@ Steve

  • Thread starter Thread starter duesentrieb
  • Start date Start date
duesentrieb":3v6mqsjw said:
You're an artist, Steve.

Looks great. But thinking of where to place the relays, I'd "neighbour" the master- and gainpots for the two modes Plexi&800s (gain/gain - master/master).
Put them side by side - you can either switch their outs or shunt them to ground with the relay. Less wire - less probs with noise, you know . . .

Also the LEDs should be either on top or bottom of the panel. My experience tells me that the supply for them shouldn't be too close to any wire carrying signals, you know . . .
Click to expand...

Here's a better layout based on your comments.

amp_switching_layout_2.JPG


Steve
 
duesentrieb":a73wwo2t said:
On a side not: if you should decide that a bigger chassis would be fine for you (if you don't have one yet),
here's the full schem for a Plexi/800s amp done by Marc Müller - with loop, deep and stuff . . .
Click to expand...

That is very cool, but I'm completely committed to this fitting this amp in a 100W Super Lead style headcase and chassis - I may have to have them custom made a bit less wide (like Splawn) on the front panel to fit the extra controls, but we'll see...

Steve
 
duesentrieb":l7meznvt said:
Now some little problems (you've expected them, didn't you? :D )

With your "Masters" after the loop and two (not speaking about the Jose mod yet) completely (levelwise) different channels, you will probably run into problems when your loop is "on". Because the input of the FX unit will see two (probably extremely) different levels - thats why normally one would place your "masters" in front of the loop (then they will act as send level masters) and put an additional Global-Master (GM) after the whole loop stuff.

If you decide to do that you could run an extra relay (simul. to the loop bypass relay) for the global master and take the GM out of the circuitry when the loop is bypassed, you know . . .
Click to expand...

This makes sense. I went back and forth on where to put the masters and there are tradeoffs either way. Let's say that I put the "channel masters" before the efx loop... Since I have a PPIMV, do I really need the Global Master? I'm assuming since I can adjust all three (Jose, Rod and Plex) masters to have the same volume hitting the effects loop (for live purposes), I can just adjust the overall volume with the PPIMV, no?

Steve
 
duesentrieb":3c0t67rn said:
Here's a pic for ya, Steve.

On top you see the principal wiring. Off the first CC you go into one side of the relay, which switches between Plexi/800s.
The Plexi line is directly hooked to the 470k/470pF combination in front of V2A. The 800s line is going thru the full circuit.

Now there will be one problem: if Plexi is active, V1B will create some noise, so either you shunt the grounds of the gainpots to ground (by using a double relay and wire them vice versa) or (thats what I do) use a VTL5C1 opto-coupler (used by Fender, Soldano, Bogner) to put the unused triode after its gainpot (or behind the 68k) to ground.

Since you will be switching the relay's "-" (= ground), you can simultanously switch the VTLs "-" (just run the "-" parallel).
Calculating the VTL:
(supplyvoltage V -1.65 V) /30 mA = R in front of "+" of the VTL - assuming its 6V
6-1.65/30 = 145 Ohm

ok?

The lower part shows that also simult. with the relay for the "input" (upper sheet) you can switch the masters for each "channel". Run the inputs of the pots in parallel and switch their outputs.
Click to expand...

I think I may have this section handled pretty well - let me put up my schem either tonight or tomorrow night (depending on if I have time to finish tonight) and let me know what you think... You are really helping me think this through, Olaf! I'm starting to "get" this switching stuff a bit...

Steve
 
sah5150":3jl27wzh said:
p... Since I have a PPIMV, do I really need the Global Master? I'm assuming since I can adjust all three (Jose, Rod and Plex) masters to have the same volume hitting the effects loop (for live purposes), I can just adjust the overall volume with the PPIMV, no?

Steve
Click to expand...
Of course a PPIMV (if you like it) is fine, Steve.
And if you should use this amp jut at home it really doesn't matter - but when you go gigging/jamming, you should locate them before the loop and either use a fx unit with in/out pots or your PPIMV.
 
duesentrieb":2y2v7flt said:
sah5150":2y2v7flt said:
p... Since I have a PPIMV, do I really need the Global Master? I'm assuming since I can adjust all three (Jose, Rod and Plex) masters to have the same volume hitting the effects loop (for live purposes), I can just adjust the overall volume with the PPIMV, no?

Steve
Click to expand...
Of course a PPIMV (if you like it) is fine, Steve.
And if you should use this amp jut at home it really doesn't matter - but when you go gigging/jamming, you should locate them before the loop and either use a fx unit with in/out pots or your PPIMV.
Click to expand...

Well, now that I've been jamming out, I want to be able to switch between the 3 modes and have the volumes exactly where I want and adjust the overall volume with the PPIMV (I actually like them - although I want the option to have it out of the circuit for recording in PLEX mode with the gain and volume on that channel cranked). Many times, I won't even need the PPIMV, unless I'm at home...

Also note - my effects loop also has send return pots (and can be switched series/parallel)...

What do you think of the new layout I posted - Should work ok, I think... Updated schems soon!

Steve
 
From the input side I'd go like this:

input/both gainpots/3 band eq/all masters/presence

Why?

Following the principal schem that would be how the parts will be found internally --> short wires, lower noise.
The switches (and LEDs) can be located anywhere, between input and gain or at the masters - those "ground" wires need some attention, but not too much.
 
Ich hoffe, dass Ihr bildet Ihr Fleisch nicht juckend lederhosen!!!
 
duesentrieb":3317leyi said:
From the input side I'd go like this:

input/both gainpots/3 band eq/all masters/presence

Why?

Following the principal schem that would be how the parts will be found internally --> short wires, lower noise.
The switches (and LEDs) can be located anywhere, between input and gain or at the masters - those "ground" wires need some attention, but not too much.
Click to expand...

Ok, How 'bout this?

amp_switching_layout_3.JPG


Never really seen a Marshall style amp layed out like this, but if it'll be less noisy, who cares?

Steve
 
Olaf - New Schematics based on all our discussion so far. Note these schems are for the Omron G5A-234P Relay, which looks like this:

Omron_G5A-234P_Relay.JPG


Below are the new preamp schems. I only show manual switches this time. Next (if these are correct) are to include the footswitching. Since I have 5 relays, I think I'll need to use a 7 pin midi connector... Let me know what you think!

Steve

100Watt2ChannelPreAmp.jpg

100Watt2ChannelEFXLoop.jpg
 
Hi Steve,

will have a close look later today.
You don't need a 7 PIN - 5 PINs is enough b/c you just have "three" sets of relays, some of them are switched simult. - 2 sets for your soundmodes, one for the loop, one PIN for 6V and one for ground = 5.

Also (just a question of wiring) take the 6.3V AC for the rectification off the power tubes, not the preamp tubes (just leave the schem as it is).
 
Steve, I'll add here what I'll find . . . will tell you when I'm done

The loop relay needs 2M2 to ground for in and output, Steve.
And those relays with a LED an R in front of the LED.
And you you need to add the VTL in front of V1B . . .you're switching that with the Rod Relay to ground. Ok.
You need to apply supply voltage to the Plex Mode Relay for the LEDs (and a R)

C16, C17 are electrolytics
 
duesentrieb":mxpbr41c said:
Steve?
Click to expand...

Hey Olaf - I'm working on the changes man! I'm a little slow today... :)

I'm not quite sure how to hook up the vactrol either. there are 4 poles - one side photocell, one side LED... I don't quite get how these work so a small explanation would help... The rest I think I have...

Be back in a few...

Steve
 
Sure:
One side (you can see a little "+") is the int. LED (values see page 1). Also minus (not labelled). Short distances = belong together)
The other two legs (opposite) are for the LDR (light dep. resistor)

- 6V into R into +
- minus hooked to the Plexi mode relay switch (or relay) - simult. switched with the relay (when relay = minus, VTL = minus = both "on")

- one leg to ground (use the cathode ground of V1B)
- one leg after the gainpot

Let me know if you need a pic . . .
 
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