B-15 layout

[txstrat]

I know I should've asked before I built two of them.
Does anybody have a layout plan for the B-15N? I troubleshooted my latest build recently (used shielded cable for the preamp grids) and the noise (crackle on top of the note) changed to the better - will know for sure after the next rehearsal.
I have some gut pics of a B-15 but a layout plan would be really great.

[andersom]

Hi Mat,

Did you evere got a complete layoutplan for the B-15???
I'm plannning on building this amp, and some guidance would be appreciated.

Thanks in advance!

Andreas

I know I should've asked before I built two of them.
Does anybody have a layout plan for the B-15N? I troubleshooted my latest build recently (used shielded cable for the preamp grids) and the noise (crackle on top of the note) changed to the better - will know for sure after the next rehearsal.
I have some gut pics of a B-15 but a layout plan would be really great.

[Enzo]

The one I just overhauled in here a week ago had a printed circuit board.

[txstrat]

They came with both PTP wiring on the early and PCB on the later versions. Would be interesting when the change happened.

[andersom]

So you dont have a complete layout of the amp?
Sorry for asking but it's quit a challenging build for me, i only build a 18 watt cageamp before.

[Enzo]

Are you building in true point to point? Or are you using an eyelet/turret board for the parts?

[andersom]

My first idea was to build it on turretboard, the thing is i'm not really good in reading schematics... So if there is a layout or sorts that would help me big time

[txstrat]

I've built both my 1st and 2nd B-15N with soldering strips. This time I mixed the layout of the TUT3 and my first build.

@andersom
Yes, I have a layout. but it's not finished yet, cause I had hum issues and changed it several times.
I'm gonna redraw the file to the latest layout and post it here. Give me some days, since I have to pick up the amp at my drummers place.

[andersom]

Ohh that would be awesome, thats really great

Thanks matt!

[Enzo]

Say guys, a thought just occurred to me, not sure where it came from. But I think that if we all entered the address:
2686 Victoria Street Baton Rouge, LA 70806 into as many information request forms as we can find, we can repay Kristine for her kindly spamming.

I am thinking Troy Built Rototillers, they send an endless stream of stuff. Oh, and AARP too. All those post cards that fall out of magazines? Send them in. Used to be Encyclopedia Brittanica, but they probably don't mail so much any more. Oh, and those Exercise/Health Spa sign ups on the counter at Chinese Restaurants.

[txstrat]

@Enzo
Good idea. See what I can do...

@andersom
I've added a layout (pdf-file) I had laying around. Redrew it from memory. Hope it's ok so far. I left out the heater wires: pins 7 and 8 on the 6SL7 and pins 2 and 7 on the 6L6GC - make sure to put pin 7 of all tubes to the same heater wire.
If you got problems reading the layout, just let me know.

BTW you should definitely learn to read a schematic. It's essential for building (tube) amps. And it's not that hard to learn. Look at the B15-N schematic and follow the signal from input to speaker -part for part- and try to compare to the layout.

One more thing:
I found that if you use the second triode (pins 4,5,6) of the 6SL7 as first stage you get less hum (because of the 6SL7s internal structure the first triode -pins 1,2,3- is more prone to hum).
I didn't draw it that way but you just have to interchange the wires to the respective pins.
Bias: the fixed resistor in the bias circuit might have to be of different value cause of different voltages - measure actual bias voltage before switching into play mode - you don't wanna blow up your power tubes.

Edit: renewed layout file

[andersom]

Hi Txstrat,

This is great... i'll let you know how things work out.


Andreas

[txstrat]

I found that the layout was missing a plate resistor for the 2nd 6SL7. The one with the red circle around it in the new layout.
And the B+ node for the preamp tubes is now after the 1k dropping resistor.

[andersom]

Hi Txstrat,

I know you are located in germany, my question is where did you buy all the parts?
Do you have a Bill of Materials?
Thanks it's looking good, should be a nice project for the fall/winter

Andreas

[txstrat]

I usually order my parts at Tube-Town - Hot Stuff cool sounds. They're less expensive than TAD in most cases and the parts are of great quality.
I have my chassis' made out of aluminum at a local metal worker (locksmith).
Good luck with the build.

Matt