Ceriatone Forum

hello there :).
i need some info, i whant to make some changes to the circuit of my jtm45 bluesbreaker amp made by ceriatone.

there some info in my amp, it is the jtm45 mk IV made by ceriatone, with shuguangs kt-66 and jj 12ax7, and with tremolo, and external bias mod and 2x celestion vintage 30 all build by ceriatone :).
i whant to know if i can make these changes without damage anything and if you think this may be good change to make.

there is no cap in my Volume I knob, i whant to add one if there not one yet "in the layout it say there one but in the pict of the jtm45 bb in ceriatone website it show none"
i also whant to change the tone stack value, changing slope resistor from 56k to 32k and changing the cap from 250pF to 500 Pf for the tone cap.

and at the V2 cathode, there is the 820 resistor, i would add a .68uF cap bypassing it so it will give more punch in the mid-range frequency.

let me know if this is possible :).

and nice work on the website, very good idea :).

and well, for everyone know my real name is mathieu, nick may remember me or no lol.

and i got a few question about the tremolo....
i have the 12ax7 tube set in the tremolo socket, i tryed biasing the amp around 20-22mA, and i tryed tremolo, low/mid/high vol, and with low/mid/high setting for the tremolo, "speed/intensity", i tryed this with and without a footswitch "a tattoo gun footswitch because i have nothing else here but it'S the same", i tryed mostly everything i could not get it to work :(.

maby it is a bad contact with the tube and the socket, i removed it and have set it back in the socket other day, but i didnt try again since i keep the amp biased to 35-36mA becasue i like him that way.

it's not that bad, i dosent really need a tremolo and can do easily without it, i don't whant to send the amp back to a tech of ceriatone because i can't let him go away of me lol "i like this amp sooo much".

so am trying to have some info on it, and so if the changes i whant to make to the amp can be done, when i get to open it and do make the changes in circuit i may check the tremolo as well.

i also whant to know if i keep tremolo not working and amp work well if there is no problem?,  am allright to keep it not working but i don'T whant that it damage the amp, but it's been doing a few week i use the amp 2-3 hour each 2-3 day and it worked well since the being :).

and well i didnt contact nik again about it yet since this isnt much a problem for me, but i like having everything working if it's possible.

and i would like to know what the model of the ceriatone jtm45bb is from?

and so the amp are soo perfectly souding :).
the way they build is art, keep this work nik.

if i had more knowledges in tubeamp i would open a shop for build and sell ceriatone amp over canada as much as i like them and the way they are build, but my knowledges about tubeamp are limited so i keep the pro doing the work lol.

keep doing that good work nik and everyone at ceriatone.

Thanks.

Hello Mathieu,

  Hey man, nice to see you here.

  As for the changes, they're doable but if possible send to a tech to be safe.

  I have posted the layout of the BB on the website:

  http://www.ceriatone.com/images/layoutPic/marshallLayout/BluesBreakerCeriatone.jpg (http://www.ceriatone.com/images/layoutPic/marshallLayout/BluesBreakerCeriatone.jpg)

  Let me know about the bright cap on the volume pot?

  As for the tremolo, what we did was the Fender style tremolo, the one that used the power tube bias to modulate it.

  Indeed, this requires for the tubes to be biased lower for it to be making much effect.

  I am still baffled as to the trem, why it isnt there.

  I think, I will make a change to the trem circuit so that it is back to the original JTM45 Bluesbreaker type.

  Thanks!

Nik

for the trem circuit no need to change it.. am still thinking the tremolo should be fine.
maby it's the tremolo tube who is broken? "don't know with transport etc".

or as i said maby it where a bad contact of the tube and socket, next time i have to take the amp out of the cab i will bias lower then try again, i may also try to swap the tremolo tube with a pre-amp one "they are all 12ax7"so if it's the tube i will know.

as for the change to the circuit, the problem is where i am there not much amp tech, and the one who are good are hard to find, and i never saw any tech around here who can touch a tube amp of any kind, and i dosent trust them too much :S.

also thanks for the bluesbreaker layout i where searching it past day but i found it yesterday in this forum lol.

also it's the same board as the jtm45, only the tremolo is added.

and so, we may do business again in the futur"few years, or maby month" if i need to buy another amp :), just for now am totally pleasured with the one i buy from you. am so happy of it :D.

Thanks!