Hughes & Kettner Rotosphere

[Fredenando]

Happy New Year for all,

For some time I am looking for information about Leslies.

I love the sound it produces from a Hammond and from a guitar, as you can hear some songs from Pink Floyd or SRV. And I've been studying the possibility of building one, but its sheer size dismiss me because of my lack of space.

Finally I have been looking at some circuit emulators, but I ended up not satisfied me her sounds, until I found the Hughes & Kettner Rotosphere, both the first and the MKII version that I have found in YouTube. Their sound has impressed me, but more so its price (about 500 €) and I raised the possibility of cloning, but I can not find no pictures or diagrams.

Anyone else has raised the possibility of cloning? Anyone can take pictures of circuit boards?

Thanks!!

[tiges_ tendres]

I have one, but save yourself the time.  I picked up mine used for $120.  There is no way I'd want to R.E this when you can pick them up used so cheaply.

[Fredenando]

Yes, this is an option, hopefully I found one so cheap something like you. 

I've saved a search that I made in eBay, to see if I have luck!!

Thank you!!

[PRR]

Everybody has tried to emulate the Leslie sound.

It's what Fender "tremolo" tries to do. Fender had patents on very elaborate high-pass low-pass trems. Others have used phase-shifters based on varistors, FETs, photoresistors.

None of them are quite right. Nothing really captures the sound of rotating speakers.

The advanced technology of long delays and digital signal processing probably gets closer than ever, and a lot more portable. If you open that H&K you probably find a custom programed DSP chip.

[Taylor]

If you open that H&K you probably find a custom programed DSP chip.

I have read someone who repaired one say it's all analog. My guess is a combination of chorus and phasing.

[Mark Hammer]

Before you drive yourself crazy. at least try a Behringer RM600 Rotary Machine.  It's a clone of the Line 6 Tone Core Roto Machine, which is also a very decent Leslie emulator....and a damn sight cheaper than most others.

[sjaltenb]

I had one of these units, I miss it so so badly. If you search youtube my clips were the PF us and them clips.

Its completely analog from what I understand, except the switching. According to Pete Cornish it is almost identical to the DynaCord CLS-222 except with a tube.

I got mine for $250 on craiglist...I would search for a used one and just snag it.

[DougH]

I  posted a link to a cls222 schem a few yrs ago. You could tackle that if you're up for it. I'm with Mark- get a rotomachine or clone. Tube or not, you will never duplicate the point source throwing sound around of a real live leslie, in a pedal. You -can- get a reasonable facsimile of what you'd hear on a recording though.

[Fredenando]

Before you drive yourself crazy. at least try a Behringer RM600 Rotary Machine.  It's a clone of the Line 6 Tone Core Roto Machine, which is also a very decent Leslie emulator....and a damn sight cheaper than most others.

I have saw one or two videos in YouTube and not so bad, and her price is ideal to test it at home for only 38€. Probably I buy one meanwhile I decide other options.

I had one of these units, I miss it so so badly. If you search youtube my clips were the PF us and them clips.

Its completely analog from what I understand, except the switching. According to Pete Cornish it is almost identical to the DynaCord CLS-222 except with a tube.

I got mine for $250 on craiglist...I would search for a used one and just snag it.

Your clips are some of what I have saw and heared in YouTube to decide me for the Rostosphere. Really sound like Pink Floyd, that is what I want.

I  posted a link to a cls222 schem a few yrs ago. You could tackle that if you're up for it. I'm with Mark- get a rotomachine or clone. Tube or not, you will never duplicate the point source throwing sound around of a real live leslie, in a pedal. You -can- get a reasonable facsimile of what you'd hear on a recording though.

I will seek the Dynacord CLS-222 schematics.

Thanks to all!!

[The Tone God]

I've worked on a bunch of these. They are just a pair of BBD based choruses, one each for the upper and lower freqs.

This is not a simple build so unless you are experienced I would just buy something similar.

Andrew

[Fredenando]

I have enough experience, hence my interest in the possibility of cloning.

I have already the schemes of Dynacord CLS-222 and the Korg CX-3 and I have seen the clone of the CX-3 of Bajaman, very interesting indeed, but which opened to implement the improvements that have incorporated the Rotosphere, as to work in stereo and the brake.

[DougH]

I have enough experience, hence my interest in the possibility of cloning.

I have already the schemes of Dynacord CLS-222 and the Korg CX-3 and I have seen the clone of the CX-3 of Bajaman, very interesting indeed, but which opened to implement the improvements that have incorporated the Rotosphere, as to work in stereo and the brake.

Bajaman did a nice job with his CX-3 roto-clone. However, I have an analog CX-3 drawbar organ with that rotary sim and it is okay but needs improvement. Like a lot of these kinds of circuits, it sounds pretty good on slow speed but gets pretty anemic on fast speed. Also, it is just mono and to get any sort of spatiality out of a simulator like this you need to go stereo.

Most of these analog roto simulators (like H&K as Tone God mentioned) are basically fancy chorus units. They may or may not split the upper & lower freqs through separate delay lines. They usually have logarithmic speed ramp up/down and maybe a brake function. Some include overdrive, but the heart of it is essentially chorus. IIRC, the CLS-222 is essentially the same idea.

If your try out the L6 rotomachine (or behringer clone) you will be ahead of the game. I have used the CX-3 with the rotomachine and it sounds very good, a vast improvement over the onboard roto-sim on the organ. BTW- the newer digital CX-3's that came out a few years ago now use a DSP rotary sim and clips I've heard sound very good. I tried out a Hammond mini-drawbar organ a few weeks ago. It had an onboard DSP leslie sim and it sounded very good as well. The rotomachine is DSP as well. Notice the pattern? One improvement I would have liked for the rotomachine would be separate speed ramp for the high and low freqs, as the woofer tends to lag the horn (or vice versa?) when a leslie spins up. But that's a minor nit, IMO.

[joegagan]

cool thread!

my low buck approach would involve sending two sides of a cheapie stereo chorus ( or one of the behringers/line6 roto) to two amps, one set trebly, the other bassy.

[joegagan]

the line6 roto-machine sells for as little as 60 shipped in the US on ebay, used. a great deal if you ask me.

[joegagan]

ok, my curiousity is up, would love to hear a direct  AB test between the rotosphere and  line 6 roto-machine, going into stereo amps.

[DougH]

For me, this would be the ultimate leslie setup for guitar.

[Mark Hammer]

ok, my curiousity is up, would love to hear a direct  AB test between the rotosphere and  line 6 roto-machine, going into stereo amps.

As a digitally modelled effect, the Roto-Machine has 3 different Leslie models, while the Rotosphere doesn't appear to have any particular "model" in mind.  That is not necessarily a criticism.  rather, depending on what it is one thinks the effect is supposed to "do", the one or the other may be more pleasing to you.

The only thing I don't like about the Roto-Machine is that the Drive control results in a volume change, without the complementary volume control.  It has a nice effect, but one wants to use it as a sort of tone control, rather than something like the gain control on a distortion pedal.  The fact that you have no way of changing the "tone" without changing the volume on the RM is a drawback.

[wavley]

For me, this would be the ultimate leslie setup for guitar.

When I worked at the repair shop there was a guy that had one of those, it sounded really great but I had to come in once a year to be serviced, I can't remember why, it was another guy that always fixed it.  That's not a big deal for guys like us, but the guy that owned it was in a local dead tribute band and it quit like clockwork at a gig once a year.  He did take the hint and started bringing in before it quit.  If you ever pick one up let me know and I'll call Josh and find out what it's issue was.

[DougH]

The only thing I don't like about the Roto-Machine is that the Drive control results in a volume change, without the complementary volume control.  It has a nice effect, but one wants to use it as a sort of tone control, rather than something like the gain control on a distortion pedal.  The fact that you have no way of changing the "tone" without changing the volume on the RM is a drawback.

Yes, that's another issue with it I forgot about.

Some guitarists complain about the heavy EQ too, but hey, that's what leslie cabinets do. And the L16 model does not instantly transform your guitar amp into a vibratone. It only emulates the vibratone rotating spkr cabinet. You need to split your signal upstream and route that to a dry amp to get the vibratone effect of the rotating cabinet sound combined (via crossover with a vibratone- via air with the pedal sim) with your guitar cabinet sound. But when you do that- it's magic.

[DougH]

For me, this would be the ultimate leslie setup for guitar.

When I worked at the repair shop there was a guy that had one of those, it sounded really great but I had to come in once a year to be serviced, I can't remember why, it was another guy that always fixed it.  That's not a big deal for guys like us, but the guy that owned it was in a local dead tribute band and it quit like clockwork at a gig once a year.  He did take the hint and started bringing in before it quit.  If you ever pick one up let me know and I'll call Josh and find out what it's issue was.

Thanks!