"Battery RIAA pre amp" by A.Sceptic

[JoeDJ]

Yeahh..

BTW....what is the best way to connect an amp to a LA battery's F1 terminals.... alligator clips?

 

[JoeDJ]

I decided to go with a "power-sonic" 12v -5ah. (PS-1250)
It's inexpensive enough.

 

[thoglette]

For best performance use a switch to disconnect the charger when the preamp is in use.

+1 but note that all batteries will vent gas and goop if faulty.

Or if the charger is faulty. I found that out the expensive way. :-(

Plan for leaks and ventilation!

 

[JoeDJ]

Yeah, when all is said and done, no matter how small , it's still a LA battery and all LA battery precautions must be taken.

Anyway, I may just unplug the charger when not in use as this would be covienent for me.

 

[thoglette]

no matter how small , it's still a LA battery and all LA battery precautions must be taken.

NiCads and NiMh also produce H2. And can leak. As can pretty much any battery type. (I've lost count of many dead toys/torches/radios I've seen that were killed by leaking batteries )

 

[JoeDJ]

I did some more experimenting with my 9v (6xAA) battery pack in my "Art DJ Pre" to see if my first impressions of improvements was really valid .

They were!
I listened to a variety of material. Battery power made everything seem a bit more clearer and more detailed.

What was the most noticeably improved is bass. It's not louder but, much more more detailed....... more musical..

Like I said I said I'm not easily impressed but, a 12v SLA will definitely be the way to go for me..... will be getting one soon .

 

[JoeDJ]

OK... I got the 12v SLA battery ..

After listening again to a variety of records and material I again confirmed that the battery made things clearer at times particularly the bass.
No, it did not make everything sound better but, when it did it was definitely noticeable . I also noticed that with the SLA the transients seemed to be handed better and sounded less restrained.

Anyway, isn't that what good audio is all about....... making little (and big) improvements where you can?
For about $15.00 for the battery and a few dollars for a charger, it was an inexpensive and worth while improvement..

BTW, I did not realize the the battery's F1 terminals accepts a standard 3/16 female spade connector that I happened to already have on hand

 

[paulb]

I built a phono preamp using the ESP board, OPA2134 op-amps, and a switchable option of battery power (2x9V) or an AC wallwart with 7812/7912 regulators. Could not tell the difference, even driving very good headphones. I was planning on building an SLA powered preamp as well but have since decided it's not worth the trouble.

 

[thoglette]

Could not tell the difference, .

You're a lucky person with non-noisy mains power.

 

[JoeDJ]

Also..........
Unless you got ES phones they can not reveal everything a good amp/speaker combo can. Even then, its questionable..

Yes, I used to have ES phones and I truly miss them.

In, any event, no battery can make a silk purse out of a sow's ear.
However, it can help good recordings to reach their full potential, depending on the phono pre of course.

Let's not loose site of the fact that any audio system is only as good as its weakest link.

 

[alayn91]

Hello,

Did anyone made measurements ??

- http://www.diyaudio.com/forums/chip...red-supplies-21.html?postid=187556#post187556

- Simple Voltage Regulators Part 1: Noise

So what ??

 

[andyr]

Hello,

Did anyone made measurements ??

- http://www.diyaudio.com/forums/chip...red-supplies-21.html?postid=187556#post187556

- Simple Voltage Regulators Part 1: Noise

So what ??

I had a brief look at that 2003 thread. Interesting - people who measure ... rather than listen!

And BTW, measurements need to be taken under load ... as that's the way you listen to it.

Regards,

Andy

 

[JoeDJ]

^ ^ ^

Yes, ....... Like I said, with the SLA loud transient now seem to less restrained.

 

[pde2000]

crimson ck1010

hi brian, good to see you, ive just joined the forum. your amplifier modules are working brilliantly. thanks for all your help. I haven't tried using the batteries with the pre yet, but reading this is encouraging. I assume I will need to take out the regulation when I switch to the 12v lead acid (I set them at 9V).

paul

 

[bepowell]

Sorry I missed this post. Yes do take out the regulators for use on 12V. If you have done this PSU change already how did it go?

 

[pde2000]

thanks brian, ive been busy fiddling with record players so haven't got onto the preamp power supply. I did fit a pair of riaa's for mm that willbewill from lencoheaven supplied as kits (cheap as chips) which take a shared supply from the shunt regulation to no ill effect (sound good). they allow me to easily compare arms and cartridges. the power amp modules get rather hot when playing at volume so an increase in heat transfer would help, maybe attaching a heat pipe. less of a problem in winter.

 

[bepowell]

I am not a fan of fans! However, if playing really loud you will not hear the fan noise. I have got some values for the disc stages which gives closer RIAA. If you are using the Crimson preamp, have you disabled the intrusive HP filter in the line stage? More info on:-

Index of /bepowell/schematics

thanks brian, ive been busy fiddling with record players so haven't got onto the preamp power supply. I did fit a pair of riaa's for mm that willbewill from lencoheaven supplied as kits (cheap as chips) which take a shared supply from the shunt regulation to no ill effect (sound good). they allow me to easily compare arms and cartridges. the power amp modules get rather hot when playing at volume so an increase in heat transfer would help, maybe attaching a heat pipe. less of a problem in winter.

 

[pde2000]

I'm not a fan of fans either, but adding more convection cooling capacity can be done with passive parts, like cpu heatsinks and heatpipes. Some old akai amps have this. The line in hpf have been replaced with bipolar electrolytics which sound ok.

winter is upon us so extra warmth from a power amp is welcome.