Marshall 2203 REEEEEEEEEEE-work

[harddriver]

Did adding the reactive load box help lower some volume? I know it does for me.

[PLX]

Enquiring minds want to know your thoughts on the whole 6ca7 verus EL34 debate. Are you going to reinstall the EL34's or keep the 6CA7's?

I changed so many things in the amp, it's tough to say.. All new filter caps, new filtering scheme, new tone-shaping caps, changed all diodes to another type, different power tubes, extreme lowered wall voltage, new choke, pulling 2 output tubes... so many changes all at once I really couldn't say one particular thing was the magical change.

It might sound this good with 2 EL-34's in there, but I don't think so.

[harddriver]

I know they sound better..... but I just wanted to hear you say it..............

The fact that you are inspired to play it so much tells me it sounds great....... so mission accomplished.......

What size ceramic cap do you have for a bright cap on the preamp 1 meg pot? it looke like a 500pf judging by the size in your pic. 500pf?

I think you would really like 1000pf or 2000pf you could put all three on three way switch. I run 1000pf and 2000pf on a switch on my 2203 1x12 amp and tend to use the 2000pf more often than not, it really gives it that crunch aggressiveness kinda the way the 5000pf bright cap does on plexi IMHO.

Are you running the plexi spec 47K NFB resistor in your amp? I don't remember...

[PLX]

I know they sound better..... but I just wanted to hear you say it..............

The fact that you are inspired to play it so much tells me it sounds great....... so mission accomplished.......

What size ceramic cap do you have for a bright cap on the preamp 1 meg pot? it looke like a 500pf judging by the size in your pic. 500pf?

I think you would really like 1000pf or 2000pf you could put all three on three way switch. I run 1000pf and 2000pf on a switch on my 2203 1x12 amp and tend to use the 2000pf more often than not, it really gives it that crunch aggressiveness kinda the way the 5000pf bright cap does on plexi IMHO.

Are you running the plexi spec 47K NFB resistor in your amp? I don't remember...

That cap is a 1000pF

I changed the NFB resistor from the stock value (100KΩ) to 47KΩ on the advice of the admin here a while back.

Oh, and on the 6CA7's.. these are the two that were in the BE-50 clone and the guys at TheAmpGarage told me to toss them because "they had taken a beating" during my struggles with oscillation in that amp, and they needed to be replaced.

They sound killer

[harddriver]

As for the NFB I like 47K on the 8 ohm tap some prefer the 4 ohm tap. The 8 ohm is a little cleaner while the 4 ohm tap it gets a little more ratty sounding.

On my 68 the NFB is on the speaker jacks like a Super Bass so wherever I set my impedance is where my NFB is on. So right now with two tubes pulled into an 8 ohm load my NFB is on the 4 ohm tap.

[harddriver]

Enquiring minds want to know your thoughts on the whole 6ca7 verus EL34 debate. Are you going to reinstall the EL34's or keep the 6CA7's?

I changed so many things in the amp, it's tough to say.. All new filter caps, new filtering scheme, new tone-shaping caps, changed all diodes to another type, different power tubes, extreme lowered wall voltage, new choke, pulling 2 output tubes... so many changes all at once I really couldn't say one particular thing was the magical change.

It might sound this good with 2 EL-34's in there, but I don't think so.

So if I glean your overview the correct way..... you seem to be saying the amp sounds better than it did before in it's earlier iteration.......

[PLX]

So if I glean your overview the correct way..... you seem to be saying the amp sounds better than it did before in it's earlier iteration.......

Oh yeah, it sounds waaaaay better, but it feels so much spongier. The lower filtering on the screens, operating at that extreme low voltage, the difference between the EL-34's and the 6CA7's..

It's more enjoyable to play.

[harddriver]

That's great..... But now it's clips or Bugera for you

[harddriver]

So the 100uf on the mains didn't make the amp stiff at all even at 120ACV?

You never did say...do you have an attenuator to use inline with the speaker cab for more volume control?

[PLX]

So the 100uf on the mains didn't make the amp stiff at all even at 120ACV?

Not at all. In fact, I tend to think that's part of what made the amp quieter - smoothing out the AC ripple.

I think the key to changing the "feel' is lowering the screens filtering. I can remove that jumper on the 32µF/32µF can, and try going even lower on the screens (from 64µF down to 32µF), but that will risk ghost notes.

You never did say...do you have an attenuator to use inline with the speaker cab for more volume control?

I wanna try that next.