Ceriatone 5e7 Bandmaster, headroom and noisefloor

[909one]

So I just got a Ceriatone 5e7 bandmaster head. I am pretty happy with it so far. This is my first tweed style amp, I love the slopiness, the natural compression, the natural distortion, but there are few things about it that I'd like to improve.

Headroom: Right now I have 6l6wgb's with a 5u4 in there. I have read that replacing the rectifier with a5AR4/GZ34 can help this issue. What other power tubes are a good recommendation for more headroom?
After re-biasing with a 5ar4 in there, this should be safe for the amp, right?

Noise Floor: The amp may not be noisy compared to other tweeds, but its al ot noisier than my Dr. Z. Any ways to lower noise floor for someone who can use a soldering iron?

Thanks.

[AndyT]

I have a tweed Bandmaster that was built by a buddy of mine. It's a great amp. I have worked on it quite a bit.

The GZ34 would definitely help. Checking the bias is a good idea after the swap.

See what preamp tube is in V1 (farthest from power tubes). The circuit was designed for a 12AY7 (lower amplification factor) and a 12AX7 will drive it harder, diminishing the headroom. You can use a 5751 instead if you can't find a 12AY7.

The power tubes you use will make a difference as well. I have NOS RCA small bottle 6L6's in mine and it gets pretty loud before it breaks up.

What speakers are you running? is it set up for 3 x 10's?

What type of noise? Is it just hissing when you have the treble turned up? Mine does that and seems to have more hiss than my BF Fenders.

[Blue Strat]

A 5AR4 and quality 6L6GCs (the suffix makes all the difference in the world) will produce more power and headroom. Rebias is necessary.

Be sure that the higher voltages with the 5AR4 don't exceed the max rating for your B+ filter caps.

[909one]

Yeah I have a 5751 on there now. I need to try the 12ay7.
I'll try the other rectifier and re-bias. Then new power tubes...

The noise is the hiss, yes. Its annoying, but not that bad. But I am also getting some hum too... But I can't say for sure its the amp, I just put together a tele from parts and I don't know if I have it grounded properly.

[AndyT]

If you turn the volume off on the guitar, you should be hearing the amp and the not your Tele humming. My 5e7 is not the quietest amp I own, but on stage you would never notice. Try turning the treble down and see if that helps. The normal channel should be quieter.

The 2 channels interact. You can turn the channel you are not using up about 1/2 way and it acts sort of like a middle control.

[Kitarist]

a nice amp people check out http://ceriatoneforum.com

we are building a nice community there

[tommytomcat]

My 5e7 is my main amp.. (w#ber kit) I just got a couple 12AV7's (NOS RCA's) from AES (tubesandmore.com) for $5.50 apiece. A 12AV7 has a gain factor of 41.. 12AY7 has a gain factor of 45. I like this 12AV7 much more than the Sovtek 12AY7 and 5751 I've tried in there before this purchase. More headroom, sweeter, fuller.. very nice for 5.50.

I don't think you're going to find very many stock (standard fender layout) bandmasters that don't have some hiss and a little hum. I would suggest the following: 1. shielded/grounded cables from the input jacks to the V1 grids, another shielded grounded cable from the treble pot wiper to pin 2 of the PI. 2. Check out the grounding.. AC cord green wire on a PT bolt by itself.. Bias circuit and the next two filter caps should be grounded to a separate PT bolt along with the PT cathodes and the presence pot. All the other grounds are the preamp grounds and they should be grounded to a point/or along a bus that terminates somewhere close to the input jacks. (I use the side wall of the chassis) It'll be OK if the preamps are grounded to a brass plate. 3. Make sure the part of the cab or panel that covers the opening of the chassis is shielded with some kind of aluminum foil/metal tape and that the chassis is pressed up close to it all the way around. 4. and if you really want to go for over kill.. put another 16uF 450v filter cap in parallel with the first filter cap (the one that feeds the OT). w#ber sells 16uF Fcap that is small and cheap ($1.05 I think). This will provide some extra filtration/hum reduction and tighten up the bass some (I like this mod, it adds some definition/tightness to those low E string pops.. I like the effect of having the bass strings cleaner and slightly less loud than the treble strings.. treble strings still retain the drive and touch sensitivity wile the bass notes don't swallow up the treble strings like can happen with a BF style amp.. Speaker choice contributes to this too). 5. Make sure the heater wires are as far away as possible from the other wires going to the socket. Get a chopstick and move things around with the amp on to see if you can reduce hum and hiss.

The change that made the most difference on my bandmasters was the shielded cable from the treble pot wiper to pin 2 of the PI. If it's not there already, I'd do that first.

Congrats on the amp!