Jubilee

[dcribbs1412]

Thanks alvarezh
I have looked at that layout for clues
my relay board is a little different from the old ones.(looks the same as afd relay.jpg)
I installed the relay on the opposite side of the traces
which in effect made the relay orientation backwards. Not sure if this makes any sense
I used the AFD #35 layout and flipped it along with the flipped 2555
layout for comparison I hope I got it right...
I'm hoping to bulb test tonight...

Darin

[alvarezh]

Not sure I follow you.

If you inverted the layout, just make sure the connections going from relay to DC supply and to board are the same.

If DC voltage wires are connected properly, signal wires misconnection may cause no output or inverted operation but no harm will be done.

Best wishes on the bulb test!

[dcribbs1412]

Thanks alvarezh
will report back when done

Darin

[dcribbs1412]

Bulb test was good...had to swap OT leads
Voltages are around 475V...bias around 30ma
it has sound...had to keep it low this morning... will crank and put it thru some tests asap

Darin

[alvarezh]

Congrats Darin, nice build!

Enjoy!

[dcribbs1412]

Thanks alvarezh
been busy lately but have had some time with the amp.
One thing is I cant get the bias down...that is the bias pot is on lowest setting
and I get 36-38ma (482V) on tubes...would like to be able to get a better sweep.
Do I adjust the 47k up or down? Sorry, cant wrap my head around the bias voltage
Trying to get it in a head cab this weekend
Comments or suggestions are greatly appreciated.

Darin

[Micky D]

Try lowering the 27k (maybe 22k) to get a colder bias setting in the middle of the pot range. This will give you more B- voltage to divide between the grids and ground. You could also raise the 47k to say 56k too.

[dcribbs1412]

Try lowering the 27k (maybe 22k) to get a colder bias setting in the middle of the pot range. This will give you more B- voltage to divide between the grids and ground. You could also raise the 47k to say 56k too.

Thanks Micky D
I should have know that...my mind is slipping, maybe not enough sleep or beer...anyways after checking closer the 47k is fine...I was turning/adjusting the bias pot upside down...I have plenty of sweep with the 47k
gonna let it burn-in a little more and get it in the cab.
Appreciate your time.

Darin

[dcribbs1412]

Had some time/beers today and got it in the cab
Cab from Sourmash, chassis/boards from Nik
The more I play it the more it plays me(may just be the beer)...sounds nice with a EV12L
FX loop works well with rack unit.
Liking this circuit ...its gotta a comfortable, raw overdrive?
Crap... I like the fake/non-tube internal stomp box OD ...OK I said it.
Actually get a decent clean sound rolling the guitar volume on the
"clean channel". Anyways here's some pics..next up SLO

Darin

[M Fowler]

Darin, the amp looks great.

I find that I can hear the difference with the channel select and rhythm clip only at high volume level. Not sure if that is normal.

Mark

[dcribbs1412]

Darin, the amp looks great.

I find that I can hear the difference with the channel select and rhythm clip only at high volume level. Not sure if that is normal.

Mark

Thanks Mark
Not sure what high volume would be...
I've been running the MV at 5-6 and the Lead Vol and Input gain at 6-7
that where the amp sounds good to me...
I can hear a difference...with the MV below 3 its hard to tell.

Darin

[M Fowler]

Yeah that about where I'm at too for best tone into 412 cab with Vintage 30's.

[dcribbs1412]

Yeah that about where I'm at too for best tone into 412 cab with Vintage 30's.

Nice...someday I hope to have the room for a 4x12 cab.
I do not have a lot of experience with Marshall amps.
How does this circuit compare to other Marshall designs? ie 900, 2203
or higher gain amps. Next up is a SLO...after that I have a extra 100 watt
Marshall style OT that will be staring at me...wondering what to try

Darin

[M Fowler]

That SLO will be nice always wanted one of those.

A 69 Plexi 100w is calling me and the Yeti 100w is on my radar.

I like my AFD #39 by DBM better then the 2550, just sounds better to me maybe I don't agree with diode clipping anymore.

Not sure why the 2203 isn't more popular I like that circuit and has about all the gain I need but it is fun to wail on a higher gain amp sometimes.

[M Fowler]

I took the chassis out of the cab today to get some finished photos I never took before. Don't look too closely.