Question for the tone god, bullit build

[donald stringer]

I have it built and I"m in the process of debugging.The first question is what do I do with pins 9, 4+5 of each tube. And as for the power supply. I have an wall wart ,12 volt at 300 ma. Now is all thats required is connecting the pos. to Vcc. and  the neg. I do have an 30 volt wart from an printer if the the other one isnt big enough. Any other specifics that you may not have mentioned I would appreciate.I cant wait to get this going. I know the tubes are good as they are left over from my retubing my amp.Thanks ahead of time. I havent seen any other build reports so maybe I will be the first   .

[donald stringer]

One more question, the op-amp power supply does pin number8 run at the 12volt 9 volts or remain unconnected?

[donald stringer]

I am going to go through and recheck all my connections first. I did follow the schem. I could have made an mistake. Maybe some more build reports will come in and I can get this thing up and going.

[The Tone God]

The first question is what do I do with pins 9, 4+5 of each tube. And as for the power supply. I have an wall wart ,12 volt at 300 ma. Now is all thats required is connecting the pos. to Vcc. and  the neg. I do have an 30 volt wart from an printer if the the other one isnt big enough. Any other specifics that you may not have mentioned I would appreciate.I cant wait to get this going. I know the tubes are good as they are left over from my retubing my amp.Thanks ahead of time. I havent seen any other build reports so maybe I will be the first   .

For 12v pin 9 is left unconnected. Pin 4 and 5 are used connected to V+ and ground respectively. And thus far you are the first report I am getting.

One more question, the op-amp power supply does pin number8 run at the 12volt 9 volts or remain unconnected?

Pin 8 goes to V+ and pin 4 ground. V+ is always 12v in this circuit. No 9v. Yes the opamp can run at that voltage.

Oh its Buillitt. Two "t"s,.

Andrew

[donald stringer]

O K Pin 4 and 5 are the first mistake. I have retraced up through the tone section and so far so good. My wiring is not the neatest but I was very careful to follow the schem. one point at a time . Thats Bullitt thanks for the help.

[The Tone God]

Let us know if you have anymore trouble. I wouldn't mind hearing how things turn out.

Andrew

[rockgardenlove]

Pins 9, 4, and 5 are always reserved for the heaters right?

[The Tone God]

Pins 9, 4, and 5 are always reserved for the heaters right?

Within the 12A*7 family they are the heater. 4 and 5 are the heater ends and 9 is the center tap.

Andrew

[donald stringer]

Ha Ha  I have glowing tubes, I am going to try to get some sound now

[rockgardenlove]

Pins 9, 4, and 5 are always reserved for the heaters right?

Within the 12A*7 family they are the heater. 4 and 5 are the heater ends and 9 is the center tap.

Andrew

Nice, yeah. 

[donald stringer]

I have audio, but the trem part is questionable. I am only operating with 300ma. Would that have anything to do with the trem. Soundwise it shows a lot of promise. A nice fat  clean boost. All the pots are working. I will check op amp wiring tomorrow, thats got to be the problem.I may go with the 30 volt into a 12volt regulator thing. Its getting late but I will try it again tomorrow.To be this close on the first build its got to be something minor.There seems to be some trem but its very subtle and intermittent.

[The Tone God]

I have audio, but the trem part is questionable. I am only operating with 300ma. Would that have anything to do with the trem.

I doubt it. The trem section should not take too much current. Check the wiring for the osc. See if there is a swinging output from it. Maybe try a LED off it to see if it's glowing.

I may go with the 30 volt into a 12volt regulator thing. Its getting late but I will try it again tomorrow.To be this close on the first build its got to be something minor.There seems to be some trem but its very subtle and intermittent.

30v to 12v is alot for a regulator to dissapate. I wouldn't try it. Stick with the 12v. I just checked that mine pulls a total of 320mA after warm up.

Andrew

[donald stringer]

The oscilator is still not oscilating, but I"m going to back up and rebuild the op-amp section again as the last one was kind of sloppy. Thank you for your help. I do have one question. The two 1uf electros that are faceing  each other in the schem, are they suppose to be pos. to pos.The part of the opamp that is feeding pin two on the tube. One of them is paralell an 1 meg res.

[The Tone God]

The two 1uf electros that are faceing  each other in the schem, are they suppose to be pos. to pos.The part of the opamp that is feeding pin two on the tube. One of them is paralell an 1 meg res.

Yes. In theory the best solution would be to use non-polarized caps but this will work. Truth be told the polarity won't matter too much but the way shown is "more correct" I guess.

Andrew

[donald stringer]

I rebuilt it according to the schem. the speed pot has no effect. The depth pot works likes a vol. control. Is that an 220 ohm res. connected to the speed pot. I am sort of baffled. Really nice vol. boost if only I could get the rest of the goods. It has something to do with that  section around the speed pot.  One more thing I biased pin3  out of two into one...jump to pin 5

[The Tone God]

I rebuilt it according to the schem. the speed pot has no effect. The depth pot works likes a vol. control. Is that an 220 ohm res. connected to the speed pot.

Yes that is a 220 ohm resistor.

It has something to do with that  section around the speed pot.  One more thing I biased pin3  out of two into one...jump to pin 5

Are you saying you are biasing pin 3 (oscillator section) off of pin 5 (bias regulator section) ? I would bias pin 3 off of the output pin 7.

You can try this. Disconnect the oscillator from the bias regulator. Meassure the output of the bias regulator. You should read 1/2 V+ (approx. 6v). Connect the oscillator and meassure the bias output again. Did it change ? It shouldn't.

Andrew

[donald stringer]

What I was trying to say was at the  top  op-amp section of your schem   I was assuming that was 1, 2,3 with 3 being the input with the 2 1meg res and the cap. I didnt think it made a difference. Thus I went from 1 [out] down into 5

• in  etc...By the way are those the tubes by themselves giving it that boost.

[The Tone God]

What I was trying to say was at the  top  op-amp section of your schem   I was assuming that was 1, 2,3 with 3 being the input with the 2 1meg res and the cap. I didnt think it made a difference. Thus I went from 1 [out] down into 5

• in  etc...By the way are those the tubes by themselves giving it that boost.
  

That is ok then as you are using the opamp as a buffer for the bias supply. The tubes are boasting. It will go near unity when the gain control is set low.

Why don't you disconnect the output of the osc from the tube and get a quick set of readings. You should get something like:

Pin 1: Near 6v, Changing
Pin 2: Near 6v, Changing
Pin 3: 6v
Pin 4: Ov
Pin 5: 6v
Pin 6: 6v
Pin 7: 6v
Pin 8: 12v

Andrew

[donald stringer]

Problem, I dont have a multimeter

[donald stringer]

I can borrow one tomorrow, I will look at it one more time. I rebuilt the op-amp section so I am sure its correct now.