Woke up sick this morning, so not able to do much other than read and comment. I'm interested to dig into this some more, so don't take it as a disagreement, but rather an inquiry.WhopperPlate wrote: ↑Tue Feb 06, 2024 6:09 pmAs I already mentioned , 5uf across the board tightens bass response . For reference , far less extreme than a Marshall bright channel with .68 bypassing each cathode and . Here’s a quick and dirty calculator to give you more understanding.imo1 wrote: ↑Tue Feb 06, 2024 3:46 pm
Regarding cathode bypass caps, I’ve messed with that before a bit and the difference was subtle to me. I know this is a much bigger deal with higher gain amps. @whopperplate, I am very aware of the difference the caps” values make, especially coupling. I actively switch those around in my builds. What I was hoping to hear was some thought on experience with cathode bypass, as I haven’t messed with that as much and most of my thought on it is theoretical, based on frequency shifting.
https://www.ampbooks.com/mobile/amplifi ... alculator/
Yes. Those calculators are good. Thankyou for the link. I always forget about them.
The reason I asked you is that you brought up, I think, earlier in the thread, that the cathode caps, as used in fenders, had kind of a different effect on the bass beyond just adding more, which intrigued me. What I've been trying to get at is what that would be. You were insinuating that they aren't necessarily adding more bass but changing the way it reacts. That is where the technical knowledge, at least what I have taken in, starts to fall away, and understanding the reactance to how it responds to the guitar, and that murky area within, becomes front and center.
When I think of the main Dumble designs, I think of powerful, clear bass. That, to me, is the biggest difference I hear and feel when I play his designs, and amps inspired by him, especially in comparison to Fender designs, which often fall apart when you try to boost the bass too much. When I played my Super reverb, I often had the bass on 2-3, because much more that that would just cause things to flub out. With the Dumbles, it seems that it is power(wattage) and filtering that do most of that lifting. I feel like I understand those really well. I have enough experience with filtering and PT's( either too big or too small), to have a pretty good feel how those both effect low end. As well, the coupling caps seem to work in a pretty intuitive way. On the deluxe build i just finished, I greatly reduced the coupling cap that followed a modified marshall gain pre-amp section. I loved the way it tightened up the low end in a way that translated to more of a gainy design.
Its gonna take some time to understand better how both the cathode caps and the neg feedback work. I know I tend to like amps without the localized neg feedback. I think I'm attracted to the "hair" on the sounds, as opposed to the super clean(tight) feel that I associate it with. To me, at this point, neg feedback seems to make it harder to play legato on the amp. It seems that when the first stage is heavily treated that the notes tend to be kind of clanky. I could see this being good for super clean, chordal stuff, but when you are playing runs of notes, it makes it sound less fluid. My test here is to play the guitar acoustically and then plugged in. If it sounds more disparate than the natural sound of the guitar, to me its doing a disservice.
I'll try tacking in some caps. I'm always a little uncomfortable using clips in an amp with high voltage. Easy to do on the tone stack, but the cathode caps are sitting really close to some high voltage areas and i would hate for them to slip!