high gain amp design

[diagrammatiks]

capacitors only stack voltages when they are in series.

say the capacitor is expected to see 500volts. if we assume that you can go up to the max...

you can use 1 * 100uf at 500volts
2 * 200uf at 250 volts
4 * 100uf at 250 volts

ideally you'd want a little bit of leeway so you'd go 525 volts and 300volts.

Voltages won't stack if you parallel the caps. Also you cannot stack a multi-can cap with itself since there is only one ground terminal.

[beinz]

understood, sorry, i probably didnt clarify,

is there any lack of efficiency with using one 100uf+100uf/500v can as opposed to two 50uf+50uf/500v cans.
voltage would remain the same, just less cans...

im guessing no difference, same capacitance, just different packaging..

[diagrammatiks]

i still don't understand what you are trying to achieve?

are you running the sections in parallel?

[beinz]

my 2204 diagram uses a 50+50 in parallel to = 100uf for the mains, and another 50+50 in parallel to = 100uf as well for the screens,
so i may as well just use a dual section 100+100 and run each half section as mains/screens....
i believe this is what big teee is suggesting, this should work right?
assuming this works, im just wondering if there is any difference in efficiency running all this from 1 can instead of 2?

[J M Fahey]

If I understan you right, no, there is not difference in "efficiency" (which in this case *might* mean losses).
Use whatever you can buy conveniently.
And ... good luck.

[beinz]

this is what i figured, just wanted to make sure. thx

[big_teee]

this is what i figured, just wanted to make sure. thx

JJ Can Capacitor 100µF x 100µF / 500V
Here You Go.
T

[beinz]

i have attached layouts for ceriatone 2204 and 2550. the 1 last part of my design i am unsure of so far is the placement of the standby switch.
i have read about marshalls blowing fuzes and other things regarding where in the circuit the standby is placed. i am still unsure if there is a "better or worse" or safer or less safe way to do this. the 2204 schem i have been using has the switch wired up as in the 2550 diagram. i have also heard people suggest the wiring in the 2204 diagram.
are there advantages to one way or another?

[beinz]

space saver!

[big_teee]

You still need one 50/50 or 32/32uf for the Preamp input stages.
I like to put it under the board.
On the Ceriatone Layout it is mounted on the board.
I built mine more on the TriodeStore Layout.
JCM8002204v1Stock.pdf
Good Luck,
B_T

[beinz]

teee - i just want to make sure im correct, but i am only basing the poweramp stage on the 2204, the preamp stage is based on the slo100 od channel, so the pre's are missing a bunch of what is in the 2204 pre section (as soldano is largely based on the marshall circuit). mine will have no clean or crunch channel, only 1 high gain channel.
to help get me there i have also been referencing a soldano avenger layout as this amp has only the od channel, and shows me what to omit from the pre stage.
i believe this 50+50 you are referring to would be left out of my layout?
please correct me if im wrong.

[big_teee]

teee - i just want to make sure im correct, but i am only basing the poweramp stage on the 2204, the preamp stage is based on the slo100 od channel, so the pre's are missing a bunch of what is in the 2204 pre section (as soldano is largely based on the marshall circuit). mine will have no clean or crunch channel, only 1 high gain channel.
to help get me there i have also been referencing a soldano avenger layout as this amp has only the od channel, and shows me what to omit from the pre stage.
i believe this 50+50 you are referring to would be left out of my layout?
please correct me if im wrong.

Where is the Layout.
I would think you would still need plate B+ Filtering for all stages.
I will try to find the avenger Schematic or Layout.
T

[beinz]

i think this is it
the 100k and 82k PI plate resistors go to a (in this case) 47uf sing can which is also connected to the 10k dropping resistor, the other end of the resistor on the avenger layout goes to a single 100uf can, but on the 2204 the 10k resistor goes from on half of a 50+50 can to the other half, from there also to the choke, screens ect.
the avenger layout does put 33uf filters after v1 and v2, is this what you are talking about?

btw, if you know where i can get my hands on a proper avenger schematic, id be a pretty happy amper, this is all i could find, i backed it up against a hotrod schem i have, but it also has the extra clean and crunch stages, then finally against the 2204.

[big_teee]

[ATTACH=CONFIG]16627[/ATTACH]
i think this is it
the 100k and 82k PI plate resistors go to a (in this case) 47uf sing can which is also connected to the 10k dropping resistor, the other end of the resistor on the avenger layout goes to a single 100uf can, but on the 2204 the 10k resistor goes from on half of a 50+50 can to the other half, from there also to the choke, screens ect.
the avenger layout does put 33uf filters after v1 and v2, is this what you are talking about?
btw, if you know where i can get my hands on a proper avenger schematic, id be a pretty happy amper, this is all i could find, i backed it up against a hotrod schem i have, but it also has the extra clean and crunch stages, then finally against the 2204.

Yes that is a lot different filtering circuit than the 2204.
All 3 Caps all look to be filtering.
They filter the B+ Twice for each stage.
Once for both Stages with the 47uf
Then each stage again with the 33uf.
They are trying to get rid of hum with the huge amount of gain.
What you could do is use one of these.
http://tubedepot.com/cp-jj-40-20x3-500v.html
You could use 2 cans under the board a 32/32 and a 47uf can or a 32/32, and a 50/50uf and use one or both portions.
I think if you get the uf in the ball park it would work.
I will have to look at the layout some more.
Very interesting.
T
Edit Note**
I didn't find the Avenger.
But, I found another 4 preamp Tube Soldano.
I like the looks of it.
Soldano Super Lead 60.
http://www.el34world.com/charts/Sche...lead%20_60.pdf

[imaradiostar]

You should probably clarify if you want 4 gain stages and a cathode follower or three gain stages and a cathode follower. It makes a huge difference!

SLO100/Dual Rect/Uberschall are four gain stages + CF. Marshall 2204 and Bogner Shiva (at least the earlier ones) are 3 plus CF. Still others (Engl for example) are four gain stages without a cathode follower. I feel like the cathode follower is crucial but I have a metalhead friend that swears by his Engl so it's really your call.

If you haven't bought Merlin's first book you should- it clarifies easy ways to improve the whole effect send/return situation. The Soldano method is really not as good as it could be with a few small changes.

You can easily build an SLO style preamp and use a mosfet for the effect send (since it's only acting as a source follower) and still have a single triode leftover for effect loop recovery. 4x12ax7's and two output tubes.

jamie