Author Topic: wireless system  (Read 738 times)

bucephylus

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Re: wireless system
« Reply #15 on: March 23, 2025, 04:52:18 AM »
"The link I included in my second post shows the Blue Box feeding the instrument -15VAC on Pin 5 and +15VAC on Pin 4; which sets the “zero” point you mentioned. But, those are AC sources. Are you suggesting that -15VDC and +15VDC can be used instead on Pins 4 and 5? That’s my specific confusion. I had presumed Ron W had put a rectification bridge in the onboard circuit; but not clear on what DC power would do there.

Hello Paul,

Slight correction:
The power supplies used with series instruments do output DC voltages. From the schematic in the link you referenced, pins 4 & 5 are fed (from the center-tapped transformer secondary) via the bridge rectifier and smoothing/filtering capacitors shown in the diagram. So there’s no need to have onboard rectification.

This is why it’s possible to build the battery packs as JimmyJ described for use with wireless transmitters.

-nate.
Many thanks, Nate, for the clarification. That makes more sense.

So, my original concept of using the CIOKS 4 EXT with a power bank should work perfectly well. I will just need to locate a source for the 5 pin jack.

FC Bass

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Re: wireless system
« Reply #16 on: March 23, 2025, 02:14:44 PM »
Fwiw: Just probed my (new) DS-5 and its +18,5 and -18,5V
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JimmyJ

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Re: wireless system
« Reply #17 on: March 23, 2025, 03:37:29 PM »
Paul,

No sorry but the CIOKS will not do the job here because it only offers "one-sided" power, only +18 and "0". You would need two of them to work at +18/-18.  Sorry if this is confusing but the Series preamp boards need plus and minus power.  Here come some wonderful technical drawings! 

The onboard batteries work like the first picture below. 

Common external battery packs using four 9V batteries are likely wired like picture 2.

Or, you could use four external 9V batteries to produce +/-18V as shown in picture 3. 

I have no idea if running +/-9 off an external pack is better or worse than running +/-18.  Maybe somebody in here knows.  But as you see you could also have six batteries (wired +/-9) or even eight batteries (wired +/-18).  But soon your strap will weigh more than the bass and you'll need a back brace. :o   

Jimmy J

FC Bass

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Re: wireless system
« Reply #18 on: March 23, 2025, 04:38:10 PM »
I'm pretty sure my battery ps is wired like #3 :-)
I have not compared the schematics, but I've had an expert look at it and he said its +18 and -18V

I've never tried the internal batteries, but I guess the output of the preamp will be much lower with +9 and -9V?
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Songdog

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Re: wireless system
« Reply #19 on: March 24, 2025, 10:15:59 AM »
I've never tried the internal batteries, but I guess the output of the preamp will be much lower with +9 and -9V?
I don't have personal experience with a Series bass, but I do have some relevant electronics knowledge. I wouldn't expect the gain to change, but the maximum output before clipping wouldn't be as high. If you turned up the volume controls and the internal gain trims all the way and played hard you might be able to hear a difference.

But that would depend on what it was plugged into. Practically speaking, it probably doesn't matter. An output signal near 18 V peak-peak (+9/-9 supply) is going to overload the inputs of amps and effects (which often run on a single 9V battery). If you heard any distortion, it probably wouldn't be the bass itself.

My Alembic bass, with a single 9V battery, doesn't seem to suffer from limited output level, I have to back off the volume to match my passive basses. (I really should turn down its internal trimpots a little.)

bucephylus

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Re: wireless system
« Reply #20 on: March 26, 2025, 08:51:42 AM »
Paul,

No sorry but the CIOKS will not do the job here because it only offers "one-sided" power, only +18 and "0". You would need two of them to work at +18/-18.  Sorry if this is confusing but the Series preamp boards need plus and minus power.  Here come some wonderful technical drawings! 

The onboard batteries work like the first picture below. 

Common external battery packs using four 9V batteries are likely wired like picture 2.

Or, you could use four external 9V batteries to produce +/-18V as shown in picture 3. 

I have no idea if running +/-9 off an external pack is better or worse than running +/-18.  Maybe somebody in here knows.  But as you see you could also have six batteries (wired +/-9) or even eight batteries (wired +/-18).  But soon your strap will weigh more than the bass and you'll need a back brace. :o   

Jimmy J

Many thanks for this information.

I confess that I am still confused about the CIOKS channels. I understand the polarity. But, those channels are supposed to be isolated; meaning they should effectively function as separate batteries. So, I would have thought that setting one negative arm to Pin 5, the corresponding positive arm and the negative arm of a different channel to Pin 1, and the positive arm of the second channel to Pin 4 should have accomplished the circuit.

Are you suggesting that the negative arms are on a common bus within the CIOKS 4? Wouldn’t that make them non-isolated? Isolated to me means that they are simply DC supplies with no common reference. As such, i would have expected them to perform as essentially separate batteries.

If that is not the case, I would very much appreciate further information about the CIOKS limitation.

Thanks again.
Paul

bucephylus

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Re: wireless system
« Reply #21 on: March 26, 2025, 09:34:12 AM »
Paul,

No sorry but the CIOKS will not do the job here because it only offers "one-sided" power, only +18 and "0". You would need two of them to work at +18/-18.  Sorry if this is confusing but the Series preamp boards need plus and minus power.  Here come some wonderful technical drawings! 

The onboard batteries work like the first picture below. 

Common external battery packs using four 9V batteries are likely wired like picture 2.

Or, you could use four external 9V batteries to produce +/-18V as shown in picture 3. 

I have no idea if running +/-9 off an external pack is better or worse than running +/-18.  Maybe somebody in here knows.  But as you see you could also have six batteries (wired +/-9) or even eight batteries (wired +/-18).  But soon your strap will weigh more than the bass and you'll need a back brace. :o   

Jimmy J

Many thanks for this information.

I confess that I am still confused about the CIOKS channels. I understand the polarity. But, those channels are supposed to be isolated; meaning they should effectively function as separate batteries. So, I would have thought that setting one negative arm to Pin 5, the corresponding positive arm and the negative arm of a different channel to Pin 1, and the positive arm of the second channel to Pin 4 should have accomplished the circuit.

Are you suggesting that the negative arms are on a common bus within the CIOKS 4? Wouldn’t that make them non-isolated? Isolated to me means that they are simply DC supplies with no common reference. As such, i would have expected them to perform as essentially separate batteries.

If that is not the case, I would very much appreciate further information about the CIOKS limitation.

Thanks again.
Paul
To follow up on my Q, I sent the following message to CIOKS Tech support:

“ Hello.

I am successfully using a CIOKS 4 Expander with a power bank to run a pedal board.

This success leads me to believe that it might be possible to use the CIOKS 4 with a power bank to power the internal preamp in my Alembic Series I Bass.

But the Alembic preamp requires both -18VDC and +18VDC with a center 0. Alembic does this with two onboard 9VDC batteries (sacrificing some headroom with 9VDC), wiring the - of one battery to the power bus, wiring the + of that same battery and the - of the 2nd battery to the 0 post, and wiring the positive of the 2nd battery to the power bus.

Are the CIOKS 4 channels sufficiently isolated to perform the same way? Or, would I need a separate CIOKS 4 to get the circuit power configuration?

Many thanks”

In response I received the following reply:

“ Like all our power supplies, each outlet/section are fully isolated. Unlike many other manufacturers, each outlet has their transformer and multifilter configuration. It is why we are able to have 4 voltage option for each outlet. Something you don’t see from any other manufacturer.

Thank you.

Cioks Support”

I infer this response to indicate that using the two channels on the 4 Expander SHOULD function similarly to two separate batteries.

I’m still waiting for parts; but, would surely appreciate any additional insight.


Second topic: my stereo 1/4” converter cable, which I built with Ron and Susan’s input around 1977, uses 2.2 kohm resistors to step down the output signal operating at 18 V P-P (8.2 mA max). But, I see that the DS5 uses 20 kohm resistors for the same purpose, operating at roughly 40 V P-P (2 mA max). Any guesses for a 36 V P-P bias? Perhaps 5 kohm? 10 kohm?
« Last Edit: March 26, 2025, 09:38:15 AM by bucephylus »

JimmyJ

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Re: wireless system
« Reply #22 on: March 27, 2025, 07:22:24 AM »
OK!  Topic 1:
So it sounds like the CIOKS could work as a +/- supply.  You could easily test it by wiring it as you've described and measuring the "end" +/- voltages to see you get 36VDC.  Sure.  But here's the thing...  Why again?

If I am understanding the info on the product page, this looks like a great pedalboard power distribution device which does its thing by way of DC-DC converters.  But it needs to be powered!  And by a fairly robust USB-C power supply.  I guess that may include the rechargeable battery bank as you mentioned although I didn't see that option described on the product page. 

If you went that route you would have an external battery pack running into this power distributor and then powering your bass.  Why not skip the middleman here and just use 9V batteries as we've described above?  If you want to have a rechargeable external pack but are concerned about the "less-than-9V" issue, then just wire four of them as above and you will get at least +/-15VDC (which is the power I use in all my home built PSUs).

So yeah, your first idea may work if you don't mind the two-box approach.  As long as it provides enough current and the power is well regulated.

Topic #2:
It turns out the summing resistor values are not critical so that's why you may see differences.  I'm only a self-taught wirehead so I can't fully explain ... but I don't think the drop in audio signal is the same as a voltage drop calculation.  The main point of those resistors is to isolate the two outputs so you don't have one output feeding directly into the other which would cause them to interact and load each other in weird ways.  (A self-taught description. :) )  So with 2.2k resistors the two channels are 4.4k apart and less likely to interact.  As long as the values are the same I believe anything in that seemingly wide range of resistance would do the job without much loss of signal.

Let us know what you figure out re the battery situation.  Nice experiment!

Jimmy J

bucephylus

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Re: wireless system
« Reply #23 on: March 27, 2025, 10:18:40 AM »
OK!  Topic 1:
So it sounds like the CIOKS could work as a +/- supply.  You could easily test it by wiring it as you've described and measuring the "end" +/- voltages to see you get 36VDC.  Sure.  But here's the thing...  Why again?

If I am understanding the info on the product page, this looks like a great pedalboard power distribution device which does its thing by way of DC-DC converters.  But it needs to be powered!  And by a fairly robust USB-C power supply.  I guess that may include the rechargeable battery bank as you mentioned although I didn't see that option described on the product page. 

If you went that route you would have an external battery pack running into this power distributor and then powering your bass.  Why not skip the middleman here and just use 9V batteries as we've described above?  If you want to have a rechargeable external pack but are concerned about the "less-than-9V" issue, then just wire four of them as above and you will get at least +/-15VDC (which is the power I use in all my home built PSUs).

So yeah, your first idea may work if you don't mind the two-box approach.  As long as it provides enough current and the power is well regulated.

Topic #2:
It turns out the summing resistor values are not critical so that's why you may see differences.  I'm only a self-taught wirehead so I can't fully explain ... but I don't think the drop in audio signal is the same as a voltage drop calculation.  The main point of those resistors is to isolate the two outputs so you don't have one output feeding directly into the other which would cause them to interact and load each other in weird ways.  (A self-taught description. :) )  So with 2.2k resistors the two channels are 4.4k apart and less likely to interact.  As long as the values are the same I believe anything in that seemingly wide range of resistance would do the job without much loss of signal.

Let us know what you figure out re the battery situation.  Nice experiment!

Jimmy J

Many Many thanks, Mr J!

Totally agreed on all points; and TBH, the point of using multiple rechargeable batteries stacked to get around the voltage issue had occurred to me.

I will try both and report back with my findings.

I am 100% certain the multiple batteries will work. We shall see what happens with the 4 Expander. The power banks hold WAAAY more charge than the batteries; so, one possibility is doing 4 whole sets with it. We shall see.

The resistor thing is sort of hilarious / sign of the times. Turns out that it is expensive to buy single resistors on line, but cheap to buy 1600 of various values; which I took the latter route. I’ll probably just use the 10k resistors and forget about it.

The whole thing is going in a belt clip box; then I’ll need to get a 3 ft cable. Stay tuned.

FC Bass

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Re: wireless system
« Reply #24 on: April 06, 2025, 01:09:17 PM »
I did a quick test to see what the output is with: Two internal batteries, 4x9V battery PS and DS-5 (all recorded with the summed mono out)
I recorded the same riff played twice with each form of power, trying to be as consistent as I could.  Looking at the peak dB in Ableton live, the results are pretty close:

-3.09 dB for the two internal 9v batteries
-2.93 dB for the portable 4x9V power supply
-2.95 dB for the DS-5



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mica

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Re: wireless system
« Reply #25 on: April 09, 2025, 02:04:39 PM »
I have lots of things on the plate now, but yes, rechargeable battery packs for Series I/II is on my to-do list.

dannobasso

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Re: wireless system
« Reply #26 on: April 09, 2025, 07:02:02 PM »
I am very pleased to know that oh princess of the mothership!

bucephylus

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Re: wireless system
« Reply #27 on: April 11, 2025, 03:38:31 PM »
Update:

In short, the CIOKS 4 Expander works flawlessly as the heart of a Wireless Series I / II belt pack.

I built the experiment using a 4 3/4” x 3 3/4” x 1 5/8” black aluminum project box from Amazon. A 5 pin panel jack and 1/4” phone jack are mounted on the bottom end panel. The 4 Expander JUST fits in the space above the internal jack connections. Right angle RCA plugs and USB-C were required. The 4 Expander channels 1 and 3 were set to 15VDC, and wired to the 5 pin jack according to -15VDC from Ch 1 to Pin 5, 0 from Ch 1 and Ch 3 to Pin  1, and +15VDC from Ch 3 to Pin 4. The Expander actually just has + and - on each channel; but, they are isolated. Pin 3 was connected through a 15kohm resistor to the 1/4”signal jack, and Pin 2 was likewise connected through a 15kohm resistor to the 1/4” signal jack.

I placed a belt clip on one external face of the box, and velcro’d a 13500 mAHr Power Bank, weighing in at 6 oz, to the other face.

The whole thing weighs about 1 1/2 pounds; which is pretty close to what I am comfortable with on a sturdy belt.

I take Mr. J’s wisdom as gospel; in that 4 rechargeable batteries would have weighed far less. I looked into converting this box. But, there were some practical issues. Those 4 batteries would have only represented maybe 3400 mAHr, and needed regular charging. I could not find quick release battery boxes for 4 batteries which would have been physically accommodated by my box. Larger boxes are available, but generally too large for belt clipping. Anyhow I did think about the matter; and just decided to go with the original plan.

The Power Bank uses up about 900 mAHr per 45 minute set. So, I’m pretty comfortable with the charge capacity.

One other learning is that for whatever reason, this box sounded a bit better than my 1975 Blue Box. This has me considering building a smaller box to mount on a plug in pedal board with a CIOKS unit. That seems to be the next project.

Songdog

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Re: wireless system
« Reply #28 on: April 12, 2025, 01:05:18 PM »
Pin 3 was connected through a 15kohm resistor to the 1/4”signal jack, and Pin 2 was likewise connected through a 15kohm resistor to the 1/4” signal jack. [...] One other learning is that for whatever reason, this box sounded a bit better than my 1975 Blue Box. This has me considering building a smaller box to mount on a plug in pedal board with a CIOKS unit. That seems to be the next project.
I wonder... the DS-5 schematic I've seen has 20kohm (not 15kohm) mixing resistors, could that account for the difference in sound?

bucephylus

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Re: wireless system
« Reply #29 on: April 12, 2025, 01:34:44 PM »
Pin 3 was connected through a 15kohm resistor to the 1/4”signal jack, and Pin 2 was likewise connected through a 15kohm resistor to the 1/4” signal jack. [...] One other learning is that for whatever reason, this box sounded a bit better than my 1975 Blue Box. This has me considering building a smaller box to mount on a plug in pedal board with a CIOKS unit. That seems to be the next project.
I wonder... the DS-5 schematic I've seen has 20kohm (not 15kohm) mixing resistors, could that account for the difference in sound?
That’s a good Q. I don’t honestly know. In principle, the resistance value shouldn’t matter a whole lot. And, I could be wrong about the diffs. Needs more effort on my part.