6G8 - Missing link in the layout?

[uki]

Hey guys !

6G8 Twin-Amp , in the schematic there is two points called C and then going to a filter cap between the two 27k/1w resistors, +350v there , those points C, as far as I understand theye are connected, yes?   But in the layout instead there are two separated wires(blue) going from those points C to the filter cap, any special reason that was done this way? Can it be rearranged and link those points then use only one wire going to the filter cap?
Schematic:
http://el34world.com/charts/Schematics/files/fender/Fender_TWIN_6G8.pdf

Related links to this amp:
http://el34world.com/Forum/index.php?topic=18650.msg190792#msg190792
http://el34world.com/Forum/index.php?topic=18968.msg194798#msg194798

http://el34world.com/Forum/index.php?topic=19371.msg200109#msg200109

Work in progress:

[sluckey]

those points C, as far as I understand theye are connected, yes?  But in the layout instead there are two separated wires(blue) going from those points C to the filter cap, any special reason that was done this way? Can it be rearranged and link those points then use only one wire going to the filter cap?

Nice looking build!

Both points C are connected together. I don't see any special reason Fender decided to use separate wires to the cap board, but it doesn't matter. You can physically connect the points however you like. I'd probably run an under board jumper from that 56K to the junction of the two 100Ks. See pic...

[uki]

Thanks Sluckey !!

I'm arranging everything as best as possible, space is tight, in this reduced version of the amp I have to think carefully before doing things, my 1st build by the way, Its been a real challege ! 

Another thing about this amp, I have found somebody else that did a small modification in the power tubes section adding a grid resistor for each of the power tubes just like it is done in the Twin-Reverb amp AB763. Some info here in this post(another forum thou, its been a while): http://vintageamps.com/plexiboard/viewtopic.php?f=8&t=108139
So I did that too, makes sense to me, what are your thoutghs about it ?

 

[sluckey]

Good mod. I do that for all my 6V6, 6L6, or 5881 amps. You can't use pin 1 on an EL34 socket though.

[uki]

Good mod. I do that for all my 6V6, 6L6, or 5881 amps. You can't use pin 1 on an EL34 socket though.

That is good info, I had no idea, thanks for the hint. I got all resistors carbon composition type, I see you have there metal film ones, I've read somewhere in some parts of the circuit is better to use other types other than carbon comp, something to do with voltages and how resistor behave to it, in order to reduce noise, is that correct ? But I don't have great understanding about it or where to use different resistors, so for now I'm sticking with the original style.
 

Here a pic of the power tubes:

[uki]

In the original 6G8 schem there is a cap 47mmf (the highlighted area in the image 2), does that cap have to be removed when there is the power tubes grid resistors mod? The amp 1 in the image doesn't have the cap this one have the mod, the other amp 2 doesn't have the mod and have the cap.

[sluckey]

does that cap have to be removed when there is the power tubes grid resistors mod?

No.

[uki]

does that cap have to be removed when there is the power tubes grid resistors mod?

No.

Thanks, why did that guy removed the cap, what this one does in the circuit exactly?

I'm almost there, few wires to go:

[sluckey]

That cap is sometimes referred to as a high frequency snubber. Tubenit calls it a smoothing cap. It will kill some high end signal or brightness. It will also kill high frequency oscillations or noise.

I have amps that have a cap at that point, and I have amps that don't have that cap. None of my Fender amps have that cap but most all of my Marshall based amps have it.

So, try it without the cap. You can always easily add it later if needed. You can also just add it directly to the PI tube socket between pins 1 and 6, if that's more convenient.

[uki]

I have amps that have a cap at that point, and I have amps that don't have that cap. None of my Fender amps have that cap but most all of my Marshall based amps have it.

Why not, any special reason not having it on Fender amps?


Please tell me about my build, for a newbie, how is it looking like?

[sluckey]

I grew up in the blackface era. The BF Fender amps had a bright sound that I really liked. So, even today, I don't put anything in my Fender circuits that will mellow that bright sound. The Marshall sound that I came to like later on was more midrangy, not as bright. That sound often benefits from taming the highs a bit.

Your build looks very good to me. I would never know you are new to this from looking at the pics. We all like to see pics so keep 'em coming.   

[uki]

I grew up in the blackface era. The BF Fender amps had a bright sound that I really liked. So, even today, I don't put anything in my Fender circuits that will mellow that bright sound. The Marshall sound that I came to like later on was more midrangy, not as bright. That sound often benefits from taming the highs a bit.

Your build looks very good to me. I would never know you are new to this from looking at the pics. We all like to see pics so keep 'em coming.   

Any advise ?

Got it, so it will mellow the sound, I like that, and if one want more bright sound then no cap at that point, good info, thanks !!

I always wanted to have a Fender twin something amp, they are really really expensive down here, even second hand ones, I have some basic electronic knowledge used to work in a guitar factory and learned some stuff, so when I found out the schematics and specially the layouts online, I was like WOW, that is it gonna make one. And here I am. It is great experience to build an amp, also I want to understand more about it.

About the pics yeah I do like em too !!
I'll have some more soon.

Thanks again

PS. My latest song: https://soundcloud.com/ukiuki/uki-nova