KR-20

[TIMBO]

Hey guys, this one is well under way.

[uki]

The chassis looks good, sturdy !

[TIMBO]

Schematic

[TIMBO]

Hey guys, Some progress

[bmccowan]

Nice neat layout Timbo. Story on the schematic? Adapted from the KR12 I see with a change to cathode bias and 5881s in place of EL-34s? Louis is not very inclined to share schematics - did you draw this up from the hand drawn one I've seen on the web? I'm contemplating a 6V6 or 6098 version once summer ends.

[scstill]

I like the vintage vibe of the transformers.
I was wondering your thinking on their same orientation.
I have always been advised (in this forum) to mount transformers so they are in different orientations
I think to avoid EMI.

[TIMBO]

Bing Videos

This schematic is roughly the above amp
I repaired this amp
BROKEN CAB
And had a sneak peck under the hood
The schematics vary a bit

[bmccowan]

Thanks for the info. Nice job on the cab - your Tolex work is always impressive.
Do you have an .sch version of that schematic you can share? It would save me some time in drawing up a 6v6 version.
Thanks

[passaloutre]

Love the wraparound baffle, how'd you make that? Or what does it look like without the cloth?

[TIMBO]

Haven't attached files in awhile
Hope this works
@passaloutre
It's a 3/4 ply baffle with a ply strip along the top edge
Fixed in place from inside the cab

[bmccowan]

Thanks

[TIMBO]

More progress...

[shooter]

nice n clean, bet your stunt-guitarist is all giddy.


so how was the winter down under??  I'm re-building my snow-blower, getting ready at the other pole.

[TIMBO]

If it's anything like the real one I'll be happy
I've got another guy wanting put his hand up, these guys just like too play something a bit different.


I'd like to say that winter in Brisbane is like this
Cams
But to see snow I've got to head south another 1000k
Been to Thredbo a couple of times and defiantly fun to play in but in Brissy the coldest it gets is about 8 deg Celsius (46F and that is fine for me

[TIMBO]

Hey guys, finish touches completed.
Injected life and we're all good

[bmccowan]

Hey Timbo, Did your stunt guitarist get a shot at it yet? I'm thinking of a build with a few changes - maybe with 6v6s, maybe with 6098s. As I look over the schematic and compare it to two amps I really like; Plexi 6V6 and Little Wing, I'm wondering if its just too much gain when plugged into channel one? Or maybe that cascade circuit allows nice gain with the MV turned down? I've got an appropriate chassis and iron, so all I need now is to escape what seems like an endless chain of med appointments.

[TIMBO]

so all I need now is to escape what seems like an endless chain of med appointments.

He mate I fell your pain
I've been sick for the past two weeks and can't seem to shake it.
6V6's would work well, the circuit has a voltage divider V1a (2x560k) that could be subbed with a 1M pot to control the gain from the first triode.
You could leave the pot on the control panel or a set and forget.
I'm hoping for a meeting with the guitarman tomorrow

[bmccowan]

Thanks Timbo - I hope you feel better soon. A pot replacing that voltage divider is a good idea.

[TIMBO]

Thanks mate, slowly getting better.
First round of testing with guitarman and positive feedback from him.


Regarding replacing the voltage divider with a pot..

This works well.