new build dlite

[dcribbs1412]

Just wondering
first power up all tubes seem to be working
although voltage is 455v pin 1 and 455v pin 3
power tubes 6v6
pre's are V3 333v...1 40v...2...3 67v 322v...6
V4 399v...395...6
V5 391v....1 393v...6
master volume works sorta Confused
low volume no other controls seem to be working
ie bass mid OD

I've checked all connections
any and all suggestions are greatly appreciated

[dogears]

You wiring is messed up. Your preamp voltages are way too high. Check the plate and cathode resistor values. Measure them. Also, check the dropping string values.

You should have about 180-2100V on V1 and V2 pins 1 and 6. (You labled them incorrectly fwiw)

[Guitarman18]

dogears wrote:

You should have about 180-2100V on V1 and V2 pins 1 and 6. (You labled them incorrectly fwiw)

dogears meant 180-210v not 2100v! Typo

[Normster]

It looks like you have no load on the tube circuit. Since you have voltage at the plates, I would say the most likely problem is your cathode grounds for V1 & V2. (V3 is high, but will likely come down when you figure out the load problem on V1 & V2.) Double check your wiring at the preamp tubes and check for voltage at pins 3 & 8. Should be between 1.4 & 1.8 VDC.

[Structo]

Yes do you have the ground wires from the cathode bypass up to the ground buss?

See on the attached layout where it says ground buss?

You need to run a wire from there up the the buss wire.

[JimiB]

first power up all tubes seem to be working
although voltage is 455v pin 1 and 455v pin 3
power tubes 6v6

You should have 0V on pin one of your 6V6's as they should be tied with pin eight to ground.

[dcribbs1412]

Thanks for the quick analysis
i've checked the resistor values with layout seems to be good

dogears wrote:

Also, check the dropping string values.

sorry not sure where this is.

Guitarman18 wrote:

dogears meant 180-210v not 2100v! Typo

thanks

Normster wrote:

It looks like you have no load on the tube circuit. Since you have voltage at the plates, I would say the most likely problem is your cathode grounds for V1 & V2. (V3 is high, but will likely come down when you figure out the load problem on V1 & V2.) Double check your wiring at the preamp tubes and check for voltage at pins 3 & 8. Should be between 1.4 & 1.8 VDC.

I did another check and found a screwup
voltage on V1 pin 1 now 210v pin 6 216v pin 3 is 2v 8 is 1.9v
still getting higher on V2 pin 1 348v pin 6 221v
V3 pin 1 328v pin 6 315v

Structo wrote:

Yes do you have the ground wires from the cathode bypass up to the ground buss?

See on the attached layout where it says ground buss?

You need to run a wire from there up the the buss wire.

This was definitely one of my problems thanks for pointing that out

JimiB wrote:

You should have 0V on pin one of your 6V6's as they should be tied with pin eight to ground

Thanks you're right

Still bass mid and treble controls don't do much. Volume is up some
and OD switch (6 pole) on front is acting like an on off switch
again I really appreciate all of your time and suggestions
any other comments are very appreciated

[dcribbs1412]

sorry double

[dcribbs1412]

yep triple

[Structo]

Do you have any relays in your amp yet?

Double check the layout I gave you.

Pay close attention to the tone stack wiring and also the shielded cable wiring in regards to where the shield is grounded at only one end.

It's a little difficult to see but the shield is shown as a very light gray on the diagram.

Also of note. Some layouts show a connection on the volume pot from the middle terminal to the red wire above. That is not correct.
Look at this close up where I have removed the error.
Also notice on the shielded cables ( thick black) the shield is grounded to the buss, only at this end. the other end should have the shield cut off and heat shrinked so just the middle conductor is soldered to the connection.

[IMG:800:236]http://i23.photobucket.com/albums/b392/ ... eStack.jpg[/img]

[dcribbs1412]

No relays yet wanted to get it going first
have rechecked layout and your new diag. (thanks)everything seems good (shielded cable and connections)tone stack is working now
OD switch...no sound from amp when up.... sound but really no OD when down ? Is this correct?
Sorry for the ?'s, but which resistors are the drop string res?
still gettin over 300v on V2 V3 pins 1
V1 is 210v pin1 and 216v pin 6

and just so I know if this is right V1 V2 V3... are preamp tubes from left to right looking at the amp upside down ?

[Bob-I]

No relays yet wanted to get it going first
have rechecked layout and your new diag. (thanks)everything seems good (shielded cable and connections)tone stack is working now
OD switch...no sound from amp when up.... sound but really no OD when down ? Is this correct?

ALmost, down should be just the clean side so something is still wrong with the OD side.

Sorry for the ?'s, but which resistors are the drop string res?

In the power supply, don't worry about them for now, get the OD working first.

still gettin over 300v on V2 V3 pins 1
V1 is 210v pin1 and 216v pin 6

Something's wrong with the V2 wiring. V3 should be fine if the clean side is ok. Pins 1 and 6 of V2 should be almost the same as V1.

What are your readings on pins 3 and 8 on V2?

and just so I know if this is right V1 V2 V3... are preamp tubes from left to right looking at the amp upside down ?

yes

[mlp-mx6]

I would suggest you check each type of circuit individually. Your wiring is STILL not right.

1. Check all cathode circuits. Ensure the correct tube pin is used, and ensure a solid ground connection. (power tubes AND preamp tubes)

2. Check all anode circuits. Start at the PS and go to each plate resistor. Ensure the correct tube pin is used.

3. Check from each plate cap (the signal cap, not the filter cap) and follow it through to the next grid. Start at the input and go to the first grid. Then start at the output cap from V1A and follow it to the 2nd grid. Repeat until you are all the way through the preamp. (This check will include all the pots in the preamp.)

4. TRIPLE check the PI. Check tube pin usage, ensure a good ground/presence circuit.

[Structo]

With the chassis upside down with the rear facing you the tubes go right to left.

V1 clean, V2 OD, V3 PI then the V4 & V5 power tubes.

Double check the underboard wires as well on the filter board and main board.

The dropping string is the resistors on the right end of the big filter caps.

You should have 1K, 22K and 2K2 with a 220K above the top filter cap.

[Guitarman18]

If you have any pictures of your build it might aid the diagnosis.



Cheers, Paul.