Nocturne Brain Seltzer Classic

reneshelle · Post by **reneshelle** » 01 Apr 2011, 17:35

Dork wrote:In the next days I´ll look how it sounds with the opa134 at 18V. Let´s see if theres more headroom then?!

Why not try it with the 741 as well? If it's better then I will be more than happy to make a verolayout with onboard charge pump. Also, try starving the power (5 volts os so). Could perhaps make it a bit dirtier sounding?

I havn't build one myself yet and I might wait a bit... until I've heard how the 18 volts worked for you.

graemey · Post by **graemey** » 01 Apr 2011, 18:13

Dork wrote:
electromatic wrote:I just want to say that I verified the layout.
+1 yep verified!

Dork, how is the tone control on yours? I still can't get mine to make any difference to the sound. I have checked the pot, wiring etc and even tried different value caps but nothing. As I said earlier, the original Nocturne tone has a subtle but noticeable effect, my build tone knob does nothing.

G5120fx · Post by **G5120fx** » 01 Apr 2011, 18:19

You´re right! The tone pot doesn´t change the sound, but I´ve only tried it for a few minutes. I´m still pretty busy at the moment, I´ll take a look at it in the next few days...

reneshelle · Post by **reneshelle** » 01 Apr 2011, 19:21

graemey wrote: I still can't get mine to make any difference to the sound. I have checked the pot, wiring etc and even tried different value caps but nothing. As I said earlier, the original Nocturne tone has a subtle but noticeable effect, my build tone knob does nothing.

You do have the lug 1 and 2 connected together on the pot right?

graemey · Post by **graemey** » 01 Apr 2011, 20:03

reneshelle wrote:
graemey wrote: I still can't get mine to make any difference to the sound. I have checked the pot, wiring etc and even tried different value caps but nothing. As I said earlier, the original Nocturne tone has a subtle but noticeable effect, my build tone knob does nothing.
You do have the lug 1 and 2 connected together on the pot right?

Yep, set up as a variable resistor wit a cap across it, if Im right?

reneshelle · Post by **reneshelle** » 01 Apr 2011, 20:09

I thought it was a bit too obvious - and I was right. Then I honestly don't have a clue. It's a simple hi-pass filter. It simply has to work!

electromatic · Post by **electromatic** » 01 Apr 2011, 22:50

Dork, love the cheetah print and the stray cat!

Anyways, just wanted to chime in, that the nocturne with Dynasonic pickups reacts WAY better with a buffer in front. I just put the pedal on my mini-board, with an older Korg DT10 pedal at the front...

WHOA. Holy-high-end-recovery-bat-man!

Now, I'm pretty sure that's what people were talking about with the dyno-brain vs the brain classic. Also way more gain in the circuit. I would say the mystery is solved.

Before I add a buffer to mine, I quickly added a 1M resistor across the lugs on the input jack. Made a difference, but no where near as much as the buffer. With the buffer, it's a bit too crispy for me, it needs some high end rolloff, so I'll tack that on too.

graemey · Post by **graemey** » 02 Apr 2011, 09:43

reneshelle wrote:I thought it was a bit too obvious - and I was right. Then I honestly don't have a clue. It's a simple hi-pass filter. It simply has to work!

That's what I thought.
I'm gonna try it today with my Marshall Vintage Modern Head. Great amp to dial in some nice valvey tones. See if I can hear the tone control doing something with that. I will also place a boss pedal before it for some buffering action.

graemey · Post by **graemey** » 02 Apr 2011, 11:56

[quote="electromatic"]
Anyways, just wanted to chime in, that the nocturne with Dynasonic pickups reacts WAY better with a buffer in front. I just put the pedal on my mini-board, with an older Korg DT10 pedal at the front...

WHOA. Holy-high-end-recovery-bat-man!
/quote]

Just tried mine with Marshall head/4x12 cab set-up. The tone control can now be heard to take some low end thump out of the sound (it's SUBTLE, though)

Electromatic is right about the buffer in front thing, seems to bring the sound to life. I am testing with my Gretsch 6120 with TV Jones filtertrons, pretty similar to what Brian Setzer plays. My Marshall Vintage Modern 100 watt head is pretty faithful to the early Marshall's that were, in turn, very similar to the Fender Bassman. What I'm trying to say is that I have quite a 'Setzer like' set-up. I wonder why the non-buffered sound is inferior (in my opinion) to the buffered sound? The buffer wakes up the tone knob and adds the required sparkle to the whole Rockabilly experience daddio's!

reneshelle · Post by **reneshelle** » 02 Apr 2011, 12:19

Looks like we're gonna have to do one with onboard buffer (and perhaps a charge pump?). How is the high-end with the buffer to your ears Graemey? Electromatic thought it was a bit much.

If a treble cut is needed that would make it at three knob preamp.

graemey · Post by **graemey** » 02 Apr 2011, 14:01

reneshelle wrote:Looks like we're gonna have to do one with onboard buffer (and perhaps a charge pump?). How is the high-end with the buffer to your ears Graemey? Electromatic thought it was a bit much.

If a treble cut is needed that would make it at three knob preamp.

The high end sounded nice to me. I suppose it all depends if you want to keep the preamp on 100% of the time (in which case you can tweek the amp settings) or switch in and out. I certainly didn't find it harsh. I really want to reserve judgement until I try the whole thing at gig volume. That will be decisive re the treble and noise issues.

reneshelle · Post by **reneshelle** » 02 Apr 2011, 14:07

I'm thinking something like this.

Just the same schematic with the buffer from http://www.beavisaudio.com/techpages/Buffers/ added on. This is using both sides of a dual opamp. The 1458 is a dual 741.

If a low-pass filter is needed, I don't know if it's best before or after the "gain-stage". After is my guess.

electromatic · Post by **electromatic** » 02 Apr 2011, 15:44

Time to breakout the breadboard again.

The beavis 'plon fentar' buffer looks like it's worth a try too.

What I will try is if a gentle low-pass sounds better before or after the gain stage. The whole point of the nocturne is to introduce a bit of warmth and boost like the roland preamp, so it might work well in front. But who knows until I try. Would be nice to have a dynobrain to see how it was done.

BTW, I have played at close to gig volumes with the buffer in front. That's why I said it's a tad on the shrill side and makes the strings feel too crisp. I will also try lifting the treble bleed cap (C1) on the vol knob, to see if that changes the tone. (On that schem with the opamp buffer, there are two C5's.

)

I'm thinking a fixed value low-pass should do the trick, or a trimmer for those who want to tweak it for their rig. If I had to do it over again, I would do the same with the bass roll-off, to keep it to one knob, Volume!

reneshelle · Post by **reneshelle** » 02 Apr 2011, 16:03

electromatic wrote:(On that schem with the opamp buffer, there are two C5's. )

Sometime you just can't have to many C5's

About the trimpots. I've thought the exact same thing. It's not worth having them mounted on the outside. I think I will try to squeeze it into an A size enclosure when I get around to building it and with only one knob.

electromatic · Post by **electromatic** » 02 Apr 2011, 16:08

BTW, here is the Billy Zoom input mod for the RE-301!
To do impedance matching.

And also an example of it installed on an RE301 input.

17VDC. Sounds like a charge pump is needed.

Chugs · Post by **Chugs** » 02 Apr 2011, 16:17

A suggestion in regards to adding a buffer on the input...

Referring to the schematic that reneshelle posted: Instead of connecting two 1M resistors to pin5 you could bias the buffer a little better, and save yourself one part, by connecting one 1M resistor from the positive input of the first half of the opamp (pin5) to the junction of the 10K/10K/10uf.

The 10K/10K/10uf junction is a VR bias.

reneshelle · Post by **reneshelle** » 02 Apr 2011, 16:23

I was thinking about that. But I thought the input impedance would be to low that way for some pickups. I might be mistaken though. I not really that clever...

reneshelle · Post by **reneshelle** » 02 Apr 2011, 17:12

@Chugs.
I just realized that I misunderstood what you were saying. My mind played the old “you-see-what-you-expect-to-see” trick on me. I had thought to connect it directly to the VR Bias and use no 1M resistors. That would give some impedance problems I thought. But what you suggested with adding ONE 1M resistor between the input and VR bias I hadn’t thought about.
I will not correct the schematic at this point. More new stuff is bound the surface. I think I will draw a new schematic and vero layout when I’ve decided how to build one for myself.

reneshelle · Post by **reneshelle** » 03 Apr 2011, 20:24

I had some spare time. I'm going to build it with the charge pump and I will do a little daughterboard with the hi-pass (and perhaps lo-pass) as trim pots. I'll glue it to the side of the 3PDT footswitch and drill hole(s) like the skreddy screwdriver thing. Stick it all in a 1590A and have only volume as a pot.

If I don't like the 18 volts it will be easy to remove the charge pump bits.

I didn't draw a new schematic but adjusted the previous one

I did make a new vero though.

Feel free to comment. Because honestly, I don't really know if I'm doing it right!

bajaman · Post by **bajaman** » 03 Apr 2011, 20:48

R and D for Nocturne

Nocturne Brain Seltzer Classic [traced]