Thunderchief cap question..

[petemoore]

Would the final coupling cap refferred to in the text accompanying the schematic be the 100nf that parallels the 4k7?

[B Tremblay]

The "final coupling cap" is the 22n between the third and fourth stages.

[Eddie]

Can I get more Bass  by increasing the value of this cap?
Or are the better ways to do it?
What cap value do you recommend?

Thanks!

Eddie

[petemoore]

I think I'll parallel one in there...possibly a switch.
 I ended up with a 100uf [big hey?] where the .68uf was under Q1.
 Q2 and Q3 didn't seem to like having their to ground caps increased much.
 I would say since small value changes at that last coupling cap [thanks for the learning tip: coupling caps between stages...learn something everyday around here...lol] reportedly make big changes in bass response, that's the one I go after today...I think I will need another spst though, the tuning I have now on the TC is quite nice.

[Gary]

Pete,

The cap to play with would be the 22n between the last J201 and the first 15k.  Try increasing that for more bass response.  Anything larger will give more low end.  If you go to, say 100n, you'll get more bass.  You may also notice it sounds a bit muddier.

Another idea to explore is to change the 68n cap on the first J201 to a 320uF or so to 1/2 emulate the bass channel of the Marshall.  That may work better for you than changing the last 22n cap.

[Eddie]

Thanks!

I tried 100 uF in parallel with the 68 uf cap.Sounds better now.

BTW I like the thunderchief alot!!!!

Eddie

[vdm]

as the TC has no tone control, i've been thinking of implementing an FAC control like on the old orange amplifiers, it's really simply a 6p1t (ummm i think thats it) with different caps the whole way round, with one end having all in parralel, then as you turn it, less and less caps are used in parralel until it passes straight through, with only the set cap before the rotary switch.

im still just planning to build mine... but the whole concept has really got me thinking, and i think, i'm just going to replace the front half of the TC with the orange preamp.... and use the 'power amp' section of the TC, simply because i'm not sure how it works. It is fairly similar to the meteor though, so i guess it's kind of tried and true.

i was never a big marshall fan - hence my decision to change the front end... it'll be interesting to see how similar it is to the original... i guess we'll have to wait and see eh...

trent

[Gary]

I tested the Orange MkII Graphic recently (in jfet form).  The FAC is a great idea.  It is very useful.  I think using the Marshall PI/power amp is also a great idea.  The Orange phase splitter was a source of unwanted fuzz.  There's not enough room for the signal to keep from being severly clipped and producing a Fuzz Face-type of effect.

Let me know if you try this hybrid simulation.  I'll bet it turns out great.  Be sure to try different values for the final drain cap, as this determines the bass content as much as the tone controls do.l

[Eddie]

I play with the thunderchief everyday now!

I changed the first 0,68uF/2k7 to 320 uF Electrolytic (ok??)/820 Ohms.
Like the Normal channel of the Superlead. The sound is beefier now. Maybe my preamp of my Amp is too bright.

Next question!

There are two Low pass filters at the output stage.Because I´m a newbie I asked myself why there are two! filters.

Could i use a pot instead of the 15 k resistors to insert a simple treble rolloff?
Do I have to use two pots because of the two LPF`s?

I´m  a newbie and I want to understand the tone control of this unit! :?:

Thanks!

Eddie