I had been thinking about the Express and the undefined bass. I allready did the fixed resonance which I like. But someone recommended to increase filtercaps. Might want to tighten things up, but then not too much that it will choke the sound. Just more bass definition.
How about 100UF for the first filter, then a 50 or 60Uf for the powertubes,
33uf for v3, 22uf for v2 and 15uf for v1?
Any thoughts?
Express filter cap experimentation
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Super_Reverb
- Posts: 188
- Joined: Tue Dec 21, 2010 6:28 am
- Location: Indianapolis, USA
Re: Express filter cap experimentation
Adjusting the reservoir cap will have the most effect on your sound. Increasing the screen filter cap size will give you a more stable B+2, but that could affect your sound. IMO, increasing the three preamp capacitors will only improve things - it would keep the power tube current draw from modulating the preamp supply voltage (reduce probability of parasitic oscillation.)
rob
rob
Re: Express filter cap experimentation
I have some caps left.. 33+33.. so I can add that to reservoir and powertubes. And a 47uf... which I can put into v3 position...Super_Reverb wrote:Adjusting the reservoir cap will have the most effect on your sound. Increasing the screen filter cap size will give you a more stable B+2, but that could affect your sound. IMO, increasing the three preamp capacitors will only improve things - it would keep the power tube current draw from modulating the preamp supply voltage (reduce probability of parasitic oscillation.)
rob
There will be a problem though with objective comparison due to the mod time... so it needs to be done with one mod at a time.. and referencing.. then undo that mod and do the other...
Basically what I am looking for is an amp that breathes a bit more and is not choking up so much with high gain levels, especially in the bass, but not too stiff, that's why I thought to leave the v1 position 22uf or perhaps a bit less if the reservoir cap is increased...
Re: Express filter cap experimentation
Oké so I tried a few things...
Reservoir 113 uf.
Powertubes 47uf
PI 32uf
v1-v2 both 22uf
Indeed a lot more tight bass... but I could not say I liked it. So I ended up back to cutting the extra 33uf on the reservoir and 10 on the PI.
The powertubes now have an extra 7uf, which is actually resulting in a bit tighter bass as well.
Reservoir 113 uf.
Powertubes 47uf
PI 32uf
v1-v2 both 22uf
Indeed a lot more tight bass... but I could not say I liked it. So I ended up back to cutting the extra 33uf on the reservoir and 10 on the PI.
The powertubes now have an extra 7uf, which is actually resulting in a bit tighter bass as well.