From jjmcs49@yahoo.com Tue Jan 04 13:11:08 2005
Subject:Re: Setting XK-3 for no Leslie (was: How can I get...)


These are three previous posts I wrote regarding the XK-3's tubes
etc.on the Hammond_XK-3 forum. They are just information I have
gathered, things I have tried and observations I have made. They
don't count for anything. So far noone else has commented on their
results with different tubes, but I doubt that I am the only one who
has tried others. It seems to me if Hammond can put different tubes
in them, so can I.

This is how I have my XK-3 set up:
I use a StudioLogic CMS-61 for a lower manual, a Fatar MP-117 for
pedals and use a Hammond EXP100F for volume/Leslie speed control.

I Replaced the Ei (Yugoslavia) tubes with NOS GE 12AX7 USA 2 Mica
Spacer 60's era tubes. These tubes seem to "sing" before they
distort. So from 0 to about 4.5, the tone gets richer ( I don't know
how else to describe it). From 4.5 to about 7.5 the tubes start to
sing. For example, hold down the highest C, add E flat and you can
hear additional harmonics, add the F and the tubes just start to
sing, the closest thing I can relate it to is a subtle ring
modulator. Turn it up from there and you add the overdrive scream.
Also, with the original tubes and with other preamps I have tried
(Blue Tube II two channel rack unit and Blue Tube pedals) there
seems to be a drop off in low and mid frequencies as the overdrive
increases. With these, there is no drop off.

In the effects loop I have a Soldano space box spring reverb with
5751 tubes. I replaced the original Sovtek 12AX7LPS tubes with these
because the Sovteks seemed to overdrive no matter what. The 5751
tubes reduce the gain somewhat, but I get a nice smooth reverb
without the buzz. According to the people at Soldano, they use those
tubes to really "hit" the springs. Although it is supposed to be
designed for both guitar and line level inputs, I think the line
level is too hot for the 12AX7LPS's and they overdrive.

Also, as overdrive increases, it causes the reverb springs to
vibrate more.

To get to the point, I run all of this into a Leslie 21 System and
the digital Leslie into a Crate KX80 keyboard amp and from there
into an old Ampeg Jet 12 with an additional external speaker. The
Leslie 21 System does a better job of reproducing the bass than the
other amplifiers. When I play the digital Leslie through the lower
unit of the Leslie with the upper unit disconnected from the lower
unit and the volume on the upper unit turned off, there is virtually
no difference in the sound (the mid range frequencies may be
slightly louder). The display on a spectrum analyzer is pretty much
identical. From what I have been able to determine, the difference
in sound between the digital and real leslies ( I'm not getting into
the pissing match regarding the Leslie 21 vs the 122 / 147) is
caused by the amp that the digital Leslie is played through and not
in the Leslie simulation itself. Now, can someone who cares tell the
difference from within 10 feet and with open eyes? Yes. Could they
tell if they couldn't see what was producing the sound? I don't
know. Probably not 100% of the time. Could you tell in a bar or
concert setting? I doubt it.

I think that if the XK-3 is going to be played through a large PA
system, the mixing board probably has a spectrum analyzer in it. The
keyboard player could set up the XK-3 to their liking / usual setup
and work with the sound guy to get the PA right and then copy the
spectrum analyzer display for reference. Once the PA is equilized to
your liking, tell the sound guy to leave it alone, that thats what
the drawbars are for.

2nd Reply:

I have never heard an Electro. The only Korg I've played was in a
music store through some little monitor speakers, and to me the bass
sounded like hitting a hanging carpet with a bat. Must have been the
speakers.

This is just my opinion, but if I were buying amplification
(starting with none) for my XK-3 this is how I would do it as my
needs / wallet grew.

1st: Leslie 2121 (Lower Unit) play w/ Digital Leslie.

Need more Volume:
2nd: Add 2nd Lower Unit - connect to Right 1/4" out or line out of
1st Lower Unit for Mono. Continue with digital Leslie.

3rd: Add Leslie 2101 Upper unit, connect it to one Lower Unit, play
digital Leslie through the other.

4th: Add 2nd Upper unit. Connect through optional Y Leslie Cable.

5th: Add 3rd Lower Unit. Connect to 1/4" output.

And so on.

Need / Want Moving Air:
2nd: Add 2101 Upper Unit. Connect to Lower unit. Play through Leslie
Cable.

3rd: Add 2nd Lower Unit. Connect to 1/4" output.

4th: Add 2nd Upper unit. Connect through optional Y Leslie Cable.

5th Add 3rd Lower unit. Connect to 1/4" output.

And so on.

This post had additional info on the tubes and how to replace them:
I bought the tubes from here:
http://www.vacuumtubes.com/12ax7.html . I talked with the owner
regarding the various brands etc. and it came down to the fact that
there is no way of knowing how any tubes will sound without trying
them and the GE's were good quality and reasonably priced. He
recommended these and he hit the nail on the head as far as I'm
concerned, and he could have recommended more expensive ones. I
wanted older tubes because I think newer ones may be "optimized" for
overdriving for guitar amps. I have no way to prove this, but when I
put the Sovtek 12AX7LPS's in the XK-3 they distorted even with the
knob at 0. The older 12AX7's that I tried (old Raytheon's that I had
from a 50 year old guitar amp) didn't distort quite as much and they
also seemed to have the low end drop off that the other tubes and
preamps I have tried have.

Regarding the tone, in the dual amp modes, turning the dial up adds
the sound as I described previously without the low frequencies
dropping out as seems to happen with other preamps I've tried, but
in the single channel mode you still get that "guitar overdrive
scream" with a reduction in the low frequencies.

I am no electronics wiz, but from what I have read and been told,
basically all 12AX7 tubes should be equal in gain and
interchangeable. There are other tubes available that would also be
useable but would have lower gain. 5751 tubes have about 70% of the
gain of a 12AX7. I put the 5751's in the reverb to stop the buzzing
that the Sovteks caused. I also tried the Ei tubes from the XK-3 in
the reverb unit and they didn't overdrive as much as the Sovteks. I
ended up with a 5751 on the input side of the reverb and a Raytheon
12AX7A on the recovery or output side. Now, the XK-3 can sound like
I'm playing in a large hall (about two seconds of fade after the
keys are released) With the Leslie at full speed and the overdrive
at max there's nothing like it to me. It's the sound I like, and I
like the real reverb better than digital reverb.

The top cover is held on by the four screws across the back just
below the top of the rear cover, and the four smaller headed screws
across the front in the metal frame where the drawbars come out. The
tubes are held in place by wire clips that slide off the top of the
tubes (the loop in the wire slides over the point in the tube). The
tubes come out easily with a slight upward and rocking motion (don't
rock too far side to side). Be careful installing the new tubes, the
PC Bd. flexes down when pressed on but there is enough room to get a
finger under the edge of the bd. to support it. There are two pots
on the bd. one is marked VR1 and High Freq. Gain, the other is just
marked VR2.

This website has additional info on tubes, but they don't seem to
have the selection of NOS available:
http://thetubestore.com/gainfactor.html

A different post regarding the tubes in someone else's XK-3 which
are 12AX7B tubes yhat are made in China apparently by a company
named Shuguang:

Thanks for looking at the tubes in the one you have. Mine came with
Ei tubes which according to this website:
http://www.vacuumtubes.com/12ax7.html are made in Yugoslavia with
equipment they bought from Telefunken. They should sound like old
Telefunken tubes but might not last as long. The 12AX7B tubes
apparently are made in China by a company named Shuguang. I did a
google search on 12AX7B and thats what I found. I wonder if this is
why some people believe the Speakeasy preamp improves the XK-3, and
others believe it doesn't. There may be several brands/types of
12AX7 tubes used and they may all sound a little different. I put
old GE 12AX7's in mine. I liked the original tubes, but the GE's
seem to have a little different tone which I prefer.

--- In CloneWheel@yahoogroups.com, "g_e_marshall"
wrote:
> > > need to work with it and explore it's functionality
> > > before giving an opinion. Now that I have worked with
> > > it daily for over a month and a half I can tell you
> > > it's functionality is extremely flexible. You can play
> > > it with or without a Leslie. The trick to playing it
> > > without a Leslie is to set the middle frequency eq to
> > > 2.0 or 2.4, then set the gain middle to the high end
> > > +9 or whatever your ears prefer. Naturally, set the
> > > key click params to zero.