Overtone HRM BLUESMASTER (new build with four 6V6)

[godi]

Hi folks

I'm building a OVERTONE HRM BLUESMASTER ''50'' from CERIATONE layout.

http://jeangodbout.com/dumble/overdrive.html Look here for more pictures ...

I bought my chassis from
http://cepedals.com/Dumble-Style-Chassis.html
who advertise on this forum, the chassis is first class, 0.125'' thick aluminium, welded corner, nice black powder paint with fancy silk screen job.

This chassis is made for a ''100 watter'' with four octal socket holes, so I decided to build the amp using four 6V6 (or two 6L6 family tubes) using my ''old'' 5E3X2 parts : http://jeangodbout.com/5E3x2/5e3x2.html I stipped this amp that had a very primitive tone stack (2 volumes and one tone) saving the cost of transformers, choke, tubes, sockets, switchs etc...

[img577]http://jeangodbout.com/dumble/chassis-01.jpg[/img]

[img452]http://jeangodbout.com/dumble/chassis-02.jpg[/img]

[img441]http://www.jeangodbout.com/dumble/chassis-08.jpg[/img]

I will keep posting as the project progress

[img1003]http://www.jeangodbout.com/dumble/chassis-10-big.jpg[/img]

I'm in need for some help here !

I tried the amp, with the volume at maximum, the amp play loud as non amplified human voice. No hum, no distortion.

How can I find where is the problem in the circuit ?

Thank for any help.

[tele caster]

Very cool! I've scrolled through your site several times over the years back when I was building my 5e3 and then a tele. Great info thanks.
I have one of these chassis as well and was thinking of building a bluesmaster in it. Having a fender and marshall in one amp suits my playing style, clean and dirty. Are you going to use a marshall ot for this build?

[Structo]

I bought one of those chassis as well. I can't wait to start on mine!

Are those real wood circuit boards?
If so, you may want to reconsider using them.

Circuit boards should never be made of anything that is flammable.

You should try to build the amp as close to industry standards as possible.
Because some day you won't be around any more but your amp may be.
So you should think of the new owner and his safety later on in time.

[godi]

This board is made with real electronic board, 1/16'' thick, witch I remove the brass coating in etchant acid, then I glue a real 0.020'' rosewood veneer on it.

Can I have suggestion about my filaments wires, is it better to layout the wires in the corner of the chassis (a la Marshall) or in the air on top of the sockets (a la Fender) ?

Thank for your comments on this.

[ChrisM]

Float them.

I see no issue in using a real wooden board myself.

[Structo]

I find running the heater wires overhead to be the best practical method.

That way you have the back of the chassis free for running other wires such as the foot switch wires, loop wires and the power wires by the transformer.

[Drumslinger]

I have actually used plexi-glass boards for a couple of projects but not for amps.

[67plexi]

nice start godi, I have to finish the fet on mine working on the combo cab now.

Regards, Steve.

[BobW]

Steve, Let us know how you like using the Xicon caps once it's completed. Maybe a few sound clips?

[sergio]

Hi Plexi , what are blue caps on your PS board? Sprague? value?

[godi]

[img500]http://www.jeangodbout.com/dumble/v-chart.jpg[/img]

After a week of review, i still get 0 Volts at pin 3 of v2 ????

313 Volts at pin 1 seems to be a little high ?

All my wiring have been check, double check, triple check, resistors value are right on, connection good, soldering fine, I can't see why I have 0 Volts, I even swap the tree 12AX7 and I get the same results.

Any ideas ???

Thank Jean

[martin manning]

V2's cathode (at pin 3) is either grounded or not connected. The plate (pin 1) is high because that triode is not conducting- notice it's plate is about the same as B4, so there is no current flowing through it's plate load resistor. Check continuity from pin 3 to the eyelet that is supposed to be the cathode resistor/cathode bypass cap junction on the board, and resistance from there to ground (should read approximately the same as the cathode resistor).

[godi]

Thank Martin. The problem is definitely around the cathode. I can't get 1 or 2 volts, every thing is fine except that I suspect a bad Sprague cap, either leaking or shorting. The problem is I have no replacement in stock to try, the closest I have is 2.5uF or 50uF, layout call for a 5uF in that position.

Thank, jean

[godi]

The problem was the jumper from pin 4 to 5 of v2, it was broken.

Now I can go on on discovery and enjoyment So happy now!

Thank, Jean

[bluesfendermanblues]

Great you've solved the problem.

Where did you source the DIN socket for connecting the pedal?