100W non-HRM pièce de résistance

[kleinm]

I was fortunate enough to acquire this bad boy from Robert Rissi, one of the engineers at Fender during the '60s. It's an original Schumacher Twin OT from 1969.

Needless to say, it sounds incredible in my 100W non-HRM Skyline. The amp feels more responsive to my playing, which I didn't expect. The highs are more open and clear, and the low mids became less growly and more articulate. The biggest change is in the bottom end at highish volumes. Very squishy and sweet...with a little something extra on top, kind of like the best crème brûlée?

While I still love the original OT I had in, this is where it is at for the tone I searched for.

[ChrisM]

Nice score!

What was originally in it?

[kleinm]

Thanks!

The original was a Heyboer I bought from Brandon years back. It sounded awesome in it's own way...but this one is really happening in this amp!

[dogears]

Nice!!!!

[Structo]

That's pretty cool Mike!

Is Mr. Rissi a friend of yours?

And if so, I'll bet he has some great stories to tell.

[David Root]

Doesn't have any more, does he?

[67plexi]

Mike now you have let the cat out of the bag.
I just finished my second build had 4 hours on it and played a gig.
After the show the star of the show told me I nailed the David Lindley's tone. I said who is that ??? HA HA. I used 1970 twin iron in that build.
The more I play it the better it sounds. The amp loves my burst but I used a tele for the gig. Great score Mike.

[kleinm]

Thanks guys!

I'm not sure if Mr. Rissi has anymore or not. He does have some really neat stuff up for sale, though. Lots of great Fender parts from the '60s.

I just met him through his listing for the transformer. He's a really nice guy, and has a pretty neat story.

I agree, there's something (I hate to use the word, but...) magical about this OT with this circuit. Definitely worth the time, hassle, and money in finding something like this.

[Tonegeek]

This is getting me pumped as I am currently building a non-HRM with 1970 DS Iron.

[talbany]

Mike

Definitely something to that Iron.. Even seasoned slightly..Wonderful..If you don't have those original CTS pots..Dumble used..try to score some.. They also make you go DAMN.. What a difference...The amp wants to RUN!!..Put them in the Vol/OD..Drive and Level and Master..Also Treble pot and Mid pot if you can..Allen Bradley mil spec also nice.. Congrats on the killer tone!!

Be Well!!

Tony

[David Root]

+1 on all that! I used the original pots from the same '67 Bassman I got the iron for, sounds great. They are Stackpoles, not CTS.

So now I have run out for the next one but I think the PEC RV4 pots are probably as good as the old stuff. At $10 a crack they should be!

[Drumslinger]

Nice upgrade Mike. Now would Mr. Rissi have a box of these in storage somewhere?

[Mill Creek Audio]

Got some transformers from him several years ago when he had stacks of 'em. Still have some from the Super twin (180 watt) that were also used in the 200w bass amp. Also have some Boogie 100w simul-class transformers I've been wanting to try, I really like the sound of my Simul 290 (2-6L6 and 2 -EL34 per ch) when used as power amp for Dumble pre, anyone try a build like that?[/quote]

[kleinm]

I've been searching for some 30% taper pots without much success. I'd try the PEC, but I think they're still in the 10-15% range. I know some might scoff, but I'm into settings that "look right". With 15% taper pots and the Skyline stack, things certainly look a little suspect.

Mr. Rissi's eBay handle is "risson" (the name of his old line of amplifiers). Right now he doesn't have much, but I think he updates it very frequently. I missed out on the matching choke.... *dammit*