komet like amp layout

[arjepsen]

Hey.

Since I have this annoying inability to leave a perfectly good layout alone, I'm trying to make my own layout of an amp a bit similar to a komet 60.
(here's a show of how far I've come:)
https://www.dropbox.com/s/mc0fyurz26xtn ... s.pdf?dl=0

I do have a few questions for those who knows their stuff:

1: How sensitive is the phase inverter tube? - specifically, how far does it have to be from the OT, and the power tubes?
2: From the pictures I've seen of real komets, the power tubes are placed quite a bit away from each other. Is there any bad interaction possible between powertubes (el34, 6l6, kt77, etc), or can you technically put them smack up against each other without a problem?
3: The original komets seem to have the choke located on the "other" side of the OT - furthest away from the PT. I always thought it'd be better to get the OT a bit away from the PT. From previous amps (using the headphone trick) I found that I could - to some exted - reduce the hum that the OT picked up from the PT, by placing the choke between them. It also places the choke closer to where it's leads are connected. Any thoughts on this?

Regards.
Anders

[M Fowler]

The fast gradual circuit is the only sensitive area I'm aware of in the K60.

EL34 spacing is large but doesn't need to be.

Can place choke where you want.

[dorrisant]

Nice looking layout... I gotta build one of those.

[arjepsen]

Nice looking layout... I gotta build one of those.

Thanks. I'm nearing completion on the layout.
This is what I've got so far:
https://www.dropbox.com/s/jhl4ul71n2o18 ... 2.pdf?dl=0

Anyone see anything problematic in it? constructive criticism??

Regards
Anders

[M Fowler]

The layout is looking good.

The first clone K60 I built and last K60 I did with my own layout

Komet 60 Build 020.JPG

.

Fowler K60 clone top.jpg

Badland 60 front.jpg

Badland 60 gut.jpg

[TUBEDUDE]

I always mount the choke between the transformers.

I think it was the Mullard tube data that listed the minimum tube spacing. IIRC it was 1.5" for the EL34.

[arjepsen]

The layout is looking good.

The first clone K60 I built and last K60 I did with my own layoutKomet 60 Build 020.JPG.Fowler K60 clone top.jpgBadland 60 front.jpgBadland 60 gut.jpg

Thanks for those.
I'm a little curious about the usage of the CC resistors in the first one. Any reason for a CC on only one of the PI plates?

Another thing I wondered about - sorry for getting into the cork sniffing - but I see people using mallory 150's. I guess it's what was used in the original. Anyone try to make a clone woth the OD mallories that were used in the trainwrecks?
From my own experimentation, I liked the yellow ones from TAD more - not as grainy, and clearer sounding. I found Jupiters to be even better, though only marginally.
However, I havent tested these out in this circuit yet.

[M Fowler]

Thanks for those.
I'm a little curious about the usage of the CC resistors in the first one. Any reason for a CC on only one of the PI plates?

Another thing I wondered about - sorry for getting into the cork sniffing - but I see people using mallory 150's. I guess it's what was used in the original. Anyone try to make a clone woth the OD mallories that were used in the trainwrecks?
From my own experimentation, I liked the yellow ones from TAD more - not as grainy, and clearer sounding. I found Jupiters to be even better, though only marginally.
However, I havent tested these out in this circuit yet.
[/quote]

It was my 2nd amp build and I did not have a supply of components. A TAG member sold me a complete kit to make this amp and I either used what he supplied plus scrounged parts. M150's were original to Komet amps but you can use whatever you want. For example I prefer Xicon film caps over all the rest.

Mark

[arjepsen]

Did you check the sound of those two amps in the pictures up against each other?

[dorrisant]

Nice looking layout... I gotta build one of those.

Anyone see anything problematic in it? constructive criticism?

Just out of convenience, I would put the Presence control on the front panel... Just sayin'. Looks nice though.

[arjepsen]

Thanks for the suggestion.
Mostly, my layout was made up, trying to shorten leads as much as possible. (hence the funky triangle layout of the tonestack).
I didn't like having to route the nfb/presence wires by the phase inverter, so I put it on the back.
I actually don't know if the PI section is all that sensitive, or if the presence wires would be noisy, but I've used this arrangement for a couple of amps now, and like the result

[stephenl]

I like the Xicon film caps as well, does anyone know of a good supplier? Most of the places I've looked only stock a few values...

[arjepsen]

I'm in europe, so that may be a problem for you.
But I mainly buy from banzai music in germany. they seem to have a stock.

[dorrisant]

Mouser...?

[M Fowler]

Both of my K60 builds sounded the same like a smoother TW Express more usable gigging then an Express in my opinion. I always ran the amp in higher gain mode (fast/gradual switch).