A few questions.....First time Express build

[lgehrig4]

...or any build for that matter.

Hi,

My name is Jeff and this is my 1st post. I recently purchased a Ceriatone kit and although the diagram is pretty intuative, there are still some areas that are vague to an inexperienced builder.

1. Nik's giagram shows pins 9 of the ecc83's (H) going nowhere? I have a pic of a finished chassis and it looks like this builder connected these to pins 7 of the el84's. Is this the case? What does "H" stand for?
2. How do you wire the bright switch? It has 6 pins, but the diagram shows only 3. Do you use the left or right side?
3. Impedance selector?? The actual selector has many more pins than the diagram and nothing is numbered. How you you wire this?
4. What is thw best order to assemble this amp?

I'm sure I'll have some more questions, but this should get me though the weekend.

Thanks!
Jeff

p.s. this is actually my 2nd time posting this tonight. The 1st post got lost somehow. My apologies if it pops up and this ends up being duped.

[Allynmey]

...or any build for that matter.

Hi,

My name is Jeff and this is my 1st post. I recently purchased a Ceriatone kit and although the diagram is pretty intuative, there are still some areas that are vague to an inexperienced builder.

1. Nik's giagram shows pins 9 of the ecc83's (H) going nowhere? I have a pic of a finished chassis and it looks like this builder connected these to pins 7 of the el84's. Is this the case? What does "H" stand for?
2. How do you wire the bright switch? It has 6 pins, but the diagram shows only 3. Do you use the left or right side?
3. Impedance selector?? The actual selector has many more pins than the diagram and nothing is numbered. How you you wire this?
4. What is thw best order to assemble this amp?

I'm sure I'll have some more questions, but this should get me though the weekend.

Thanks!
Jeff

p.s. this is actually my 2nd time posting this tonight. The 1st post got lost somehow. My apologies if it pops up and this ends up being duped.

1. H=Heaters. Pin 4,5 and 9 on a 12ax7 are the heaters (filaments).
2. Use the right side of the switch. Three pins vertically.
3. i'm not sure which imp. selector nik sent you. attach a picture.
4. You maybe in over your head with this build going by the first 3 questions.

Take your time and follow the safety rules. This NOT a beginners kit. You may want to table this project for a couple of weeks and get a small beginners kit to get your feet wet. There is lots of help here for you. However if you want to trod forward i'll try to help you not kill yourself.

Allynmey

[lgehrig4]

Actually, a few years ago I assembled a 5E3 so I have a little more knowledge than I let on. I know enough not to get electrocuted which is most important.

Thanks for your response. I'll post a pic of the impedence selector as requested.

In regards to my first question, I was asking where the lead goes to from the ecc83. He shows it on pin9 of this tube, but it is not clear where is goes from there.

Also, I would still like to know the proper or most logical order in which to wire the amp. Keep in mind the boards are pre-wired.

Thanks again
Jeff

[VaughnC]

Actually, a few years ago I assembled a 5E3 so I have a little more knowledge than I let on. I know enough not to get electrocuted which is most important.

Thanks for your response. I'll post a pic of the impedence selector as requested.

In regards to my first question, I was asking where the lead goes to from the ecc83. He shows it on pin9 of this tube, but it is not clear where is goes from there.

Also, I would still like to know the proper or most logical order in which to wire the amp. Keep in mind the boards are pre-wired.

Thanks again
Jeff

The 6.3 volt secondary winding of the power transformer supplies voltage to power all of the tubes' filaments (heaters), which are all in parallel with each other. So, with the ecc83 preamp tubes, one side of the transformers 6.3 volt winding connects to pins 4 & 5 and the other side of the 6.3 volt winding connects to pin 9. The output tubes (el34, 6L6, ect.) filament connections are usually pins 2 & 7....you only need to use two pins on the output tubes because their filament voltage is 6 volts, whereas the preamp tubes filaments are 12 volts (with two 6 volt filaments connected in parallel).

If the 6.3 volt winding has a center tap it should be connected to ground. However, if there's no center tap on your particular transformer, you'll need to install two 100 ohm resistors between each leg and ground to simulate the tap.

Hope this helps.

[lgehrig4]

Thanks, that does help! I wonder why the Ceriatone layout neglects to indicate the pin 7 connection?

I have a Moose trannie. Do you know if his have the center tap? How is this indicated on his transformer diagram?

edit: I just looked at his diagram again and there are 2 browns on either side of a brown/white labelled at 6.3V. Do the brown wires represent the 6.3V and the brown/white the center tap?

Jeff

[UR12]

edit: I just looked at his diagram again and there are 2 browns on either side of a brown/white labelled at 6.3V. Do the brown wires represent the 6.3V and the brown/white the center tap?

Jeff

Yes

[d2camero]

Hi Jeff, not sure if the kit has a "pre power up check list", but in case it doesn't, follow these steps before powering it up:

1. take a schematic and yellow highlighter. Trace through the entire circuit making sure you made each connection properly. Use the highliter to mark off on the schematic what parts you check - be picky!

2. carefully inspect **every** solder joint. On the tubes use an ohmmeter to check each connection side-by-side to ensure you do not have a short.

3. With your ohm meter, check all grounds and make sure they are grounded.

4. Remove all tubes, connect a speaker, turn power on, but leave it in standby. Check all the heater voltages to the tubes. CAUTION - high voltage: test with caution

5. Turn on standby, check the B+ voltages - they should match the schematic. CAUTION - lethal voltages: test with caution

6. Power down, (CAUTION: lethal power still exists in the caps - drain them). Put in the tubes, make sure speaker is connected, all controls down, power it up. Check all tube voltages and compare with others upto 10% difference is OK.

This may seem boring, but it will save you time, money and blown parts. This is not a complete list - to see my full powerup check list, take a look at: http://www.cameronsoftware.com/amp/BuildCheckList.html

Don

[lgehrig4]

Awesome! Thank you. I'm taking this one very slowly. Good stuff!