Note the word "build" in the OP
Noted mate.
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4th gain stage in 2204
- Thread starter m1989jmp
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Noted mate.
johan.b
Well-Known Member
There is an alternative ppimv you could try instead of the dual pot version. Do a Google picture search for vox ac30 schematic. Locate the tone cut pot(after the p.i.) and do that but without the capacitor. .. Since it is inside the nfb loop, just like the regular ppimv, it will mess with the feedback too, but this one since it loads the p.i. anodes reduce the gain in the p.i.
It gives a slightly different sound, but i like it...a 50 or 100 watter is never a bedroom amp, but you can take the level down to usable level and it sound good and it is easy to implement
j
It gives a slightly different sound, but i like it...a 50 or 100 watter is never a bedroom amp, but you can take the level down to usable level and it sound good and it is easy to implement
j
FutureProf88
Well-Known Member
JMP, whereabouts are you located? I have a 2204 with the modification that you are talking about. I have a YouTube video of it up. If you are near-ish to St. Louis I can let you play mine. Or if you like the mod you can see what has been done to mine. It was modded when I got it. It does hiss a little bit but it is not overpowering. It will eat a Mesa Triple for breakfast as far as gain goes if you want it to.
gldtp99
Active Member
This is often called the "Crossline" Master Volume------ It is simple to install and some people like the way it sounds----- a very old MV design.
There are many different MV designs and all have their strengths and weaknesses, none are perfect.
There is also a MV type circuit known as "Power Dampening" as used in Mojave Amps----- this circuit puts a 50K RA pot between the cathodes of the LTP PI (tied together) and the first resistor in the LTP tail section (470 ohm in a 2204 circuit)------ this circuit operates by changing the bias of the PI tube (making it colder as the control is turned up)---- I've used it other builds and the owners of those amps find it to be a useful MV.
This Power Dampening circuit works ok but it isn't the perfect solution either--- I have it in a Sound City 120 that I converted/rebuilt into the Soldano SLO lead circuit----- this amp has the usual pre-PI MV and also the Power Dampening (I call it Power Damping----"it makes the tone wetter"---- none of my customers get the play on words).
In the 2204 circuit I like the combination of the stock pre-PI MV and the Lar/Mar PPIMV------one can get a large range of volume and some Tone adjustment by manipulating/balancing the two MV's.
This seems to work the best, for me, and it doesn't cost @$500+ like some of the fancy modern attenuators----- It also is contained within the amp itself, no need to run extra cables to an external unit.
But volume management (MV's/Attenuators,etc) is kind of like asking what the best flavor of ice cream is-----you'll get different answers from different people and one opinion is as valid as the next one................... gldtp99
gldtp99
Active Member
I'm surprised that nobody has mentioned diode (and other solid state devices) clipping yet--
The orig Jose MV mod (pre tonestack MV with clipping diodes attached) was the "hot ticket" years ago----- versions of this approach can be found in the Friedman BE-100 amps today, as well as some of the Cameron amps.
The orig Marshall Silver Jubilee amps (that have been re-issued and have their legions of fans) owe most of their distortion tone to another take on diode clipping.
I've been working on a 50 and a 100 watt version of the diode clipping as used in the EVH 5150 III amp----- I'm working on a preamp design that bridges the gap between hard rock and true modern metal and could be used for either----- I'm using the 16V zener diode clipping from the EVH 5150 III schematic but the rest of the amp has my own ideas (and some "borrowed" from other designs).
No vids of these amps yet but the true 7/8 string modern metal players seem to be very impressed so far------ they're getting the drive/easy pinch harmonics they crave but still the amps retain some Marshall-y vintage feel/tone (2204/2203 are vintage amps to them).
Here's the EVH 5150 III schematic---- check out the zener diode clipping arrangement on the lead channel (Ch3):
http://support.evhgear.com/schematics/EVH_100W_combined.pdf
This type of tone may be too much for classic/80's rock players but I find it interesting from an ampbuilder's standpoint................... gldtp99
The orig Jose MV mod (pre tonestack MV with clipping diodes attached) was the "hot ticket" years ago----- versions of this approach can be found in the Friedman BE-100 amps today, as well as some of the Cameron amps.
The orig Marshall Silver Jubilee amps (that have been re-issued and have their legions of fans) owe most of their distortion tone to another take on diode clipping.
I've been working on a 50 and a 100 watt version of the diode clipping as used in the EVH 5150 III amp----- I'm working on a preamp design that bridges the gap between hard rock and true modern metal and could be used for either----- I'm using the 16V zener diode clipping from the EVH 5150 III schematic but the rest of the amp has my own ideas (and some "borrowed" from other designs).
No vids of these amps yet but the true 7/8 string modern metal players seem to be very impressed so far------ they're getting the drive/easy pinch harmonics they crave but still the amps retain some Marshall-y vintage feel/tone (2204/2203 are vintage amps to them).
Here's the EVH 5150 III schematic---- check out the zener diode clipping arrangement on the lead channel (Ch3):
http://support.evhgear.com/schematics/EVH_100W_combined.pdf
This type of tone may be too much for classic/80's rock players but I find it interesting from an ampbuilder's standpoint................... gldtp99
Blacque Jacque
Well-Known Member
There's always more than one way to skin a cat, the hard part with modding amps is knowing which approach will get you the tone you hear in your head.
I appreciate the offer, but I'm on a different continent
You could post or PM a youtube video of it with mod info, that would be awesome
Years ago I added to my 2204 clone a cascaded gain stage on a switch with its own gain knob. If I were to do it again, I wouldn't... I would simply go with a pedal. I replaced that extra 12AX7 with a 12AU7. It was just too much. I don't use the extra gain stage anymore.
Having said that, if you really want more gain, it will do the job.
Having said that, if you really want more gain, it will do the job.
tschrama
Well-Known Member
I'm surprised that nobody has mentioned diode (and other solid state devices) clipping yet--
The orig Jose MV mod (pre tonestack MV with clipping diodes attached) was the "hot ticket" years ago----- versions of this approach can be found in the Friedman BE-100 amps today, as well as some of the Cameron amps.
The orig Marshall Silver Jubilee amps (that have been re-issued and have their legions of fans) owe most of their distortion tone to another take on diode clipping.
I've been working on a 50 and a 100 watt version of the diode clipping as used in the EVH 5150 III amp----- I'm working on a preamp design that bridges the gap between hard rock and true modern metal and could be used for either----- I'm using the 16V zener diode clipping from the EVH 5150 III schematic but the rest of the amp has my own ideas (and some "borrowed" from other designs).
No vids of these amps yet but the true 7/8 string modern metal players seem to be very impressed so far------ they're getting the drive/easy pinch harmonics they crave but still the amps retain some Marshall-y vintage feel/tone (2204/2203 are vintage amps to them).
Here's the EVH 5150 III schematic---- check out the zener diode clipping arrangement on the lead channel (Ch3):
http://support.evhgear.com/schematics/EVH_100W_combined.pdf
This type of tone may be too much for classic/80's rock players but I find it interesting from an ampbuilder's standpoint................... gldtp99
The Zeners in the EVH 5150 III are there for protection of the channel-switching-JFET. They dont add overdrive in that place. Clipping point of V4-A is 1.6V.. those zeners clip at 17.1V.
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Ken
Well-Known Member
I have to agree. The DSL really has way more gain on tap than anyone needs; it's like an extra preamp stage. NO ONE uses a DSL on the highest gain settings. Why? Because it compresses way too much. A pedal combined with a lower gain setting will be a lot tighter. If you want the compression, go for it, but I also question how sweet the tone will be.
Ken
Oculophilia
Active Member
My 2204 has a fourth 12AX7 and I love it.
I have added a 4th stage to my Ceriatone 2204 clone. I added the extra tube between v2 and v3. I am only using one triode of the new stage. I didn't add a filter cap, I just jumped the heaters from V3 and got the B+ from the V1 intersection.
The amp sounds awesome, and is not noisy. It is not dead quiet, but it is much quieter than a MARSHALL JVM.
The amp sounds awesome, and is not noisy. It is not dead quiet, but it is much quieter than a MARSHALL JVM.
This is a common misconception. Depending on how you configure the stages, a 4 stage can actually have less OD than a super hot 3 stage. When modding my amp, I tried 3 vs 4 and I settled on 4 because it sounds better..
My amp is setup to have a hard rock/80's thrash type crunch at 6 on the preamp pot, and 10 is blistering high gain, bordering on too much. But the preamp pot is useable from 1-10.
My amp now gives a treble attenuated, fatter sounding SIR 36 type tone.
If I understand correctly, you use this new triode as a voltage amplifier (output from anode) ?
What are plate, cathode, grid resistor values? Coupling cap value to the next stage? Did you bypass the anode resistor with a cap?
Yes..
Those values mean nothing without having the right values on the other triodes so they sound right and play nice. Having said that, the added 3rd stage is the same as a 2204's V1b... 10k cathode, 100k plate, 0.022uF coupling, 68k grid.. No anode bypass..
Those values mean nothing without having the right values on the other triodes so they sound right and play nice. Having said that, the added 3rd stage is the same as a 2204's V1b... 10k cathode, 100k plate, 0.022uF coupling, 68k grid.. No anode bypass..
jgab
Well-Known Member
bulldozer you should post a link to your sound clip or the link to the thread you put up a while back. Everyone should hear your amp. It sounds amazing, hence the reason I asked you for a schematic. Hope to build an amp with your mod someday.
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gldtp99
Active Member
I played my 50 watt proto tonight with/without the 16V zener diodes in the circuit------ I thought I was going to prove you wrong, at least to myself.
You are absolutely right, those diodes in that part of the circuit are not clipping----- the amp had as much distortion without them as it did with them------ the amp actually sounded better without them, a bit smoother.
Signed......................... I are a Dumba$$
