Ceriatone Forum

Got my 18Watt Kit from Nik back in May. Got it put together, no problem...I thought.
Did not have the funds to purchase tubes at the time ( tight budget at home )... Until last week. Got my tubes from TubeDepot.com... Downloaded a copy of there manual and read it. Wanted to see how there process of putting a 18Watt kit together, from start to finish. Followed their instruction in Chapter 8 on powering up the Amp, made a Dim Bulb Tester, and proceeded.

Their instruction is pretty much common sense...just going 1 step at a time. Adding tubes with each step, to see if you have voltage at certain spots.

As I started, with no tubes in the Amp and had a 40 watt bulb in the DimBuld tester. My bulb never powered up.... but my Indicator Light on the Amp did... knew that's not right... Went back and checked my DimBulb tester. It checked good.

So I went on and added the EZ81 power tube. Same thing... but my Power tube glowed very low as though it were at 1/2 or 1/3 power... no light on the dimbulb.

I checked the voltage at the "B" terminal of the can capacitor... 429 VDC... hmmm.  That seemed to be correct.

So with all that said... question is... Is it just simply a "Cold Solder" or would this indicate a incorrect connection of my GDS power transformer?

Should I use a lower wattage bulb for the dimbuld tester?

I Followed the Ceriatone 18 Watt TMB Layout March 2010... double checked and triple checked my connections per the drawing.

Any suggestions would be greatly appreciated...

Thanks, Mule3

The best way to help us trouble shoot your build is to take as many clear, close photos as you can. Then post them here. We take a look at you solder joints for instance and maybe spot a bad or improper connecton.

Making sure the PT is wired properly is important. Did your PT come with wiring specs?

Thanks Chris for your response....

Pictures... I'll try...we'll  see how it works.

No... the GDS Power Amp came to me with no instructions.

Thanks, mule

Not sure what the problem is. The power light comes on?
The bulb test will tell you if you have a short circuit by lighting bright if shorted.

Pics dont show much but one thing I will mention is that all wire connections should have a good mechanical connection before being soldered. Meaning the wire ends should be looped through and crimped so that they are a tight connection before soldering. Just pushing the wire in the hole and then using solder as a glue is just asking for trouble if not now in the future.

Todd

Thanks Todd for your input... Yeah the indicator light comes on...not  very bright.

I connected all the tubes just to see what I'd get... plugged in the speaker and guitar........ nothing..... The Power Transformer does not get hot or warm to the touch. So I've got a wrong connection or defective connection or my power transformer is defective.

I don't think the transformer is bad.... I think it's something I did...

If and when I figure it out... I'll let you guys know...

Sorry to be such a "newbe" .... still is fun ... how else can one learn?

Thanks, mule

No worries
If you can post more pics that show the rest of the guts we may be able to help track down the issue. It does sound as if an open ckt somewhere, which BTW is better than a short ckt .
If you have double checked all connections to the layout I would suggest reflowing the solder at each connection. If any solder looks cloudy reflow it for sure.
Also, do you have a meter? If you can power up without blowing fuse I would next check some voltages. Make sure you know how to do this safely before proceeding though.

Todd

Here is link to voltage chart
http://www.ceriatone.com/tlbrBorderSub/link.htm

Click on voltage chart at bottom then in Excel file at bottom arrow over to tab that says TMB. Your voltage readings should be reasonably close to the voltages posted. All reading are measured in DC to ground. Once again only proceed if you know how to do this safely as there are voltages inside the amp that can kill you.

Todd

Just noticed something!
Cant see all because of pic but it appears there is no wire to ground off the speaker jacks. Should be landed right where your OT (0v) is!
On the layout it shows it going to star ground.

On both the Ctone layout and pics on the site it shows the impedance switch to the right of the speaker jacks. On your pic it is not. I am now a little confused.

The cap and diodes at the rectifier tube should be insulated.

Todd

I see the PT has the voltages marked so as long as you got those correct then your good. But did you happen to check the PT to be providing the proper supply before wiring?

The pics are good, but more with a bit more light would be better. Have the camera facing straight on for the components on the bottom of the chassis and then angled as best you can to get straight on for the stuff on the walls of the chassis. I know taking photos is a pain, but can be really helpful.

Check out what Todd noticed and then from there a methodical voltage check from mains on through would be in order. I notice many times when you start tracing the circuit to take voltages you will find any mistakes in wiring.

Don't worry about us pointing out errors or being a "newb". It's the only way to learn.  ;)

Having said that, like Todd mentioned, some of your connections are a little on the questionable side of things. I hate having to do this, but sometimes just cutting the connection and redoing it is what is best. Sometime I will try to rework a connection that didn't quite go the way I intended and end up making it even worse. So out come the snips and strippers. And I don't mean the kind that dance with poles. :o

FOUND IT!!!!!......OR PART OF THE PROBLEM.....

I CAN'T BELIEVE IT..... HOW COULD I HAVE DONE SOMETHING SO STUPID!!!!

POWER IS REVERSED.... I GOT MAIN AND NEUTRAL BACKWARDS AT THE POWER PLUG.

I'M EMBARRASSED  :-[

I guess most people would not told this on themselves...

DimBuld is doing right now....
 
Also took off those resistor and cap at the stanby switch and resoldered.

No smells... no magic smoke.... no mushroom clouds...... So I went ahead and plugged all the tubes in..... Plugged in the Speaker..... Plugged in the guitar.

Still not quite normal...

It sounds as though it's half power.... both EL84'S are lit up.... one is brighter than  the other... But.... I am getting sound!!!

You are right Todd!!!! I did miss the ground at the speaker jacks....

And thanks for the Voltage Chart...just what I've been wanting. Now I have a reference to check by...because your right some of my connections are pretty bad. I left plenty of slack in the wire at V1 thru V6 and all the POTS, just in case.

THANKS TO BOTH YOU GUYS... YOU'VE BEEN A GREAT HELP.... CAN'T SAY IT ENOUGH

THANKS, Mule

PS.... I can post more pictures... if you like.

Thats great man ;D

Yeah, try to post more pics of the full amp guts and we will try to help get this thing working the way it should be.
Do you have a solder sucker? If so I would suggest desoldering about 5 points at a time, crimp the wire into a loop on the terminal and then resolder. Sounds like a lot of work but I bet you could get them all done in about an hours work and it will make the amp more reliable/gig worthy for a much longer time. Like Chris said some of the wires may be worth restripping if they turn out to be too much of a PITA. On the wires you restrip tin the stripped end of the wire before sticking through terminal hole and crimping, it will keep the wire from fraying when you bend it.
Let us know if all the voltages are checking out, if so the problem will be in the signal path most likely and will narrow down the problem

Todd

Very cool. 8)

Believe me, I've done some very silly mistakes too. It's really par for the course. Either it's late and you should have stopped an hour earlier or you just do it wrong. Keep checking connections and voltages and get back to us.

More Pic's

Thought I'd show V1 thru V5.

It's pretty ugly..... Like I said before...I left plenty of slack from the board feeding the tubes and the pots.

Guys....

If I wanted to drain the voltage off the can capacitor...is that done by draining it to a good ground source?

That is... Running a wire from the B post to ground...

Is their any other place that would hold voltage... that would ned to be drained?

Thanks

Hi

  Just use something like a 1K 5W resistor, from + of cap to ground, held for a few seconds. Check with meter to see any voltage left.

  As for this, did you check the voltages?

  I am not sure if the GDS PT is same color codes as ours, so do check on that. For all we know, the OT center tap could be the blue wire instead.

  But voltages do tell a lot.  If your EL84 glows brighter on 1 side, it could be the OT wiring. or perhaps the cathode pin wiring - I see how your soldering is forming a blob on one of em. This could, possibly, mean that the other wire is not making good connection.

And, I guess, PI section can also contribute to this, check there too.

Usually, when soldering, you make good connection first. Ie, affix the wire to the lug well. You can insert and then form 1/2 a loop with the post, for eg. Do for both wires, in this case, and only then solder.

It'd also make good looking solder, done this way.

Thanks!

nik

And - it may go without saying - make sure you take it OFF BEFORE PLUGGING BACK IN!!!

One thing good about leaving more slack is you have enough wire to redo things.

One this to be very aware of when reworking the tube socket pins is be very careful not to let solder flow down inside the pin socket. This is a big PITA and usually means needing to get a new socket. Oh, and remove the tube first.

Follow what Nik was pointing out. There are definitely some bad solder connections on the tubes. What type of solder are you using and what temp do you have the soldering iron set at? Or what type/wattage iron are you using?

Thanks Nik....

Yeah I'm planning to drain the capacitor and start resoldering each pin.

Chris... the solder iron I was using when I first started was the major problem.

It was a cheap, piece of junk I had that was old. Had used it for for other projects around the House. Would not heat up. Thought I'd start with it.... see how it would work.... big mistake.

Went to HomeDepot and got a Weller 40watt... you can almost see the difference on the Pic's..... The good solder joints and clean and shinny... but their are some That I rushed.... made a mess...

But one thing I did not know is making the "hook" for each wire... makes sense.
I did "tin" each wire... but did not hook.

Thanks, Craig
 

Yes, a good soldering iron will do wonders. Sounds like you picked a good one. I think you're on your way to getting things sorted out. You'll be jamm'n in no time.  ;)

Thats cool, thanks guys.

Talkin abt iron, we usually use Hakko. Forgot the model name but its not that pricey. Usually, they'd last 2 years or so, and thats with heavy  daily use (8 hrs a day).

Be sure, if you use regularly to change the tip when necessary. Dont be stingy with that :)

Thanks!

nik

This a really good point. Mine is in need of a new one now. I've been nursing it along, but the last time I used it, it was really making things difficult. I'm too stingy!  :-[

Sorry to say Guys....Still having same problems

After 90% resolder.... some did not need at the pots positions... Still same issue.

Have to turn volume all the way up to here the guitar... on both channels normal and TMB.

Took voltage readings... V6 is within specifications 272v at pin 1 and pin 6... all others are way over the top... hot.

Here are the others:

.....................Pin 1........................pin 6

v1................ 284 .......................330
v2................. 307 ...................... 337
v3................ 308 ....................... 356

....................pin 7 ........................ pin 9

v4................382......................... 379
v5................ 382....................... 379.

Here are more pic's...... Still think I have done something wrong on the power feed.

Are the Diodes pointed in the right direction?

Thanks, Craig

Yes diodes are in correct direction but they should be insulated!

 There should be a cap and a resistor at the standby switch!


Cant tell where the wires are going on the first pot next to the power switch but does not look right! Should just go to next pot over ( Mid ).

This is the layout you are following right ?>  http://www.ceriatone.com/images/layoutPic/marshallLayout/18wattTMBceriatone.jpg

I still do not see speaker ground at star ground! is this pic taken since that fix?

Please try to take some pics that will show the whole amps guts if possible as well as closeups of the tubes socket area and all the pots as well.

Todd

Yeah, I took off the heat shrink insulation that I had on the diodes, to show them... I'll put the heat shrink back later...

The cap and resistor at the standby switch I took off... but I can't remember why I did that??? ???

The pot next to the power switch is correct per the layout.... and speaking of layout, I did follow the 18watt layout March 2010... In fact before I started this build, got a big piece of cardboard. Did a "Blowup" of the layout and taped it to my cardboard.

Then got online and found a resistor chart to make sure I had the right "values" of resistors going to the right places.... Then taped each resistor and capacitor on the "Cardboard Blowup" before I ever soldered anything.

When I got ready for a certain resistor or capacitor I just removed it from the cardboard and solder it in.....

However.... I could have made a mistake... but I did double check all.

Got the "sleeve" of the output jacks grounded.... per the picture to follow.

Thanks, Craig

OK I hate to keep asking for more pics but I still dont see any pics that show the wiring at all the pots, jacks,etc.

On the full gut pic you posted it appears to be missing a 100 ohm resistor going from the tone knob to the ground buss. I cant see much more due to the lip of the chassis

One thing I cannot help you with is making sure the resistors are the correct value ( I am colorblind, thank god for digital multimeters ) but I am pretty good at finding miswiring so keep the pics coming and I will see if there is anything you are missing. You said you resoldered 90%, may want to reflow the other 10% for good measure.

Dont give up, I think you are getting closer

Todd

Todd,  I've noticed something before on the Ceriatone Layout that is on the PT...

By the 120v tap is 0 for ground and also "E" which goes to ground... what is "E"???

On my GDS PT their is a tap mark "SCN" not sure what this is for either...

Pic's to follow

Thanks, Craig

I do not know what SCN stands for, but it is in the same location on the PT as E so that makes me wonder?
I recommend you contact the manufacturer and ask before grounding it. Appears GDS uses hyboer or EMS trafos but I still cant find any specs that show SCN! I bet this needs to be grounded just dont want you to ground it until sure.

It is a little blurry but the middle lug of your bass pot appears to be a cold joint! Solder should not be balled up like that

Also, I do not see any wires landed on the turrets of the main board coming from your pots. If you landed them on the bottom of the board you should double check that each wire is going to the correct spot and that the solder joints are good. Turrets need a little more heat to get good solder joints.

I would still like to see pics of the rest of your internal wiring, such as the jacks and the rest of the pots to the right side of the last pics you just posted.

I will be pretty busy today but when I get some free time I will check back this afternoon

Todd

FIXED!!!!!!!

Emailed Graydon at GDS... He set me strait.... ;D

Thanks, Craig

Was it the SCN to ground?
And how does everything sound now?

Todd

YES...... SCN needs to be hooked to ground.

Also, Graydon's picture had "0" and "CT" on the 6.3v feed... different than mine.

So I changed mine, to mirror his....

Before and After.....

Cool ,
So how does it sound?
Also, did he tell you what SCN stands for? Just curious

Todd

I HAVE A TONE MONSTER!!!!!!!!!!!!!!!.................Wow!!!!!!!!!...........

THANKS TODD.....THANKS CHRIS......THANKS NIK..........THANKS GRAYDON