Stock 68 spec W/2"OT and such...

[rgorke]

Sorry guy's I've just been really out of it and running on fumes these last three weeks. My right knee is almost normal while my left knee continues to need hard work (and drugs) for strength building. Robert lent me his Throback OD and I finally got the computer to not crash long enough where I could get a clip in the can. The mix cap is now a 470pf instead of the 560pf. The solo tone is a little crisper now. I like the OD and will continue to explore what it can do. Also this clip was done with a modified SM-57, see topic in the recording section.
http://soundclick.com/share.cfm?id=11765584" onclick="window.open(this.href);return false;

When were the other two clips on your soundclick page done? I like the NFB one better than this. This one seems really compressed to me. I am not sure what the CS or OD is doing or adding.

What I am hearing I don't think is due to the SM57 mod. If you could do an A/B with the Throbak and then without.

With a lower mix cap, there should be more gain, right? You might be on the verge of TOO much gain. I think the voicing is right but there seems to be a veneer of something.

Keep up the good work and work on that knee and the KNE.

[Strat78]

Here is my NOS 12xxx in progress with some fun obscure stuff. Finally dumped the 100k/4ohm tap and realized Ralle was right all along, no more mud, what a change!

[JimiJames]

Killer ! love that Slider !

[julkke]

Just beautiful man! I'm planning on building a 12xxx when I get some money.. Building is so much fun! I too like a lot of NFB, makes the amp a bit tighter and much more pleasing to stand in front of the cab.

Great work!

[emmjaydubya]

Wow, sick!!! So, 33k NFB on what tap? Are the mains 100uf? I think I recognize those RS caps from ebay.

Dig the standby cap too.

[Strat78]

Wow, sick!!! So, 33k NFB on what tap? Are the mains 100uf? I think I recognize those RS caps from ebay.

Dig the standby cap too.

I've had those NOS RS 100uf cans for a couple of years now and am amazed how perfectly they formed. I'm on the 16ohm tap which gives me a nice tight low E string, perfect for songs like On Fire. I think the 4ohm/100k was definitely post 1980 in the 12301. This is also with a MM 2.2 2" OT, so with a Dognal 1998 this would work nicely. No loss of perceived gain either in fact the power section (biased a little hotter with the old GE fat bottles) sizzles beautifully. That is actually a .068 cap to simulate the polarity switch. I found that there does not seem to be much effect on the tone unless that cap is up around .082, so if anybody has some .082 Hunts 1000v caps lying around I'd be glad to take them off your hands.
I've got the my other NOS 12xxx on the bench now, it's going to get the Keven treatment!

[vanhalen5150]

Awesome Phil!, Where did you get the slider? Whats the voltage rating on those?

[rgorke]

So, what does the polarity switch on yours do?

[rgorke]

Another question...do you hear a difference with between having the Lemco silver mica on the tone stack and the flat Lemco (?) on the mixer? I have these caps but in the opposite positions.

[Strat78]

I'm keeping the mix and tone caps right where they are. The polarity cap or "death cap", is really not necessary, and if it were to fail, my chassis would go live and probably kill me, so I don't recommend this particular set up, which is more about aesthetics than anything ells.
Found this post from Ben on another site around the time we were first trying the 2.2k ot. He explanes petty well what we were originally tying to do in this thread:
"I asked Mercury Magnetics to do a custom wind based on what I think is the OT Ed had in his amp. I'm not sure if it's the right one, but it sounds pretty spot on to me. It's a 2" core 2.2k based on a r"are Drake that I think came in some Park amps around 66.

Pure speculation here, but I'm kind of wondering if that's what Arson didn't make a batch of for jose and Ed when Ed burned one up. Those things were very rare and would be difficult to find, but you could tear it apart, spec it out and make a few. If Ed just wanted a "beefed up" transformer, the 1202-132 Drakes were much more plentiful and easy to obtain. there's plenty of Super Basses floating around that you could snag one from, but they don't do what this OT does.

John Suhr and Dave Friedman have both confirmed Ed's amp had a 100k/4ohm NFB setup. Try that NFB setup with a 68 Plexi spec amp and put it to the test. Put 100k on the 4 ohm tap with a C1998 Dagnall or a Drake 1202-132 and the low-end will get flubby and the highs will get fizzy and harsh. The higher primary impedance helps soften the highs and clean up the low-end. This OT sounds a little more linear in it's response, which might help lessen some of the added NFB from the 100k/4ohm being fed back in.

The affect this OT has on the mids is a more rounded vocal like affect. It's an awwwwwww as opposed to ehhhhhhhhh. Sorry, I don't have a better way to describe it. Even though the mids are rounder and more 3D-like, the flater, more linear response of the OT seems to necessitate bumping them up to get them in the mix like what you hear in Ed's tone. Here's where the V2 fat cap paralleled over the .68uf/820 comes in. I think the value on Ed's amp was like 330uf. Try that on a 68 Plexi spec amp with a Dagnall C1998 OT and a 100k/4ohm NFB setup and you will have a muddy mess...at least I did. With the right OT, the pieces fall into place."

[Dunkmop]

That's interesting, because this is one area where my '68 falls flat: the low end.

Its still crap on the low end, but I've made progress. I found I can only run the Friedman spec. with 47K on the 8 Ohm tap without the low end getting too muddy/loose (using the C1998 OT). Are you guys using a bright cap at all?

It sounds like the bigger transformer tightens the whole amp up, thus allowing the looser, but gainier component changes?!

I know I do not have a pure 12000, as I have a PPIMV and the current EVH/Heritage greenbacks, but don't think i would be too far out in this situation.

[Strat78]

That's interesting, because this is one area where my '68 falls flat: the low end.

Its still crap on the low end, but I've made progress. I found I can only run the Friedman spec. with 47K on the 8 Ohm tap without the low end getting too muddy/loose (using the C1998 OT). Are you guys using a bright cap at all?

It sounds like the bigger transformer tightens the whole amp up, thus allowing the looser, but gainier component changes?!

I know I do not have a pure 12000, as I have a PPIMV and the current EVH/Heritage greenbacks, but don't think i would be too far out in this situation.

5k on the bright channel pot seems good.

[Tazin]

Is that RS slider really only 27k as noted on the box? That can't be right. Also, in the pics you posted of your lastest creation you only have the one jumper wire (jump from Treble pot to Bass pot) hooked up on lug #1 of the Treble pot....Looks like the 0.022uF feed wire is just capped out resting against the chassis. What's the scoop on that?

[neikeel]

Is that RS slider really only 27k as noted on the box? That can't be right. Also, in the pics you posted of your lastest creation you only have the one jumper wire (jump from Treble pot to Bass pot) hooked up on lug #1 of the Treble pot....Looks like the 0.022uF feed wire is just capped out resting against the chassis. What's the scoop on that?

I've got 47k/100k/250k and 500k sliders to be added to different amps (100k and 250k probably most useful!

[Tazin]

I've got 47k/100k/250k and 500k sliders to be added to different amps (100k and 250k probably most useful!

I kinda knew that they had different value sliders but was unfamiliar of some of the exact values with exception of the 100k which I assume was typically used in Marshall amps.