Re: Hello to everyone old and new.
Correct. It also applies to a single two (or more) way HiFi speaker. If one of the drivers isn't connected properly, i. e. in phase, one will observe a nasty notch in the xover region, acoustically and by (SPL) measurement. An incorrect, out of phase connnection more or less cancels frequencies next to the xover frequency. Test it, it's reproducible, but not irreparable ;-).
?
Best regards!
|
Re: Hello to everyone old and new.
Flipping the wires to the treble driver in a Leslie indeed changes the phase relationship, and while this might seem subtle in some contexts, the impact on the crossover region is real and provable. Phase alignment, or lack thereof, can lead to cancellations or reinforcements around the crossover frequency, creating notches or peaks in the frequency response. These are measurable and audible as inconsistencies in tonal balance and imaging. Uwe's point about "notches" reflects well-documented acoustic principles, and tools like an RTA or phase response plots can demonstrate this. Aligning phase ensures smoother frequency response and coherent sound, which is why it¡¯s so critical in crossover design.
And I'll say this again, in a Leslie speaker system, with the horn rotations ongoing, whether this drastically affects the sound is debatable.
My 142 was wired out of phase and I flipped the?polarity 2 weeks ago. I hase only did one gig so far, but I am positive the frequencies in the 800-1200hz range were much more easily heard.
I know Christoph knows a lot more than I do, and I think he is simply misunderstanding what we are talking about. It's the same as having the HF horn driver and the 15" LF driver polarity reversed in a regular speaker enclosure.
It might be the use of 'phase' instead of 'polarity'. ?
Hi Christoph,
Not to beat the dead horse too badly, but the stereo example was to illustrate the original concern about how to phase a speaker so it will play well next to another speaker.? Indeed to solve the general case of bringing any random other speaker into the room and not have to worry about their relative phase.? ?Perhaps the manufacturer did not specify or pay attention to this at all in design/manufacture (odd as thst would be), perhaps the 2 models in the original discussion were wired "correctly" for each model, perhaps there was a mistake in assembly with one of them,? or maybe something else.? ?So I think this is what the OP has been trying to get to. Subwoofers generally do have 0/180 deg switches.? I don't believe most leslies or organ speakers do.? ?Also, I maybe should, but I don't know if + on the red terminal of every speaker in the world is supposed to make the cone move out (or in). In the end,? the OP can and will wire his speakers so they move in-phase, but I believe his question about which wires should go to which connector pins and speaker terminals on each model is valid.
Thanks for bringing some inspirational thoughts to my stalled restoration projects!
-Hugh
Hugh,
I¡®m not speaking of a stereo system with its two speakers. And also not about two Leslies.
The issue is alone about the question whether it is important to wire the woofer and the treble driver in a single Leslie ?in phase¡° and otherwise there were ?notches¡° in the frequency response ?nearby the takeover frequency¡°. And this I was criticizing.?
And a side note: it¡®s enter the room, not ?root¡°, as I mistakenly wrote below.
Good luck with your CV. I just finished a revision of a CV. Sounds great. Wonderful Chorus C3 Vibrato with a 122 hooked up to it.
¡ª Christoph? ? Christoph,
Please sit in front of your stereo speakers and listen to something with bass,?maybe in mono.? ?Then reverse the polarity of one of the speaker connections.? ?In one case the bass will appear to come from the middle of your head (in phase), and in the other case (out of phase), the sound will be all wrong.? So for low frequencies the phase of the woofers is quite important and Uwe's question is quite relevant.? ?(otherwise why would it be important to wire one's speakers with the correct polarity)? (the wavelength in air of a 100Hz sound is around 3.5 meters).? It is the interference here that is important, not the exact phase of a single signal.
Sorry to sound pedantic.?
One of these days I will get to working on the 3 tonewheel organs and leslie in my house (C3, Cv and M100, and 142 leslie (i think, missing its label)).? They I will be around with all sorts of sophomoric questions for the group!
-Hugh The human ear cannot hear the phase. It only can hear a phase change. If you enter the root with the Leslie spinning, you cannot say, whether is in phase or out of phase. Also the phase is frequency dependent on your position in the room.
Either is out of phase, you cannot say this or that is "out of phase".
In my remark to Uwe below, I was referring to the situation in a single Leslie in which you flip the wires going e.g. to the treble driver. And Uwes statement about "notches" in the range near the takeover frequency was what I was putting into doubt.
-- Christoph
Am 01.01.2025 um 18:10 schrieb Dennis Wage (N9OQ) < dwage@...>:
I witnessed it with my own ears. I put a sine wave tone at 600-700hz with the motors stopped and then physically reversed or flipped the phase of one of the drivers. It very easy to tell which way was in phase and which way was out of phase.?
Now, how much this affects the overall sound of the Leslie when motors are going fast and slow is debatable.? Uwe,
I believe you are wrong in your claim, that "out of phase connection of both drivers will result in a considerable notch in overall frequency response in the xover frequency region".
This is a nebulous statement lacking any mathematical or scientific substance.?
-- Christoph
You're absolutely right regarding the AC thing. But an out of phase connection of both drivers will result in a considerable notch in the overall frequency response in the xover frequency region. And, similar to a stereophonic setup, two Leslie's need to be connected in phase to get proper sound. ? Best regards!
|
Re: Hello to everyone old and new.
Hi Christoph,
Not to beat the dead horse too badly, but the stereo example was to illustrate the original concern about how to phase a speaker so it will play well next to another speaker.? Indeed to solve the general case of bringing any random other speaker into the room and not have to worry about their relative phase.? ?Perhaps the manufacturer did not specify or pay attention to this at all in design/manufacture (odd as thst would be), perhaps the 2 models in the original discussion were wired "correctly" for each model, perhaps there was a mistake in assembly with one of them,? or maybe something else.? ?So I think this is what the OP has been trying to get to. Subwoofers generally do have 0/180 deg switches.? I don't believe most leslies or organ speakers do.? ?Also, I maybe should, but I don't know if + on the red terminal of every speaker in the world is supposed to make the cone move out (or in). In the end,? the OP can and will wire his speakers so they move in-phase, but I believe his question about which wires should go to which connector pins and speaker terminals on each model is valid.
Thanks for bringing some inspirational thoughts to my stalled restoration projects!
-Hugh
Hugh,
I¡®m not speaking of a stereo system with its two speakers. And also not about two Leslies.
The issue is alone about the question whether it is important to wire the woofer and the treble driver in a single Leslie ?in phase¡° and otherwise there were ?notches¡° in the frequency response ?nearby the takeover frequency¡°. And this I was criticizing.?
And a side note: it¡®s enter the room, not ?root¡°, as I mistakenly wrote below.
Good luck with your CV. I just finished a revision of a CV. Sounds great. Wonderful Chorus C3 Vibrato with a 122 hooked up to it.
¡ª Christoph? ? Christoph,
Please sit in front of your stereo speakers and listen to something with bass,?maybe in mono.? ?Then reverse the polarity of one of the speaker connections.? ?In one case the bass will appear to come from the middle of your head (in phase), and in the other case (out of phase), the sound will be all wrong.? So for low frequencies the phase of the woofers is quite important and Uwe's question is quite relevant.? ?(otherwise why would it be important to wire one's speakers with the correct polarity)? (the wavelength in air of a 100Hz sound is around 3.5 meters).? It is the interference here that is important, not the exact phase of a single signal.
Sorry to sound pedantic.?
One of these days I will get to working on the 3 tonewheel organs and leslie in my house (C3, Cv and M100, and 142 leslie (i think, missing its label)).? They I will be around with all sorts of sophomoric questions for the group!
-Hugh The human ear cannot hear the phase. It only can hear a phase change. If you enter the root with the Leslie spinning, you cannot say, whether is in phase or out of phase. Also the phase is frequency dependent on your position in the room.
Either is out of phase, you cannot say this or that is "out of phase".
In my remark to Uwe below, I was referring to the situation in a single Leslie in which you flip the wires going e.g. to the treble driver. And Uwes statement about "notches" in the range near the takeover frequency was what I was putting into doubt.
-- Christoph
Am 01.01.2025 um 18:10 schrieb Dennis Wage (N9OQ) < dwage@...>:
I witnessed it with my own ears. I put a sine wave tone at 600-700hz with the motors stopped and then physically reversed or flipped the phase of one of the drivers. It very easy to tell which way was in phase and which way was out of phase.?
Now, how much this affects the overall sound of the Leslie when motors are going fast and slow is debatable.? Uwe,
I believe you are wrong in your claim, that "out of phase connection of both drivers will result in a considerable notch in overall frequency response in the xover frequency region".
This is a nebulous statement lacking any mathematical or scientific substance.?
-- Christoph
You're absolutely right regarding the AC thing. But an out of phase connection of both drivers will result in a considerable notch in the overall frequency response in the xover frequency region. And, similar to a stereophonic setup, two Leslie's need to be connected in phase to get proper sound. ? Best regards!
|
Re: Hello to everyone old and new.
Hugh,
I¡®m not speaking of a stereo system with its two speakers. And also not about two Leslies.
The issue is alone about the question whether it is important to wire the woofer and the treble driver in a single Leslie ?in phase¡° and otherwise there were ?notches¡° in the frequency response ?nearby the takeover frequency¡°. And this I was criticizing.?
And a side note: it¡®s enter the room, not ?root¡°, as I mistakenly wrote below.
Good luck with your CV. I just finished a revision of a CV. Sounds great. Wonderful Chorus C3 Vibrato with a 122 hooked up to it.
¡ª Christoph?
toggle quoted message
Show quoted text
Am 01.01.2025 um 20:25 schrieb hughvartanian via groups.io <bouncev@...>:
? Christoph,
Please sit in front of your stereo speakers and listen to something with bass,?maybe in mono.? ?Then reverse the polarity of one of the speaker connections.? ?In one case the bass will appear to come from the middle of your head (in phase), and in the other case (out of phase), the sound will be all wrong.? So for low frequencies the phase of the woofers is quite important and Uwe's question is quite relevant.? ?(otherwise why would it be important to wire one's speakers with the correct polarity)? (the wavelength in air of a 100Hz sound is around 3.5 meters).? It is the interference here that is important, not the exact phase of a single signal.
Sorry to sound pedantic.?
One of these days I will get to working on the 3 tonewheel organs and leslie in my house (C3, Cv and M100, and 142 leslie (i think, missing its label)).? They I will be around with all sorts of sophomoric questions for the group!
-Hugh The human ear cannot hear the phase. It only can hear a phase change. If you enter the root with the Leslie spinning, you cannot say, whether is in phase or out of phase. Also the phase is frequency dependent on your position in the room.
Either is out of phase, you cannot say this or that is "out of phase".
In my remark to Uwe below, I was referring to the situation in a single Leslie in which you flip the wires going e.g. to the treble driver. And Uwes statement about "notches" in the range near the takeover frequency was what I was putting into doubt.
-- Christoph
Am 01.01.2025 um 18:10 schrieb Dennis Wage (N9OQ) < dwage@...>:
I witnessed it with my own ears. I put a sine wave tone at 600-700hz with the motors stopped and then physically reversed or flipped the phase of one of the drivers. It very easy to tell which way was in phase and which way was out of phase.?
Now, how much this affects the overall sound of the Leslie when motors are going fast and slow is debatable.? Uwe,
I believe you are wrong in your claim, that "out of phase connection of both drivers will result in a considerable notch in overall frequency response in the xover frequency region".
This is a nebulous statement lacking any mathematical or scientific substance.?
-- Christoph
You're absolutely right regarding the AC thing. But an out of phase connection of both drivers will result in a considerable notch in the overall frequency response in the xover frequency region. And, similar to a stereophonic setup, two Leslie's need to be connected in phase to get proper sound. ? Best regards!
|
Re: Hello to everyone old and new.
Christoph,
Please sit in front of your stereo speakers and listen to something with bass,?maybe in mono.? ?Then reverse the polarity of one of the speaker connections.? ?In one case the bass will appear to come from the middle of your head (in phase), and in the other case (out of phase), the sound will be all wrong.? So for low frequencies the phase of the woofers is quite important and Uwe's question is quite relevant.? ?(otherwise why would it be important to wire one's speakers with the correct polarity)? (the wavelength in air of a 100Hz sound is around 3.5 meters).? It is the interference here that is important, not the exact phase of a single signal.
Sorry to sound pedantic.?
One of these days I will get to working on the 3 tonewheel organs and leslie in my house (C3, Cv and M100, and 142 leslie (i think, missing its label)).? They I will be around with all sorts of sophomoric questions for the group!
-Hugh
The human ear cannot hear the phase. It only can hear a phase change. If you enter the root with the Leslie spinning, you cannot say, whether is in phase or out of phase. Also the phase is frequency dependent on your position in the room.
Either is out of phase, you cannot say this or that is "out of phase".
In my remark to Uwe below, I was referring to the situation in a single Leslie in which you flip the wires going e.g. to the treble driver. And Uwes statement about "notches" in the range near the takeover frequency was what I was putting into doubt.
-- Christoph
Am 01.01.2025 um 18:10 schrieb Dennis Wage (N9OQ) < dwage@...>:
I witnessed it with my own ears. I put a sine wave tone at 600-700hz with the motors stopped and then physically reversed or flipped the phase of one of the drivers. It very easy to tell which way was in phase and which way was out of phase.?
Now, how much this affects the overall sound of the Leslie when motors are going fast and slow is debatable.? Uwe,
I believe you are wrong in your claim, that "out of phase connection of both drivers will result in a considerable notch in overall frequency response in the xover frequency region".
This is a nebulous statement lacking any mathematical or scientific substance.?
-- Christoph
You're absolutely right regarding the AC thing. But an out of phase connection of both drivers will result in a considerable notch in the overall frequency response in the xover frequency region. And, similar to a stereophonic setup, two Leslie's need to be connected in phase to get proper sound. ? Best regards!
|
Re: Hello to everyone old and new.
The human ear cannot hear the phase. It only can hear a phase change. If you enter the root with the Leslie spinning, you cannot say, whether is in phase or out of phase. Also the phase is frequency dependent on your position in the room.
Either is out of phase, you cannot say this or that is "out of phase".
In my remark to Uwe below, I was referring to the situation in a single Leslie in which you flip the wires going e.g. to the treble driver. And Uwes statement about "notches" in the range near the takeover frequency was what I was putting into doubt.
-- Christoph
toggle quoted message
Show quoted text
Am 01.01.2025 um 18:10 schrieb Dennis Wage (N9OQ) < dwage@...>:
I witnessed it with my own ears. I put a sine wave tone at 600-700hz with the motors stopped and then physically reversed or flipped the phase of one of the drivers. It very easy to tell which way was in phase and which way was out of phase.?
Now, how much this affects the overall sound of the Leslie when motors are going fast and slow is debatable.? Uwe,
I believe you are wrong in your claim, that "out of phase connection of both drivers will result in a considerable notch in overall frequency response in the xover frequency region".
This is a nebulous statement lacking any mathematical or scientific substance.?
-- Christoph
You're absolutely right regarding the AC thing. But an out of phase connection of both drivers will result in a considerable notch in the overall frequency response in the xover frequency region. And, similar to a stereophonic setup, two Leslie's need to be connected in phase to get proper sound. ? Best regards!
|
Re: Hello to everyone old and new.
I witnessed it with my own ears. I put a sine wave tone at 600-700hz with the motors stopped and then physically reversed or flipped the phase of one of the drivers. It very easy to tell which way was in phase and which way was out of phase.?
Now, how much this affects the overall sound of the Leslie when motors are going fast and slow is debatable.?
Uwe,
I believe you are wrong in your claim, that "out of phase connection of both drivers will result in a considerable notch in overall frequency response in the xover frequency region".
This is a nebulous statement lacking any mathematical or scientific substance.?
-- Christoph
You're absolutely right regarding the AC thing. But an out of phase connection of both drivers will result in a considerable notch in the overall frequency response in the xover frequency region. And, similar to a stereophonic setup, two Leslie's need to be connected in phase to get proper sound.
?
Best regards!
|
Re: Hello to everyone old and new.
Uwe,
I believe you are wrong in your claim, that "out of phase connection of both drivers will result in a considerable notch in overall frequency response in the xover frequency region".
This is a nebulous statement lacking any mathematical or scientific substance.?
-- Christoph
toggle quoted message
Show quoted text
You're absolutely right regarding the AC thing. But an out of phase connection of both drivers will result in a considerable notch in the overall frequency response in the xover frequency region. And, similar to a stereophonic setup, two Leslie's need to be connected in phase to get proper sound.
?
Best regards!
|
Re: T500 Leslie (Tremolo) Slow/Fast switch loud bang on switching
My schematic shows a 47R resistor R699 as part of the snubber
network,
On 01/01/2025 10:36, Uwe Menrath via
groups.io wrote:
Happy new year to all!
?
The Leslie control schematics show a SPDT contact set relay
with a pair of 0.1 ?F capacitors (C621, C622) across the points.
No resistor. Yes, due to their age these capacitors are the
first suspects and can/should be replaced without measurements.
But also check the suppressor diode (D607) across the relay
coil. It must not be open (OL) with your DMM's red probe at the
anode and the black one at the cathode. This inhouse numbered
diode can easily replaced by 1N4007 or the like.
?
Best regards!
--
|
Re: T500 Leslie (Tremolo) Slow/Fast switch loud bang on switching
This forum doesn't display email addresses,? My email is
clifton.christopher@....
On 01/01/2025 15:00, Chris Clifton via
groups.io wrote:
The components you're looking for are C621, C622 and R699 in
the schematic. Two 0.1uF capacitors and a 47R resistor. These
capacitors,
at CPC? would be ideal. I've got some here I could send to you.
Send me an email, and we can discuss cost etc.
On 01/01/2025 13:29, paul_english via
groups.io wrote:
Hi, thankyou for the help. I am in the UK, can you advise
the best place to order the parts.
?
Happy New Year to you all.
cheers
--
--
|
Re: T500 Leslie (Tremolo) Slow/Fast switch loud bang on switching
The components you're looking for are C621, C622 and R699 in the
schematic. Two 0.1uF capacitors and a 47R resistor. These
capacitors,
at CPC? would be ideal. I've got some here I could send to you.
Send me an email, and we can discuss cost etc.
On 01/01/2025 13:29, paul_english via
groups.io wrote:
Hi, thankyou for the help. I am in the UK, can you advise the
best place to order the parts.
?
Happy New Year to you all.
cheers
--
|
Re: T500 Leslie (Tremolo) Slow/Fast switch loud bang on switching
In the UK, Mouser usually is the best distributor. But take care of their minimum order.
?
Years ago I bought a bag full of 0.1 ?F 275 V~ X2 capacitors from a German surplus dealer for almost nothing. But they're out of stock now.
?
Best regards!
|
Re: T500 Leslie (Tremolo) Slow/Fast switch loud bang on switching
Hi, thankyou for the help. I am in the UK, can you advise the best place to order the parts.
?
Happy New Year to you all.
cheers
|
Re: Hello to everyone old and new.
You're absolutely right regarding the AC thing. But an out of phase connection of both drivers will result in a considerable notch in the overall frequency response in the xover frequency region. And, similar to a stereophonic setup, two Leslie's need to be connected in phase to get proper sound.
?
Best regards!
|
Re: T500 Leslie (Tremolo) Slow/Fast switch loud bang on switching
Happy new year to all!
?
The Leslie control schematics show a SPDT contact set relay with a pair of 0.1 ?F capacitors (C621, C622) across the points. No resistor. Yes, due to their age these capacitors are the first suspects and can/should be replaced without measurements. But also check the suppressor diode (D607) across the relay coil. It must not be open (OL) with your DMM's red probe at the anode and the black one at the cathode. This inhouse numbered diode can easily replaced by 1N4007 or the like.
?
Best regards!
|
Re: T500 Leslie (Tremolo) Slow/Fast switch loud bang on switching
Underneath the amplifier chassis, near the speed control relay
there is a suppressor network consisting of two 0.1uF capacitors
and a small resistor (33 ohm if I recollect). At least one of
those two capacitors has failed short circuit resulting in the
resistor burning out. This was quite a common fault on T-series
organs, I'd replace both capacitors with modern X2 suppressor
capacitors and replace the resistor with a new 1/2 watt resistor
of the correct value as shown in the schematic. X2 rated
capacitors are specifically designed for use in this type of
suppressor network, standard capacitors tend to fail when subject
the high voltage impulses generated when motors are switched. To
gain access to the underside of the amplifier chassis, you'll need
to undo all the wire ties holding wiring to the front of the organ
above the chassis. when the wires are all loose, undo the four
screws at the corners of the chassis and carefully lift the
chassis out and tilt it towards you.
On 31/12/2024 19:50, paul_english via
groups.io wrote:
Hi,?
when switching slow to fast or vice versa on the red Tremolo
switch, there is quite a bang through the speakers.
I seem to remember that a while ago my local organ tech (now
retired) advised it may be a capacitor on the amplifier though I
didn't get the details.? ?I have the T500 service manual and I
think I can work it out from there if someone can point me in
the right direction. Many thanks.
?
By the way I downloaded the manual from a website called
archive.org.?
?
?
--
|
Re: T500 Leslie (Tremolo) Slow/Fast switch loud bang on switching
Hi Paul!
I'm not at the same location as my service manuals at the moment, but I strongly suspect that if your T500 is still in reasonably original condition that you'll be able to find a capacitor across the leslie switch itself which will need to be replaced. It swallows the "spit," the spark that jumps between the contacts the moment before contact is made.
It's probably a low value like 0.1uF or even 0.01uF, but it'll bridge the switch. The voltage at that switch is probably?about 12V.
Now I think about it, there's also one across the relay, hidden inside the amp chassis. That voltage is 120/240V.
If you don't feel up to going under the chassis you could even put one across the 5 pin leslie plug, providing you can identify the two power pins.
Oh. Now I recall FURTHER, (it's been 12 years or more) there's three power pins at that plug, one going to fast, one to slow, and one common, so you'd need two capacitors if you were doing it there, one for each pair, whether the slow or fast motor is being engaged.
It's been a year or two since I've fooled about with all this stuff!I asked?Chris SO many questions back then.
Best wishes, -Brendon Wright
On Wed, 1 Jan 2025 at 08:50, paul_english via <paul_english= [email protected]> wrote: Hi,?
when switching slow to fast or vice versa on the red Tremolo switch, there is quite a bang through the speakers.
I seem to remember that a while ago my local organ tech (now retired) advised it may be a capacitor on the amplifier though I didn't get the details.? ?I have the T500 service manual and I think I can work it out from there if someone can point me in the right direction. Many thanks.
?
By the way I downloaded the manual from a website called .?
?
?
|
T500 Leslie (Tremolo) Slow/Fast switch loud bang on switching
Hi,?
when switching slow to fast or vice versa on the red Tremolo switch, there is quite a bang through the speakers.
I seem to remember that a while ago my local organ tech (now retired) advised it may be a capacitor on the amplifier though I didn't get the details.? ?I have the T500 service manual and I think I can work it out from there if someone can point me in the right direction. Many thanks.
?
By the way I downloaded the manual from a website called archive.org.?
?
?
|
Re: 1959 B3 and 122R Leslie recommended upgrades
That would sound great. I used to do something similar with a H&K Tube Rotosphere... I would simply go through that to get the drive, and then also go into the Leslie amp. This gave a simulated Leslie effect combined with the real Leslie, which was different but sound good.
?
?
On Tue, Dec 17, 2024 at 07:01 AM, Dave Hawnt wrote:
Hi, using a Hammond A100 and a Leslie 145... the Hammond has a variable line output that I feed into a Neo Ventilator, which in turn feeds two active 150w studio speakers. The Neo Ventilator has a very nice adjustable level overdrive effect that I balance with the audio to the Leslie 145... This can give me an ultra clean sound to a 'Jon Lord' growl when needed. :)
|
Re: 1959 B3 and 122R Leslie recommended upgrades
I like that.
toggle quoted message
Show quoted text
On 12/17/2024 8:01 AM, Dave Hawnt via groups.io wrote: Hi, using a Hammond A100 and a Leslie 145... the Hammond has a variable line output that I feed into a Neo Ventilator, which in turn feeds two active 150w studio speakers. The Neo Ventilator has a very nice adjustable level overdrive effect that I balance with the audio to the Leslie 145... This can give me an ultra clean sound to a 'Jon Lord' growl when needed. :)
DaveH (Deep South, UK)
--
Rich Reid
208-861-9263
|
Uwe Menrath
Dennis Wage (N9OQ)
Christoph