New Express Build

[eazilyled]

I finally finished my Express last night, after just over 2 years! The delay was largely due to the arrival of our second son, so spare time has become rare of late. But this made me go slow as opposed to rushing it which is probably a good thing.

This is my second amp build, my first being a Champ type clone.

The amp was largely a Ceriatone Expression kit with the following exceptions:
Heyboer PT and OT (vintage 6K6).
Vishay BC Components filter caps.
Sozo coupling caps (standard).
I also used a switchcraft input just to be a bit closer to Francesca.

So far I've only been able to play it using my Hotplate attenuator on its lowest fizzy type setting as the kids were in bed by the time I got to try it out, so frustratingly I don't know how it truly sounds yet. The cleans sound great though. I'm thinking of setting up some sort of line out rig for home playing.

But it all seems to work, it cleans up OK with the guitar volume and luckily no oscillations as far as I can tell.

I'm currently running some winged C EL34s and TungSol 12AX7s, but I've got some RFT EL34s and a few NOS 12AX7s to try out. I'll probably try and break the Sozos in before I start investigating other tubes though.

In terms of a cab, I got a cab builder here in the UK (Chris Uff) to make me a tolex version. For the speaker cab, I've got an oversized 2x12 (Zilla Fatboy which is supposed to mimic the sound of a 4x12) loaded with Scumback M75 65 watters.

Here are some of the hurdles I encountered during the build:

- The Ceriatone chassis came prepunched for the Ceriatone PT, with separate holes for the primaries / secondaries. The Heyboer PT has all of its primaries and secondaries coming out of the same hole, and didn't fit through either hole in the chassis. The solution was to punch another hole in the chassis using a cheap punch (think it was a QMax?) and fit another grommet.
- I struggled with soldering the ground buss to the back of the pots until I followed rfgordons method in this post: http://www.ampgarage.com/forum/viewtopi ... 28438512e3
- The Ceriatone boards come with prewired teflon leads and I found them impossible to strip until I learned from searching posts here that you have to use your strippers to cut only, and then pull the insulation off with your fingers.
- The boards also had the teflon wires soldered to the bottom of the board. I managed to snap one of these out of the bottom of the turret whilst failing to strip it (see above). At that point I had already connected a lot of the wires up and didn't want to redo them, so I ended up soldering a new one to the side of the turret on top of the board. The lesson for me here was that I will always solder to the top of the boards if I can for future builds as it will make maintenance a lot easier.

Other than that, I tried to follow the excellent build guide and Francesca pics as best I could.

Here are some pics:

[Dr-Joned]

Looks Great! I have always loved the green tolex with gold faceplates. Nice looking cabinet below it as well. Did your fellow make it as well?

[eazilyled]

Looks Great! I have always loved the green tolex with gold faceplates. Nice looking cabinet below it as well. Did your fellow make it as well?

Thanks! Actually the head is just sitting on a coffee table type thing in that pic. I haven't taken a shot of the speaker cab yet, but it was made by Zilla - a cab company here in the UK:
http://zillacabs.com/2x12_cabs.php
The model I have is the Fatboy and I got it in the same colour tolex as the head.

[Koop]

Beautiful work! I'm sure it'll be worth the wait.

[eazilyled]

Another pic of my new amp setup. I switched the knobs to Davies 1510 types which looks a bit better to me.

For preamp tubes I settled on a Tungsram NOS in V1, and a Mullard in V2 / V3 (used but OK). For power tubes I put in some NOS RFT EL34s. These tubes made the amp sound a bit smoother.

I also tried a used Mullard ECC82 (12AU7) in V1 and I was surpised with how good that sounded. I basically got a larger clean region on the amp volume, but with a great crunch at higher settings. Still cleaned up well with the guitar volume. Turned it into more of a medium gain amp I guess.

The small box to the left of the amp is an EH Magnum 44 power amp which works great for low volume bedroom playing.

So the connection chain is Amp speaker out -> Hot plate speaker in (set to load) -> Hot plate line out -> EH power amp -> speaker cab.

I need to record some clips at some point.

[eazilyled]

Just posted this over on the For Sale section, which describes a problem I had using the Bud chassis cover with the Ceriatone chassis and forgot to mention it above. As posts in the For Sale section get culled eventually, I figured I would post it here in case it helps someone down the road:

I bought the 'official' Bud plate from the BOM for my Ceriatone, but you have to be careful because the Ceriatone chassis only has lips at the sides where the cage nuts are, not at the front / back.

The first thing is that you have to cut out holes in the cover so the cab bolts can reach the cage nuts, but you'd have to do this for any cover (see build guide).

The real problem I had with the Bud chassis cover was that it has four protuding 'feet' which extend out below the bottom of the plate. If the protusion of the feet is greater than the height of the bolts used to secure the cover to the chassis, the feet will touch the bottom of the cab and the cover will bend inwards towards the circuit as the cab bolts are tightened. I had a bit of a fright when I saw one of my power tubes was redplating when hitting a hard chord because the cover was shorting on the impendance selector.

The way I got around this was to add washers to the cover bolts, making the overall height of these greater than the protuding feet, so that the protuding feet didn't touch the bottom of the cab.

I also added a chassis to cover dowel as in Francesca to ensure that the cover stayed in its correct position.

So short story long, use flat aluminium for your cover , although I suppose you could use the Bud cover upside down.

[LarryLarry]

Awesome, green is my favorite color.

Might I suggest a great alternative to the Hotplate? - Babysitter

[eazilyled]

Ha ha great idea! Thanks man

[leadfootdriver]

Nice. That's a long time to wait!