Pass Pearl 2 MC on Batteries?

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Hi everyone,
I searched for this but could only find something on the "old" Pass Pearl 1, so I was wondering, if any of you have ever tried the "new" Pass Pearl 2 MC phono stage on battery power with e.g. lead acid batteries of 24 V or 36 V or something? Although of course it says in the layout that one should use 30 V.
Does any of you have experience in charging the batteries while listening? What would the design of that circuit look like? Did any of you compare that to a good PSU?
Thanks a lot!
poli
 

6L6

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If you charge the batteries while listening you defeat the advantage of batteries! :)

You could use a pair (well, 2 pair, actually...) of lead-acid batteries to make 2 sets of 24v if you remove the regulator.

If you use the regulator you would want at least 27v, preferably 28v or 29v on the PCB inputs so the regulator regulates properly.
 
Hi 6L6,
yeah, might be - although there are phonestages around that run on constantly-charged lead-acid batteries and sound really good (e.g. the Holfi Batteriaa). Anyway, it was just an idea, since I like the idea of batteries - I will try it probably with a good PSU, but I am not sure how I will built it.
Hey, your photos and descriptions of the Pass Pearl 2 look really cool and promising! Thanks for that!
Have you ever played around in using different capacitors and resistors? Like e.g. Mundorf or oil-paper vooddoo-gear or coal-resistors?
Cheers
poli
 

6L6

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As Nelson himself says, the passive components will never impart as much sonic signature on a circuit as the active ones.

However, the parts used are mainly the ones the circuit was designed around--- Dale resistors, Wima film caps, Silmic output capacitor with a big film bypass, etc...

Just buy good parts and don't worry.
 

PRR

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Joined 2003
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> lead acid batteries of 24 V or 36 V or something?

It is 48V from rail to rail. That's a lot of battery cells.

Clean lead-cells don't need the two 24V regulators. (The circuit is not too fussy about voltage.) A large Lead cell ought to be pretty benign to audio. However it already has the whopping 3,300uFd caps which will also bypass the rails pretty dang good. Would you rather listen to Lead or Aluminum? When you have so much of either, does it really matter? (The AL caps are a lot cheaper than a stack of lead.)

> charging the batteries while listening?

Why? The smallest Leads you are likely to find may be 2AH. The circuit draws like 20mA, 0.020A. It will run 100 hours. You can't stay awake that long. (Yeah, you can, but you won't be doing critical listening.)

Run a 24VAC winding as a 2-diode voltage-doubler to put 72V peak across the 48 Volts of Lead. Use two 100 ohm resistors to limit the charging current to about 0.1A. This may buzz bad. Turn it off when you turn-on the system. If you listen no more than 80% of the time (sleep at least 20% of the time) it will always be fully charged.

Point to ponder. If something shorts, the 3,300uFd and the 7_24 regs will pass enough energy to smoke a part but not start a fire. The energy in even D-size Lead-cells stacked to 48V can be like a stove-burner for a large fraction of a minute, easily enough to start a house fire. Things would have to go just-right (rather, just-wrong), but Murphy's Law may apply.

If you like battery phono, there are other plans which will run days on a 9V and are very good listening.
 
Hi everyone,
I searched for this but could only find something on the "old" Pass Pearl 1, so I was wondering, if any of you have ever tried the "new" Pass Pearl 2 MC phono stage on battery power with e.g. lead acid batteries of 24 V or 36 V or something? Although of course it says in the layout that one should use 30 V.
Does any of you have experience in charging the batteries while listening? What would the design of that circuit look like? Did any of you compare that to a good PSU?
Thanks a lot!
poli

Hi there
I was using a LM317 and transistor
Battery charger circuit using LM317. - Electronic Circuits and Diagram-Electronics Projects and Design

There was a bit of difference in sound lost of focus and a bit of hier noise floor but it was an OP amp circuit so discrete may be different


More info (almost all that is worth knowing about batteries in the folowing link)
batteryuniversity.com

I had 2 X 2.1 AH cells for 24 V (nominal) and those lasted about 3 days while I was using just the cells.

Big help of bateries is that you are virtualy totaly disconected from the ground
so no hum from that side of things.

If you need 30 volts why not use 3 X 12 V cels and a decent regulator like Sallas Reflektor to get 30 V

The voltagge on the Cells changes from 13.5 (full charge) to 11.5 (dead cells)
as you such up the juce from them so a regulator is needed any way
 

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And another thing
If one need split rails bateries do not charge / discharge at the same rate
so to bateries with same spec will end up with different voltages.
I got around that with a Buffer like BUF04 and voltagge divider to provide the virtual ground
 
And another another thing.

PRR is quite right when he ask if you rather listen to Lead or Aluminium
LAC have their own Jhonson noise
Lithium is a bit beter but I would not use a Lithium batery on anithink that I make as if sometink goes wrong they EXPLODE and START FIRES.

The Suply to my old MC stage in the pictures
 

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I'm just building a XOno with batteries

Hi everyone,
I searched for this but could only find something on the "old" Pass Pearl 1, so I was wondering, if any of you have ever tried the "new" Pass Pearl 2 MC phono stage on battery power with e.g. lead acid batteries of 24 V or 36 V or something? Although of course it says in the layout that one should use 30 V.
Does any of you have experience in charging the batteries while listening? What would the design of that circuit look like? Did any of you compare that to a good PSU?
Thanks a lot!
poli


Hi Poli,
I'm also building a PASS Phono Pre, the Xono according RSTAUDIO DIY PCBs.

I use 6 12V7,2Ah Yuasa lead batteries to get +/- 36V raw supply. Then I regualte these with Paul Hynes regs to +/-30V.

-->>>> I mainly do this to get stable working points in the circuit. Batteries drift along their discharge (logical) so its not what I want.

Paul Hynes also explained me that regulation (voltage + current) of even batteries makes definetly sense as its cures the typical battery sound. Something about relation to harmonics. I'll know when I try it, for now its just theory as I haven't tried it before - but I guess its absolutly worse as batteries are noisy as well :mad: and don't have a linear (an even dynamic!) impedance used naked.
:D



:shhh::shhh: For charging: LM 317 doesn't work as I need +/-41V something.
I use four TL783 it has 125V spec. >>>It can be used
to regulate the negative rail for charging the battery if you keep the
transformer secondaries separate and build two separate
rectified/regulated supplies. The charger supply for the negative rail
batteries will then have the negative connection of the regulator
connected to the negative rail and it’s positive output connection
connected to the 0v rail between the battery rails. This will not
cause any problems as long as the two charger supplies are separate
floating supplies.<<< (sic! Paul Hynes)


For charging method I do like this:
My circuit is always "ON". I have a rotary switch "Listening" & Charging" just meaning that Pauls +/-30V regulators for the Xono are supplied either by battery alone (listening) or by the batteries + the dirty charging ;) supply (charge).

The charging is a bit unusaul from the first approach: I red a lot of batteries specs and learned about lifetime issues. How to select the best charge method - by the typical discharge cycles and by the ambient temperatures.

Therefore I chose 13,7V floating / battery. (Any typical standard charger uses 14,2V with U/I curve --- read the Panasonic specs to learn why).




:pIn general I believe that powering sensitive Pre's with batteries do have alot of benefits: 1. Always the same sound no matter which day time 2. Galvanic behaviour 3. No supply ripples to cure. 4. Maaaaybe even less lossy elco caps needed (but here sounds test can judge how much is good or not)


Good luck with your PASS Pearl

Grüße Jochen
 
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Why is that?
The charger suply a given current at a variable voltagge (by variable Iwould say between 12.5 and 14 V over a periode of 10 hours, reccomended charging rate for small LAC)
same of this go to the pre same stay in the LAC it just take longher to charge the batery.

What about your car and all the milions of cars around batery is charging discharging all the time?
 
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