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Title: I could use a little more help Post by: djroge1 on August 29, 2009, 04:27:24 AM I'm stumped as to why I don't have good voltage readings on V1 and V2.
All the others are pretty much righ on par with where they are supposed to be. Where wires L & M connect do any of you happen to know what that should be reading? I'm getting 52 - obviously I am getting 52 from L on the power board. Does that sound right? Any thoughts? Title: Re: I could use a little more help Post by: bluesfendermanblues on August 29, 2009, 05:31:07 AM No, I sounds absolutely wrong.
Turn of the power and check all wiring in your amp. Use the 'layout' on the ceriatone webpage. If your amp is the latest overtone version, then use http://ceriatone.com/images/layoutPic/OvertoneLayout/Overtone-Special-V2.jpg Check every single wire, one at the time. It sounds like your have made an error in the PSU wiring, so check this part of the thorughly. This is the best peice of advise I can provide you. Title: Re: I could use a little more help Post by: djroge1 on August 29, 2009, 05:50:33 AM I didn't think that sounded right.
I had an earlier post questioning my power tranny because the numbers and order were all off and I was confused. Basically this is what my PT reads on the transformer when compared with the wire diagram. In the wire diagram one side reads from left to right: 6-0-60-0-3.15-0-3.15-E Mine reads from left to right: 3.15v-0-3.15v 230v-120v-100v-0- E The other side of the wire diagram reads left to right: 240-220-120-0 - - 345-0-345 Mine reads left to right: 50v-0-6v-0-345v-0-345v (http://i492.photobucket.com/albums/rr282/djroge1/IMG_0123_0130_edited-1-1.jpg) (http://i492.photobucket.com/albums/rr282/djroge1/IMG_0127_0132.jpg) Title: Re: I could use a little more help Post by: hywelg on August 29, 2009, 06:17:22 AM Better if you were to provide a good photo of the innerds of your amp showing how you've connected the PT then we moght be able to help. The PT is pretty self explanatory, they might not be in the same order as on the layout but they are labeled and they are colour coded so that the '0' that goes with the 50v is the same colour so you can't confuse the pairing. So check your wiring to make sure that where the 60-0 pair go to on the layout drawing your 50-0 pair do also, an similarly for all the others.
Title: Re: I could use a little more help Post by: bluesfendermanblues on August 29, 2009, 08:10:16 AM Exactly, since the amp has the correct voltages on the output tubes and phaseinverter (v3), it doesn't sound likely that the powertransformer should be connected wrong.
More likely that you have wired the amp wrong. Title: Re: I could use a little more help Post by: djroge1 on August 29, 2009, 03:34:14 PM Ok here are some shots. It is possible that something is wrong since I am color deficient (not color blind), but when I couldn't figure out a color (red, green, brown) I had both my wife and kids help.
(http://i492.photobucket.com/albums/rr282/djroge1/IMG_1008_0142_edited-1.jpg) (http://i492.photobucket.com/albums/rr282/djroge1/IMG_1009_0143_edited-1.jpg) (http://i492.photobucket.com/albums/rr282/djroge1/IMG_1010_0144_edited-1.jpg) (http://i492.photobucket.com/albums/rr282/djroge1/IMG_1011_0145_edited-1.jpg) (http://i492.photobucket.com/albums/rr282/djroge1/IMG_1012_0146_edited-1.jpg) (http://i492.photobucket.com/albums/rr282/djroge1/IMG_1013_0147_edited-1.jpg) (http://i492.photobucket.com/albums/rr282/djroge1/IMG_1014_0148_edited-1.jpg) (http://i492.photobucket.com/albums/rr282/djroge1/IMG_1015_0149_edited-1.jpg) (http://i492.photobucket.com/albums/rr282/djroge1/IMG_1016_0150_edited-1.jpg) Title: Re: I could use a little more help Post by: hywelg on August 29, 2009, 05:29:17 PM Has this joint been soldered? Can't see it properly as the photos are a bit blurred.
Title: Re: I could use a little more help Post by: djroge1 on August 29, 2009, 08:06:23 PM Yes that spot has been soldered.
In fact, it is the connection just before that spot with the 22k 2w where I loose voltage. On the side towards the PT that connection reads 386. on the other side of that it reads 54 and is low from there on out going on to the L & M connection point. Title: Re: I could use a little more help Post by: bluesfendermanblues on August 29, 2009, 09:11:57 PM Yes that spot has been soldered. In fact, it is the connection just before that spot with the 22k 2w where I loose voltage. On the side towards the PT that connection reads 386. on the other side of that it reads 54 and is low from there on out going on to the L & M connection point. Try to solder it again! Title: Re: I could use a little more help Post by: djroge1 on August 29, 2009, 09:46:18 PM I re-soldered that point and it remained the same.
New problem... I was checking voltages in some other locations to see if they were the same V1 pin 1 - 10 V2 pin 2 - 30 V3 Pin 3 441... then suddenly there was a blue spark and the volts dropped down to 60. :'( I think something broke... (blew up) because now it's completely dead and there is no reading. Any suggestions on where to buy a new transformer that will work? I live in the states. Title: Re: I could use a little more help Post by: hywelg on August 29, 2009, 10:04:39 PM So did the blue spark come from the place where you had your probe or somewhere else? Are there any signs of charring? Fuses? Transformer wiring continuity? ( you will have to de-solder the leads to check these, on the output side anyway)
Title: Re: I could use a little more help Post by: erwin_ve on August 29, 2009, 10:40:22 PM 441v on your Phase Inverter cathode is bad stuff, thats normally a voltage reading for the plates at the powertubes.
* make sure your tube at v3 is OK, replace it, check fuses(measure them) *Is your wiring at the dropping string correct? *Check with amp off: the resitance between the 110k PI resistor to V3 pin 3, the resistance between 100k PI resistor to v3 pin 3. *What is the resistance of the -supposed to be- 22k resistor in the dropping string, please measure it(with amp off, of course). *Is your Output Transformer ok?: measure resistance between a primary lead and a secondary lead(amp off). *Check your wiring for the presence control;is it accidently on the primary side of the Output Tranny? I re-soldered that point and it remained the same. New problem... I was checking voltages in some other locations to see if they were the same V1 pin 1 - 10 V2 pin 2 - 30 V3 Pin 3 441... then suddenly there was a blue spark and the volts dropped down to 60. :'( I think something broke... (blew up) because now it's completely dead and there is no reading. Any suggestions on where to buy a new transformer that will work? I live in the states. Title: Re: I could use a little more help Post by: djroge1 on August 30, 2009, 01:43:13 AM Ok after that spark I had to leave and go work out... frustration.
The HT fuse .5a fast blow is out and I don't have another one right now so I'll hit the store tomorrow. I'll measure and look at all the suggestions in a bit. Thank you guys for the encouragment and help... I know I can get thru this. Title: Re: I could use a little more help Post by: djroge1 on August 30, 2009, 03:25:10 AM 441v on your Phase Inverter cathode is bad stuff, thats normally a voltage reading for the plates at the powertubes. * make sure your tube at v3 is OK, replace it, check fuses(measure them) *Is your wiring at the dropping string correct? *Check with amp off: the resitance between the 110k PI resistor to V3 pin 3, the resistance between 100k PI resistor to v3 pin 3. *What is the resistance of the -supposed to be- 22k resistor in the dropping string, please measure it(with amp off, of course). *Is your Output Transformer ok?: measure resistance between a primary lead and a secondary lead(amp off). *Check your wiring for the presence control;is it accidently on the primary side of the Output Tranny? I re-soldered that point and it remained the same. New problem... I was checking voltages in some other locations to see if they were the same V1 pin 1 - 10 V2 pin 2 - 30 V3 Pin 3 441... then suddenly there was a blue spark and the volts dropped down to 60. :'( I think something broke... (blew up) because now it's completely dead and there is no reading. Any suggestions on where to buy a new transformer that will work? I live in the states. I made a mistake in giving you information. the 441v was on V4 NOT V3. The spark was where I had my probe. I think I may have made an arc - like when you weld to get the weld started? The only charring I've found so far is on the fuse and there was no smoke or burning smell when it sparked. I'm not sure which one is the 110k PI resistor to V3 pin 3 - I know where that pin is, but I don't see a 110k or 100k resistor. As for the PT and measuring... I putting one lead on the 120v (on/off switch) and tried reading on the rectifier board - nothing. I tried again on the switch relay board - nothing. It's late and I'm tired and I need to think with a clear head tomorrow. Title: Re: I could use a little more help Post by: bluesfendermanblues on August 30, 2009, 08:05:06 AM 441v on your Phase Inverter cathode is bad stuff, thats normally a voltage reading for the plates at the powertubes. * make sure your tube at v3 is OK, replace it, check fuses(measure them) *Is your wiring at the dropping string correct? *Check with amp off: the resitance between the 110k PI resistor to V3 pin 3, the resistance between 100k PI resistor to v3 pin 3. *What is the resistance of the -supposed to be- 22k resistor in the dropping string, please measure it(with amp off, of course). *Is your Output Transformer ok?: measure resistance between a primary lead and a secondary lead(amp off). *Check your wiring for the presence control;is it accidently on the primary side of the Output Tranny? I re-soldered that point and it remained the same. New problem... I was checking voltages in some other locations to see if they were the same V1 pin 1 - 10 V2 pin 2 - 30 V3 Pin 3 441... then suddenly there was a blue spark and the volts dropped down to 60. :'( I think something broke... (blew up) because now it's completely dead and there is no reading. Any suggestions on where to buy a new transformer that will work? I live in the states. I made a mistake in giving you information. the 441v was on V4 NOT V3. The spark was where I had my probe. I think I may have made an arc - like when you weld to get the weld started? The only charring I've found so far is on the fuse and there was no smoke or burning smell when it sparked. I'm not sure which one is the 110k PI resistor to V3 pin 3 - I know where that pin is, but I don't see a 110k or 100k resistor. As for the PT and measuring... I putting one lead on the 120v (on/off switch) and tried reading on the rectifier board - nothing. I tried again on the switch relay board - nothing. It's late and I'm tired and I need to think with a clear head tomorrow. I know the frustration from my own building process, but your amp will get up and running, so don't worry too much about it. Title: Re: I could use a little more help Post by: erwin_ve on August 30, 2009, 09:59:02 AM It's frustating when something doesn't work: please be as accurate as you can; all the measurement suggestions I gave you were for my concerns on the 441v on the v3 cathode.
Maybe it's handy for you to use a schematic like the #124; the topology is basiclly the same. And please learn the basic amp talk language and understandings: if you're building something like this you HAVE to know what the 110k resistor is at the phase inverter(PI). #124 is here: Ok after that spark I had to leave and go work out... frustration. The HT fuse .5a fast blow is out and I don't have another one right now so I'll hit the store tomorrow. I'll measure and look at all the suggestions in a bit. Thank you guys for the encouragment and help... I know I can get thru this. Title: Re: I could use a little more help Post by: bluesfendermanblues on August 30, 2009, 01:10:07 PM ditto
Title: Re: I could use a little more help Post by: djroge1 on August 30, 2009, 07:31:09 PM Well you're right I should learn more. This is the 2nd amp I've built, the first was a single ended class A amp with one 12AX7, one 6L6, and one rectifier tube built and it wasn't a kit. But I'm learning now as I build.
Title: Re: I could use a little more help Post by: erwin_ve on August 30, 2009, 08:26:45 PM Well you're right I should learn more. This is the 2nd amp I've built, the first was a single ended class A amp with one 12AX7, one 6L6, and one rectifier tube built and it wasn't a kit. But I'm learning now as I build. Well sorry if I was a bit grumpy :-[ But it's easier to help you out if we both talk the same language... Maybe a good link is: http://www.valvewizard.co.uk (http://www.valvewizard.co.uk) It sure helped me a lot to understand how tubes work. http://en.wikipedia.org/wiki/12AX7 (http://en.wikipedia.org/wiki/12AX7) on the pin layout of a 12ax7. I also did understand more of the schematics when somebody told me that a 12ax7 tube does have 2 triodes which appear apart from each other in a schematic(dUHH). Maybe you already know this stuff, maybe others will benefit from it: Plate is where the high voltage is. Pin1 and 6 on a 12ax7. Grid is where the signal is coming in. Pin 2 and 7 on a 12ax7 Cathode is where current flows to plate when a incoming signal is applied at the grid. pin 3 and 8 on a 12ax7. Title: Re: I could use a little more help Post by: djroge1 on August 30, 2009, 08:49:41 PM Well you're right I should learn more. This is the 2nd amp I've built, the first was a single ended class A amp with one 12AX7, one 6L6, and one rectifier tube built and it wasn't a kit. But I'm learning now as I build. Well sorry if I was a bit grumpy :-[ But it's easier to help you out if we both talk the same language... Maybe a good link is: http://www.valvewizard.co.uk (http://www.valvewizard.co.uk) It sure helped me a lot to understand how tubes work. http://en.wikipedia.org/wiki/12AX7 (http://en.wikipedia.org/wiki/12AX7) on the pin layout of a 12ax7. I also did understand more of the schematics when somebody told me that a 12ax7 tube does have 2 triodes which appear apart from each other in a schematic(dUHH). Maybe you already know this stuff, maybe others will benefit from it: Plate is where the high voltage is. Pin1 and 6 on a 12ax7. Grid is where the signal is coming in. Pin 2 and 7 on a 12ax7 Cathode is where current flows to plate when a incoming signal is applied at the grid. pin 3 and 8 on a 12ax7. I know some of the language, but obviously not enough. I'll check out those web sites. I have read The Guitar Amp Handbook by Dave Hunter and Dave Funk's Tube amp Workbook. Both have a lot of info, but perhaps I just didn't retain nearly enough. Anyway, I have a new fuse in and all of the V readings are about where they were before. Title: Re: I could use a little more help Post by: erwin_ve on August 30, 2009, 08:53:38 PM Ok! Did you measure the 22k resistor(is it really 22k with amp off)?(at the power supply dropping string)
Title: Re: I could use a little more help Post by: hywelg on August 30, 2009, 09:20:50 PM The spark was where I had my probe. I think I may have made an arc - like when you weld to get the weld started? OK you just might have been lucky ;) Before you go again, get some heatshrink tubing and cover all but the last 6-8mm of the probe ends. If they have a little notch near the end cover just up to that. That might prevent this happening again. It happened to me once, the probe slipped but thankfully it didn't contact with anything. Title: Re: I could use a little more help Post by: djroge1 on August 31, 2009, 03:18:27 AM Ok! Did you measure the 22k resistor(is it really 22k with amp off)?(at the power supply dropping string) It reads 20.6 Title: Re: I could use a little more help Post by: hywelg on August 31, 2009, 08:18:16 AM Can you go through the attached layout and read the voltages at the marked points? All DC. That should help pinpoint where your problem is
Title: Re: I could use a little more help Post by: djroge1 on August 31, 2009, 10:18:58 PM I'll check those and post as soon as I get home from work. Thanks.
Title: Re: I could use a little more help Post by: djroge1 on September 01, 2009, 12:46:33 AM OK here are those voltages
1. 437 2. 439 3. 379 4. 53 5. 53 6. 19 7. 10 8. 14 9. 33 10 37 Title: Re: I could use a little more help Post by: parrhasius on September 01, 2009, 03:07:04 AM What about that 22uF 450V electrolytic cap on the wall near the first tube - shouldn't that be the other way around?
Compare it to this photo from the Ceriatone web site: http://www.ceriatone.com/images/completeAmpsPic/CTOvertone/board/Leftend2B.jpg Phil Title: Re: I could use a little more help Post by: djroge1 on September 01, 2009, 03:58:14 AM What about that 22uF 450V electrolytic cap on the wall near the first tube - shouldn't that be the other way around? Compare it to this photo from the Ceriatone web site: http://www.ceriatone.com/images/completeAmpsPic/CTOvertone/board/Leftend2B.jpg Phil Bingo! I bet that is a major problem and I don't have to look at your link I see it in the wire diagram. ??? :o >:( :-[ :-[ :-[ I can't believe I missed that. I'm going to turn that around and I'll post the results. Thanks. Title: Re: I could use a little more help Post by: djroge1 on September 01, 2009, 04:25:49 AM Still no sound from the input jack but the voltages are looking better. I hear a hum and I get a crackle when measuring V3.
V1: Pin 1 - 152 pin 3 - 1.6 pin 6 - 172 pin 8 - 1.5 V2: Pin 1 - 164 pin 3 - 1.8 pin 6 - 182 pin 8 - 1.5 V3: Pin 1 - 285 pin 3 - 59 pin 6 - 273 pin 8 - 59 V4: pin 3 - 450 pin 4 - 449 pin 5 - 37 pin 6 - 450 V5: pin 3 - 450 pin 4 - 449 pin 5 - 37 pin 6 - 451 Title: Re: I could use a little more help Post by: parrhasius on September 01, 2009, 06:51:20 AM preamp plate voltages are still low - they should be around 200V.
What are the new voltages at points 5, 6, 7, 8, 9 & 10 on hywelg's layout? Title: Re: I could use a little more help Post by: erwin_ve on September 01, 2009, 07:35:19 AM What about that 22uF 450V electrolytic cap on the wall near the first tube - shouldn't that be the other way around? Compare it to this photo from the Ceriatone web site: http://www.ceriatone.com/images/completeAmpsPic/CTOvertone/board/Leftend2B.jpg Phil Bingo! I bet that is a major problem and I don't have to look at your link I see it in the wire diagram. ??? :o >:( :-[ :-[ :-[ I can't believe I missed that. I'm going to turn that around and I'll post the results. Thanks. You are lucky that cap didn't explode! Title: Re: I could use a little more help Post by: bluesfendermanblues on September 01, 2009, 11:18:37 AM Djroge1,
You are close to getting the amp to work now. When it does, you might want to move the yellow (cathode) and red (plate) wires close to each other. This has a major impact on the notes 'blooming' when you play. Kind of a compressor effect that is part of the signature sound of the Dumble amps. Looking forward to you getting some sounds thorough! :) Title: Re: I could use a little more help Post by: erwin_ve on September 01, 2009, 11:23:56 AM . I hear a hum and I get a crackle when measuring V3. The crackle is normal when measuring your PI(V3). Probably your power amp does work. Title: Re: I could use a little more help Post by: bluesfendermanblues on September 01, 2009, 11:48:25 AM I guess you mean preamp is not working.
If the power amp is not working, why would djroge1 beable to hear hummmm ??? Title: Re: I could use a little more help Post by: erwin_ve on September 01, 2009, 01:06:31 PM I guess you mean preamp is not working. Can't they read in Denmark? ;DIf the power amp is not working, why would djroge1 beable to hear hummmm ??? Title: Re: I could use a little more help Post by: René F on September 01, 2009, 01:35:19 PM Some of us... :)
As Erwin said if he can hear crackle then there must be some output through the poweramp... Voltage readings also look fine at the 6L6 tubes Title: Re: I could use a little more help Post by: djroge1 on September 01, 2009, 01:52:34 PM I took a quick reading of those previous 10 points and here they are in order - I didn't wait for the amp to really warm up because I'm on my way out the door for work.
455 454 429 318 319 312 174 188 174 191 Title: Re: I could use a little more help Post by: bluesfendermanblues on September 01, 2009, 03:29:13 PM I guess you mean preamp is not working. Can't they read in Denmark? ;DIf the power amp is not working, why would djroge1 beable to hear hummmm ??? :-[ ups! 8) Title: Re: I could use a little more help Post by: hywelg on September 01, 2009, 06:34:47 PM You should now be getting some sound out of it, the voltages are in the right region, though a little low on V1 and V2, though I wouldn't worry about that for now.
Try pluging a lead in to the Power Amp IN socket just to see if the poweramp section is working properly (touch the tip of the other end of the lead). If you do then plug in normally and if you get nothing from either clean or OD then check and re-check your wiring from input jack up to V3 pin 2 and 7. This is the point at which its helpful to have both the schematic and the layout to guide you whilst checking, but you can do this with just the layout checking every joint that you have made whilst marking them off with a highlighter pen. Any join that looks suspect re-do it. You have wired your input jacks the right way haven't you?? ;) Have you tried the FET input? Title: Re: I could use a little more help Post by: djroge1 on September 01, 2009, 07:35:36 PM I do the power amp In test and recheck my wiring tonight when I get home.
I already checked for continuity from input to V1 pin one and it looks good for both input and FET input. I plugged in a cable and read it from cable to pin one. Title: Re: I could use a little more help Post by: René F on September 01, 2009, 07:41:05 PM I do the power amp In test and recheck my wiring tonight when I get home. I already checked for continuity from input to V1 pin one and it looks good for both input and FET input. I plugged in a cable and read it from cable to pin one. If you are testing the FET-input for signal through the amp, then remember to adjust the FET trimmer (on the small board mounted on the side of the chassis). If its turned all the way down, you won't get any signal through the FET input Title: Re: I could use a little more help Post by: bluesfendermanblues on September 01, 2009, 08:14:30 PM I do the power amp In test and recheck my wiring tonight when I get home. I already checked for continuity from input to V1 pin one and it looks good for both input and FET input. I plugged in a cable and read it from cable to pin one. Pin one?? you mean pin 2, right? Title: Re: I could use a little more help Post by: djroge1 on September 01, 2009, 08:47:02 PM Ooops yes pin 2.
I do the power amp In test and recheck my wiring tonight when I get home. I already checked for continuity from input to V1 pin one and it looks good for both input and FET input. I plugged in a cable and read it from cable to pin one. Pin one?? you mean pin 2, right? Title: Re: I could use a little more help Post by: djroge1 on September 02, 2009, 12:48:24 AM I plugged a cord into the Power Amp In and it appears to be working. Now, I'm going to re-check all of my work up to the points you suggest.
You should now be getting some sound out of it, the voltages are in the right region, though a little low on V1 and V2, though I wouldn't worry about that for now. Try pluging a lead in to the Power Amp IN socket just to see if the poweramp section is working properly (touch the tip of the other end of the lead). If you do then plug in normally and if you get nothing from either clean or OD then check and re-check your wiring from input jack up to V3 pin 2 and 7. This is the point at which its helpful to have both the schematic and the layout to guide you whilst checking, but you can do this with just the layout checking every joint that you have made whilst marking them off with a highlighter pen. Any join that looks suspect re-do it. You have wired your input jacks the right way haven't you?? ;) Have you tried the FET input? Title: Re: I could use a little more help Post by: Corinthian on September 07, 2009, 10:02:26 AM Djroge1, ...you might want to move the yellow (cathode) and red (plate) wires close to each other. This has a major impact on the notes 'blooming' when you play. Kind of a compressor effect that is part of the signature sound of the Dumble amps. This is interesting. Is this something that Nik does in the ready assembled amps? Looking on the layout, there are two red wired and two yellow lines to V1 and V1. Would you mind marking on the layout which ones should be moved close together? If it is not standard I'd like to do this to mine when it arrives. Thank you C~ Title: Re: I could use a little more help Post by: bluesfendermanblues on September 07, 2009, 02:47:29 PM Check the wiring on this pic
Title: Re: I could use a little more help Post by: Corinthian on September 08, 2009, 02:30:02 PM Check the wiring on this pic Sweet. Thanks! |