Lower Filtering

[nix]

Anyone else play around with dropping the filtering below what is generally considered canon?

I've found I tend to prefer a pair of 100uf caps in the power supply over the stiffer sounding 220uf, 300uf, 330uf, etc.

Am I alone in this? Is this cause for having my Dumble-license revoked?

I'm genuinely curious if anyone else has experimented with these values and perhaps others (16uf as opposed to 20-22uf). I'd be interested in your findings/views on this subject.

[dogears]

I've seen a pic of a real Dumble with 2X33uf for the V1 and V2. There is your 16uf. I've seen 50uf total in the PS too. But on the 50 watter and the Music Man stuff.

Fwiw, the Landau Suhr stuff has like 10uf on the preamp. If memory serves me correct. Real spongy. Great for blues, but not so much for the bop type lines..... Imo.

[nix]

That's interesting.
I was surprised in my experiments wih lower filtering. I do prefer lower filters on plexis (16 on the pre, etc.), but i figured the Dumble thing would dissipate without the bigger caps. I have built a couple for myself and always ended up preferring the lower values.
It's weird: I don't have a problem blowing bop-style lines with the lower values. I know what you're talking about, though. I guess I just like things to sound a bit less 'refined'...much like my playing!
I love the sound you get with yours, Scott... I guess we just have different hands.

Also interesting about the filtering in Landau's Suhr. John Suhr and I have discussed doing an amp for years and he's repeatedly told me that I would get along with Landau's. Of course, it would have to be a non-master, but we'll see what happens if we get around to it.

[Structo]

Are you talking about a 4 x 6L6 amp or 2 x 6L6?

I know in my D'lite I have 50uF (2 x 100uF in series) and it is fine with that.

On my latest 100w amp I went with two 320uF in series for 160uF.

They were some nice Sprague Powerlytics (thanks Steve!)

The bottom end does not seem stiff at all, and I was thinking about raising my filter for V2 a bit to see if I can tighten the OD a bit.

[nix]

Actually, four EL34's. I like those a bit more than 6L6's in these amps. The funny thing is, I built one that ended up very similar to #183 after some extensive tweaking, before any of those specs were known to the rest of us. I flipped when I saw (Tony's layout) over how similar it is.

[Structo]

That's pretty cool, you must know what you're doing.

[nix]

Not really! I just listen and swap parts in and out. I know just enough to not get killed...

[sound mind]

I have no experience with Dumbles or clones (I joined this site recently to learn more) but I do have with other amps. I have always preferred the tone in Fenders with smaller first filter caps such as a pair of 70, 80 or 100uFs. There is a technical reason for it too. The larger cap values filter the rectified voltage better. Hum is dependent mainly on the balance of the output tubes of course. With lower first filter cap values there is more hum component, which will cancel out anyway with well balanced and matched output tubes. But when the instrument is played, the hum component is mixed with the signal. Eric Pritchard calls this "fat". He even simulates the effect with his solid state amp designs. It is an essential part of vintage tone in my view.