6SJ7 Pentode 18 watt Lite...Formerly the ABSOLUTE Minimum

kyoungsteadt · Post by **kyoungsteadt** » Thu 09/30/10 9:19 pm

It will totally rock.

StarGeezers · Post by **StarGeezers** » Fri 10/01/10 7:55 am

There's just something very special about these 18watt amps ... Got 4 now

They're always first up at gig time ... Out of them all the Dog Sled (6U8>6N2P> (4) 6P1Pev ) is the Most snarling snapping biting amp ...

There's just something Nice about a a pentode up front !!! Sweetness!!!

brewdude · Post by **brewdude** » Fri 10/01/10 8:22 pm

Hey SG,
Do you have a schematic for the Dog Sled too?

StarGeezers · Post by **StarGeezers** » Sat 10/02/10 7:21 am

Brew, It's basically a Pushy Croaker (Wattkins - Tone per buck club) with 4 output tubes.. Russian Tubes (6N2Pev PI and (4) 6P1Pev )made the build INEXPENSIVE... and gave it a Cool Marshally' sound... Built for just a little over the goal price of a "croaker" (100USD) ... not including shipping ...

A very aggressive amp that Rocks !!!

Somewhere in the neighborhood of 18watts ...

insanecopilot · Post by **insanecopilot** » Sun 10/03/10 5:24 am

Looks sweet! Any clips?

StarGeezers · Post by **StarGeezers** » Sun 10/03/10 7:10 am

Just this old one http://www.ppwatt.com/node/16611 I need to make a new one to show off the tremendous gain of this amp ...

Dustpuppy · Post by **Dustpuppy** » Thu 10/14/10 1:09 pm

I didn't see this question posed in this thread, how much would need to be changed on the board if you swapped 2 6sj7's for the V2 12ax7? Is it worth considering to make the preamp out of 3 6sj7's?

StarGeezers · Post by **StarGeezers** » Thu 10/14/10 4:38 pm

It's possible , but really not necessary as the single Pentode in the preamp gives you the SWEET Tone !!! Would give you lots more gain than the single ... But with ZP's LTP values , it really cooks now, just the one 6SJ7 !!!

bigbeck · Post by **bigbeck** » Fri 10/15/10 7:50 am

Why not try a Superlite circuit with 2 6SJ7's or 6SL7's in front of the PI?

kyoungsteadt · Post by **kyoungsteadt** » Fri 10/15/10 7:57 am

That could be cool, BB.

StarGeezers · Post by **StarGeezers** » Fri 10/15/10 11:03 am

Ya' know Insane did some double 6SJ7 experiments ... said it sounded pretty Good !!! I think those were SE amps , but as Big said , should be easy to marry it to a Superlite...
Er, as long as they sound like an 18 watt Marshall (sorry , I had to say that here )

Dustpuppy · Post by **Dustpuppy** » Fri 10/29/10 10:36 am

I'm wanting to build this amp so I threw together a layout. If anyone has free time, would you mind checking it for errors?
I'm thinking I'll use a Hammond 270dx to get 385vdc rectified.
I have a MPS 20w OT at 5k that should work.

StarGeezers · Post by **StarGeezers** » Fri 10/29/10 11:26 am

Nice looking layout DP!!!

Dustpuppy · Post by **Dustpuppy** » Fri 10/29/10 7:03 pm

Thanks man, I'm still learning to read and understand schematics.
What do you think? Will she hunt?

StarGeezers · Post by **StarGeezers** » Sat 10/30/10 7:28 am

Looks good to me , but I'm Not the one to check layouts (just a builder) ... much better to have one of the Masters do this ... just to make sure ...

But I do know you're gonna' Love the Tone !!! and it is LOUD !!! ...especially through a 4/12 cab ...

mcrracer · Post by **mcrracer** » Sat 10/30/10 8:10 am

Hey Dustpuppy, The MPS OT20 doesn't have a 5k primary. Did you mean the 6.6k? That would be better for a pair of 6V6, IMO. I just built one of these recently (same OT tranny) using a 12AX7 in the PI. I am a bass player so I have guitar players come over to play thru my amps as I build them. You should have seen the smile creep up on this guys face as he started playing this one!
Hey SG did you try one of your special "red" tubes in one of these yet? I just pulled those two I got from you out this week. Will try them the next time I get one of the guitar players over.

StarGeezers · Post by **StarGeezers** » Sat 10/30/10 8:38 am

Racer, Love those Red tubes... !!! All I use anymore on these ... keeping the 6SJ7s for spares...

Funny as I get older , find myself using the "good stuff" First, instead of saving it for "something special" .... WTF? ... at my age , every day is Special !!!!

Dustpuppy · Post by **Dustpuppy** » Sat 10/30/10 10:26 am

Mcracer, you're right. I was going from memory which is shot. I can't wait to hear this thing.

TWANG · Post by **TWANG** » Sat 10/30/10 8:55 pm

that minimalist looks fun and I have a vj cab and chassis laying around..

StarGeezers · Post by **StarGeezers** » Sun 10/31/10 7:20 am

DP, just looking at your layout, I got to thinking

about the input jack ... Why not put it on the back of the amp so you have a direct feed to the 6SJ7... simpler , less chance for noise problems, and saves a bit of shielded wire ...no reason why you can't plug the guitar in the back , older amps had everything in the back , combos plug in the top ...
Just trying to keep everything to a Minimum ... I did mine that way (P2P) , with just the input R between the jack and tube socket pin direct ... but my tubes were on the front ... Different layouts require different alternatives/compromises ... All Good though !!! Just part of the Fun !!!

And you're gonna' LOVE the Tone!!! Pentode "Sweetness" ... If you can get your hands on the 5693 Red tube, they work great and meant for many hours use and much abuse (rugged) .. made for missiles

... basically a put it in and forget it tube... Sounds great and looks kinda' cool too ...

Twang , It's really a simple build ... try to keep it to the Minimum... and it will fit ...

New disclaimer: This is NOT a "bedroom" amp ...

Do Not try to make it one with VVR and other such devices ... Made to play LOUD !!!!!!! Turn it UP !!!!!

Played into my 4-12 cab , it makes the drummer disappear...

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6SJ7 Pentode 18 watt Lite...Formerly the ABSOLUTE Minimum