Pro-ject Phonobox SE upgrade to battery supply, anyone help?

[windy]

I have owned this phono stage for a number of years now and wondered if anyone has ever converted one to use a battery supply rather than via the supplied wall wart supply. The instructions mention that it can be done via the rear input marked power DC which looks to be a 5 pin connection but doesn't mention how to go about it. I have also wondered whether it would be worthwhile upgrading some of the internals as it is a pretty sturdy unit.:scratch:

[Arkless Electronics]

Lets just say that there are better ways of improving the sound from vinyl.... ;)

[prestonchipfryer]

Hello Peter and welcome to the AoS. I'm sure that someone here will be able you. I have a Project, it's just for a back-up though. Obviously there are better phono pre-amps, but for a modest system the Project should do quite well.

John

[windy]

I take it that I should bin it and start again then Mr. Arkless? I can't see that it would make it worse than it obviously is and I was hoping for help on how I should go about converting it, you convert Cambridge audio amps I believe and that is a lower starting point than the Pro-ject that I own as I listened to both before buying. Shame I don't have available funds to go out and buy something to justify the rest of my system

[The Grand Wazoo]

Steady there now chaps.
Jez, you have a cracking knack for driving off potential customers!

[Arkless Electronics]

Steady there now chaps.
Jez, you have a cracking knack for driving off potential customers!

What the hell did I do wrong this time..... :scratch: That was me being subtle! I didn't even plug the product as was hoping someone who's heard my offerings would come along and mention it!

Whatever..... Windy, if you want to try the demo unit you are welcome. The starting point is irrelevant as much of it is replaced in the Arkless 640P.

I'm confident that it will easily beat the Project!

[windy]

Does he own a Linn LP12 by any chance! Unfortunately I don't have the funds at the moment for his turbocharged phono amps which I am sure are wonderful to behold, had I got the funds, my money would go on an Icon ps1 which I heard a couple of years ago and sounded lovely. I just hoped I could get some advice on getting more from what I had for minimal outlay and I do enjoy a bit of tweaking, when nobody is around of course!

[Arkless Electronics]

Does he own a Linn LP12 by any chance! Unfortunately I don't have the funds at the moment for his turbocharged phono amps which I am sure are wonderful to behold, had I got the funds, my money would go on an Icon ps1 which I heard a couple of years ago and sounded lovely. I just hoped I could get some advice on getting more from what I had for minimal outlay and I do enjoy a bit of tweaking, when nobody is around of course!

£160 for the base model plus a 640P as a donor unit BTW.

I can proudly say I own nothing made by Linn :eyebrows: Other than an LVX tone arm which I believe was actually made by Jelco.

Personally I wouldn't bother with a battery supply....

[windy]

I guess I had better start saving for the Icon ps1 then:(

[The Grand Wazoo]

That's one opinion, made by someone with an agenda of making a sale. I wonder if any members who've been messing with batteries have an alternative one?

[PaulStewart]

Hi Peter,

I have only heard the Pro-ject units with their wall warts, but there is a good chance that either a quality power supply or batteries will help the sound quality. I use a Sim Audio phono stage in our bedroom system, this came with a fairly awful wall wart so at first I used lead acid batteries from a burglar alarm this greatly improved noise performance. After a while, I got a high quality linear supply from MCRU, this does the job at least as well and doesn't need recharging. What's the voltage of your unit?

Paul S

[windy]

Hi Paul,
Thanks for your constructive advice, the supply from the wall wart is 16 volts so I guess that is what I need to match with a battery supply. I know that the supplied wall wart would be of average quality due to the price of the unit when new so it seems that a more stable power supply would have to give an improved result. As I don't at present have the funds available to upgrade to a pre amp of higher quality, I thought it would be fun to have a play about with what I already have. What I would like to do is make a battery box with some form of rechargeable batteries but not sure how best to implement it, I am an engineer by trade but electronics are not a strong point

[wee tee cee]

Peter,
Quite a few of us run digital set ups DAC/D or T amps having reaped the benefits that batteries bring-lower noise floor removal of mains noise. Dont know much about vinyl set ups but you could try a lead acid battery/ cam corder battery pack or a linear PSU from maplin. Battery power is a great upgrade sonically in the digital sphere, I would be interested to hear how you get on.

[AlanS]

I made up a battery box and lead/plug sometime ago. Because it used NiCads to see if it was worth it I got fed up with recharging the batts and was not using the TT much so went back to the wart when I did use the TT.

I certainly sounded different to the wall wart and if I used vinyl a lot would have been worth the effort and faff recharging batteries. If you have something less hassle to use Lead/Acid for example and vinyl is a major feature of your listening then do it.

Best of luck

[Arkless Electronics]

That's one opinion, made by someone with an agenda of making a sale. I wonder if any members who've been messing with batteries have an alternative one?

No agenda..... I don't agree that batteries are any advantage that's all.... Ultimately the lowest noise regulators have lower noise than batteries!

[windy]

So are you saying that the supplied wall wart that came with my Phonobox se will have lower noise than a battery supply? If so then why would Pro-ject have a rear panel option for a battery supply:scratch:

[The Grand Wazoo]

No, what Jez is saying is that the lowest noise ones are quieter.
What he doesn't say is whether yours is one of those. Like you seem to, I suspect it isn't.

[Arkless Electronics]

No, what Jez is saying is that the lowest noise ones are quieter.
What he doesn't say is whether yours is one of those. Like you seem to, I suspect it isn't.

Indeed!

[The Grand Wazoo]

Just a thought Jez, but have you ever considered a career with Microsoft?
The above is a great example of what they seem to look for in the people who write stuff for them - what you said is 100% true in all respects, but of absolutely no use whatsoever to the person asking the question.
A talent I often share with you!

[Ali Tait]

Might be worth trying a better power supply?

Something like this perhaps-

http://www.ebay.co.uk/itm/Adjustable-DC-Regulated-Linear-Bench-Power-Supply-0-18V-0-2A-/221286090989?pt=UK_BOI_Electrical_Test_Measurement _Equipment_ET&hash=item3385adc8ed

[Arkless Electronics]

Just a thought Jez, but have you ever considered a career with Microsoft?
The above is a great example of what they seem to look for in the people who write stuff for them - what you said is 100% true in all respects, but of absolutely no use whatsoever to the person asking the question.
A talent I often share with you!

:D

I was addressing a general point rather than trying to offer anything of particular use to the op....

Here is something actually useful.... Having had a look at some photos of the pcb the internal psu arrangement is particularly crude and the provision for battery power seems to bypass the T092 100mA regulators, so, in this case there may be some gains from battery power. TWO 12v batteries are needed and sealed lead acid batteries should be a good bet. Use short thick cable for best results. The gains will not be much though (if noticeable at all) as it is an all op amp design and they have good PSRR.

[lurcher]

Can you take it apart and send some pictures, if we see inside it may give a better idea what is needed.

This thread on another site may be of help

http://www.diyaudio.com/forums/analogue-source/21833-schematic-pro-ject-phono-box.html

[Arkless Electronics]

Might be worth trying a better power supply?

Something like this perhaps-

http://www.ebay.co.uk/itm/Adjustable-DC-Regulated-Linear-Bench-Power-Supply-0-18V-0-2A-/221286090989?pt=UK_BOI_Electrical_Test_Measurement _Equipment_ET&hash=item3385adc8ed

It wouldn't work! It needs AC from its external supply or + & - supplied to the "battery" input (which doesn't need to be battery of course).

[337alant]

Actually that project phonobox SE looks good, it uses the same 3 op amp design that the Buggle 2 uses and that is very good.
Don't know what op amps it uses ?, but I liked the LM4562 in my little Chinese clone version of the same thing.
You could try some other wall warts try and get 16VAC 30 - 50va, if you can as they tend to be a better quality, that said most wallwarts now are the switch mode types and are poor IMO so check before you buy.
I ended up using batteries with mine and it worked fine. Looking at the specs it will work from 2 x 12V battery's so try and pick up a cheap gel battery like a yauser, I have bought a few from car boots lately and they have all been fine ( a few quid each), Im using 2 x 7.2AH ones and they last ages before needing a charge. All you would need to do is take the top off to sus out the DC wiring to the 5 pin din plug which are available from Maplin.
Another option is an external DC regulated supply that plugs into the 5 pin din

Alan

[Ali Tait]

That was my thought, use it in place of a battery.

[Arkless Electronics]

That was my thought, use it in place of a battery.

You'd need two! Or a dual output version... and it would probably offer no advantage over the (what appears to be from fuzzy pic) 78l12 and 79l12 regulators on the board....

[prestonchipfryer]

Correct me if I'm mistaken I think Peter means the Project Phono pre-amp like this.




http://i766.photobucket.com/albums/xx309/prestonchipfryer/din2_zpsfaee12f7.jpg (http://s766.photobucket.com/user/prestonchipfryer/media/din2_zpsfaee12f7.jpg.html)


http://i766.photobucket.com/albums/xx309/prestonchipfryer/din1_zps81e52843.jpg (http://s766.photobucket.com/user/prestonchipfryer/media/din1_zps81e52843.jpg.html)


http://i766.photobucket.com/albums/xx309/prestonchipfryer/din_zpse7c37122.jpg (http://s766.photobucket.com/user/prestonchipfryer/media/din_zpse7c37122.jpg.html)

[Arkless Electronics]

Correct me if I'm mistaken I think Peter means the Project Phono pre-amp like this.




http://i766.photobucket.com/albums/xx309/prestonchipfryer/din2_zpsfaee12f7.jpg (http://s766.photobucket.com/user/prestonchipfryer/media/din2_zpsfaee12f7.jpg.html)


http://i766.photobucket.com/albums/xx309/prestonchipfryer/din1_zps81e52843.jpg (http://s766.photobucket.com/user/prestonchipfryer/media/din1_zps81e52843.jpg.html)


http://i766.photobucket.com/albums/xx309/prestonchipfryer/din_zpse7c37122.jpg (http://s766.photobucket.com/user/prestonchipfryer/media/din_zpse7c37122.jpg.html)

And your point is? :scratch:

[prestonchipfryer]

To establish if this is the Project phono which Peter was asking about. Ok! Nowt to do with you personally.

[windy]

That is the correct model, here is a pic of the internals[/ATTACH]11004 Hope the resolution is ok

[lurcher]

Ok, so as said before its a split rail supply. One of those thee wires will be connected to ground, thats the 0v. Find a pin out for a op amp, find the +ve and -ve pins on that and trace back the PCB to the plug, that will give you the +ve and -ve pin to connect to. Then you have the pin outs to use to connect a pair of battery to it. Pair of 9v maybe, larger current ones if possible. Maybe a couple of PP9's. Or some C/D cells to get to 12v or so.

[Arkless Electronics]

It seems to be marked on the silk screen on the board + & - 15V from the photo which makes it a bit easier. I'd go the SLA 12V accumulator route myself if I was going to use batteries at all (which I wouldn't personally).

[Qwin]

I Built a DIY battery powered Phono Stage for LOMC as per HypnoToads thread on AudioKarma.

http://www.audiokarma.org/forums/showthread.php?t=501186

My project: http://www.jkwynn.co.uk/HTMCPS_HTML/HTMCPS_Thumbs.html

People building this and HypnoToads previous project seemed to find that larger Sealed Lead Acid Batteries worked better than the smaller C, D or AA’s etc. The SLA’s were the type used in burglar alarms as the back up. People have also built mains supply units for the project with great success but I think its fair to repeat that batteries have no technical advantage over a good mains power supply. The main reason for using them, is that a cheap battery set up will outperform a poor low cost wall wart etc. You will have to spend a bit more to get a well sorted PSU. There again, by the time you add the cost of a charging set up for the batteries the difference is not as signifficant.

Just for the record, in its first incarnation (made a few changes since) my phono stage was tried back to back with one of Jezz’s at a bake off. I would say that on the day his had the edge over mine and performed extremely well, having plenty of drive without ever sounding harsh or ragged.

[windy]

Thanks for that gents, I think that a battery supply would offer me a small upgrade over the supplied wall wart but some good points have been made and costs would likely make it less viable than sourcing a better linear supply especially when I consider a device to recharge the batteries. The battery route just seemed like a good fiddle as there is the option on the rear panel.
Jez, I apologise if my initial replies were a little curt but I wanted advice on how to go about doing something like this with little knowledge on how best to implement it rather than being told my preamp is very poor.
In the meantime, I will look into a better quality linear supply for reasonable costs and start saving for a better quality preamp to do my TT and carts the justice they deserve