Hi guys,

I just moved to a new house back in January, and finally got a chance to set up my amp.  Problem is, no output.  This amp was built by Ceriatone, with some mods/finish work by Henry (tenguitars) of this forum.

Here's what I'm observing:

1)  My c-lator seems to be receiving input from the preamp.  I have a Lexicon reverb unit in the c-lator, and it's got an input meter showing a signal. So, I'm reasonably sure the preamp section works.

2)  I bypassed (unplugged) the c-lator to isolate the rest of the amp - no luck.

3)  The output tubes LOOK fine.  (I realize that's hardly an adequate test.)  I did pull the inner pair, and then the outer pair, both with no luck.

4)  The speaker cabinet and speaker cable are working -- I tried them with another amp.

So, that seems to narrow things down to somewhere in the output section, possibly excluding the output tubes.  I think that leaves the OT, speaker output jack, impedance switch, other?  Could one of the 12AX7s be causing this? Because these amps are relatively complex, I thought I'd run this by you all before I start buying new output tubes or an output tranny. 

Any thoughts or ideas?

Thanks much in advance.
Tim

Thanks Todd.  (Would love to hear about that TW Express clone sometime.)

I've swapped out each 12ax7 (serially) for a new one.  Still no luck.

I can pull the chassis and get voltage readings, but it'll have to wait at least until Wednesday and possibly until Saturday.  I inherited a nice big workbench from the previous owner, so that should be relatively painless.

Is there a voltage chart somewhere on here for the OTS 100 FM?  My search turns up a bunch of folks posting voltages, but no generally accepted list of what to expect.

I'll be surprised if a connection came loose in the move, as I moved the head myself in the back seat of my car, and it's already survived shipping from Asia to Southern California to Maine.

Thanks again for your suggestions!

Gregg,

I have - see #2 in my original post.

Thanks.

Hey Tboulette

The ceriatone website has a voltage chart that covers most of the amps in the links section. a very handy chart.

As for the TW express, I could not seem to bond with that amp. It is very raw and loud. I left it at a friends house who is in a punk band hoping he would find a use for it and although he likes it a little more than myself he prefers his JCM800. maybe turn it into a rocket or liverpull and see if I like those circuits better.

Todd

Hi Tim,

Sent you a couple more emails.

Thanks,
Henry

Have ya checked the HT fuse?

Gregg

The HT fuse is the fuse on the HT (high voltage) winding of the transformer, in other words the voltage to the plates, screens, and grids of the tubes when you switch the amp off of standby to operate. It is located on the bottom of the chassis. The light on front will not glow if the mains fuse is blown, in other words, no power will go from the mains to the power transformer at all. That is the fuse on the rear of the chassis.

Gregg

Might have a winner, Gregg! Looks like the HT fuse is blown. It's too late to get a new one, but I'll try to pick one up tomorrow and report back.