Recently i read a thread about Blockhead amps. In summary, they make modded marshalls with the Jose mod. Found one in the sold listings on Reverb, and saw some gut shots. One thing that caught my eye were these 330uf filter caps. What is this cap mod doing to the amp besides reducing hum?
more filter capacitance would give the amp a "tighter" feel all things being equal is it worth it? maybe it could also be that they got a good deal on 330uf in bulk so used them where otherwise they'd use smaller values
@JM5010 I tried adding more capacitance to my 2204, didn't know that was a mod. I was just testing whether the ripple was reduced. It is reduced but the amp did get a stiffness some might call that tight. I don't know if my ears were playing tricks on me but it seemed more hiss too. I played it on the bench for a while and my ears got fatigued quickly so I stopped. Next day I removed the jumpered in caps and played again. It seemed much better to me and the spikeyness was not there. I would test it on the bench a couple days with it in and out and then make a decision of your own. Tone is so subjective. Remember to test at stage volumes to be sure.
Perhaps this is best combined with plate bypass capacitors? The Blockhead amp that i looked at specifically was based on the SE Lead Mod (Doug Aldrich mod). Maybe in order to tame the extra capacitance and hiss that is added, it is also a good idea to add some caps across the plate resistors. They did this on V1
Wow, seems like this is counterintuitive and taking some of the life and feel away from these amps . Plate bypass capacitors? If the amp needs to be tamed then by all means neuter it!
Can you provide a schematic to this mod so we can look at it? My amp is still on the bench and will be until I fully test out the mods I want. Then I am rebuilding/rewiring it. The point is I want to use it as my test model until I find the tone and capabilities I want.
Here’s the closest thing to the SE Lead Mod schematic. It’s basically the Lead channel of the CAE 3+ SE preamp inside of a JCM 800 with the increased filtering. http://millerguitar.com/schematics/CAA-3_SE.png
Well, that is the goal and that’s how they are designed. If Martin Golub was still alive maybe he’d be able to chime in. The SE Lead Mod does not sound like a typical marshall at all
