Flubby bass on Ceriatone Express. Upgrade transformer?

[Steve in Florida]

My Ceriatone expression sounds flubby on the low end.

it has Mercury transformers from classictone.net I believe.

should I try an upgraded output transformer? Maybe from RJ?

[xtian]

Replacing the OT is a drastic step. Have you evaluated your speakers? Power filtering? Coupling caps? Are you an amp tech?

[Shai`tan]

I heard those are not bad transformers. Doubt it is a transformer issue. Have you tried tube rolling?

[Steve in Florida]

No I am not an amp tech. Speakers are all good, Celestion Gold, G12H30, Scumback, etc. Same problem.

The Ceriatone was built by Sourmash Cabs, I believe. The work looks very clean (see attached photo). I'm no expert at all. The Mercury transformers are way cheaper than RJs Pacifics. That's about all I know.

I was talking with John from BadCat Amps, mentioning that I really liked the lead tones on this TW Express clone, but the low E string has a "flub" or "garble" that is pretty unusable for playing anything low on the neck.

John said that's why he uses "massive iron" -- and he gets no flub. So I figured I must need bigger iron too. Like I said, I'm no expert.

Right now, it's a one-trick pony (soloing, with volume knob touch-sensitivity)... but almost a half-trick pony because the low-end is just too garbly to be acceptable for more pedestrian duties (like rhythm playing down low).

I've tried to accept the low end... but ultimately I can't. Either it is fixed (drastic measures are OK), or the amp is not right for me.

Is John right about bigger iron in general?

Thanks in advance,

Steve

[Shai`tan]

I am not sure about the Iron, but can say my Heyboers from RJ made a huge difference in my Ceriatone Expression. No flub at all. But I as well changed all my caps to the Vintage Series Sozos. I hope you find the culprit. Good luck man.

[M Fowler]

I built an Express with those Magnetic Components Trainwreck transformers and they sound great. I also have one with Pacific transformers from Allynmey. Also built a couple with Edcor transformers and with rj Pacific transformers and even one with JTM45 PT and Fender 6k6 OT combo format.

You need to figure out the primary problem before wasting money on new transformers.

[Littlewyan]

Could we have a clip so we can hear the problem?

Also I know it may sound petty but have you tried playing in a different room? The room you are in will have a big effect on the sound.

[bcmatt]

I notice you have a PPIMV installed. I'm not sure how they affect an Express on the low end, but have you tried playing with the PPIMV cranked (out of the circuit)?

[Jana]

Change the 1k5 || 22uf on the first stage cathode to an 820 || 1uf.

[Steve in Florida]

Wow, thanks for all the great replies....

1) Sounds like I don't need a transformer. (Thanks all, and M Fowler in particular!)

2) PPIMV. Yes it is there, but I don't use it. It really thins the tone out. Better to have the PPIMV it cranked all the way, and then attenuate back with a BadCat Unleash, or with a Celestion Gold FluxTone speaker (which is really cool). Flub still present.

3) Playing in different rooms. Yes, that was a surprise for me, the extreme changes of brightness and darkness with this amp in a variety of different rooms. Flub in all rooms though.

4) I have not tried different tubes. Would you try power tubes or preamp tubes first?

5) I can't post a clip now... On a business trip for a week. I made this original post from my phone as the plane was backing out from the gate...

To describe the sound... It starts around the 7th fret on the low E... with a bit of undesirable "fizz" mixed in with the "correct" sounds. As you go lower, the clarity just goes. Becomes more garbled, and much less "tight."

Again, I am not an amp tech. I know very little. I have built a couple Firefly PCB amps, that's about it. It would take some thinking for me to figure out Jana's suggestion, and I don't belong inside there doing it myself.

Can anyone suggest a decent amp tech near Jacksonville? I could ship it back to the Sourmash guys... they're a couple hours away. They built it I believe, and they did what appears to be very clean work...

Thanks again for everyone's suggestions...

I'm still open to ideas. Outside of trying different tubes (again, should I try power or preamp tubes first?), I'm not sure of my best plan of action.

Thanks again, I really appreciate all the help...

Steve

[Littlewyan]

I actually have a similar issue where I don't feel I'm getting much clarity from the amp. First thing to try for both of us is probably different pre amp valves, thats what I'm going to try anyway and that can have a big effect on the sound. I have changed Power Valves recently which made the bass tighter but thats about it.

[M Fowler]

Lower the bias, I think the EL34 bias is set too high.

[rooster]

I can see that they added that extra cap to V2, no doubt doubled it up. Do you see the Blue cap paralleled to the Orange cap? Take the blue cap off, lift one end, the one towards V1.

Also, those V1 and V2 cathode caps.... are they Vishay brand? I would change those maybe. Try Nichicon, something in the Gold series.

And maybe more importantly, we didn't talk about your guitar. When you say the low end is fluffy, are you playing a generic neck pickup on a copy LP? Or a great neck PAF on a '59 Burst? You have to be more help than this if you want some real help.