  There probably would not be a performance benefit if you got the bigger choke and filtered the whole amp's current; I'd stick with what you have now.

[beckspeed]

OK  - issues persist with this amp. After moving the OT primary like you guys told me it got a lot better, but above 8.5 on the volume the distortion turns into a ugly mess.  So I finally crawled every connection in this "5F4" - I used a Mojotone layout to check the connections and found some VERY interesting differences. (top image is original - bottom is mine)

Main differences:
1) 1 volume and mid control in tone stack
2) No jumper for pin 1 & 8 on the 6L6G's - they are grounded with 1 ohm resistors
3) different values for caps and resistors shown in RED on lower diagram

Why would he have done these mods?  I like the idea of TMB tone stack and one volume - but it sounds like shit when I crank it. Suggestions? THANK YOU!

link to full size PDF http://beckspeed.com/blog/wp-content/uploads/2017/07/MK-SUPER-WD_ab_2_Flat.pdf

[PRR]

Pin 1 is the tube metal shell. Very few 6L6G-types have any exposed metal, and pin 1 is no-connection. So that is don't-care.

Pin 8 is cathode. Traditionally just grounded. If you are going to futz with the amp, it is very nice to put a 1 Ohm resistor there. This has NO effect on "tone" (would take over 10 Ohms to have any audible effect, and 50r to change the sound).

IMHO all Fendery tonestacks should have a MID knob. The alternative is a fixed resistor to set a default Mid level. If the mid pot is turned to about 10K to ground, it is the same as the no-Mid-knob option; but you can dial more or less scoop.

I don't think these changes are significant.

[beckspeed]

Interesting - what about the different cap/resistor values - especially with the elimination of the one Volume and the 47 pf cap instead of 100?

what else could cause it to sound pretty good until 8 and blubbery/distorted over 8.5?


Thanks for the quick reply!

[shooter]

from reply #14;

I rolled off 90% of the mid and about 90% of the bass and it cleaned way up.

do you have a distortion or gain pedal?, what happens when you keep the vol at 8 n use the pedals?  good "dirt?"