Dumble - help needed urgently!

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xtian
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Re: Dumble - help needed urgently!

Post by xtian »

Mousey Dung wrote:QUESTION 4:
Do any of the transformers need to be earthed? As in, do I need to file away the powder coating and use star nuts to ensure the iron connects to the chassis?
No.
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xtian
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Re: Dumble - help needed urgently!

Post by xtian »

Mousey Dung wrote:QUESTION #3a:

According to the latter image, am I correct that to get 230V, I am to connect the Black-White wire with the Brown wire together

Yes.
Mousey Dung wrote:, and connect the Black and White wires to the main Power on/off switch?
Yes, you will be applying your 230v wall voltage to the black and white primary wires. But I cannot see, from the layout, how this is suggested to be accomplished. Some amps (Marshall) run BOTH 230v primary wires thru the DPDT switch. Others (Fender) run only the neutral wires thru the switch, while the hot wire runs thru the fuse, then into the PT.
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xtian
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Re: Dumble - help needed urgently!

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Mousey Dung wrote:QUESTION #3b:
To do the first bulb-limiter test, am I to connect the Black and the White wires from the OT to the main Power on/off switch, ensure that all other wires from the OT are disconnected and then turn on the switch to see if the bulb lights up?
You've confused two different operations.

The headphone test does not require the bulb limiter. This comes EARLY in the build, like now. Be aware if the PT is charging up any caps. (You'll have to know how to measure the DC voltage in them and safely discharge them. This is PRIMARY knowledge--make sure you know it NOW.) Looks to me like you have not installed the reservoir or power filter caps yet...but can't be sure from your photos.

The power up process benefits from the bulb limiter, but comes LAST in the build process. You're not there yet.
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Re: Dumble - help needed urgently!

Post by Mousey Dung »

xtian wrote:You've confused two different operations.

The headphone test does not require the bulb limiter. This comes EARLY in the build, like now.
Actually, I was referring to the power-up bulb-limiter test. I thought I was ready for that :-/

I know I wasn't a good boy, but I haven't exactly been following the generally recommended order of doing things. I assembled the boards, controls, etc. first and left the transformers for last. :-p

For the OT, I've decided to put it where I think it was meant to go, if not for the holes. I also decided drill new holes and to stick to the usual orientation (in my pic I had the OT turned 90 degrees from how it usually is), because I think that probably has significant bearing on the hum factor.
xtian wrote:Be aware if the PT is charging up any caps. (You'll have to know how to measure the DC voltage in them and safely discharge them. This is PRIMARY knowledge--make sure you know it NOW.) Looks to me like you have not installed the reservoir or power filter caps yet...but can't be sure from your photos.
Sorry, but what are the reservoir/power-filter caps, what do they look like? :-p If you mean the caps on the board on the left, in the pics I uploaded I had connected the secondary wires from the OT to that board.
Just in case, could you please explain or point me to a page where I can double-check how to measure and discharge DC voltage (tried looking but couldn't find anything.
xtian wrote:The power up process benefits from the bulb limiter, but comes LAST in the build process. You're not there yet.
Now that I've re-oriented the OT and given the installations I've completed so far, what do you recommend I do next?
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xtian
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Re: Dumble - help needed urgently!

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Do you think you're finished? I guess it's time for you to post new photos. The ones you posted don't even show the main board nor the power filter board installed!

I'm worried for you, man! The layout illustration you posted isn't complete--it does not show the power switch wiring, for example. And you don't even know which are the dangerous capacitors?

how to discharge capacitors in tube amp
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Re: Dumble - help needed urgently!

Post by Mousey Dung »

xtian wrote:Do you think you're finished? I guess it's time for you to post new photos. The ones you posted don't even show the main board nor the power filter board installed!

I'm worried for you, man! The layout illustration you posted isn't complete--it does not show the power switch wiring, for example. And you don't even know which are the dangerous capacitors?

how to discharge capacitors in tube amp
I have the boards all assembled and ready to be spliced together. I was under the impression I shouldn't do that yet until I'd tested the PT step by step.. maybe I'm totally wrong.

Should I do this now or post pics of the boards first?

I also posted a link to the BM88 which is what I've been basing my AC wiring on.
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Re: Dumble - help needed urgently!

Post by Mousey Dung »

I must be doing a really poor job of communicating :-/ I've been doing the AC wiring based on this http://brownnote.net/BMKIT/BMK-V2.jpg

You are right though! I don't know where the dangerous caps are. I'm well aware this is potentially lethal stuff. I know that I need guidance here, which is why I didn't go ahead without M's help. But he disappeared a few days ago, which is why I came here . I know that the large high-voltage caps are probably the most dangerous of all.
Last edited by Mousey Dung on Mon Oct 06, 2014 6:34 pm, edited 1 time in total.
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Re: Dumble - help needed urgently!

Post by Mousey Dung »

These are the two other boards that are ready to be spliced together with the rest of the amp. Based on your comments, I guess I should go ahead and do this now and save the PT bulb-limiter tests for later. Just shout if I'm wrong! Thanks!
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Mousey Dung
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Re: Dumble - help needed urgently!

Post by Mousey Dung »

QUESTION #5:
xtian wrote:Did you find the wiring legend for the OT? For the primary, the red center tap goes to the standby switch, same place as the choke (see your layout).
Can you confirm this?

On the layout, it appears as though the standby switch connects to the positive end of one of the large caps.

Thanks!
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Re: Dumble - help needed urgently!

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Yes, the standby switch, when closed, allows current into the reservoir cap, which is, by definition, the first and usually largest electrolytic cap(s). In this build, all of the power filter caps are on the smaller board together. Those are the ones that can hold on to lethal voltage.

There will be no powering up until you have completed your build, so yes, put those two boards into the chassis and make all the hookups.

You will check, check, recheck, and quadruple check your connections by eye. You should check against the layout AND the schematic. Then turn the amp 180 degrees and check again. When you are convinced every connection is good, you will apply power for the first time, using your lightbulb limiter, with NO tubes installed, following Ruby's guide, and check for voltages at key points. Then you will safely discharge the caps.

Go get 'em!
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Mousey Dung
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Re: Dumble - help needed urgently!

Post by Mousey Dung »

xtian wrote:Yes, the standby switch, when closed, allows current into the reservoir cap, which is, by definition, the first and usually largest electrolytic cap(s). In this build, all of the power filter caps are on the smaller board together. Those are the ones that can hold on to lethal voltage.
Okay, just need to double-check, as the layout doesn't seem show what you're describing.

QUESTION #5b:
You mentioned that the red wire from the OT goes to the "same place as the choke" -- so I'll connect the red wire from the OT to the middle pin of the standby switch, plus run another wire from there to the positive end of the large cap as shown in the picture -- correct?

If not, just yell at me -- you can use large caps! I'm sure there was a joke in there somewhere...
xtian wrote:There will be no powering up until you have completed your build, so yes, put those two boards into the chassis and make all the hookups.

You will check, check, recheck, and quadruple check your connections by eye. You should check against the layout AND the schematic. Then turn the amp 180 degrees and check again. When you are convinced every connection is good, you will apply power for the first time, using your lightbulb limiter, with NO tubes installed, following Ruby's guide, and check for voltages at key points. Then you will safely discharge the caps.
Go get 'em!
Okay, great! This is really what I need! I'm truly grateful. This being a kit, I was really expecting a step-by-step instruction, but all I got was a layout diagram and some checklist I couldn't make much sense out of. I thought I would be okay as long as M. was there overseeing my build...
Last edited by Mousey Dung on Mon Oct 06, 2014 6:34 pm, edited 2 times in total.
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drew
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Re: Dumble - help needed urgently!

Post by drew »

Mousey Dung wrote:
QUESTION #5b:
You mentioned that the red wire from the OT goes to the "same place as the choke" -- so I'll connect the red wire from the OT to the middle pin of the standby switch, plus run another wire from there to the positive end of the large cap as shown in the picture -- correct?
No. Look again. (And is there a web link to that diagram, or were you only given a printed copy of it and we're left to trying to work with a photo of the printed copy?)
Okay, great! This is really what I need! I'm truly grateful. This being a kit, I was really expecting a step-by-step instruction, but all I got was a layout diagram and some checklist I couldn't make much sense out of. I thought I would be okay as long as Moss was there overseeing my build...
Were you at least advised by someone to look at Normster's build guide for the original D'Lite? - there should be a link to it somewhere on the Brownnote website forum.
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Re: Dumble - help needed urgently!

Post by Mousey Dung »

drew wrote:
Mousey Dung wrote:
QUESTION #5b:
You mentioned that the red wire from the OT goes to the "same place as the choke" -- so I'll connect the red wire from the OT to the middle pin of the standby switch, plus run another wire from there to the positive end of the large cap as shown in the picture -- correct?
No. Look again.
OK, I still don't get it then. Xtian said to connect the OT red wire to the standby switch, the same place as where the choke goes. The choke at the standby switch goes to the middle-right pin of the DPDT switch... right? Sorry, please be patient. I'm doing my best here...
drew wrote:(And is there a web link to that diagram, or were you only given a printed copy of it and we're left to trying to work with a photo of the printed copy?)
Okay, great! This is really what I need! I'm truly grateful. This being a kit, I was really expecting a step-by-step instruction, but all I got was a layout diagram and some checklist I couldn't make much sense out of. I thought I would be okay as long as Moss was there overseeing my build...
Were you at least advised by someone to look at Normster's build guide for the original D'Lite? - there should be a link to it somewhere on the Brownnote website forum.
Yes, I was only given a printed copy and couldn't find anything for the BM44 online.

No, nobody recommended Normster's build to me, but I did manage to find it myself. I gleaned what I could from there, but this BM44 seems to be quite a different build. Factor that in with confusing/conflicting instructions or no instructions at all from the source, terminology I couldn't make sense of from a check list compiled for another model, the expressed confidence that I would do just fine from just looking at the layout diagram, a lot of guesswork and an extended and tiresome deductive-reasoning process, a multitude of reading different opinions on builds by different people... and you have me, all deflated and lost about what to do next... *sob sob*
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Re: Dumble - help needed urgently!

Post by Mousey Dung »

:oops:
Last edited by Mousey Dung on Tue Oct 07, 2014 9:28 pm, edited 2 times in total.
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Re: Dumble - help needed urgently!

Post by Mousey Dung »

QUESTION #6:

Where does the red wire from the reverb transformer go?

I've figured out that the blue wire attached to V3 pin-6 is from the Reverb transformer, and the black and green wires going to the RCA originate from there as well... but where does the red wire from the reverb transformer go? Could it be the dotted line that goes to the small board on the left?
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