fine ill do it....chassis salvage project

[kwijabo]

With all the 5b6's being built here I've been itching to give this one a build. Well. As luck would have it this chassis was being thrown away at work. Got it drilled out and transformers mounted. transformers were what I had laying around. An unused MC TW style PT and a heyboer express OT. Because the PT voltage isn't that high I'm going to diode rec this. Well see what happens. Thanks for all your precedence. Especially mark and then synchu for the layout.

[M Fowler]

I'm pulling up a chair and popcorn, can't wait for the final product.

Mark

[RWood]

'Bout time!

I'm glad the new Russian 6sc7s I've gotten are not microphonic, unlike the high dollar NOS ones that were.

Also takes pedals better than I expected.

5B6 is my new workhorse.

Hope you have as good luck as I did with mine.

Randy

[Synchu]

Looks good and looking forward to see the finished one
Great amp. Pure tone and character and concur to RWood takes pedals like a champ.

Are you going with the Bassman OT?
Niki

[Phil_S]

Everyone should have a 5B6. It is simple and elegant. It lends itself to a bone pile build. Only 2 knobs means you don't have to label anything. Anyone who can't distinguish V from T doesn't get to plug in.

[M Fowler]

It lends itself to a bone pile build. Only 2 knobs means you don't have to label anything. Anyone who can't distinguish V from T doesn't get to plug in.

Or use labelled guitar volume and tone knobs but most are push on not set screw type is the only problem using these knobs.

[kwijabo]

phil nice headcab! looks great.

no not a bassman OT. i had a used heyboer express OT that i'm going to use. i didn't really plan on this build until i found the chassis so i wasn't looking to buy anything i didn't need to buy. and then this OT i had was just sitting on the shelf with no plans for it.

progress pic...

[Phil_S]

phil nice headcab! looks great.

Thanks. I put a lot of effort into getting it right. I can say this here...when I applied the tolex, I wrote on the top, "Top" and I wrote on the tolex the spot to glue to the top, so that the seam would be on the bottom. It is probably the best seam I'll ever make. I had to because for reasons I still don't understand, it ended up on the top It is visible, but not that noticeable! There must be a moral to the story somewhere. Maybe I'll figure it out at some point.

Good luck with your 5B6. I love this amp. I might build another just because I can. I like it even more than the JTM45 I built and that's a winner, too. It is too bad that both of them are too loud to play at home and I don't play out.

[RWood]

[/quote] It is too bad that both of them are too loud to play at home and I don't play out.[/quote]

I'm thinking of trying VVR on one of mine. Anyone tried on octals?

I concur with how well the cab looks Phil.

[kwijabo]

finished it during the week but it wasn't quite right. some value adjusting and now its a great little amp. my B2 and B3 voltages were a little high, and the preamp plate voltages were quite low. also, this thing sounded amazing at low volumes but was too bassy at high volume. it wasn't flubbing out, but there was just too much. so the changes were

6SC7 cathode cap is 6.8uF and it sounds just right.
Preamp plate resistors are 220k, but really measure just over 200k. they're carbon comp so i'm not surprised.

and one input has the 2.2M to gnd, the other input is a 1Meg to gnd with a 68k grid resistor. there is a difference but its very subtle and neither is bad.

PT: Classictone TW power using the 300-0-300 taps.
OT: Heyboer 5199 TW express style 6k6

i'll add in two extra diodes to the rectifier when i get them. i ran out.

B1: 402 V
B2: 338 V
B3: 318V

Output tubes:
Plates: 399 V
Screens: 338 V
Cathode: 26.7V

6SL7
Plate: 172 V
Cathode: 2.50 V
Plate: 170 V
Cathode: 2.71 V

6SC7
Plate: 140 V
Cathode: 1.94 V

it sounds perfect for my guitar and speakers, but if i was making this for multiple guitars and speakers i would do two things. 1.) put a bright switch in and 2.) set the 6SC7 cathode cap at 5uF and put a switch on it to add in 22uF in parallel.

thanks for all who built and shared before...

[Synchu]

Looks very nice (and I bet it sounds great )!
Myself, being too cautious, would (as I did on mine) put some heat shrink or silicone tubing over bare leads.
Niki

[Structo]

If it is too bassy for a guitar, you could try lowering the .1uF caps feeding the power tube.
Like .05uF.