Finally finished modding my 100w metroamp !

[cyndicate]

Gutted the superlead circuit and changed it to a 2203 and added the following:

- switchable extra preamp tube
- feedback knob (Variable from 1 to 250k) (To the right of the FX loop)
- depth knob (placed right after impedance switch)
- SDM fx loop

The ordering of the circuit got shifted over, so the extra tube is the 1st stage but I had a extra half of a preamp tube left so I just bridged the 2nd half for a extra amount of gain. Thread is probably useless without clips but oh well, will try to get some up next weekend when I have a camera. Amp has more balls now for sure, not a crazy amount of gain, will probably have to tweak some values but so far it's pretty cool. No clue how it sounds at higher volumes yet since I can't play it loud but its sounds pretty good with the Pre-PIMV. If anyone want's to try out the mod let me know and I can send you whatever I have on doing it. It's pretty much the "SIR" mod from the layouts that were floating around on the Metroamp forum with the added feedback/loop/depth Not 100% sure if its wired correctly but it doesn't sound like shit so I guess it is? Can only tell once I get some more volume on this thing.

 

[jet66]

Very cool! I am shooting for the 2203 kit some time in the near future, I'll probably asking about the loop, depth, and extra gain stage. I was looking around their forum, and didn't see too many drawings of those mods right off, mostly just descriptions. I'll have to dig a little deeper.

Did you star ground everything, or did you use the bus wire across the pots? I'm thinking star ground, for mine.

 

[cyndicate]

Very cool! I am shooting for the 2203 kit some time in the near future, I'll probably asking about the loop, depth, and extra gain stage. I was looking around their forum, and didn't see too many drawings of those mods right off, mostly just descriptions. I'll have to dig a little deeper.

Did you star ground everything, or did you use the bus wire across the pots? I'm thinking star ground, for mine.

It took a awhile to find the layouts and info for doing the mod, seems most of them were taken down in that thread, let me know if you need any info later on it and I can forward whatever layouts/schematics I have. I was too lazy to redo all the grounding, noise wasn't too bad on this amp, if it was a new build I would star ground everything, much cleaner. The way it is right now is just the bus wire across the pots.

 

[wIsEbLooD]

nice man. how do you like that loop?

 

[jet66]

It took a awhile to find the layouts and info for doing the mod, seems most of them were taken down in that thread, let me know if you need any info later on it and I can forward whatever layouts/schematics I have. I was too lazy to redo all the grounding, noise wasn't too bad on this amp, if it was a new build I would star ground everything, much cleaner. The way it is right now is just the bus wire across the pots.

That would be much appreciated! Is it easier to do the mods first, during the initial build, or does it matter? I want to do the build first, and see if I even need the mods. Except for the loop, that I definitely want right off the bat.

 

[stephen sawall]

Kick A$$.

 

[cyndicate]

It took a awhile to find the layouts and info for doing the mod, seems most of them were taken down in that thread, let me know if you need any info later on it and I can forward whatever layouts/schematics I have. I was too lazy to redo all the grounding, noise wasn't too bad on this amp, if it was a new build I would star ground everything, much cleaner. The way it is right now is just the bus wire across the pots.

That would be much appreciated! Is it easier to do the mods first, during the initial build, or does it matter? I want to do the build first, and see if I even need the mods. Except for the loop, that I definitely want right off the bat.

I would build it first without mods just to make sure the amp is working and so you can test all the voltages correctly. Same with the loop, I would add it after I know the amp is working correctly, the loop taps into PI supply for the B+ and you have to run it with all the tubes in, in the initial testing stage of testing the amp it has you test it without any tubes in so if the loop draws in too much B+ it has a chance to damage it. The instructions for the loop has a note on the safe range of B+ going to the loop, which I think is ~285 to 310 DC.

 

[jet66]

Good advice. In that case, I'll do the build straight up, first. I am dying to get my hands on a kit. I'll probably start selling some stuff I don't use anymore, priced to move, to fund it.

 

[Deleted member 3860]

...

 

[johnnyjellybean]

I just finished tweaking mine that I built last month. It has a pre phase inverter master volume and a post phase inverter master volume which gives you great tones at any volume. I chose to go with the cascade "Arredondo" mod for my gain boosts. Has quite a bit of gain and is footswitchable from medium gain crunch to mid/high gain lead. Somewhere between channel 3 and channel 4 of my VH4. I also played with the voicing to get that 80's mid push. Extremely happy with the amp and I'm thinking about doing a few more for friends that want one.

 

[cyndicate]

I just finished tweaking mine that I built last month. It has a pre phase inverter master volume and a post phase inverter master volume which gives you great tones at any volume. I chose to go with the cascade "Arredondo" mod for my gain boosts. Has quite a bit of gain and is footswitchable from medium gain crunch to mid/high gain lead. Somewhere between channel 3 and channel 4 of my VH4. I also played with the voicing to get that 80's mid push. Extremely happy with the amp and I'm thinking about doing a few more for friends that want one.

Sweet, I need to try out one of the jose mods. Did you use relays for footswitching?

 

[johnnyjellybean]

I just finished tweaking mine that I built last month. It has a pre phase inverter master volume and a post phase inverter master volume which gives you great tones at any volume. I chose to go with the cascade "Arredondo" mod for my gain boosts. Has quite a bit of gain and is footswitchable from medium gain crunch to mid/high gain lead. Somewhere between channel 3 and channel 4 of my VH4. I also played with the voicing to get that 80's mid push. Extremely happy with the amp and I'm thinking about doing a few more for friends that want one.

Sweet, I need to try out one of the jose mods. Did you use relays for footswitching?

No because it's not switching channels. It's a gain boost and just switches inputs with different resistors. The 1st input actually becomes the footswitch jack and channel 2 becomes the main input .

 

[Vrad]

That's very close to what I want to build at some point. Glad you're digging it.

 

[Hollywood]

Looks good. I heard JJB's amp he built and it sounds really good.
You got the extra pre tube hooked up the way my newest creation is set up. Enjoy .......

 

[cyndicate]

I just finished tweaking mine that I built last month. It has a pre phase inverter master volume and a post phase inverter master volume which gives you great tones at any volume. I chose to go with the cascade "Arredondo" mod for my gain boosts. Has quite a bit of gain and is footswitchable from medium gain crunch to mid/high gain lead. Somewhere between channel 3 and channel 4 of my VH4. I also played with the voicing to get that 80's mid push. Extremely happy with the amp and I'm thinking about doing a few more for friends that want one.

Sweet, I need to try out one of the jose mods. Did you use relays for footswitching?

No because it's not switching channels. It's a gain boost and just switches inputs with different resistors. The 1st input actually becomes the footswitch jack and channel 2 becomes the main input .

Ah I see, I should change one of my input jacks to a footswitch jack for the extra gain stage, right now I disabled the other 2, and the 3rd one is where I put the DPDT switch.

That's very close to what I want to build at some point. Glad you're digging it.

Thanks vlad, still room for improvement and tweaks, still deciding what to do with the other half of the extra preamp tube, not sure if its a good idea to bridge it at the 1st stage Was just messing around with it. Same with the feedback knob, the sweep is way too large, might raise the NFB resistor and change the pot. Right now its a 1K to 250K sweep, most of it is unusable

Awesome!!!

Looks good. I heard JJB's amp he built and it sounds really good.
You got the extra pre tube hooked up the way my newest creation is set up. Enjoy .......

Thanks! Sweet, I'm probably going to change the circuit a bit again. What is this newest creation of yours?

 

[Hollywood]

I got a marshall 100 watt plexi 1959 SLP over at FJA.
Jerry is building me an amp kinda like the big mac.
It's gotta alot on it.

 

[Vrad]

Thanks vlad, still room for improvement and tweaks, still deciding what to do with the other half of the extra preamp tube, not sure if its a good idea to bridge it at the 1st stage Was just messing around with it. Same with the feedback knob, the sweep is way too large, might raise the NFB resistor and change the pot. Right now its a 1K to 250K sweep, most of it is unusable

Isn't this stuff great!? There's always room for improvement.

 

[Shask]

I built a 2203 based amp with an extra gain stage and depth knob. It sounds pretty good, but of course, it has the problem knowing that I built it, which makes me always want to tweak it instead of leave it alone

I based it off that Egnater Guitar Player article thats floating around over there. Its basically the stock circuit, with a gain stage in front of it, so it basically the stock sound with more...

 

[bravedude2]

looks awesome brother!

 

[MARK1970]

Looking forward to playing it Wil. Should I bring a fire extinguisher?