Just finished first kit - no sound - Hellllllllp PLEASE [Archive]

Denny

10-31-2008, 07:56 AM

:dunnoI just finished my frist kit build. No sound. Tubes heat up, a very faint hum from the trannys - (like "they're on). Nuttin. I went back to the layout and checked my build and connections 3 times - nuttin. Thought it might be the impedence selector switch - bypassed it - nuttin. The pilot light lights. Everything appears to be right where it should be - I tugged on the wires for a bad/cold joint - nuttin. Any ideas? I was so happy and proud I got it built and now I'm bummin cause it doesn't work. I've actually thought of disassembling it and starting over but if it's something simple - that would be stupid. Thanks ahead of time. I'm at work today - 802-747-4606 and can take calls all day and can go on speaker phone if anyone has the time or inclination to call.

D.

LowWatt

10-31-2008, 08:34 AM

:worthless

Can't help you if we can't see it.

VaughnC

10-31-2008, 08:36 AM

If you have a voltmeter and know how to use it, I'd start by checking to make sure the power supply DC voltages are correct and are reaching the tube plates & screens. If you don't understand basic electronics it might be best to have an experienced eye check it, especially considering the high DC voltages lurking inside a tube amp.

doctorx

10-31-2008, 08:38 AM

Pull the tubes. Check all the voltages, plate, heater, etc. Triple check that all the electrolytics are installed correctly, ie, polarity.

Go here and read. (http://www.geofex.com/)

What kind of kit is it?

Denny

10-31-2008, 09:02 AM

It's a Ceriatone VibroChamp - Nik is awesome. My amp tech is bill carruth (Trey anastasio's tech in VT) and I'm waiting for a call from him. I can't post [pix today but will later tonight or tomorrow. I'm sure it's something simple and relitively stupid (on my part) I'm very awere of the voltage thing and don't go probing around without Bill on the other end of the phone. He might be out of town this weekend so that's why I've posted here. I was very careful while building (at least I thought I was LOL). The tubes do heat up - if that's any help. and there is a slight pulsing humm (almost inaudible) from the speaker which doesn't get louder when the volume is turned up.

Denny

10-31-2008, 09:16 AM

OK - the pulsing I mentioned is the trem circuit - I turned those knobs down and it stopped - if this helps.

hamfist

10-31-2008, 12:18 PM

Unfortunately, I have no words of wisdom to impart, but I can empathise with you. I've just spent the last few days rebuilding an old amp to Marshall 2204 spec. THis is very much my first build, as I've only really tweaked a few components before. Got to the point this afternoon of switching it on, and ............ nada !!! absolutely nothing.

Been through all the components and connections again. Checked all the voltages. Just couldn't work it out. Then I realised I'd completely left out one resistor in the PI circuit, because I'm waiting for some of that value to come in - -doh !! What a doofus. I sure hope that is the cause of my own silent amp. I suspect it is.
I was so seriously pissed off before my discovery of the missing resistor.

Anyway, I sure hope you can get to the bottom of your own "silent amp syndrome".

Sounds like you're in much the same boat as me, in that you can wield a soldering iron, and generally follow a schematic and a layout, but troubleshooting a faulty amp ... that's another ballgame entirely !!

Denny

10-31-2008, 12:49 PM

thanks for the support. I'll keep posting

donnyjaguar

10-31-2008, 01:44 PM

Its a wiring problem. :) I'd check that the right wires are on the right tube pins first myself.

skipm45

10-31-2008, 06:33 PM

Agreed. It probably is a wiring error.
Check the input jack wiring as well.

Skip
www.skipzcircuits.com (http://www.skipzcircuits.com)

Structo

10-31-2008, 07:16 PM

Here is the layout diagram.
http://www.ceriatone.com/images/layoutPic/fenderLayout/VibroChampCeriatone.jpg

A lot of times a first time builder will leave out or miswire the under board wires.

These are the dotted lines on the diagram. Make sure those are right.

The other things to check are the grounds to make sure they are wired right.

You have a speaker connected right? I'm not kidding, it's the simple things that most often are overlooked.

With tube amps it's important to always have a speaker connected anytime the amp is turned on.

The best way to start a new amp is with a current limiter made with a light bulb.

You start it with no tubes and if the bulb does not glow brightly ( big draw of current will make it glow) you turn it off and install the tubes and turn it on again.
If the light bulb stays a low glow then it is probably wired right.

Denny

10-31-2008, 07:57 PM

OK - I now have some moderate volume - I left out a couple of ground wires to the filter caps. The tone is good, but no where as loud as it should be. Like not enough gain. also, when I turn ON the Intensity (from fully counter-clockwise to about 8/9 o-clock) for the Trem, the volume drops right out. I'm going to check the wiring again. if anyone has any ideas - I'd appreciate it. My techie (Bill) had me do some voltage tests this afternoon - both DC and AC - things were a bit squrilly but since I connected those wires and have some sound, things are looking better. I do use the light bulb gadget - it works great. One thing - I was so neat and clean when I did the build, and now, since I've had to check and recheck it - it's beginning to look like Fender did the wiring LOL. I'm enjoying this. I have another of the same kit but won't start that one until I know this one is 100%.

D.

Tonefish

10-31-2008, 09:30 PM

Is that a little grounding leg on the volume pot? Looks easy to miss.

banjoze

11-01-2008, 01:08 AM

Denny, we would all LOVE to hear it when you get it right... Please record it and share so we can celebrate with you... :)

Denny

11-01-2008, 08:34 AM

yes the V pot is grounded tho the ground rod. I'm just trying to figure out the trem. Intensity problem now. any ideas.

Yes I will record some stuff when she's 100%.

Structo

11-01-2008, 11:56 AM

Yeah if you could post some close up gut shots it would help us help you .

RedMan

11-01-2008, 01:45 PM

I don't know but looking at that wiring diagram I can't imagine anyone not having troubles with the tremolo circuit. That looks really screwy to me.

Denny

11-01-2008, 04:40 PM

OK - I'll post pix tonight with the agreement that no one laughs at the freakin mess it's turned into LOL - Like previously said - before I started troubleshooting, she was pretty neat and clean - especially for a FIRST build. Now, she looks a bit "messy" from pulling, tugging and tracing wires, soldering and changing this and that, etc. - however - once everything is 100%, I will put her back to a nice, clean, neat unit that she deserves to be. Pix to come tonight after band practice.

D.

Denny

11-01-2008, 04:48 PM

OK - here they are - I've since grounded all the filter caps. Also - the 25 cap to the left of the "holy Grail" cap was pulled for diagnosis but has be re-soldered. Remember - I have low to moderate volume now but definitely no where near what it should be - tone is ok - the issues now are not enough volume and the intensity knob shuts off the volume.???? Thanks

http://i41.photobucket.com/albums/e271/Dennis1953/IMG_0026.jpg
http://i41.photobucket.com/albums/e271/Dennis1953/IMG_0027.jpg
http://i41.photobucket.com/albums/e271/Dennis1953/IMG_0028.jpg

3th3r

11-02-2008, 01:51 AM

Hi Denny

(First, you have already grounded the Holy Grail cap to the ground bus, right?)

In your picture, I don't see the 68k input resistors that are shown on the layout diagram. Do you have these in your build?

It appears that you are using shielded coax cable for the input to V1a and for the input to V1b. Do you have the shield wired to ground at one end? If so, be extremely careful soldering this type of cable because heat from the iron can easily melt the plastic dielectric and will cause an short that is not visible to the eye.

Denny

11-02-2008, 06:15 AM

yes the 68K's are there - I'll check for a short on the coax - thanks.

Blue Strat

11-02-2008, 09:05 AM

Print out a layout sheet, get some different colored Hi-Lighters, and start comparing your work to the layout, hi lighting each wire on the layout drawing as you go.

This is how it's done.

Also, try the tubes you're using in another amp to be sure they all work properly.

Good luck.

Denny

11-02-2008, 10:23 AM

yes I will do the highliting thing already checked the tooobs.

Denny

11-02-2008, 03:03 PM

GOT IT!!!!!! SOUNDS GREAT - I'LL EXPLAIN WHAT IT WAS LATER - I MISSED ONE WiRE TOTALLY !!!!! GONNA GO PLAY FOR A WHILE, THEN POST WHAT IT WAS.

Thanks everyone for all the help!!!

hamfist

11-02-2008, 03:52 PM

GOT IT!!!!!! SOUNDS GREAT - I'LL EXPLAIN WHAT IT WAS LATER - I MISSED ONE WORE TOTALLY !!!!! GONNA GO PLAY FOR A WHILE, THEN POST WHAT IT WAS.

Thanks everyone for all the help!!!

Excellent !!!! Got mine working too !!! We are Masters of the Universe !!!!

Blue Strat

11-02-2008, 04:09 PM

GOT IT!!!!!! SOUNDS GREAT - I'LL EXPLAIN WHAT IT WAS LATER - I MISSED ONE WORE TOTALLY !!!!! GONNA GO PLAY FOR A WHILE, THEN POST WHAT IT WAS.

Thanks everyone for all the help!!!

Retracing does it almost every time!

Enjoy!

zzmoore

11-02-2008, 06:00 PM

GOT IT!!!!!! SOUNDS GREAT - I'LL EXPLAIN WHAT IT WAS LATER - I MISSED ONE WiRE TOTALLY !!!!! GONNA GO PLAY FOR A WHILE, THEN POST WHAT IT WAS.

Thanks everyone for all the help!!!

Come on man, what was it? ;)

banjoze

11-02-2008, 06:04 PM

This thread is such a great example of what makes TGP great... People being helpful with great advice and ideas (and no bickering based on some grudge from days gone by...)

I love reading this type stuff, seeing the pictures, learning by example how folks debug these problems....

Very sweet!

Denny, can't wait to hear what was wrong and how you found it... if you can show it using a picture that would be cool too...

Plus, we need to hear your creation now!

Congrats!

Peeb

11-02-2008, 06:21 PM

Any luck yet?
:munch

Denny

11-02-2008, 07:01 PM

OK - I've circled and drew in black the connection I didn't even see on the layout - If you look at the layout, you'll see what I mean - that's no excuse - I should have seen it, because now when I look at it, it's as plain as day, but with all the dotted lines there, it was a little hard to make out - anyway, besides no grounding a few caps - this was the culprit - I thank everyone on TGP - you guys are great support. I'll record some tracks and post them tomorrow night. It sounds great and the trem is to die for!!!
http://i41.photobucket.com/albums/e271/Dennis1953/fix.jpg

Tonefish

11-02-2008, 07:11 PM

Glad you got it going.

banjoze

11-03-2008, 01:28 AM

So, if I'm looking at the pic / layout correctly, it was a dotted line that you missed, right?

Denny

11-03-2008, 05:53 AM

yes - the "dreaded dotted line!!" LOL

D.

Denny

11-03-2008, 07:57 PM

I just recorded a couple of tracks but cant get my computer to read the card, so I'll post them from work tomorrow. sorry about the delay.

D.

Denny

11-03-2008, 08:14 PM

OK - i got it - Here's a link to the tracks. Just click on the vibrochamp titles. Remember - I'm not auditioning for a record deal here - this is to give an example of the AMP NOT my playing prowess LOL!!!. It's done on the VC through a 1x12 open-back combo with a Weber silver Bell - no FX except for the trem. I' playing with a cut on the left hand index finger. (excuses - excuses). Here goes:

http://www.soundclick.com/bands/default.cfm?bandID=712626

VaughnC

11-03-2008, 08:35 PM

FYI:
From your photo, it looks like there's a missing ground connection on one of the filter caps (the one that's furthest from the end of the tag board). The amp will still work without this connection but won't sound the way its intended.

Denny

11-03-2008, 08:38 PM

correct - I mentioned in a few post previous that I did connect all the grounds properly including the ones I missed LOL - she's sounding like a "champ" (pun intended) - listen to the clips. Thanx for the help.